List of Titles

Chemical analysis and biological activities of crude extracts and essential oil of selected medicinal plants from the Eastern Cape, South Africa, and Volta Region of Ghana

Authors: Agbo, Irene Adzo
Date: 2023-12
Subjects: Medicinal plants , Lantana camara , Peptic ulcer -- Treatment , Traditional medicine - South Africa -- Eastern Cape , Traditional medicine -- Ghana
Language: English
Type: Master's theses , text
Identifier: http://hdl.handle.net/10948/62431 , vital:72728
Description: Lantana camara and Khaya grandifoliola extracts are among many plants found traditionally effective for the treatment of wounds and ulcers. This study assessed the phytochemical content, isolation and identification of single compounds from methanol and ethyl acetate extracts of Lantana camara and Khaya grandifoliola. Further, the bioactivity testing including antioxidant, antimicrobial and cytoxicity of the extracts was done to confirm the wound healing potential discovered by the traditional healers. Materials and methods: Extraction was done successively using maceration method with 100 % ethyl acetate and 100 % methanol with a biomass-to-solvent ratio of 1:3 (w/v) to obtain L. camara ethyl acetate extracts of berry (ELB), flower (ELF) and leaf (ELL) and methanol extracts of MLB, MLF, MLL and K. grandifoliola ethyl acetate extracts of leaf (EKL), root (EKR) and stem bark (EKSB) and methanol extracts of MKL, MKR, MKSB respectively. L. camara leaf essential oil (EO) was extracted using the hydro-distillation method with a Clevenger apparatus. Total phytochemical content was assessed for each extract using spectrophotometric methods and a calibration curve of standards: bromocresol green method with atropine; Folin–Ciocalteu colorimetric method with gallic acid, aluminium chloride colorimetric method with quercetin and concentrated sulphuric acid chloroform with linalool for total alkaloid, phenolic, flavonoid and terpenoid contents respectively. Single compound isolation and purification was conducted using chromatographic techniques. Elucidation of single compounds was done using spectrometric method, high resolution- mass spectrometry, and one and two-dimensional (1D and 2D)-NMR. Stereochemistry of each compound was confirmed using electronic circular dichroism spectra. A Crystalline compound was identified by single crystal X-ray diffraction using CuKα-radiation. In vitro bioactivities were assessed with methods such as 3-[4,5-dimethylthiazole-2-yl]-2,5-diphenyltetrazolium bromide, free radical scavenging activity of 1,1-diphenyl-2-picrylhydrazyl, inhibitory effect on nitric oxide production in lipopolysaccharide-activated RAW 264.7 macrophages, and 96-well plate micro dilution for cytotoxicity, ant-inflammatory and antimicrobial activity testing. Results: Methanol extracts of both plants retained high phytochemical concentrations of all the phytoconstituents investigated compared with the ethyl acetate extracts which retained lower concentrations. The results of the L. camara methanol extracts include; total alkaloid content (TAC) (2.05±0.18, 1.87±1.54 and 2.60±1.10 mg AEQ/100 mg); total phenolic content (TPC) (14.05±4.04, 34.59±3.01 and 18.58±1.87 mg GAEQ/100 mg); the total flavonoid content(TFC) of flower (12.45±1.87, 20.41±2.69 and mg QEQ/100 mg); total terpenoids (TTC) (20.74±2.34, 20.74±2.34 and 15.97±1.19 mg LIN EQ/100mg) of MLB, MLF and MLL respectively. Whereas that of the K. grandifoliola methanol extracts include; TAC (7.32±0.14,8.49±0.34, 10.67±0.22 mg AEQ/100 mg); TPC (37.49±1.40, 44.41±0.69, 53.57±1.50 mgGAEQ/100 mg); TFC (6.54±0.55, 9.58±0.89 and 10.26±0.92 mg QEQ/100 mg); TTC(10.16±1.41, 35.78±2.14 and 23.45±1.76 mg LIN EQ/100mg) of MKL, MKR and MKSB respectively. The major components of essential oil, out of the 71 constituents identified include Davanone D (32.91 %), Caryophyllene (5.07 %), Nerolidol 2 (3.56 %) and GermacreneD (3.13 %). Compounds 3.47 was isolated from the methanol extract of L. camara flowers. This compound is reported for the first time from the L. camara flower extract. Two compounds, compounds 4.23, and 4.26, were isolated from the methanol extract of K. grandifoliola roots, compound 4.22 was isolated from the ethyl acetate root extract while compounds 4.24 and 4.25 were isolated from the ethyl acetate stem bark extract as isomers in a mixture. Compounds 4.22 and 4.23 are reported from K. grandifoliola root for the first time. The isolated compounds (compounds 3.47 and 4.23) were nontoxic to the Vero cell line and this may contribute to possible stimulation of cell proliferation, promoting wound healing. Cytotoxicity describes extract virulence to Vero cell line. MLF and ELB were found nontoxic even at the highest concentration of 200 μg/mL. The MKSB and MKR, as well as the EKSB were nontoxic. Antioxidant activity results, described by the percentage inhibition in the DPPH assay, showed that MLF and MKSB had the highest antioxidant activities compared with the ascorbic acid standard, with IC50 of 38.68±5.09 and 37.03±11.95 μg/mL for L. camara and K. grandifoliola respectively. ELB exhibited a significant anti-inflammatory activity inhibiting NO• radical generation in the LPS-stimulated RAW 264.7 macrophages at concentration ranging from 50 and 100 μg/mL. EKSB and MKR showed significant anti-inflammatory activity at 100 and 200 μg/ml respectively. ELL and ELF demonstrated potent growth inhibition against S. pyogenes with an MIC value ≤ 0.125 mg/mL, while the MICs of the ELB and MLL were 0.5 mg/mL and 2 mg/mL respectively. MKSB and MKR and EKSB extract exhibited an effective growth inhibition against S. aureus with MIC of 1 mg/mL. The growth of S. pyogenes was supressed by both ethyl acetate and methanol extracts of all plant parts tested with MIC ranging from 0.25–2 mg/mL. Conclusion: The potent bioactivity shown in the results of the cytotoxicity, antioxidant activity, anti-inflammatory and antimicrobial activity testing, and the nontoxic singlecompounds of L. camara and K. grandifoliola extracts led to the conclusion that the two plants had wound healing potential. The study therefore confirmed their traditional uses for treatment of wounds. , Thesis (PhD) -- Faculty of Science, School of Biomolecular and Chemical Sciences, 2023
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Date Issued: 2023-12

Selected medicinal plants leaves identification: a computer vision approach

Authors: Deyi, Avuya
Date: 2023-10-13
Subjects: Deep learning (Machine learning) , Machine learning , Convolutional neural network , Computer vision in medicine , Medicinal plants
Language: English
Type: Academic theses , Master's theses , text
Identifier: http://hdl.handle.net/10962/424552 , vital:72163
Description: Identifying and classifying medicinal plants are valuable and essential skills during drug manufacturing because several active pharmaceutical ingredients (API) are sourced from medicinal plants. For many years, identifying and classifying medicinal plants have been exclusively done by experts in the domain, such as botanists, and herbarium curators. Recently, powerful computer vision technologies, using machine learning and deep convolutional neural networks, have been developed for classifying or identifying objects on images. A convolutional neural network is a deep learning architecture that outperforms previous advanced approaches in image classification and object detection based on its efficient features extraction on images. In this thesis, we investigate different convolutional neural networks and machine learning algorithms for identifying and classifying leaves of three species of the genus Brachylaena. The three species considered are Brachylaena discolor, Brachylaena ilicifolia and Brachylaena elliptica. All three species are used medicinally by people in South Africa to treat diseases like diabetes. From 1259 labelled images of those plants species (at least 400 for each species) split into training, evaluation and test sets, we trained and evaluated different deep convolutional neural networks and machine learning models. The VGG model achieved the best results with 98.26% accuracy from cross-validation. , Thesis (MSc) -- Faculty of Science, Mathematics, 2023
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Date Issued: 2023-10-13

Evaluation of the toxicity of secondary metabolites in Solanum incanum L. to advance community knowledge

Authors: Zivanayi, William
Date: 2023-04
Subjects: Solanum -- Zimbabwe , Pesticides -- Toxicology , Medicinal plants
Language: English
Type: Doctoral theses , text
Identifier: http://hdl.handle.net/10948/61018 , vital:69686
Description: The effects of pests and the need to produce adequate food have influenced small-scale farmers in disadvantaged communities to adopt and utilise natural plant pesticides to improve harvests in many Southern African Development Communities. However, the phytochemistry associated with these indigenous plants’ pesticide activity still needs to be explored. The lack of evidence of scientific knowledge of the plant species has caused a lot of health issues among the users of indigenous plant pesticides. Solanum incanum is among the plants utilised to control cabbage aphids in Mkoba village, Zimbabwe. Solanum species are known for their steroidal compounds which comprise glycoalkaloids and saponins. This study evaluated the knowledge, opinions, and attitudes of the vegetable peasant farming community in Gweru regarding their use of the indigenous plant (S. incanum) as a pesticide. The study also reported the phytochemical profiling, structural characterisation of the isolated compounds, and biological and pesticidal activity evaluation of phytochemicals isolated from S. incanum. A descriptive survey was carried out to assess the knowledge, attitude, and practices of a conveniently sampled group of vegetable farmers in Mkoba village who use S. incanum as a pesticide. Forty-nine respondents comprised of 19 males and 30 females of ages ranging from 15 to above 60 years took part in the study by answering an open and closed-ended questionnaire. The survey revealed that parents and neighbours were instrumental in disseminating pesticidal information in the community. Brassica napus were the most grown.vegetable and vulnerable to cabbage aphids. Mixed opinions amongst the respondents varied regarding the health and environmental impact of S. incanum as a pesticide. Seventy-five percent (75%) of the respondents supported the use of S. incanum as a pesticide whilst 25% claimed that the use of S. incanum was the source of the health problems experienced in the community. The survey demonstrated that (45)91% of the farmers displayed poor practices regarding the disposal of empty pesticide containers and the use of personal protective clothing. The most prevalent symptoms in the community were skin rash, nausea, headache, and poor vision and these symptoms were common in the age group 30 to 60 years. , Thesis (PhD) -- Faculty of Science, School of biomolecular and Chemical Sciences, 2023
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Date Issued: 2023-04

