A comparative study of the in vitro antidiabetic properties, cytotoxicity and mechanism of action of Albuca bracteata and Albuca setosa bulb extracts
- Authors: Odeyemi, Samuel Wale
- Date: 2015
- Subjects: Medicinal plants Herbs -- Therapeutic use Diabetics -- Alternative treatment
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/3154 , vital:28327
- Description: The search for cheap, non toxic and readily available antidiabetic drugs has been a challenge for researchers and the pharmaceutical industries. Diabetes mellitus is a metabolic disease characterized by defects in the synthesis of insulin and/or insensitivity to the action of insulin at the target cells. The disease has been on the increase mostly in developing countries where large proportions of the population have little access to good medical care due to either accessibility or non availability of synthetic drugs. This has led to the use of medicinal plants to treat diabetes because it is safe, cheap and with few side effects. There is little scientific evidence on the dosages, active compounds, mechanisms of action and toxicity of these traditionally used plants. Two of the most frequently used plants; Albuca setosa and Albuca bracteata were investigated in this study. The qualitative analysis of different extractions of these plants revealed the presence of phenolics, alkaloids, tannins and saponins. The antioxidant properties of aqueous, acetone and methanollic extracts of Albuca setosa and Albuca bracteata were investigated using models such as Diphenyl-1-Picrylhydrazyl (DPPH), 2, 2’-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), Ferric ion reducing antioxidant potential (FRAP), Nitric Oxide and Hydrogen Peroxide (H2O2). Both plants revealed inhibitions against DPPH in a concentration - dependent manner with Albuca setosa (0.330 mg/ml) showing higher activity than Albuca bracteata (0.647 mg/ml) determined from the IC50. The aqueous extract of Albuca setosa showed a higher inhibition against DPPH radical compared to the Albuca bracteata aqueous extract at all concentrations investigated. The isolated saponins from Albuca bracteata had a higher DPPH scavenging activity than the crude methanolic extract of the plant in a concentration - dependent manner but are significantly different from each other at 0.4, 0.6 and 1.0 mg/ml only. The IC50 of the saponins was also observed to be higher than the crude extracts and standards.The Albuca setosa aqueous extract showed a higher percentage inhibition of ABTS radicals than Albuca bracteata at all the concentrations investigated. Overall, the Albuca setosa aqueous extract (0.0809 mg/ml) showed maximum activity against ABTS radicals. The iron reducing power was significantly higher (P < 0.05) in the methanolic extract of both plants compared to the aqueous counterpart. Overall, the Albuca bracteata aqueous extract (0.344 mg/ml) showed maximum activity as indicated by the IC50. The aqueous extracts of both plants also revealed percentage inhibitions in a concentration - dependent manner against NO2. The aqueous extract of Albuca bracteata bulb was more active against nitric oxide and hydrogen peroxide inhibition. In this study, the cytotoxicity of the extracts was evaluated at a high dose of 100 μg/ml on Chang liver cells and determined using MTT, crystal violet, glucose consumption, lactate production and lactate dehydrogenase release and FRAP. The aqueous extracts of both Albuca setosa and Albuca bracteata were non-toxic on Chang liver cells at the concentrations investigated. The MTT revealed that the aqueous extract of Albuca setosa bulb had the optimum cell viability of 108.09 percent while the acetonic extract of Albuca bracteata showed the least cell viability (37.72 percent) compared with the control. The crystal violet test also revealed the acetone extract of Albuca bracteata to have the least percentage of cell viability at 31.47 percent, while the aqueous extract of Albuca setosa showed the maximum cell viability at 112.5 percent. The aqueous extracts of both plants showed higher percentage cell density on the second day of incubation from the proliferation assay. All the tested samples were observed to consume more glucose than the blank except for the methanollic and acetone extracts of Albuca bracteata bulb. The aqueous and methanolic extracts of Albuca setosa bulbs produced the highest lactate with 120.2 μg/ml and 113.7 μg/ml respectively. The acetone extracts of both Albuca setosa and Albuca bracteata revealed toxicity with a higher lactate dehydrogenase release compared to the control.
