Biogenic synthesis of Silver nanoparticles (AgNPs) and its effects on Zebrafish (Danio rerio)
- Authors: Siguba, Busiswa
- Date: 2019
- Subjects: Biogenic synthesis -- Zebrafish , Nanoparticles – Silver , Zebrafish
- Language: English
- Type: Thesis , Masters , M Sc
- Identifier: http://hdl.handle.net/11260/1339 , vital:32260
- Description: The increase in use and production of engineered nanoparticles in recent years points towards their inevitable release into freshwater ecosystems. Subsequently, exposure to organisms in freshwater ecosystems is to be expected. The aim of this dissertation was to synthesize silver nanoparticles (AgNPs) using silver nitrate, gelatine and maltose as precursor, capping and reducing agent respectively. Cytotoxic effects of the as-synthesized AgNPs was evaluated at concentrations of 0.031 μg/L, 0.250 μg/L and 5.000 μg/L on selected target organs in zebrafish (Danio rerio ) after 96 hr of exposure, under a 24 hr static renewal system. Formation of AgNPs was investigated by UV-Vis spectrophotometry, which displayed absorption maxima peak characteristic of plasmon resonance band for silver at 419 nm. From transmission electron microscopy, AgNPs was found to be small, well dispersed and spherical in shape with a narrow size distribution, and an average particle size of3.76 ± 1.00 nm. Histopathological alterations following exposure to AgNPs was noticed in the gills, epidermis, muscle tissue and kidney. Secondary lamellae hypertrophy, oedema and epithelial lifting was observed in all experimental groups. Curling and clubbed tips of secondary lamellae were observed at the lowest concentration (0.031 μg/L). Hyperplasia and lamellae fusion was most common at the median concentration (0.250 μg/L) of AgNP exposure. Hypertrophy of endothelial cells along with blood vessel congestion was also observed. Reduced secondary lamellar length, lamellar erosion and thinning were observed at the highest concentration (5.000 μg/L).AgNP exposure also altered the shape of alarm cells. In addition, hyperplasia and hypertrophy of goblet cells were observed at the highest concentration (5.000 μg/L) at 96 hr. At 5.000 μg/L of AgNP, PAS reaction was intense (deep purple), while the number and size of these cells decreased. Staining with AB pH 2.5 demonstrated an intense deep purple staining at the lowest and at the median concentration (24 hr). Moderate staining was seen at the higher concentrations. Muscle bundles with severe oedema, their thickening and separation were more pronounced in all treated groups. Histopathological tubular deformation and mononuclear cell infiltration were observed in kidney tissues. In addition; an increase in melano‐macrophage aggregation intensity was identified on the 48 hr in the treated groups. An increase in tubular epithelial cell regeneration/ proliferation, resulting in production of new epithelial cells which was indicative of recovering of kidney tissues from AgNP induced injury at 96 hr of exposure. Results presented here shows that fish respond to the presence of AgNPs.
- Full Text:
- Date Issued: 2019
- Authors: Siguba, Busiswa
- Date: 2019
- Subjects: Biogenic synthesis -- Zebrafish , Nanoparticles – Silver , Zebrafish
- Language: English
- Type: Thesis , Masters , M Sc
- Identifier: http://hdl.handle.net/11260/1339 , vital:32260
- Description: The increase in use and production of engineered nanoparticles in recent years points towards their inevitable release into freshwater ecosystems. Subsequently, exposure to organisms in freshwater ecosystems is to be expected. The aim of this dissertation was to synthesize silver nanoparticles (AgNPs) using silver nitrate, gelatine and maltose as precursor, capping and reducing agent respectively. Cytotoxic effects of the as-synthesized AgNPs was evaluated at concentrations of 0.031 μg/L, 0.250 μg/L and 5.000 μg/L on selected target organs in zebrafish (Danio rerio ) after 96 hr of exposure, under a 24 hr static renewal system. Formation of AgNPs was investigated by UV-Vis spectrophotometry, which displayed absorption maxima peak characteristic of plasmon resonance band for silver at 419 nm. From transmission electron microscopy, AgNPs was found to be small, well dispersed and spherical in shape with a narrow size distribution, and an average particle size of3.76 ± 1.00 nm. Histopathological alterations following exposure to AgNPs was noticed in the gills, epidermis, muscle tissue and kidney. Secondary lamellae hypertrophy, oedema and epithelial lifting was observed in all experimental groups. Curling