Pharmacological, toxicological and phytochemical evaluation of helichrysum petiolare hilliard & b.l. burtt - an indigenous plant traditionally used in the treatment of diabetes in the eastern cape province of South Africa

Authors: Aladejana, Adebowale Emmanuel https://orcid.org/0000-0003-1871-926X
Date: 2022-04
Subjects: Diabetes -- Alternative treatment , Traditional medicine , Medicinal plants
Language: English
Type: Doctoral theses , text
Identifier: http://hdl.handle.net/10353/22787 , vital:52755
Description: Diabetes mellitus is one of the leading causes of death in South Africa, and it has already placed significant stress on the country’s health sector and economy. The orthodox hypoglycaemic drugs are not only ineffective in the management of the disease and its complications, but they also possess unwanted side effects. The need for alternative non-toxic drugs is therefore imperative. Various studies have listed several medicinal plants that can be successfully used in the herbal treatment of diabetes and have investigated them for their anti-diabetic potentials in vivo and/or in vitro. Out of the different potential herbal species, plants belonging to the Asteraceae family possess highly potent hypoglycaemic properties with negligible toxicities. Five Asteraceae plants widely used in different parts of South Africa for the treatment of diabetes were reviewed. The review provided an update of scientific evidence on the hypoglycaemic properties of the plants. However, Helichrysum petiolare was studied extensively in this study for its antidiabetic activity H. petiolare has been listed in many ethnobotanical surveys as a plant with potent hypoglycaemic potential, this, however, has not been properly verified in scientific literature and there has hardly been any study on the essential oil and nutritional composition, and antioxidant, antidiabetic, and cytotoxicity potentials of the plant. The effects of hydro-distillation (HD) and solvent-free microwave extraction (SFME) methods on the chemical constituents of H. petiolare-derived essential oils were evaluated. The SFME method had a higher yield of essential oil than the HD. There were substantial amounts of monoterpenes, monoterpene alcohols, sesquiterpenes, and sesquiterpene alcohols in both essential oils obtained, but these compounds were more profound in the SFME derived essential oil which has 62 compounds compared to the 52 derived through HD. The SFME derived essential oil can therefore be said to be of better quality than the HD method. The compounds obtained in the essential oils have high pharmaceutical and cosmetic value, and as observed in this study, their quantity is dependent on the method of extraction (Ibáñez and Blázquez, 2021; Kaur et al., 2021). The proximate analysis of the whole plant of H. petiolare showed high levels of Acid Detergent Fibre (ADF), vitamins (A, C and E), Neutral Detergent Fibre (NDF), and minerals. The high ADF level is believed to be responsible for the low energy, fat and carbohydrate levels observed in the study. The result showed a high level of oxalate and therefore suggests cooking of the plant before human consumption. Overall nutrition and mineral compositions of the plant showed that H. petiolare is immensely rich in vital nutrients that are of great importance to health and metabolism; these nutrients are suggested to be partly responsible for the plant’s useful medicinal properties. The phytochemical contents of the acetone (ACQ), ethanol (ETQ), and boiled (BAQ) and cold (CAQ) aqueous whole-plant extracts of Helichrysum petiolare were determined using standard phytochemical reaction methods. ABTS, DPPH, NO and TAC assays were used to evaluate their antioxidant properties. The highest total phenolic content (212,963 mg/g) was reported in the BAQ extract, while the ETQ had the highest flavonoid (172.393 mg/g) and proanthocyanidin contents (65.855 mg/g). Alkaloids, flavonols, and saponin were highest in the ACQ extract, while the CAQ had the lowest phytochemical content. Among the extracts, the BAQ had the highest DPPH•+ (IC50 0.02 mg/mL) and ABTS•+ (IC50 0.07) inhibition capacities, while the ETQ exhibited the highest NO• Inhibition (IC50 0.41 mg/mL) and TAC (IC50 0.19 mg/mL). These findings justify the use of H. petiolare in traditional medicine and further recommend the ETQ and BAQ extracts of the plant as more effective extracts for medicinal treatment. The hepatotoxicity (cytotoxicity, mitotoxicity and lipotoxicity) potential of the BAQ, CAQ and ETQ extracts of Helichrysum petiolare was evaluated using standard procedures. The results showed negligible BAQ and CAQ cytotoxicities, which were further, corroborated by stability in the mitochondrial membrane potentials and were congruent with the CAQ and BAQ results for steatosis and phospholipidosis. The data suggested favourable CAQ and BAQ toxicity profiles with limited risks for hepatotoxicity. The ETQ extract, however, showed significantly high levels of cytotoxicity and lipotoxicity, and a low level of mitotoxicity. Our result suggested a potential risk of the ETQ extract for hepatotoxicity but appears partly independent of direct mitochondrial involvement. Glucose uptake assay showed significantly increased glucose uptake in the BAQ and CAQ treated L6 and C3A cell lines. The CAQ extract enhanced glucose uptake more in the L6 myocytes than in the C3A cell-lines hepatocytes. The BAQ extract showed higher levels of inhibition on α–amylase and α-glucosidase activities as compared to CAQ. The BAQ and CAQ extracts of H. petiolare may, therefore, contain pharmacologically active and relatively non-toxic hypoglycaemic chemicals, which may be effective substitutes in the treatment of diabetes mellitus. This study provides up to date scientific information on the use of H. petiolare in the treatment of diabetes mellitus in the Eastern Cape of South Africa. It justifies the use of this plant in herbal medicine and sheds more light on its previously vaguely understood nutritional and medicinal potentials. More studies, however, need to be done to isolate, identify and purify the constituent bioactive compound(s). Their dosage of application and mode of action also needs to be understood. , Thesis (PhD) -- Faculty of Science and Agriculture, 2022
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Date Issued: 2022-04

Outcomes of Drug Resistant Tuberculosis in Two Rural District Hospitals, Eastern Cape Province, South Africa

Authors: Lotz, John-D Knipe
Date: 2021-02
Subjects: Medicinal plants
Language: English
Type: Masters theses , text
Identifier: http://hdl.handle.net/11260/6834 , vital:51018
Description: Tuberculosis (TB) is still rampant in South Africa, and drug resistant tuberculosis (DR-TB) forms a significant part of this burden on both the health care system and economy. A number of interventions have recently been introduced to help curb the growing epidemic of DR-TB, including increasing access to novel and repurposed drugs, decentralisation of care, and a new shorter (9-11 month) treatment regimen recently endorsed by the World Health Organization (WHO). Significantly, this new regimen has now also become injectable-free (also known as an all-oral regimen). However, at the time of implementation in 2017, the shorter regimen was yet to be proven effective in a programmatic setting in South Africa. This is a retrospective cohort study to describe the outcomes in patients on short and long DR-TB treatment regimens, over five years, at two treatment sites in a rural setting in the Eastern Cape province of South Africa. It is the hope that elucidation of factors involved in affecting outcomes in DR-TB may direct future interventions in these two facilities, and the wider DR-TB program in South Africa , Thesis (Masters) -- Faculty of Health Sciences, 2021
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Date Issued: 2021-02

Contested environmental knowledge: Struggles over meanings and uses of medicinal plants in Kabokweni, Mpumalanga Province, South Africa

Authors: Mbeng, Emiline Oben Otang
Date: 2020-09
Subjects: Medicinal plants , Ethnobiology
Language: English
Type: Master's theses , text
Identifier: http://hdl.handle.net/10353/21146 , vital:47143
Description: The main aim of this study was to examine the meanings attached by locals to medicinal plants in Kabokweni, Mpumalanga and how such meanings tend to shape the character of local struggles over access to, use and even commercial benefits of medicinal plants. This study draws its theoretical schema from political ecology, especially ethnoecology where the goal is to elucidate environmental conflict, most especially in terms of contestations over knowledge, power and practice, as they relate to the meaning and control of medicinal plants in Kabokweni. The study, therefore, recognises the complex interconnections between nature and society through a careful analysis of what one might call the forms of access and control over resources and their consequences for environmental health and sustainable livelihood. In-depth interviews, oral histories and non-participant observation were used to collect data and thematic analysis was used to analyse the data into meaningful themes according to the research questions and objectives of the study. The study found that Swati medicinal plant names are not subjective, but depend on socio-cultural and pragmatic perspectives, and meanings shape local struggles over medicinal plants in Kabokweni. Four underlying discourses were identified from the analysis of local narratives on the meanings and uses of medicinal plants. Each discourse offered a noticeably different concept of medicinal plants and people-plant relationships. Firstly, the ‘sustainability discourse’ referred to the role of foresters and environmentalists in sustainably managing plant resources. Secondly, the ‘livelihood discourse’ was entrenched in the local culture and economy. Thirdly, the ‘knowledge discourse’ conceptualises medicinal plants predominantly in terms of species richness and natural processes, while the ‘economic discourse’ emphasised the economic potential of medicines derived from plants as their major concern. Powerful social actors who influenced decisions about use and management of indigenous medicinal plants controlled these discourses. Finally, the study argues that rural communities would continue harvesting natural resources, even if illegally. Hence, to avert conflicts between indigenous actors and environmental agencies, communities need to be integrated into management programs, so they can be aware of some crucial issues such as sustainable harvesting of medicinal plants. , Thesis (MSoc) -- Faculty of Social Science and Humanities, 2020
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Date Issued: 2020-09

Usage of traditional medicines and other indigenous practices by childbearing women during pregnancy in Makoni District, Zimbabwe

Authors: Chituku, Sibongile
Date: 2020-09
Subjects: Traditional medicine -- Zimbabwe , Medicinal plants
Language: English
Type: Doctoral theses , text
Identifier: http://hdl.handle.net/10353/20142 , vital:45347
Description: Use of traditional medicinal plants (TMPs) during pregnancy, labour and delivery is common globally although evidence on their therapeutic effectiveness and safety is scarce. Research relating to indigenous practices and utilisation of traditional medicinal plants by childbearing women during pregnancy in Makoni District, Zimbabwe was carried out. The study included identification of culturally important indigenous knowledge (IK) practices and TMPs used by pregnant women in order to understand how such plants and practices may affect maternal, foetal, labour, and infant outcomes. Four hundred questionnaires were distributed to postnatal mothers in Makoni District, aimed at obtaining information on IK practices associated with utilisation of TMPs by childbearing women during pregnancy. In addition to this, five focused group discussions were carried out between September 2016 and December 2017 with 66 traditional healers from Makoni District. Documented information included names of utilised plants, plant parts used, dosage, methods of preparation and administration, and reasons for use. Voucher specimens of the utilised plant species were collected. Brine shrimp lethality test was used to evaluate potential toxicity of the documented plant species. The collected data were analysed used Epi info version 7.1 and SPSS version 16.5. Quantitative data revealed that 168 (42.0percent) of pregnant women in Makoni District use TMPs and 95 (23.8percent) used traditional practices (including elephant dung) for maternal and childcare. Among the women who used TMPs were those who experienced precipitated and prolonged labour. Correlation was found between demographic factors and utilisation of TMPs. For example, being a Christian was significantly associated with using TMPs with relative risk (RR) value of 8.9. Postnatal mothers who used TMPs during their pregnancy were 82.0percent less likely to have their membranes ruptured artificially, RR = 0.2 and more likely to experience late decelerations during active phase (RR = 2.8) than those who did not use TMPs. The differences between those who used TMPs and those who did not during pregnancy and labour, showed no significant differences in infant outcomes. The ethnobotanical survey revealed that a total of 47 plant species from 27 families and 13 non-plant products were used as herbal, complementary and alternative medicines (CAM) by pregnant women. More than half of all the documented plant species (59.8percent), belonged to the Fabaceae (19.1), Asteraceae, (8.5percent), Convolvulaceae (6.4percent), Asparagaceae, Euphorbiaceae, Malvaceae, Rubiaceae, Vitaceae and Xanthorrhoeaceae (4.3percent each) families. The most used plants were shrubs (40.4percent), trees (27.7percent), climbers (17.0percent), herbs (12.8percent) and a grasses (2.1percent). The most used plant parts were roots (61.7percent), leaves (25.5percent), fruits (12.8percent) and bark (10.6percent). A total of 26 medical conditions were treated with the majority of medicinal plants used to dilate or widen the birth canal (55.3percent) and to augment labour or speed up the delivery process (46.8percent). Interviews with traditional healers revealed that 14.9percent of the documented herbal medicines were used to guard against witchcraft and to prevent the infants’ illnesses. Other major uses of herbal medicines during pregnancy included their use to lower blood pressure or hypertension during pregnancy (12.8percent), to prevent caesarean section (10.6percent) and to loosen or relax muscles during pregnancy (8.5percent). Widely used non-plant products included soil of a burrowing mole (relative frequency citation (RFC) value of 0.61), elephant dung (RFC = 0.59), wasp nest (RFC = 0.32) and soap (RFC = 25). The majority of these non-plant products (22.8percent) were used to dilate birth canal (7.6percent) and augment labour (15.2percent). None of the twenty-five species with (RFC) > 0.05 evaluated for potential toxicity were categorised as toxic, but Albizia amara, Datura stramonium and Ricinus communis were categorised as having medium toxicity levels, nine species as having low toxicity levels while 13 species were categorised as non-toxic. This study provides valuable insights into the use of medicinal plants used by women during pregnancy, labour, delivery and post-delivery in Makoni District, Zimbabwe. Medicinal plants play an integral role in the provision of basic health care in Zimbabwe. However, the brine shrimp lethality test results categorised some of the prescribed species such as Albizia amara, Datura stramonium and Ricinus communis as having medium levels of toxicity and this is a cause of concern regarding utilization of TMPs during pregnancy. Therefore, TMPs used during pregnancy should be subjected to detailed phytochemical, pharmacological and toxicological experiments aimed at identifying some of the potential toxic compounds and side effects associated with intake of TMPs and associated herbal products. , Thesis (PhD(Nursing)) -- Faculty of Health Sciences, 2020
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Date Issued: 2020-09

Pharmacological Evaluation and Medicinal Potential of Vachellia Karroo (Hayne) Banfi & Galasso Pods traditionally used to treat Sexually Transmitted Diseases in the Eastern Cape, South Africa.

Authors: Maposa, Sandisiwe
Date: 2019
Subjects: Medicinal plants
Language: English
Type: Thesis , Masters , MSc
Identifier: http://hdl.handle.net/10353/14583 , vital:40017
Description: Vachellia karroo is widely used in folk medicine in the Eastern Cape Province South Africa, however, the pods are usually discarded as waste. The current study was conducted to evaluate the phytochemical content and the antioxidant activity of V. karroo pods. The pods were extracted using acetone, distilled water, hexane and methanol. The total phenol, flavonoid, proanthocyanidin, alkaloid and saponin contents of the various extracts were determined spectrometrically and antioxidant activity was evaluated using inhibition of 2,2-diphenyl-1- picrylhydrazyl (DPPH), 2,2´-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid (ABTS), nitric oxide (NO) radicals, while total antioxidant capacity (TAC) was estimated by the phosphomolybdenum assay. V. karro pods had significant amounts of total phenols, flavonoids and proanthocynadin, although, proanthocynadin was not detected in the aqueous and hexane extracts. Methanol and acetone extracts showed higher phenolic, proanthocynadin and flavonoids contents (52.47 ± 6.82 and 29.31 ± 1.49), (334.8±85.1 and 231.22 ±1.80),(288±4.26 & 208.2±17.7) compared to the aqueous and hexane extracts. The alkaloid and saponin contents were 26.67 and 12.85 % respectively. The IC50 values of the methanol extract for DPPH, ABTS and total antioxidant capacity (TAC) were 0.345, 0.017 and 0.116 mg/mL, respectively. Methanol extract of V. karroo pod showed higher polyphenolic content of all the extracts analysed with corresponding strong free radical scavenging potential. These underutilized pods could serve as a new source of antioxidant compounds which could help in combating various ailments. The great antioxidant activity displayed by V. karroo pods extract supports the therapeutic use of this plant in traditional medicine and are attributed to the phytochemical content.The current information suggests that extracts from Vachellia karroo pods might be a ix cheap potential source of natural antioxidants that could be of great importance for the treatment of free radical related diseases. Furthermore, it makes a case for the utilization of the pods instead of discarding them as waste materials. The evaluation of antimicrobial potential of Vachellia karroo extracts was carried out using agar dilution assay against 8 bacterial strains-4 gram-positive [ Enterococcus faecalis (ATCC 29212), Staphylococcus aureus (OK), Bacillus subtilis KZN, Bacillus cereus, and Streptococcus pyogenes] and 4 gram-negative strains[ Vibrio cholera, Klebsiella pneumonia (ATCC 4352), Pseudomonas aeruginosa (ATCC 19582), Salmonella typhi (OK) ]. Six fungal isolates[ Trichophyton mucoides ATCC 201382, Candida albicans (ATCC 10231), Candida glabatra, Penicillium chrysogenum, Aspergillus fumigatus, Penicillum aurantiogriseum] were usedor antifungal assessment. The methanol extract exhibited broad-spectrum activity, with Gram-positive strains being more sensitive than Gram-negative strains. The extracts also showed great inhibition against Candida albicans the fungal isolate responsible for causing candidiasis in women. Since the pods showed promising antimicrobial activity, they could serve as a cheap source for the treatment and management of these sexually transmitted infections. The brine shrimp toxicity test revealed successful hatching of the cysts was in the order: Aqueous extract> methanol extract> hexane extract> acetone extract. The hatching of nauplii was in a concentration dependent fashion, with hatching success decreasing with increase in concentration of extracts. Lethality of extracts determined based on Meyerʼs index of toxicity, showed that the acetone and hexane extracts of V. karroo were moderately toxic. The results of this study indicated that aqueous and methanolic extracts of Vachellia karroo pods were not toxic, therefore supporting its traditional therapeutic usage. This implies that rather than discard x the pods as is waste as it being currently done, Vachellia karroo pods could be salvaged and processed along with the leaves, thus reducing environmental pollution. Proximate parameters (moisture, ash, crude fibre, crude fat, proteins, and carbohydrate) were evaluated using ALASA methods, and elemental analysis by ICP-OES technique. Nutritional analysis showed that V. karroo pods had low content of crude fat and high content of crude fibre, ash, crude protein, and carbohydrate sufficient to meet the recommended dietary allowances. The pods were rich in major minerals Ca, K, P and Mg, with sufficient amount of trace elements Na, Fe, Zn, and Cu. The outcome of this study suggests that Vachellia karroo pods have good nutritional potentials to support or complement the recommended dietary allowance and could be a cheap source of essential nutrients that could help in ameliorating most nutritional challenges as well as contribute remarkably to the amount of nutrient intake in human and animal diets.
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Date Issued: 2019

In vitro evaluation of antimicrobial and antioxidant activities of olea europaea subsp. africana and euryops brevipapposus used by Cala community folkloric medicine for the management of infections associated with chronic non-communicable diseases