and clubbed tips of secondary lamellae were observed at the lowest concentration (0.031 μg/L). Hyperplasia and lamellae fusion was most common at the median concentration (0.250 μg/L) of AgNP exposure. Hypertrophy of endothelial cells along with blood vessel congestion was also observed. Reduced secondary lamellar length, lamellar erosion and thinning were observed at the highest concentration (5.000 μg/L).AgNP exposure also altered the shape of alarm cells. In addition, hyperplasia and hypertrophy of goblet cells were observed at the highest concentration (5.000 μg/L) at 96 hr. At 5.000 μg/L of AgNP, PAS reaction was intense (deep purple), while the number and size of these cells decreased. Staining with AB pH 2.5 demonstrated an intense deep purple staining at the lowest and at the median concentration (24 hr). Moderate staining was seen at the higher concentrations. Muscle bundles with severe oedema, their thickening and separation were more pronounced in all treated groups. Histopathological tubular deformation and mononuclear cell infiltration were observed in kidney tissues. In addition; an increase in melano‐macrophage aggregation intensity was identified on the 48 hr in the treated groups. An increase in tubular epithelial cell regeneration/ proliferation, resulting in production of new epithelial cells which was indicative of recovering of kidney tissues from AgNP induced injury at 96 hr of exposure. Results presented here shows that fish respond to the presence of AgNPs.
- Full Text:
- Date Issued: 2019
Comparative study of phytochemical composition and insecticidal properties of Lemon species from Eastern Cape and KwaZulu-Natal
- Authors: Nodola, Phumelele
- Date: 2019
- Subjects: Phytochemical -- Insecticidal properties Lemon - - Species – Eastern Cape - - South Africa Citrus limon
- Language: English
- Type: Thesis , Masters , M Sc
- Identifier: http://hdl.handle.net/11260/1348 , vital:32261
- Description: Citrus limon commonly known as lemon is the third most cultivated citrus genus in South Africa mainly cultivated for its juice. This study aims at analysing the chemical composition of Citrus limon waste (leaf and peel) and evaluation of their insecticidal properties. Leaves and peels of Eureka lemons were collected from three South African citrus farms (Addo, Riverside and Mystic), while Lisbon lemons were only collected from two citrus farms (Addo and Riverside) in 2017 and 2018. A total of 36 essential oils were extracted using the Clevenger like apparatus. Analyses of these oils were done using GCMS. An infusion extract of C. limon was prepared according to the standard method and subjected for phytochemical screening to detect and quantify secondary metabolites present. D-Limonene was the major compound identified in all the 36 oils from Eureka and Lisbon peels and leaves (27.9-74.8%). Other dominant compounds identified in Eureka leaf and peel oils were -pinene (5.8-13.2%), -terpinene (4.8-6.7%), geranial (4.0-15.4%), z-citral (6.7-11.7%), sabinene (4.5-6.3%), nerol (4.0-5.4%) and neryl acetate (6.3-9.5%). Some compounds were however present only in some oil such caryophyllene (6.5%) in Mystic dry leaf oil, geraniol (8.0%) in Addo dry leaf oil, as significant compounds. Lisbon leaf and peel essential oils -pinene (4.4- 11.8%), p-cymene (4.2-6.3%), -terpinene (4.4-6.9%), geranial (8.6-17.3%), z-citral (7.1-13.6%), neryl acetate (4.7-9.1%) (5.4-5.9%) were the other prominent peaks identified in the oils. These C. limon essential oils were further tested for insecticidal activities against maize weevils by conducting repellent assay, fumigant assay and contact toxicity; also plant viii powder was used against maize weevils. In general, for all the bioassay, mortality of the insect increased as the contact days with the oil increased. Contact toxicity assays of C. limon peel essential oils were most effective against S. zeamais in which all weevils were dead by day 3 (100% mortality) at 300 μL, while at other concentrations (50, 100, 200 μL) over 50% mortality was observed. The fumigant potential was high with the peel oil with over 50% mortality at 32 and 40 μL in day 4. The oil had moderate repellent effect on the maize weevil. Riverside Eureka dried powder peel was the most effect in all. These results unveil the medicinal potential of South African citrus waste in post-harvest crop protection and good sources of some chemical compounds which are of medicinal value. Furthermore, this study also reveals the economic potential of these wastes in job creation.