Authors: Adegborioye, Abiodun
Date: 2016
Subjects: Antioxidants , Medicinal plants , Traditional medicine -- South Africa -- Eastern Cape
Language: English
Type: Thesis , Masters , MSc
Identifier: http://hdl.handle.net/10353/4869 , vital:28624
Description: Chronic non-communicable diseses are a global public health challenge that continuously threatens the development and health of humans. Risk factors such as unbalanced diet-the high consumption of processed food or food from animal origin are responsible for NCDs. NCDs result in weakened immune system, making the host susceptible to opportunistic infections. Thus, the NCDs burden is most times chronic and multiple with the illness and suffering of the affected person numerous. The lack of cure for NCDs, the high cost of drugs, their high side-effects, and the emergence of multiple drug resistance has given rise to the investigation of other sources for therapeutic cure such as medicinal plants. The ethanol, n-hexane and ethyl acetate extracts of Olea europaea were analysed for their antioxidant and antimicrobial activities. The essential oil was also analysed for their chemical constituents. The n-hexane extracts of O. europaea exhibited no inhibition against all of the microorganisms tested, while the ethyl acetate and ethanol extracts exhibited inhibition, with minimum inhibitory concentration values between 0.625 mg/ml to 1.25 mg/ml. The ethanol leaf and ethyl acetate stem extracts exhibited significant activity in the inhibition of 2, 2-azinobis-(3-ethylbenzothiazolin - 6-sulfonic acid diammonium salt (ABTS) free radical, the n-hexane leaf extract had the overall significant lipid peroxidation inhibition activity, while in the inhibition of 2, 2- diphenyl-1-picrylhydrazyl radical (DPPH), the ethanol and ethyl acetate leaf extracts had strong activity. Nonanal, phytol, α-Pinene, α-Phellandrene, spatulenol and farnesol were some of chemical components identified after the GC-MS analysis of O. europaea oil. In the final part of the dissertation, Euryops brevipapposus essential oil was assessed for the antioxidant activities using free radical scavenging assays. In addition to this, the antimicrobial activities were assessed and the chemical composition was analysed using GC-MS. The essential oil demonstrated significant antioxidant activity against 2, 2-diphenyl-2-picryl-hydrazyl free radical (DPPH), 2, 2′-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) and lipid peroxides with IC50 value of 0.0000000671 mg/ml, 1.05 mg/ml, and 1.170 mg/ml respectively. The essential oil also showed significant activity against all microorganisms tested with minimum inhibitory concentration (MIC) values between 0.055 mg/ml to 0.5 mg/ml. α-pinene, α- Phellandrene, germacrene D, β-pinene, trans- β.-Ocimene, bicyclogermacrene and β -Phellandrene were some of the chemical compounds identified in E. brevipapposus oil. The study has shown that E. brevipapposus and O. europaea are abundant in phytochemical compounds which were thought to be the root cause for the activities demonstrated. Therefore, these therapeutic properties observed validate and elucidate the traditional usage of the both plants in the treatment /management of diseases.
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Date Issued: 2016

Phytochemical analysis and antibacterial properties of aqueous and ethanol extracts of Brachylaena elliptica (Thurb.) dc. and Brachylaena ilicifolia (Lam.) Phill & Schweick

Authors: Sagbo, Idowu Jonas
Date: 2015
Subjects: Medicinal plants , Traditional medicine , Herbs -- Therapeutic use
Language: English
Type: Thesis , Masters , MSc (Biochemistry)
Identifier: vital:11297 , http://hdl.handle.net/10353/d1021289 , Medicinal plants , Traditional medicine , Herbs -- Therapeutic use
Description: Resistance of human pathogenic bacterial strains results in selective pressure against known antibiotic. However, plant derived compounds that possess antibacterial potential are currently being investigated for treatment of wound infections in diabetic patients as they are inexpensive and non-toxic. Hence, this dissertation was designed to evaluate two medicinal plants (Brachylaena elliptica and Brachylaena ilicifolia) traditionally used in the treatment of various diseases such as diabetes, and its secondary complications in diabetic patients. The in vitro antioxidant activity of both plants were evaluated using DPPH (1, 1-diphenylhydrazl), ferric reducing power, ABTS (2, 2’-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid), NO (nitric oxide) and H2O2 (hydrogen peroxide) techniques. The antibacterial test and Minimum inhibitory concentration (MIC) was determined by agar dilution method against 5 bacteria strains (Pseudomonas aeruginosa, Staphylococcus aureus, Streptococcus pyogene, Proteus vulgaris and Proteus mirabilis) infecting wounds in diabetic patients using amoxicillin and ciprofloxacin as positive control. The phytochemical analyses were assessed using standard published methods. Identification of bioactive components in essential oils of both plants were assessed using GCMS. The aqueous and ethanol extracts of both plants were also evaluated to identify bioactive components using LC-MS. The results of the phytochemical analysis revealed the presence of phenols, tannins, flavanoids, flavanols, proanthocyanidins, saponins and alkaloids in both plants. Both plants indicated strong antioxidant activities which might be due to the presence of bioactive compounds. The aqueous and ethanol leaf extracts of both plants demonstrated appreciable broad spectrum activities against these wound pathogens with MIC ranging between 5 and 0.3 mg/ml. The GC-MS analysis of the essential oils of both plants revealed the presence of monoterpenes, oxygenated sesquiterpenes, phenolics and esters. The LC-MS analysis of the aqueous and ethanol leaf extracts of both plants showed that both plants are rich in alkaloids, terpenes, terpenoids, monoterpernoids, and flavanoids. Conclusively, this study has partially justified the ethnomedicinal use of B. elliptica and B.licifolia leaves for the treatment of various diseases, including diabetes and wound infections caused by bacteria in diabetic patients. These may be attributed to the presence of antioxidant compound such as phenols, flavanoids, saponins, tannins, alkaloids and other phytochemical compounds.
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Date Issued: 2015

The antifungal activity of an aqueous Tulbaghia violacea plant extract against Aspergillus flavus

Authors: Belewa, Xoliswa Vuyokazi
Date: 2015
Subjects: Medicinal plants , Antifungal agents , Fungi -- Biotechnology
Language: English
Type: Thesis , Doctoral , PhD
Identifier: http://hdl.handle.net/10948/5858 , vital:21001
Description: Phytochemical analysis of both HEA1 and the crude plant extract showed the presence of phenolics, tannins and saponins. Saponins were the predominant secondary metabolites and were mostly abundant in the plant extract and to a lesser extent in the active compound. Steroidal saponins, tannins and phenolics were also detected in the plant extract, but only the phenolics were detected in the active compound. The results of the phytochemical analysis showed that those compounds that were not present in the active compound could be removed from the crude extract during the TLC purification process. Investigation on the mechanism of action of the crude plant extract on the sterol production by A. flavus showed that the plant extract affected ergosterol biosynthesis by causing an accumulation of oxidosqualene in the ergosterol biosynthetic pathway resulting in a decline in ergosterol production. An oscillatory response in lanosterol production was observed in the presence of the plant extract, which may be an adaptation mechanism of A. flavus to unfavourable conditions and compensation for the loss of enzyme activity which may have occurred as a result of the accumulation of oxidosqualene. The antifungal activity of the plant extract on ergosterol production by A. flavus may also be due to saponins which target the cell membrane and ergosterol production in fungi. The effect of the plant extract on the fungal cell wall of A. flavus also showed that the plant extract caused a decline in β-(1, 3) glucan production by inhibiting β-glucan synthase. The plant extract also affected the chitin synthesis pathway of A. flavus, by causing a decline in chitin production, which was due to the inhibition of chitin synthase. Investigation of chitinase production using 4MU substrates showed that the plant extract caused an accumulation of chitobioses, by activating chitobiosidases and endochitinases. A decline in N-acetylglucosaminidase activity in the presence of the plant extract was observed and this prevented the formation of N-acetylglucosamine. The accumulation of chitobiosidase and endochitinase may be as a result of autolysis that may be triggered by A. flavus as a survival mechanism in the presence of the plant extract and as a compensatory mechanism for the loss of β-glucans and chitin. The antifungal effect of the plant extract on various components of the cell wall of A. flavus, makes T. violacea aqueous plant extract an ideal chemotherapeutic agent against both human and plant pathogens of Aspergillus. The broad spectrum of antifungal activity of T. violacea against A. flavus also eliminates any chances of the fungus developing resistance towards it and would make it a candidate for use as a potential antifungal agent. Further identification and possible chemical synthesis is needed to shed light on the safety and efficacy of the active compound for further development as a chemotherapeutic agent.
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Date Issued: 2015

Molecular characterization, antibiograms and activity of medicinal plants against streptococcus pneumoniae and haemophilus influenzae isolates from clinical samples of patients in the Eastern Cape province, South Africa

Authors: Morobe, Isaac Christopher
Date: 2015-00
Subjects: Medicinal plants
Language: English
Type: Master's/Doctoral theses , text
Identifier: http://hdl.handle.net/11260/6469 , vital:46340
Description: H. influenzae and S. pneumoniae are important causes of community acquired respiratory tract infections including, pneumonia, acute sinusitis, otitis media, meningitis, bacteremia, sepsis, osteomyelitis, pericarditis, septic arthritis, endocarditis, peritonitis, cellulitis and brain abscesses. The ability to effectively treat bacterial infections has been compromised in recent years due to the acquisition of antibiotic resistance, particularly to β-lactam drugs. The increasing trends in antibiotic resistance have prompted incessant searches aimed at unraveling new effective sources for the management of microbial infections. Plant derived antimicrobial compounds that have no or minimal toxicity to host cells are considered candidates for developing new antimicrobial drugs. Safety is therefore critical in the development and formulation of such antimicrobials. In addition to studies on the structural elucidation of active compounds of selected medicinal plants and determination of their toxicity levels, concerted investigations on the molecular landscape of the designated bacteria, including genes coding for resistance and virulence, the phylogenetic profiles of isolates from different sources and the abilities of isolates to withstand the normal bactericidal activities of human serum samples from different blood groups are critical for a thorough understanding of the management, pathogenetic and clinico- epidemiological trajectories of the pathogens. Therefore, the aims of the various studies were to characterize local H. influenzae and S. pneumoniae isolates by serological and molecular methods; ascertain the antibiotic susceptibility profiles of isolates in order to provide updated data and guide clinicians and other health care workers on the empiric management of patients; determine genes coding for virulence and phylogenetic relatedness of isolates of H. influenzae and S. pneumoniae from diverse sources; ascertain the bactericidal activity of human serum samples from different blood groups against H. influenzae and S. pneumoniae and also to determine the activity of active compounds and toxicity levels of selected medicinal plants. In order to achieve these goals, relevant samples were collected and screened using an array of microbiological, serological, molecular and phytochemical methods, which would be espoused in the relevant chapters, presented hereunder. Key findings of the various chapters including their contributions to knowledge are highlighted. The studies are presented in eight chapters and each chapter, with the exception of chapter one (General Introduction and Literature Review) consists of an introduction, materials and methods, results, discussions, conclusions and references. Each chapter is therefore designed as a publishable unit. Chapter 1 gives an account of the background to the study and the literature review. The morphology, cultural characteristics, laboratory diagnosis, pathogenesis, antibiogram and clinical manifestations of H. influenzae and S. pneumoniae were reviewed. Furthermore, the activities of medicinal plants and their various applications in the management of infections in different countries, including their possible active compounds and toxicity levels were also explored in order to provide a suitable background for the study. Similar reviews were undertaken for molecular aspects of both pathogens as well as the activities of human serum samples against microbial infections. In Chapter 2 the prevalence and antibiotic resistance profiles of H. influenzae and, S. pneumoniae isolates from clinical samples of patients in Mthatha, Eastern Cape Province were investigated. Clinical samples were obtained randomly from individuals attending different hospitals in Mthatha district. Samples were analysed using the Kirby Bauer disk diffusion test (antibiotic susceptibility testing) and MIC breakpoints were determined using E-test strips. From a total of 475 clinical samples tested, 323 (68.0%) were positive for both H. influenzae and S. pneumoniae. Most of the positive isolates were obtained from children under 9 years. Out of 323 isolates, 187 (57.89%) were positive for H. influenzae and 136 (42.1%) were positive for S. pneumoniae. From 10 hospitals selected for sampling in this study, Mthatha General Hospital recorded the highest number of isolates, 42 (25.15%) and 31 (22.79%) of H. influenzae and S. pneumoniae positive isolates respectively, followed by Nelson Mandela Academic Hospital 33 (19.76%) and 26 (19.12%) respectively while ST. Patricks 8 (4.79%) recorded the least number of isolates for H. influenzae and Khotsong 4 (2.94%) recorded the least number of isolates for S. pneumoniae. Antibiotic susceptibility tests revealed Amoxicillin (MIC50, 0.125μg/ml) and Vancomycin (MIC50,0.12μg/ml) as the most effective antibiotics against S. pneumoniae isolates and Co-amoxiclav (MIC50,0.3µg/ml) and Cefuroxime (MIC50,0.15µg/ml) against H. influenzae isolates. These data highlight the need for education and to consider predominant resistance when choosing empiric therapies to treat bacterial infections. Chapter 3 was designed to investigate the virulence factors of H. influenzae and S. pneumoniae isolates from clinical specimens of patients with respiratory tract infections in Mthatha district, the Eastern Cape Province. PCR and sequencing methods were used to verify the genetic determinants responsible for virulence in H. influenzae and S. pneumoniae strains. Results indicated that, of the 187 H. influenzae isolates studied, 26 (13.9%) were typeable, positive by genotypic determination, while 161 (86.1%) were non typeable (NTHi) strains. On the other, out of the 136 S. pneumoniae isolates 24 (17.6%) were typeable while 112 (82.4%) were non typeable strains. All isolates tested contained the metS2 gene for both H. influenzae and S. pneumoniae. The phylogenetic clusters identified by maximum-parsimony analysis were also compared to the results of 16S rRNA sequences. Twenty five percent of none typeable strains were typed by 16S rRNA sequencing. The phylogenetic tree yielded 7.7% H. influenzae similarities while S. pneumoniae yielded 25% similarities with other typeable strains. The presence of genes coding for virulence in this study suggest a significant contribution of genes encoding for virulence to antimicrobial resistance among respiratory tract organisms studied. This study underlines the importance of understanding the virulence composition and diversity of pathogens for enhanced clinico-epidemiological monitoring and health care delivery. The findings will also provide a genetic foundation for future research into mechanisms of pathogenesis of H. influenzae and S. pneumoniae and may accelerate the development of safe and effective vaccines to prevent and control diseases caused by H. influenzae and S. pneumoniae. In Chapter 4, cytotoxic effects and safety profiles of extracts of active medicinal plants from the OR Tambo District Municipality in the Eastern Cape of South Africa were carried out. The most prominent families of medicinal plants (Solanacea and Euphorbiaceae) were used. Extracts of nine South African medicinal plants were screened for cytotoxic activities against MAGI CC5+ cells using MTT assay. Results indicated that nine plant extracts (methanolic and aqueous) used in the MTT assay revealed Herb 2 (Cyanthula inculata) as the most potent extract identified with activity of 1.4 Cc50 values of 25.6 mg/mL and induced over 50% of cell deaths, followed by herb 3 (Croton grattismus) and Herb 4 (Cassine trasvaalensis) with activity of 0.2 Cc50 values of 3.7 mg/mL each. The herbs that induced the least cell death, were herbs 5 (Capris tomentosa) and 7 (Hypoxis hemerocallidea), with the activity of 0.05 Cc50 values of 0.9 mg/mL each. Of the nine plant extracts 2(22%) exhibited minimal toxicity on MAGI cells and 7(77.8%) exhibited 50% toxicity. Two (22%) of the methanolic extracts exhibited anti-HIV1 IIIB activities and against Mycobacterium tuberculosis (TB) only one medicinal plant extract (Lysium inerme) exhibited 29% activity. Cytotoxicity tests will provide comprehensive reference data bases for the profiling and eventual considerations of medicinal plants as potential templates for drug designs and medical applications. In chapter 5 Chemical Components of the volatile and non-volatile extractives of Croton species and their microbial activities were screened. Isolation of the essential oils from the leaves of Croton pseudopulchellus and C. gratissimus from the Eastern Cape and KwaZulu-Natal Provinces in South Africa were performed using an all glass Clevenger apparatus according to the British Pharmacopeia method. The minimum inhibitory concentrations of the oils were assessed against the seven different standard strains of bacteria: H. influenzae, Bacillus pimitus, Staphylococcus aureus, S. pneumoniae, Escherichia coli, Klebsiella pneumoniae, Serratia marcescens and Entarobacter cloacae using micro dilution technique on a 96 well microtitre plate. Results showed golden to very light yellow oils obtained with percentage yield of 1.03 -1.25 respectively (w/w). Analysis of the oils was performed using Gas Chromatography and Gas Chromatography/Mass Spectrophotometry. The leaf oil of Croton pseudopulchellus had germacrene (24.2%),β-phellandrene (17.4%), myrcene (13.4%) and β-caryophyllene (11.4%) as the prominent compounds identified in the oil. The chemical composition of the leaf oil of C. gratissimus was characterized by sabinene (14.6%), β-phellandrene (12.3%), α-phellandrene (10.7%), α-pinene (6.0%) and germacrene D (5.9%). Chemical profiles of the essential oils of Croton species reported in literatures are specific to their geographical location. The oils from C. pseudopulchellus and C. grattisimus were found to have significant antibacterial activities and therefore could be used as natural antimicrobial agents for the treatment of several infectious diseases caused by pathogenic and antibiotic resistant organisms. Chapters 6 and 7 were designed to isolate two bioactive compounds from the stem bark of Lycium inerme and the leaves of Croton grattisimus and were screened for their biological activities against H. influenzae and S. pneumoniae. A qualitative phytochemical screening and bioassay of the plants extracts was carried out. Antimicrobial screening was by broth microdilution and bioautography. Bioassay results showed that compounds with Rf –values between 0.67 to 0.80 were very active against H. influenzae and S. pneumoniae. However, the most active of these compounds was observed at 0.70 for H. influenzae and 0.69 for S. pneumoniae from the dichloromethane extract. Column chromatography, Preparative Thin Layer Chromatography (PTLC) and Sephadex LH20 were used for isolation, sample clean-up and purification of this extract. Two active compounds: a coumarin (7-hydroxy-6-methoxy-coumarin) and two triterpenoids, Ursolic acid (3-oxo-19-hydroxyl-6-methoxylpomolic acid) and Moronic acid (3-oxoolean-12-en-28-oic acid) were isolated from the dichloromethane fraction. The presence of Coumarins and Terpenoids in this herb was observed from the TLC fingerprints. NMR spectroscopic methods were used for the structural elucidation of the active compounds while the GC-MS was used to determine the presence of essential oils from volatile samples obtained from the leaves of C. grattisimus and L. inerme. C. grattisimus extracts possess strong free radicals with scavenging, antimicrobial and antifungal activities; therefore, further studies are needed to determine their efficacies in vivo or clinical usefulness. L. inerme stem bark can therefore be used as a source of alternative medicine or new pharmaceutical and health care product or as a starting material for synthesis of drugs. In chapter 8, general conclusions and perspectives of various parts of the findings were captured. The multi-drug resistance was observed among the emerging respiratory tract bacterial pathogens. It was recommended that measures should be put in place to control the spread of drug resistance in pathogens through improved and standardized laboratory practices, proper and regular surveillance to help guide against the indiscriminate use of antibiotics in empirical treatment. The recognition but cautious use of medicinal plants as alternative sources of therapies and a probable means to solve the emerging resistance problem was recommended. Improved standard of hygiene in hospital settings and the communities is important to prevent the spread of infections. The thesis provides a novel reference document on the genes coding for resistance, antibiograms and phylogenetic profiles of local isolates of H. influenzae and S. pneumoniae as well as the activities, active compounds and toxicity levels of medicinal plants investigated in an endeavour to effectively understand the possible therapeutic, molecular and epidemiological trends in respect of the designated pathogens. , Thesis (Phd) -- Faculty of Health Sciences, 2015
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Date Issued: 2015-00

Assessment of the anti-Listerial properties of Garcinia kola (Heckel) seeds

Authors: Penduka, Dambudzo
Date: 2014
Subjects: Microbial sensitivity tests , Garcinia , Medicinal plants , Traditional medicine
Language: English
Type: Thesis , Doctoral , PhD (Microbiology)
Identifier: vital:11278 , http://hdl.handle.net/10353/d1015527 , Microbial sensitivity tests , Garcinia , Medicinal plants , Traditional medicine
Description: A follow-up of traditional medicinal plants uses is an important tool in highlighting their therapeutic potentials, as they have been found to be a source of a wide range of bioactive compounds that can be used as base compounds for new pharmaceutical drugs. This study therefore focuses on assessing the anti-Listerial properties of the seeds of Garcinia kola (Heckel) plant, which is a traditional medicinal plant of west and central African origin, and was and is still used to traditionally treat several ailments. Four different solvents crude extracts of the seeds were assessed for their anti-Listerial activities in-vitro, against a panel of 42 Listeria bacteria, which included Listeria monocytogenes, Listeria ivanovii and Listeria grayi species. At 10 mg/ml concentration the aqueous extract had activity against 29% of the test isolates while the other three crude extracts namely dichloromethane, n-hexane and the methanol extracts had activity against 45% of the test bacteria. The minimum inhibitory concentration (MIC) ranges of the extracts were 0.079-0.313 mg/ml for the dichloromethane extract; 0.079-0.625 mg/ml for the n-hexane extract; 0.157-0.625 mg/ml for the methanol extract; and 10->10 mg/ml for the aqueous extract. The minimum bactericidal concentration (MBC) ranges of the extracts were 0.625–10 mg/ml for both the n-hexane and the dichloromethane extract; 5-10 mg/ml for the methanol extract; and those for the aqueous extract were above 10 mg/ml against all the susceptible Listeria isolates. The rate of kill analysis was then determined for the three most active crude extracts that is excluding the aqueous extract and it was assessed against four representative Listeria species namely L. monocytogenes (LAL 8), L. grayi (LAL 15), L. ivanovii (LEL 30) and L. ivanovii (LEL 18). All the three extracts showed a general trend of being concentration and time dependent in their rate of kill profiles such that most bacteria cells were killed at the highest test concentration of 4× MIC value after the maximum exposure time of 2 h. The n-hexane, dichloromethane and methanol extracts were bactericidal against 4, 3 and 1 isolates out of the four test Listeria isolates respectively.
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Date Issued: 2014