- Full Text:
- Date Issued: 2019
- Authors: Nodola, Phumelele
- Date: 2019
- Subjects: Phytochemical -- Insecticidal properties Lemon - - Species – Eastern Cape - - South Africa Citrus limon
- Language: English
- Type: Thesis , Masters , M Sc
- Identifier: http://hdl.handle.net/11260/1348 , vital:32261
- Description: Citrus limon commonly known as lemon is the third most cultivated citrus genus in South Africa mainly cultivated for its juice. This study aims at analysing the chemical composition of Citrus limon waste (leaf and peel) and evaluation of their insecticidal properties. Leaves and peels of Eureka lemons were collected from three South African citrus farms (Addo, Riverside and Mystic), while Lisbon lemons were only collected from two citrus farms (Addo and Riverside) in 2017 and 2018. A total of 36 essential oils were extracted using the Clevenger like apparatus. Analyses of these oils were done using GCMS. An infusion extract of C. limon was prepared according to the standard method and subjected for phytochemical screening to detect and quantify secondary metabolites present. D-Limonene was the major compound identified in all the 36 oils from Eureka and Lisbon peels and leaves (27.9-74.8%). Other dominant compounds identified in Eureka leaf and peel oils were -pinene (5.8-13.2%), -terpinene (4.8-6.7%), geranial (4.0-15.4%), z-citral (6.7-11.7%), sabinene (4.5-6.3%), nerol (4.0-5.4%) and neryl acetate (6.3-9.5%). Some compounds were however present only in some oil such caryophyllene (6.5%) in Mystic dry leaf oil, geraniol (8.0%) in Addo dry leaf oil, as significant compounds. Lisbon leaf and peel essential oils -pinene (4.4- 11.8%), p-cymene (4.2-6.3%), -terpinene (4.4-6.9%), geranial (8.6-17.3%), z-citral (7.1-13.6%), neryl acetate (4.7-9.1%) (5.4-5.9%) were the other prominent peaks identified in the oils. These C. limon essential oils were further tested for insecticidal activities against maize weevils by conducting repellent assay, fumigant assay and contact toxicity; also plant viii powder was used against maize weevils. In general, for all the bioassay, mortality of the insect increased as the contact days with the oil increased. Contact toxicity assays of C. limon peel essential oils were most effective against S. zeamais in which all weevils were dead by day 3 (100% mortality) at 300 μL, while at other concentrations (50, 100, 200 μL) over 50% mortality was observed. The fumigant potential was high with the peel oil with over 50% mortality at 32 and 40 μL in day 4. The oil had moderate repellent effect on the maize weevil. Riverside Eureka dried powder peel was the most effect in all. These results unveil the medicinal potential of South African citrus waste in post-harvest crop protection and good sources of some chemical compounds which are of medicinal value. Furthermore, this study also reveals the economic potential of these wastes in job creation.
- Full Text:
- Date Issued: 2019
Evaluating the Prevention of Mother to Child Transmission (PMTCT) of HIV Services in the Eastern Cape: subtitle if needed. If no subtitle follow instructions in manual
- Authors: Sigovana, Khuthala
- Date: 2019
- Language: English
- Type: Masters theses , text
- Identifier: http://hdl.handle.net/11260/3176 , vital:43182
- Description: Abstract text To effectively reduce HIV transmission to newborns requires a reduction of HIV prevalence among pregnant women and a full understanding of its epidemiology. There is however, a literature gap: few recent HIV studies focus on women attending antenatal care in rural areas in South Africa. A Cross-sectional study of women attending antenatal care in four Primary Care facilities was conducted. An interviewer-administered questionnaire to collect information on socio-demographic characteristics and medical history was used. Binomial logistic regression analyses were used to determine factors associated with HIV and to estimate the prevalence ratio (PR). The 95% confidence interval (CI) is used for precision of estimates; p≤0.05 for statistical significance. A total of 343 participants were recruited. Most participants (n = 341 or 99.42%; CI: 97.91 – 99.93) knew their HIV status. The antenatal HIV prevalence was 38.19% (CI: 33.17 – 43.48). Participants older than 40 years were 3.99 and 3.81 times more likely to be HIV positive compared to teenagers (PR = 3.99; CI: 1.11 – 14.30; pstxvalue = 0.034) and those in the 20-29 age group (PR = 3.81; CI: 1.07 – 13.60; pstxvaluevalue = 0.039) respectively; and this was statistically significant. Unemployed participants were 34% (PR = 1.34; CI: 1.16 – 1.55; p-value less than 0.0001) and 41 percent (PR = 1.41; CI: 1.23 – 1.61; p-value less than 0.0001) more likely to be HIV positive when compared to tertiary students and self-employed individuals respectively. The antenatal HIV prevalence remains high and is increasing in this population. However, findings suggest a changing and maturing epidemic. , Thesis (MMED) -- Faculty of Health Sciences, 2019
- Full Text:
- Date Issued: 2019
- Authors: Sigovana, Khuthala
- Date: 2019
- Language: English
- Type: Masters theses , text
- Identifier: http://hdl.handle.net/11260/3176 , vital:43182