Efficacy of two medical plant extracts and metformin in the prevention of diet induced fatty liver

Authors: Tshidino, Shonisani Cathphonia
Date: 2014
Subjects: Plant Extracts -- Therapeutic use , Medicinal plants
Language: English
Type: Thesis , Doctoral , PhD
Identifier: http://hdl.handle.net/10948/9066 , vital:26461
Description: Non‐alcoholic fatty liver diseases (NAFLD) is manifested in the absent of alcohol abuse. This disease is the major cause of liver failure and death among adults and children worldwide, including South Africa. Its increasing prevalence urges the need of therapeutic intervention. The main objectives of this study were to investigate the following: (1) The effect of 38.9% high fat diet (HFD)‐induced insulin resistance and fatty liver in male Wistar rats, (2) The efficacy of aqueous extracts from Sutherlandia frutescens leaves and Prunus africana bark and metformin in the treatment of HFDinduced insulin resistance and fatty liver. Male Wistar rats were fed on HFD (the HF group) or normal rat chow (the LF group) for 12 weeks. Even though the HFD‐fed rats had developed insulin resistance by week 12, fatty liver developed by week 16. After week 12, the HF group was divided into four groups of 6‐7 rats each and three of those groups were gavaged with either 0.125 mg P. africana extract/kg bwt/day (the HF+Pa group) or 50 mg S. frutescens extract kg bwt/day (the HF+Sf group) or 16 mg metformin/ kg bwt/day (HF+Met group), while kept on the same diet for an additional of 4 weeks, to investigate whether two medicinal plant extracts and metformin can prevent HFD to induce fatty liver or not. After 16 weeks, the liver histological images revealed that the HF group developed fatty liver in the form of both microsteatosis and macrosteatosis. Fatty liver was confirmed by significant increased liver total lipid (TL) and activities of glucose‐6‐phosphate dehydrogenase (cG6PD) and xanthine oxidase (XO), mitochondrial NADH oxidase (mNOX) and by a decrease (P<0.05) in the activities of the homogenate superoxide dismutase (hSOD) and mitochondrial complex II in the HF group, when compared to the LF group. Since the activities of mCS and cACL enzymes were not changed in the HF group, hence increased cG6PD activity in the HF group indicates that there was increased NADPH demand for lipid accumulation from activated NEFAs taken up by the liver from circulation and for maintenance of the NADPH‐dependent antioxidants and oxidants, respectively. The obtained data also show that mitochondria of the HFD‐fed rats adapted to an increase in energy availability, thereby compensation through decreasing complex II activity, to allow electron flux from β‐oxidation to respiratory chain in the HF group. Liver TL content was significantly decreased in the rats treated with metformin and P. africana extract, but not in the rats treated with S. frutescens when compared to the HF group (P < 0.05). However, the TL content remained >5% per liver weight in all treated groups. The present study demonstrates that these two plant extracts and metformin have different glucogenic and lipogenic effects from that presented by HFD alone when compared to the LFD alone. In conclusion, metformin and P. africana extract can attenuate HFD‐induced fatty liver without changing the dietary habits. Hence S. frutescens extract is less effective in the prevention of HFD‐induced fatty liver. A change in the dietary habits is recommended to be considered during the use of these three remedies in the treatment of HFD‐induced insulin resistance and fatty liver. All three treatments enhanced antioxidant capacity, and may improve insulin resistance and fatty liver mediated by the present HFD through different mechanism of actions in the liver.
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Date Issued: 2014

Phytochemical analyses and Brine shrimp (Artemia Salina) lethality studies on Syzygium cordatum

Authors: Chiguvare, Herbert
Date: 2013
Subjects: Artemia , Crustacea , Chromatographic analysis , Medicinal plants , Essences and essential oils , Traditional medicine
Language: English
Type: Thesis , Masters , MSc (Chemistry)
Identifier: vital:11336 , http://hdl.handle.net/10353/d1004352 , Artemia , Crustacea , Chromatographic analysis , Medicinal plants , Essences and essential oils , Traditional medicine
Description: Syzygium cordatum Hoscht ex. C Krauss, also known as water berry, is normally used by the people of South Africa for respiratory ailments including tuberculosis, stomach complaints, treatment of wounds and as emetics. An extract of the leaves can be used as a purgative for diarrhoea treatment. The leaves of Syzygium cordatum Myrtaceae were obtained from the Eastern Cape Province of South Africa, air dried and sequential solvent extraction was done to obtain various non volatile crude extracts. The volatile extract, that is the essential oil was extracted from the leaves using hydrodistillation and analysis of compounds was done by GC/MS for composition. 32 compounds were obtained from the fresh leaves and 18 compounds were obtained from the dry leaves. The fresh oil contains caryophyllene (11.8 percent) and caryophyllene oxide (11.1 percent) as the main sesquiterpene component. α-Pinene(5.0 percent) was the only monoterpene compound identified in the fresh oil in substantial amount. The dry leaves oil had copanene (17.0 percent), β-Caryophellene (26.0 percent), cubenol (6.5 percent) and caryophellene oxide (14.2 percent) as the dominant constituent of the oil. Summary of the classes of compounds in the oil revealed that the chemical profile of both oils were dominated by sesquiterpenoid compounds. This is the first time that terpenoids compounds are being identified in both the fresh and dry leaf oil of S. cordatum. Hexane leaf extract was selected due to the interest in the terpenoid compounds. Column chromatography of the hexane crude gave five (5) of which two are fully reported. The isolates were fully elucidated using spectroscopic methods to be β-Sitosterol (HC3) and Friedela-3-one (HC1A/HC1D). Cytotoxicity analysis was carried out on the crude using the Brine shrimps assay. Isolates 1C and1D showed significant lethality using the brine shrimps assay with lethality values (LC50) of 4.105mg/ml for HC1C and 4.11mg/ml for 1D/1A respectively.
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Date Issued: 2013

The effect of in vitro digestion on selected biological activities of Hypoxis sobolifera corms

Authors: Van Rooyen, Anzel
Date: 2013
Subjects: Potatoes -- Therapeutic use , Medicinal plants
Language: English
Type: Thesis , Masters , MSc
Identifier: vital:10344 , http://hdl.handle.net/10948/d1020058
Description: In South Africa part of the cultural and religious beliefs of the African people is the use of traditional remedies to treat diseases. These remedies are obtained from medicinal plants (Steenkamp, 2003). One of the most frequently traded plants in the Eastern Cape is Hypoxis, commonly known as Afrika patat, or African potato. South African traditional healers instruct patients to brew the fresh Hypoxis corm as a tea and then ingest it (Steenkamp, 2006a). This prompted an investigation into the digestive stability of a traditionally prepared Hypoxis extract. The H. sobolifera extracts were digested using a simulated gastric/small intestinal digestion and their biological activity determined. The hot water H. sobolifera extract before digestion only showed cytotoxic activity against cancer cell lines at very high concentrations which are not likely to be achieved under normal ingestion circumstances. In Chang liver cells on the other hand, chronic exposure to the hot water H. sobolifera extract increased glucose uptake in amounts similar to that of metformin. On the negative side, the glucose utilization stimulation was lost due to the simulated digestion process. The significant inhibition of AGEs by hot water H. sobolifera extract (IC50 of 6.3 Ig/ml) is a very encouraging result as treatment in the management of diabetes. This activity was only slightly reduced by the in vitro digestion process. Also observed was enzyme inhibition activity by traditionally prepared H. sobolifera, with ∝-amylase being inhibited (IC50 of approximately 250 Ig/ml) and therefore preventing or limiting starch breakdown. From the DPPH results it was clear that H. sobolifera, even when digested, is a potent anti-oxidant (IC50 of 134.4 Ig/ml when undigested compared to 162.9 when digested with β-glucosidase added to stomach digestive step). HPLC and TLC experiments revealed that rooperol which has previously been thought to be the compound responsible for the anti-oxidant activity in Hypoxis extracts, was absent from the traditional extract of H. sobolifera and therefore cannot be the sole compound exhibiting anti-oxidant activity; other compounds such as phenolics may be contributing. The phenolic and flavonoid content results revealed very highconcentrations of these compounds in the traditionally prepared H. sobolifera extract. These compounds may therefore play major roles in all of the biological activities observed from treatment with Hypoxis spp. The ROS results yielded interesting and promising results. Using standard or traditionally prepared H. sobolifera extracts, activation of differentiated U937 cells with PMA was greatly enhanced by cotreatment with the extracts, while extracts on their own did not cause significant activation. Future studies should investigate this property of the extracts as a promising immune boosterThe HPLC results showed that hypoxoside was undetectable in the hot water traditional extract and the TLC anti-oxidant experiment proved that rooperol is not present in the hot water traditional extract after treatment with β-glucosidase. This indicates that neither one of the Hypoxis compounds previously believed to be responsible for the biological activities observed are present in the extract when prepared the traditional way. Therefore, the biological activities observed in this study can be attributed to other phytochemical compounds.
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Date Issued: 2013

The medicinal plant Sutherlandia Frutescens regulates gene expression to reverse insulin resistace in rats