- Description: Abstract text To effectively reduce HIV transmission to newborns requires a reduction of HIV prevalence among pregnant women and a full understanding of its epidemiology. There is however, a literature gap: few recent HIV studies focus on women attending antenatal care in rural areas in South Africa. A Cross-sectional study of women attending antenatal care in four Primary Care facilities was conducted. An interviewer-administered questionnaire to collect information on socio-demographic characteristics and medical history was used. Binomial logistic regression analyses were used to determine factors associated with HIV and to estimate the prevalence ratio (PR). The 95% confidence interval (CI) is used for precision of estimates; p≤0.05 for statistical significance. A total of 343 participants were recruited. Most participants (n = 341 or 99.42%; CI: 97.91 – 99.93) knew their HIV status. The antenatal HIV prevalence was 38.19% (CI: 33.17 – 43.48). Participants older than 40 years were 3.99 and 3.81 times more likely to be HIV positive compared to teenagers (PR = 3.99; CI: 1.11 – 14.30; pstxvalue = 0.034) and those in the 20-29 age group (PR = 3.81; CI: 1.07 – 13.60; pstxvaluevalue = 0.039) respectively; and this was statistically significant. Unemployed participants were 34% (PR = 1.34; CI: 1.16 – 1.55; p-value less than 0.0001) and 41 percent (PR = 1.41; CI: 1.23 – 1.61; p-value less than 0.0001) more likely to be HIV positive when compared to tertiary students and self-employed individuals respectively. The antenatal HIV prevalence remains high and is increasing in this population. However, findings suggest a changing and maturing epidemic. , Thesis (MMED) -- Faculty of Health Sciences, 2019
- Full Text:
- Date Issued: 2019
Exploring Teacher Assessment Practices in The General Education and Training Level in Junior Secondary Schools in Mthatha Education District
- Authors: Novukela, Cawe Sandys
- Date: 2019
- Language: English
- Type: Masters theses , text
- Identifier: http://hdl.handle.net/11260/3460 , vital:43409
- Description: Diabetes mellitus is one of the largest and most important public health emergencies of our time that has resulted in human suffering and huge financial implications for organisations, governments and individuals (IDF Atlas, 2015). Furthermore there is growing evidence that a number of employees are overstretched in their work environments and this has resulted in stress and burnout (McCormack and Cotter, 2013). This study investigated the effects of diabetes mellitus on burnout among WSU employees as well as the prevalence of diabetes mellitus and burnout. A mixed method research design using quantitative and qualitative approaches was employed in order to explore the effects of diabetes on burnout as well as the prevalence of diabetes and burnout at WSU. A cross-sectional survey was used to gather quantitative data and semi-structured interviews were used for the qualitative data collection. A total number of 169 participants were involved in this study. This included 154 participants and 15 participants who were selected for the quantitative and qualitative respectively using random sampling technique and purposive sampling method. The quantitative data was analysed using Stata version 13. The study findings indicated that the prevalence of diabetes at WSU was 16% and 57% participants were burned out. It was further found that the majority of participants (58%) who were diabetic also suffered from burnout. The relationship between diabetes and burnout was found to be significant. Qualitative data analysis involved coding data and analysing the emerging themes to form the basis of the findings. The results of the study found an emerging problem of high level of burnout and also a significant number of employees who were diabetic. A combination of these two conditions poses a challenge to the continued uninterrupted functioning of WSU. It is recommended that the university should educate its employees about diabetes and burnout as well as create an environment that promotes healthy lifestyle. A model has been developed that could help deal with diabetes and burnout. , Thesis - Faculty of Health Sciences, 2019
- Full Text:
- Date Issued: 2019
- Authors: Novukela, Cawe Sandys
- Date: 2019
- Language: English
- Type: Masters theses , text
- Identifier: http://hdl.handle.net/11260/3460 , vital:43409
- Description: Diabetes mellitus is one of the largest and most important public health emergencies of our time that has resulted in human suffering and huge financial implications for organisations, governments and individuals (IDF Atlas, 2015). Furthermore there is growing evidence that a number of employees are overstretched in their work environments and this has resulted in stress and burnout (McCormack and Cotter, 2013). This study investigated the effects of diabetes mellitus on burnout among WSU employees as well as the prevalence of diabetes mellitus and burnout. A mixed method research design using quantitative and qualitative approaches was employed in order to explore the effects of diabetes on burnout as well as the prevalence of diabetes and burnout at WSU. A cross-sectional survey was used to gather quantitative data and semi-structured interviews were used for the qualitative data collection. A total number of 169 participants were involved in this study. This included 154 participants and 15 participants who were selected for the quantitative and qualitative respectively using random sampling technique and purposive sampling method. The quantitative data was analysed using Stata version 13. The study findings indicated that the prevalence of diabetes at WSU was 16% and 57% participants were burned out. It was further found that the majority of participants (58%) who were diabetic also suffered from burnout. The relationship between diabetes and burnout was found to be significant. Qualitative data analysis involved coding data and analysing the emerging themes to form the basis of the findings. The results of the study found an emerging problem of high level of burnout and also a significant number of employees who were diabetic. A combination of these two conditions poses a challenge to the continued uninterrupted functioning of WSU. It is recommended that the university should educate its employees about diabetes and burnout as well as create an environment that promotes healthy lifestyle. A model has been developed that could help deal with diabetes and burnout. , Thesis - Faculty of Health Sciences, 2019
- Full Text:
- Date Issued: 2019
Factors influencing English reading competencies of Grade 4 learners in the Libode-Mega District of the Eastern Cape Province of South Africa
- Authors: Nomkopo, Cornas Ngephi
- Date: 2019
- Subjects: English reading competency -- School learners Reading(Primary) -- Eastern Cape
- Language: English
- Type: Thesis , Masters/Doctoral , M Ed
- Identifier: http://hdl.handle.net/11260/1400 , vital:34371
- Description: Reading has become the national and international centre of debate as learners persistently read below the required levels and matriculation results are due to learners‟ poor reading competencies. The concerns about poor reading competencies has mounted into inflammatory statements in articles and popular media nationally, continentally and internationally. Without the ability to read learners are deprived access to pertinent information and knowledge that can assist individuals in lifelong learning. Being a language teacher, the researcher in this study strongly believe that every learner can read appropriately and teachers can assist learners to improve their reading competencies. The purpose of the study was to identify the factors contributing to poor reading competencies of grade 4 learners and to provide recommendations to assist in dealing with poor reading competencies. Qualitative research approach was undertaken to deal with all aspects related to research methodology. The data were collected using research instruments such as observation of six learners from three selected primary schools. The observation was conducted during reading of text by learners in the presence of English teachers. The questionnaires were distributed to eleven teachers offering English in grade 4 as another means of data collection instrument. Major findings of the study revealed that factors affecting reading competencies are hugely emanated from schools, teachers, family background, departmental policy and learners themselves. Despite reading problems exist in schools, there are always positive solutions to bring hope and success to the learners.
- Full Text:
- Date Issued: 2019
- Authors: Nomkopo, Cornas Ngephi
- Date: 2019
- Subjects: English reading competency -- School learners Reading(Primary) -- Eastern Cape
- Language: English
- Type: Thesis , Masters/Doctoral , M Ed
- Identifier: http://hdl.handle.net/11260/1400 , vital:34371
- Description: Reading has become the national and international centre of debate as learners persistently read below the required levels and matriculation results are due to learners‟ poor reading competencies. The concerns about poor reading competencies has mounted into inflammatory statements in articles and popular media nationally, continentally and internationally. Without the ability to read learners are deprived access to pertinent information and knowledge that can assist individuals in lifelong learning. Being a language teacher, the researcher in this study strongly believe that every learner can read appropriately and teachers can assist learners to improve their reading competencies. The purpose of the study was to identify the factors contributing to poor reading competencies of grade 4 learners and to provide recommendations to assist in dealing with poor reading competencies. Qualitative research approach was undertaken to deal with all aspects related to research methodology. The data were collected using research instruments such as observation of six learners from three selected primary schools. The observation was conducted during reading of text by learners in the presence of English teachers. The questionnaires were distributed to eleven teachers offering English in grade 4 as another means of data collection instrument. Major findings of the study revealed that factors affecting reading competencies are hugely emanated from schools, teachers, family background, departmental policy and learners themselves. Despite reading problems exist in schools, there are always positive solutions to bring hope and success to the learners.