Authors: Fortuin, Melissa
Date: 2013
Subjects: Insulin resistance , Medicinal plants , Genetic regulation , Insulin resistance -- Animal models
Language: English
Type: Thesis , Masters , MSc
Identifier: vital:10349 , http://hdl.handle.net/10948/d1020823
Description: Obesity can lead to Type 2 Diabetes, both conditions increase in association with physical inactivity and high-energy diets, resulting in elevated blood glucose, decreased insulin sensitivity and increased insulin resistance. Sutherlandia frutescens (S.frutescens), an anti-diabetic plant, reverses and prevents insulin resistance in a rat model and human cell culture model. Gene expression analysis in hepatocyte cultures, identified genes down regulated in insulin resistance and up regulated by S.frutescens. These included genes encoding vesicle transporter proteins, hypothesised to be linked to hepatic lipid accumulation and lipid droplet formation during insulin resistance. The aim of this study was to investigate critical genes involved in lipid droplet formation, vesicle assembly and transport in high fat diet (HFD)-induced insulin resistant rat liver tissue during the development of insulin resistance and the reversal of these changes by S.frutescens. Rats were fed a low fat diet (LFD) or HFD supplemented with S.frutescens for 2, 4 and 8 weeks. Rats fed a HFD for 12 weeks developed insulin resistance, confirmed by plasma glucose and insulin levels (compared to normal controls). Groups of these rats were gavaged with S. frutescens (50mg/kg BW), Metformin (13mg/kg BW) or water for a further 4 weeks and starved for 12 hours, anaesthetized and blood removed by heart puncture. Liver was stored in RNA-Later™ for qRT-PCR and snap-frozen in liquid nitrogen for western blotting and confocal microscopy analysis. Changes in expression of vesicle transporter genes VAMP3 and NSF were analysed by qRT-PCR and changes in the protein expression by western blotting analysis. Proteins were localised within the liver by confocal immunohistochemistry using ZEN lite™ software. Statistical analysis was performed using One-Way ANOVA and unpaired t-test. mRNA gene expression of vesicle transport components VAMP3, NSF and SNAP25 showed relatively moderate changes with considerable individual variation within control or experimental groups. Uncorrelated changes in mRNA and protein products were found and may be due to differential regulation by siRNA. Proteins also showed altered staining patterns in high fat diet rats that reverted towards normal on S. frutescens treatment, potentially reflecting functional changes associated with transport of lipid-filled vesicles.
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Date Issued: 2013

Biological activities and mechanisms of action of two ethnobotanically selected South African medicinal plants on some bacteria associated with gastrointestinal infections

Authors: Olajuyigbe, Olufunmiso Olusola https://orcid.org/0000-0002-7889-0416
Date: 2012-08
Subjects: Medicinal plants , Herbs -- Therapeutic use , Gastrointestinal system
Language: English
Type: Doctoral theses , text
Identifier: http://hdl.handle.net/10353/25439 , vital:64249
Description: In this study, 36 plant species representing 24 families were found to be commonly used for the treatment of a variety of gastrointestinal disorders in Eastern Cape, South Africa. The family Fabaceae had the highest number of species. Out of these, 47.06percent were used in the treatment of dysentery alone while 46.15percent were used in the treatment of diarrhoea. Acacia mearnsii De Wild and Ziziphus mucronata subsp. mucronata Willd were selected for this research because they are extensively used in folkloric medicine in South Africa and there was lack of scientific reports that documented their biological activities. The phytochemical screening, antioxidant activities, in vitro antimicrobial activities, cytotoxicity, the synergistic potentials and mechanisms of actions of these plants were investigated. The phytochemical screening and the antioxidant activities of the two species showed that the quantity of the phenolic compounds, flavonoids and proanthocyanidins detected differ significantly in the various extracts. Of the aqueous, acetone, ethanolic and methanolic extracts of A. mearnsii, the ethanolic extract had the highest flavonoids while the acetone extract had the highest phenolic contents. The proanthocyanidins were highest in the methanol extract while aqueous extracts had the least phytochemicals. Aqueous extract showed the least ferric reducing power but methanol extract indicated the highest reducing power. The reducing power of the extracts was lower than those obtained from the reference standard such as butylated hydroxytoluene (BHT), rutin and ascorbic acid. 2,2’-azinobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) diammonium salt showed that ethanol extract exhibited the highest antioxidant activity at the highest concentration tested. Also, 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay indicated that ethanol extract had the highest radical scavenging activity at the lowest concentration and the activities of all the extracts decreased with increase in their concentrations. In Z. mucronata subsp. mucronata, the phenolics were significantly higher than the flavonoids and proanthocyanidin contents in all the extracts investigated. The ethanol extract had the highest antioxidant activity, followed by the acetone extract while the aqueous extract was the least active. Reacting with ABTS, the 50percent inhibitory concentrations (IC50) were (0.0429 ± 0.04 mg/ml) for aqueous, (0.0317 ± 0.04 mg/ml) for acetone and (0.0306 ± 0.04 mg/ml) for ethanol extracts while they inhibited DPPH radical with 50percent inhibitory concentration (IC50) values of 0.0646 ± 0.02 mg/ml (aqueous), 0.0482 ± 0.02 mg/ml (acetone) and 0.0422 ± 0.03 mg/ml (ethanol). The investigation showed that a positive linear correlation existed between the total phenolic content and antioxidant activity of the extracts and that these plants have strong antioxidant property and free radical scavenging capability. The in vitro antibacterial activities of Acacia mearnsii and Z. mucronata subsp. mucronata showed that their minimum inhibitory concentrations ranged between 0.039 mg/ml and 1.25 mg/ml. With the exception of acetone extract of A. mearnsii having MICs greater than 1.0 mg/ml for Enterococcus faecalis ATCC 29212 and Bacillus subtilis KZN, all other isolates had MICs less than 0.7 mg/ml. In all the bacteria treated with Z. mucronata subsp. mucronata extracts, Enterobacter cloacae ATCC 13047 had MIC greater than 1 mg/ml in methanol extract, Enterococcus faecalis ATCC 29212 and Staphylococcus aureus ATCC 6538 had MICs greater than 1 mg/ml in acetone extract while all other isolates were highly susceptible to the different extracts of Z. mucronata subsp. mucronata and had MICs less than 0.7 mg/ml. While aqueous extract was as active as the alcoholic extracts in A. mearnsii, that of Z. mucronata had no effect. The ethanol extracts exhibited the highest degree of antibacterial activity in both plants. This study, also, showed that the antifungal activity of A. mearnsii ranging 0.3125 – 5.0 mg/ml was higher than those of the different extracts of Z. mucronata subsp. mucronata ranging 1.25 – 10.0 mg/ml. It is evident from the results of the brine shrimp lethality assay that the crude extracts of A. mearnsii with the LC50 equaled 112.36 µg/ml and having the highest levels of toxicity (100percent) death at 500 μg/ml was non toxic (LC50 > 100 μg/ml) while the LC50 for Z. mucronata subsp. mucronata equaled 90.27 µg/ml indicated a low level of toxicity. The effects of combining the crude extracts of these plants with eight antibiotics were investigated by means of checkerboard and agar diffusion methods. On using the methanol extract of A. mearnsii, the agar diffusion assay showed that extract-kanamycin combination had zones of inhibition ≥ 20 ± 1.0 mm in all the bacteria tested (100percent), followed by extract chloramphenicol (90percent) > extract-ciprofloxacin = extract-tetracycline (70percent) > extract amoxicillin (60percent) > extract-nalidixic acid (50percent) > extract-erythromycin (40percent) > extract metronidazole (20percent). The checkerboard showed synergistic interaction (61.25percent), additivity/indifference (23.75percent) and antagonistic (15percent) effects. I, therefore, concluded that the antibacterial potentials of the antibiotics were improved and combining natural products with antibiotic could be a potential source of resistance-modifying agents useful against multi-drug resistant bacteria. The influences of these extracts on the ultrastructures, elemental components, protein and lipid leakages of five different bacteria were determined as the possible mechanisms of action of the extracts investigated. The scanning electron microscopy indicated varied ultrastructural changes in the morphology of bacterial cells treated with the extracts. The X-ray microanalysis showed significant differences between the elemental contents of extract-treated and untreated bacteria while lipids and proteins were leaked to a great extent from the extract-treated bacterial strains in comparison with the untreated ones. The possible mechanisms of action of the extracts may include inhibition of a significant step in peptidoglycan assembly, inhibition of metabolic processes, disruption of cell wall and cell membranes resulting in the efflux of lipid and protein in all the bacteria tested. The possible mechanism of action involved in the lipid and protein leakages in the bacterial cells could be attributed to lipid peroxidation and protein oxidation owing to the antioxidant activities of the extracts that were active beyond the protective levels. I concluded that the morphological changes and the observed leakages showed rapid killing, significant membrane depolarization resulting in leakages and efflux of disintegrated cellular materials. In general, this study has justified the ethnotherapeutic importance of A. mearnsii and Z. mucronata subsp. mucronata in the treatment of microbial infections by indicating the possible mechanisms of action of the crude extracts on the tested bacteria. , Thesis (PhD) -- Faculty of Science and Agriculture, 2012
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Date Issued: 2012-08

Biochemical evaluation of Tulbaghia violacea harv.rhizomes in diet induced hypercholestrolemic rats