- Full Text:
- Date Issued: 2019
Gender stereotyping in traditional healing practices
- Authors: Mayaba, Nothemba
- Date: 2019
- Subjects: Gender identity -- Traditional healing -- Education Traditional medicines -- Primary health care Female traditional healers - - South Africa – Eastern
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/11260/1354 , vital:32262
- Description: People residing in rural areas use traditional medicines as their primary health care. They consult traditional healers. Traditional healing is a gender-based practice, although both men and women engaged in this practice. In some communities there are more female traditional healers than male traditional healers, including Mhlontlo Local Municipality. The main aim of the study was to investigate gender stereotyping in traditional healing in Mhlontlo Local Municipality. This study also investigated the relationship between male and female traditional healers, challenges faced by female traditional healers, transfer of traditional knowledge by female traditional healers and traditional healers’ unions. Snowball sampling was used to identify and select 79 traditional healers from Mhlontlo Local Municipality. Data was gathered using a questionnaire. The majority of traditional healers in the study area were females. Most of them have primary education, some with secondary education, and others with no formal education, and few with tertiary school. Most traditional healers were between 46-60 years. Female traditional healers constitute 70% of the study. The majority of them see between 11 and 20 patients per month. Most of the traditional healers had an experience of 21-30 years in traditional healing. The study also revealed that female traditional healers experience challenges in traditional healing. Diviners and herbalists work together, this denotes a relationship between them. Female traditional healers also have a problem in transferring their knowledge and registering under traditional healers’ unions. In conclusion, the study found out that traditional healing is gender stereotyped. There are more diviners than herbalists, where most diviners are females and herbalists are males. There is no transfer of knowledge among diviners, as being a diviner is an ancestral calling.
- Full Text:
- Date Issued: 2019
- Authors: Mayaba, Nothemba
- Date: 2019
- Subjects: Gender identity -- Traditional healing -- Education Traditional medicines -- Primary health care Female traditional healers - - South Africa – Eastern
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/11260/1354 , vital:32262
- Description: People residing in rural areas use traditional medicines as their primary health care. They consult traditional healers. Traditional healing is a gender-based practice, although both men and women engaged in this practice. In some communities there are more female traditional healers than male traditional healers, including Mhlontlo Local Municipality. The main aim of the study was to investigate gender stereotyping in traditional healing in Mhlontlo Local Municipality. This study also investigated the relationship between male and female traditional healers, challenges faced by female traditional healers, transfer of traditional knowledge by female traditional healers and traditional healers’ unions. Snowball sampling was used to identify and select 79 traditional healers from Mhlontlo Local Municipality. Data was gathered using a questionnaire. The majority of traditional healers in the study area were females. Most of them have primary education, some with secondary education, and others with no formal education, and few with tertiary school. Most traditional healers were between 46-60 years. Female traditional healers constitute 70% of the study. The majority of them see between 11 and 20 patients per month. Most of the traditional healers had an experience of 21-30 years in traditional healing. The study also revealed that female traditional healers experience challenges in traditional healing. Diviners and herbalists work together, this denotes a relationship between them. Female traditional healers also have a problem in transferring their knowledge and registering under traditional healers’ unions. In conclusion, the study found out that traditional healing is gender stereotyped. There are more diviners than herbalists, where most diviners are females and herbalists are males. There is no transfer of knowledge among diviners, as being a diviner is an ancestral calling.
- Full Text:
- Date Issued: 2019
Phytochemical Analysis and Biological potential of leaves and peels of three Eastern Cape Citrus Species
- Authors: Matuka, Thandiswa
- Date: 2019
- Subjects: Phytochemical -- Analysis Biology -- Leaves and peels Citrus species -- Eastern Cape -- South Africa
- Language: English
- Type: Thesis , Masters , M Sc
- Identifier: http://hdl.handle.net/11260/1362 , vital:32263
- Description: Citrus sinensis, Citrus reticulata and Citrus clementine are citrus species that belong to a large family Rutaceae. Citrus leaves and peels are often regarded as waste products. In view of the environment pollution impact, the search for end use of citrus waste products for economic value and medicinal purposes was sort after. The aim of this study was to investigate chemical composition of citrus waste products (leaves and peels) essential oils and determine biological active volatile compounds from Citrus sinensis, Citrus reticulata and Citrus clementine Leaves and peels of Citrus sinensis, Citrus reticulata and Citrus clementine collected twice from citrus farm were extracted for essential oils using hydrodistillation method and analysed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) for plant samples collected in 2016 and, gas chromatography (GC) and gas chromatography-triple quadrupole-mass spectrometry (GC-MSMS) for plant samples collected in 2017. The oil yield for Citrus sinensis was 0.19 - 0.85 %v/w for fresh and dried leaf and peels for samples collected in 2016 and 0.26 – 0.87% v/w for those collected in 2017. Analysis of the essential oils analyses identified sabinene (20.4% GCMS, 22.6% GCMSMS), terpinen-4-ol (13.2% GCMS, 6.8% GCMSMS) and linalool (7.6% GCMS, 19.3% GCMSMS) as major compounds in fresh leaves essential oils while β-elemene (16.3% GCMS, 21.4% GCMSMS) and sabinene (10.7% GCMS, 20.8% GCMSMS) were major compounds characterized in dried leaves essential oils. Fresh and dried peels essential oils had limonene as the major constituent (49.6% GCMS, 87.1% GCMSMS) and (73.6% GCMS, 88.3% GCMSMS) respectively. Citrus reticulata essential oils percentage yield range between 0.44-0.80% v/w for fresh and dried leaf and peel oils. Analyses of the GCMS and GCMSMS chromatogram of the volatile oils analyses revealed linalool (33.4% GCMS, 19.6% GCMSMS), (+)-spathulenol (15.2% GCMS, 10.1% GCMSMS) and terpinene-4-ol (4.5% GCMS, 11.9% GCMSMS) as major compounds in fresh leaf essential oils while, sabinene (20.8% GCMS, 32.5% GCMSMS) and linalool (17.2% GCMS, 20.4% GCMSMS) were the major compounds found in dried leaf essential oils. Limonene (55.2%, 75.4% GCMS; 39.5%, 80.8% GCMSMS) was the major prominent compound identified in the C. reticulata peel essential oils in fresh and dried peels respectively, followed by linalool (12.8%, 2.9% GCMS; 48.4%, 7.4% GCMSMS). Percentage yields for the essential oils from C. clementine fresh and dried leaves and peels ranges from 0.40-0.62% v/w for. Fresh and dried leaves volatile oils had sabinene (22.7-27.1%) for GCMS and GCMSMS respectively), linalool (18.5- 20.9% GCMS and GCMSMS) and terpinene-4-ol (6.5- 11.8% GCMS and GCMSMS) as main compounds while fresh and dried peels oils were dominated by limonene (38.9- 86.5% GCMS and GCMSMS). Phytochemical screening experiment of the three citrus species leaves and peels aqueous extract reveal the prominent presence of flavonoids and phenolic compounds in high concentrations. C. reticulata and C. clementine peels and leaves volatile oils exhibited higher antioxidant activity as DPPH free radical scavengers and Ferric reducing power (FRAP) ability, when compared to C. sinensis essential oils which exhibited minimum antioxidant activity. Antioxidant activity of leaves and peels essential oils maybe due to the presence of oxygenated monoterpenes and high limonene content. C. sinensis peels oils showed non-toxic to extremely very low toxicity effect at highest dose 2000 mg/kg. C. reticulata and C. clementine peels oils showed toxicity effect in mice at high dose levels. It is suggested that citrus volatile oils could be safe to use at lower dose levels. Citrus species peels and leaves volatile compounds limonene linalool and sabinene exhibited antiinflammatory activity by significantly reducing rats paw oedema size induced by fresh egg albumin. The study suggests the use of Citrus waste products (leaves and peels) as natural antioxidants with antiinflammatory properties for medicinal value and volatile oils compounds for aroma in beverages and cosmetic industries.