Authors: Olorunnisola, Olubukola Sinbad
Date: 2012
Subjects: Violaceae , Anticoagulants (Medicine) , Antineoplastic agents , Rats , Hypercholesteremia , Cardiovascular agents , Medicinal plants
Language: English
Type: Thesis , Doctoral , PhD (Biochemistry)
Identifier: vital:11273 , http://hdl.handle.net/10353/d1006900 , Violaceae , Anticoagulants (Medicine) , Antineoplastic agents , Rats , Hypercholesteremia , Cardiovascular agents , Medicinal plants
Description: Discovery of cheap, nontoxic and readily available antiatherosclerotic drugs is an extraordinary challenge in this modern world. Atherosclerosis and cardiovascular diseases have been predicted to be the leading cause of death by the year 2030. Hence, this thesis was designed to search for plant (s) with anti-atherogenic properties, investigate its possible side effects and extrapolate its likely mechanism(s) of action. An ethnobotanical survey was employed in identification of locally important plants used for the management and treatment of cardiovascular diseases and its predisposing factors in Nkonkobe Municipality, Eastern Cape in South Africa. Information on the names of plants, their parts used and methods of preparation was collected through a questionnaire which was administered to herbalists, traditional healers and rural dwellers. The most frequently used plant (Rhizomes of Tulbaghia violacea Harv.) was investigated for toxicity using brine shrimp lethality (in vitro) and in vivo toxicity test (acute and subchronic) on rats to determine safety dosage. The in vitro antioxidant and free radical scavenging activity of the plant was investigated using models such as 1,1-diphenyl-2- picrylhydrazyl (DPPH), superoxide anions, hydrogen peroxide (H2O2), nitric oxide (NO), 2,2’- azinobis [3-ethylbenzothiazoline-6-sulfonic acid] diammonium salt (ABTS), lipid peroxidation inhibition and the ferric reducing agent. Phytochemical content and the effect of oral administration of fresh methanolic extract rhizomes of Tulbaghia violacea (250, 500 mg/kg. bwt/day) on Lipid peroxidation (TBARS), serum and tissue antioxidant enzymes in normal, hypercholesterolemic and diet induced atherogenic rats were also assessed. More so, the potential of the extract (250 and 500 mg/kg. bwt) to protect against atherogenic diet (4 percentage cholesterol 1 pecentage cholic acid and 0.5 percentage thiouracil) induced fatty streaks formation, dyslipidemia, oxidative stress and endothelial dysfunction was also investigated. Ethnobotanical study revealed that 19 plant species are used for the treatment of heart related diseases in the Municipality. 53 percentage of the plants mentioned were used for the management of chest pain, 47 percentage for high blood pressure, 42 percent for heart disease, 16 percentage for stroke and 11 percentage for the treatment of hypercholesterolemia. Tulbaghia violacea was repeatedly mentioned as the plant species used for the treatment of high blood pressure and predisposing factors in the study area. The brine shrimp cytotoxicity test revealed that fresh, dried methanolic extracts and essential oil of the T. violacea exhibited a high degree of cytotoxic activity with IC50 values of 18.18 (fresh) and 19.24 (dried) μg/ml. An IC50 value of 12. 59 μg/ml was obtained for the essential oil of the plant. The low cytotoxicity values obtained, suggested that rhizome of T. violacea may serve as a potential source of antimicrobial and anticancer agents. In vivo acute study of single oral administration of 5g/kg dose does not produce mortality or significant behavioral changes during 14 days observation. In the sub-chronic study, the extract (250, 500 mg/kg/bwt/ day) administered for a period of 28 days showed no mortality or morbidity. The weekly body and organ weight of the rats showed no significant differences between the control and the rats treated with the extract. The extract at all doses does not show any effect on of biomarkers of liver or renal damage. However, a significant decrease in the activity of ƔGT was observed in the extract treated groups. Hematological evaluation revealed that oral administration of fresh methanolic extracts of rhizomes of T. violacea does not cause anaemia or leucocytosis in the animals. Furthermore, histopathology results of the internal organs revealed no detectable inflammation. These results demonstrated that the rhizome extract of T. violacea was potentially safe for consumption orally even in chronic concentration. In vitro antioxidant evaluation showed that the essential oil, fresh and dried methanolic extracts exhibited potent antioxidant activities in a concentration dependent manner. Phytochemical investigation reveals that the fresh and the dry extract of RTV are rich in flavonoid, flavonol, phenols, tannin and proanthocyanidin, while the essential oil contained dimethy disulfide, dimethyl trisulfide, (methyl methylthio) methyl, 2,4-dithiapentane (11.35 percent) and (methylthio) acetic acid, 2- (methylthio) ethanol, 3-(methylthio) - and propanenitrile (7.20 percent). The fresh extract had higher radicals scavenging activity than the essential oil or dried extract, with 50 percentage inhibition of DPPH, hydrogen peroxide and lipid peroxidation at a concentration of 35.0 ± 0.12, 19.3 ± 0.11 and 17.9 ± 0.15 μg/ml respectively. Oral administration of methanolic extract of RTV in 125, 250 and 500 mg/kg to female Wistar rats significantly inhibited reduction of glutathione (GSH), superoxide dismutase (SOD) and catalase (CAT). The extracts also inhibited (p< 0.05) lipid peroxidation in normal, high cholesterol and diet induced atherosclerosis fed rats in a dose dependant manner. Also the extract (250 and 500 mg/kg/bwt/day) caused a significant (p<0.05) improvement in body weight of treated animals compared with untreated hypercholesterolemia control rats. The extracts also protected significantly (p<0.05) against atherogenic diet induced liver damage or fatty streaks formation in the aorta as revealed by histological examination. The anti-cholesterolemia and anti-atherosclerotic activities of the extract compared favorably well with standard drugs Gemfibrozil and Atorvastatin respectively. Conclusively, rhizomes of T. violacea possess significant anti-atherogenic activity and its mechanism of action(s) may be due to its antioxidant and anti-hypercholesterolemia properties. The results of this study also suggested that rhizome of T. violacea is relatively safe for human consumption and it may be used as an alternative to garlic.
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Date Issued: 2012

In vitro cytotoxic effects of selected Nigerian medicinal plant extracts on cancer cell lines

Authors: Baatjies, Lucinda
Date: 2012
Subjects: Cancer -- Treatment , Cancer cells , Medicinal plants , Plant extracts , Traditional medicine , Public health
Language: English
Type: Thesis , Masters , MSc
Identifier: vital:10316 , http://hdl.handle.net/10948/d1008191 , Cancer -- Treatment , Cancer cells , Medicinal plants , Plant extracts , Traditional medicine , Public health
Description: Cancer is a disease that imposes a heavy burden on public health and poses a challenge to science. The World Health Organization estimates that 80 percent of people in developing countries of the world rely on traditional medicine for their primary health needs, and about 85 percent of traditional medicine involves the use of plant extracts. This is particularly true in Africa where a large percentage of the population depends upon medicinal plants for health care. Therefore, detailed screening and evaluation of bioactive substances for chemotherapeutic purposes of African plants are urgently warranted. Furthermore, this will serve to validate the efficacy and safety of African traditional medicine. The current study investigated the in vitro cytotoxic effects of 17 ethanolic extracts of the following 16 plants used in traditional anticancer medicine in Nigeria: Sapium ellipticum leaves, Sapium ellipticum stembark, Combretum paniculatum, Celosia trigyna, Pupalia lappacea, Justica extensa, Hedranthera barteri leaves, Alternanthera sessilis, Ethulia conyzoides leaves, Lannea nigritana stembark, Combretum zenkeri root, Combretum molle leaves, Adenanthera parvoniana, Lannea acida, Cyathula achyranthoides, Drymaria cordata, Cyathula prostrata, against HeLa cancer cells. Five of the most promising extracts (Sapium ellipticum leaves, Combretum paniculatum, Celosia trigyna, Drymaria cordata, Cyathula prostrata) were selected for further screening against HT29 and MCF-7 cancer cells. Of the five, the first two were investigated further based on their activities in the screening phase. The S. ellipticum leaf extract yielded IC50 values of 88.60 ± 0.03 and 93.03 ± 0.03 μg/ml against HeLa and MCF-7, respectively. The toxicity was also evaluated on normal cells and an IC50 of 77.66 μg/ml was obtained for peripheral blood mononuclear cells (PBMCs). The IC50 values for proliferating and confluent Chang liver cells were both >125 μg/ml. These results suggest that the extract may be selective for specific cell types. Bio-assay guided fractionation of the S. ellipticum ethanolic extract yielded two active fractions; chloroform and ethyl acetate. Two compounds isolated from the chloroform extract were screened against the three cancer cell lines and found to be inactive. Three compounds were isolated from the ethyl acetate fraction and revealed IC50 values < 62.5 and < 31 μg/ml against MCF-7. Unfortunately these two compounds soon lost activity before any further work could be done on them and work was continued with the crude extract.
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Date Issued: 2012

Showing items 1 - 20 of 33

Chemical analysis and biological activities of crude extracts and essential oil of selected medicinal plants from the Eastern Cape, South Africa, and Volta Region of Ghana

Selected medicinal plants leaves identification: a computer vision approach

Evaluation of the toxicity of secondary metabolites in Solanum incanum L. to advance community knowledge

Pharmacological, toxicological and phytochemical evaluation of helichrysum petiolare hilliard & b.l. burtt - an indigenous plant traditionally used in the treatment of diabetes in the eastern cape province of South Africa

Outcomes of Drug Resistant Tuberculosis in Two Rural District Hospitals, Eastern Cape Province, South Africa

Contested environmental knowledge: Struggles over meanings and uses of medicinal plants in Kabokweni, Mpumalanga Province, South Africa

Usage of traditional medicines and other indigenous practices by childbearing women during pregnancy in Makoni District, Zimbabwe

Pharmacological Evaluation and Medicinal Potential of Vachellia Karroo (Hayne) Banfi & Galasso Pods traditionally used to treat Sexually Transmitted Diseases in the Eastern Cape, South Africa.

In vitro evaluation of antimicrobial and antioxidant activities of olea europaea subsp. africana and euryops brevipapposus used by Cala community folkloric medicine for the management of infections associated with chronic non-communicable diseases

Phytochemical analysis and antibacterial properties of aqueous and ethanol extracts of Brachylaena elliptica (Thurb.) dc. and Brachylaena ilicifolia (Lam.) Phill & Schweick

The antifungal activity of an aqueous Tulbaghia violacea plant extract against Aspergillus flavus

Molecular characterization, antibiograms and activity of medicinal plants against streptococcus pneumoniae and haemophilus influenzae isolates from clinical samples of patients in the Eastern Cape province, South Africa

Assessment of the anti-Listerial properties of Garcinia kola (Heckel) seeds

Efficacy of two medical plant extracts and metformin in the prevention of diet induced fatty liver

Phytochemical analyses and Brine shrimp (Artemia Salina) lethality studies on Syzygium cordatum

The effect of in vitro digestion on selected biological activities of Hypoxis sobolifera corms

The medicinal plant Sutherlandia Frutescens regulates gene expression to reverse insulin resistace in rats

Biological activities and mechanisms of action of two ethnobotanically selected South African medicinal plants on some bacteria associated with gastrointestinal infections

Biochemical evaluation of Tulbaghia violacea harv.rhizomes in diet induced hypercholestrolemic rats

In vitro cytotoxic effects of selected Nigerian medicinal plant extracts on cancer cell lines