- Full Text:
- Date Issued: 2019
- Authors: Matuka, Thandiswa
- Date: 2019
- Subjects: Phytochemical -- Analysis Biology -- Leaves and peels Citrus species -- Eastern Cape -- South Africa
- Language: English
- Type: Thesis , Masters , M Sc
- Identifier: http://hdl.handle.net/11260/1362 , vital:32263
- Description: Citrus sinensis, Citrus reticulata and Citrus clementine are citrus species that belong to a large family Rutaceae. Citrus leaves and peels are often regarded as waste products. In view of the environment pollution impact, the search for end use of citrus waste products for economic value and medicinal purposes was sort after. The aim of this study was to investigate chemical composition of citrus waste products (leaves and peels) essential oils and determine biological active volatile compounds from Citrus sinensis, Citrus reticulata and Citrus clementine Leaves and peels of Citrus sinensis, Citrus reticulata and Citrus clementine collected twice from citrus farm were extracted for essential oils using hydrodistillation method and analysed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) for plant samples collected in 2016 and, gas chromatography (GC) and gas chromatography-triple quadrupole-mass spectrometry (GC-MSMS) for plant samples collected in 2017. The oil yield for Citrus sinensis was 0.19 - 0.85 %v/w for fresh and dried leaf and peels for samples collected in 2016 and 0.26 – 0.87% v/w for those collected in 2017. Analysis of the essential oils analyses identified sabinene (20.4% GCMS, 22.6% GCMSMS), terpinen-4-ol (13.2% GCMS, 6.8% GCMSMS) and linalool (7.6% GCMS, 19.3% GCMSMS) as major compounds in fresh leaves essential oils while β-elemene (16.3% GCMS, 21.4% GCMSMS) and sabinene (10.7% GCMS, 20.8% GCMSMS) were major compounds characterized in dried leaves essential oils. Fresh and dried peels essential oils had limonene as the major constituent (49.6% GCMS, 87.1% GCMSMS) and (73.6% GCMS, 88.3% GCMSMS) respectively. Citrus reticulata essential oils percentage yield range between 0.44-0.80% v/w for fresh and dried leaf and peel oils. Analyses of the GCMS and GCMSMS chromatogram of the volatile oils analyses revealed linalool (33.4% GCMS, 19.6% GCMSMS), (+)-spathulenol (15.2% GCMS, 10.1% GCMSMS) and terpinene-4-ol (4.5% GCMS, 11.9% GCMSMS) as major compounds in fresh leaf essential oils while, sabinene (20.8% GCMS, 32.5% GCMSMS) and linalool (17.2% GCMS, 20.4% GCMSMS) were the major compounds found in dried leaf essential oils. Limonene (55.2%, 75.4% GCMS; 39.5%, 80.8% GCMSMS) was the major prominent compound identified in the C. reticulata peel essential oils in fresh and dried peels respectively, followed by linalool (12.8%, 2.9% GCMS; 48.4%, 7.4% GCMSMS). Percentage yields for the essential oils from C. clementine fresh and dried leaves and peels ranges from 0.40-0.62% v/w for. Fresh and dried leaves volatile oils had sabinene (22.7-27.1%) for GCMS and GCMSMS respectively), linalool (18.5- 20.9% GCMS and GCMSMS) and terpinene-4-ol (6.5- 11.8% GCMS and GCMSMS) as main compounds while fresh and dried peels oils were dominated by limonene (38.9- 86.5% GCMS and GCMSMS). Phytochemical screening experiment of the three citrus species leaves and peels aqueous extract reveal the prominent presence of flavonoids and phenolic compounds in high concentrations. C. reticulata and C. clementine peels and leaves volatile oils exhibited higher antioxidant activity as DPPH free radical scavengers and Ferric reducing power (FRAP) ability, when compared to C. sinensis essential oils which exhibited minimum antioxidant activity. Antioxidant activity of leaves and peels essential oils maybe due to the presence of oxygenated monoterpenes and high limonene content. C. sinensis peels oils showed non-toxic to extremely very low toxicity effect at highest dose 2000 mg/kg. C. reticulata and C. clementine peels oils showed toxicity effect in mice at high dose levels. It is suggested that citrus volatile oils could be safe to use at lower dose levels. Citrus species peels and leaves volatile compounds limonene linalool and sabinene exhibited antiinflammatory activity by significantly reducing rats paw oedema size induced by fresh egg albumin. The study suggests the use of Citrus waste products (leaves and peels) as natural antioxidants with antiinflammatory properties for medicinal value and volatile oils compounds for aroma in beverages and cosmetic industries.
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- Date Issued: 2019
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