- Full Text:
- Date Issued: 2015
Assessment of the quality indices and prevalence of Escherichia coli pathotypes in selected rivers of Osun state, Southwestern Nigeria
- Authors: Titilawo, Osuolale Yinka
- Date: 2015
- Language: English
- Type: Thesis , Doctoral , PhD (Microbiology)
- Identifier: vital:11295 , http://hdl.handle.net/10353/d1021274
- Description: Surface waters are important freshwater sources used for domestic, industrial, agricultural and recreational activities, and the availability of good quality freshwater is indispensable for preventing water-borne diseases and improving quality of life especially in communities that lack pipe-borne water. Water samples were collected from ten rivers at different locations in Osun State, Southwestern Nigeria. A total of 12 physicochemical parameters, counts of total coliforms (TC) and Escherichia coli isolates were determined using standard analytical procedures. Confirmed Escherichia coli isolates (n=300) were assessed for the presence of 10 virulence genes (VGs) associated with Escherichia coli strains causing intestinal and extra-intestinal infections. The recovered Escherichia coli isolates were elucidated for their antibiogram profiling by disk diffusion method and the resistant isolates were further profiled for their genotypic antimicrobial resistance by polymerase chain reaction technique. The physicochemical qualities ranged as follows: pH (6.9 - 7.6), temperature (26 – 29 ºC), turbidity (2.28 – 9.46 NTU), electrical conductivity (229 – 581 μS/cm), nitrate (0.03 – 0.05 mg/L), nitrite (0.00 – 0.01 mg/L), sulphate (3.33 – 20.33 mg/L), chloride ions (7.83 – 27.33 mg/L), dissolved oxygen (4.23 – 5.57 mg/L), total dissolved solids (56 – 184 mg/L), total hardness (78 – 519 mg/L) and alkalinity (50.67 – 146.67 mg/L). Statistical analysis showed that pH, temperature, electrical conductivities, nitrates, nitrites, chloride, dissolved oxygen, total dissolved solid, total hardness and alkalinity were significantly different (P < 0.05), whereas turbidity and sulphate were not significantly different (P ˃ 0.05) from each parameter with respect to sampling sites. While the VG lt for enterotoxigenic E. coli had the highest prevalence of 45%, the enteropathogenic E. coli genes eae and bfp were detected in 6% and 4% of the isolates respectively. The VGs stx1 and stx2 specific for the enterohemorrhagic E. coli pathotypes were equally detected in 7% and 1% of the isolates respectively. Also, the VG eagg harboured by enteroaggregative pathotype and diffusely-adherent E. coli VG daaE were detected in 2% and 4% of the isolates respectively and enteroinvasive E. coli VG ipaH was not detected. In addition, the VGs papC for uropathogenic and ibeA for neonatal meningitis were frequently detected in 19% and 3% of isolates respectively. While all the isolates tested were susceptible to imipenem, meropenem, amikacin and gatilofloxacin, others were variously susceptible, and resistant as follows; ciprofloxacin (96%), kanamycin (95%), neomycin (92%), streptomycin (84%), chloramphenicol (73%), nalidixic acid (66%), nitrofuratoin (64%), gentamycin (63%), doxycycline (58%), cefepime (57%), tetracycline (49%) and cephalothin (42%). Conversely, all the isolates were resistant to sulphamethoxazole, and high levels of resistance were equally observed against amoxycillin (59%), ampicilin (57%) and cefuroxime (40%). Cefepime, cephalothin, cefuroxime, nalidixic acid, nitrofuratoin, chloramphenicol and tetracycline were not significantly different in their effect against the isolates from all locations (P > 0.05), whereas the resistance profile of the isolates against gentamycin, ciprofloxacin, sulphamethoxazole, ampicillin and amoxicillin were significantly different (P < 0.05). Amikacin, kanamycin, streptomycin, meropenem, imipenem and gatilofloxacin were statistically excluded from the analysis since all tested isolates showed total susceptibility to these antimicrobials. The multiple antibiotic resistance indexing ranged from 0.50 to 0.80 for all the sampling locations and exceeded the threshold value of 0.2. Prevalence and distributions of the 19 resistance determinants assessed were obtained as follows; [sulfonamides (sulI (8%), sulII (41%)], [beta-lactams; (ampC 22%; blaTEM, (21%), blaZ (18%),], [tetracyclines (tetA (24%), tetB (23%), tetC (18%), tetD (78%), tetK (15%), tetM, (10%)], [phenicols; (catI (37%), catII (28%), cmlA1 (19%)] and [aminoglycosides; (aacC2 (8%), aphA1 (80%), aphA2 (80%), aadA (79%) and strA (38%)]. The Pearson chi square exact test revealed many strong significant associations among ampC, blaTEM, blaZ and tetA genes with some determinants screened. In the same vein, a grand total of 366 resistance gene fingerprints were spotted across the sampling locations and among the resistant pathotypes, the modal prevalent gene prints were found among the ETEC strains in 148 (40%), being the predominant pathotype observed, followed by UPEC strains 80 (22%) while the lowest was the least occurring EAEC pathotype 14 (4%). While some physicochemical parameters exceeded prescribed standards for drinking water, some fell within. The total coliforms obtained in all the sampling sites were above the acceptable limits. Findings reveal the presence of diarrhoeagenic and non-diarrhoeagenic E. coli in the selected rivers and suggest a potential public health risk as the rivers are important resources for domestic, recreational and livelihood usage by their host communities. The multiple drug resistance indexing signifies isolates and pathotypes of high antimicrobial usage origin. An increase in the antimicrobial resistance signatures towards conventionally used antibiotics as observed in this study necessitates for safe water supply, adequate sanitation facilities and proper surveillance programs towards the monitoring of antimicrobial resistance determinants in water-bodies. Generally, results from this study indicate that the river waters are not suitable for consumption, domestic or recreational use and re-echo the importance of safeguarding the freshwater resources of Southwestern Nigeria.
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- Date Issued: 2015
Effect of post-slaughter handling on physico-chemical and microbiological quality of red meat along the distribution chain in the Eastern Cape Province, South Africa
- Authors: Rani, Zikhona Theodora
- Date: 2015
- Subjects: Meat -- Microbiology Meat -- Transportation -- South Africa -- Eastern Cape Meat -- Quality -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/2490 , vital:27875
- Description: The broad objective of the study was to investigate the effect of post-slaughter handling in the distribution chain on red meat quality and safety. A survey was conducted among 300 consumers and 100 meat handlers in five different municipalities (Buffalo City, Nkonkobe, Ngqushwa, Lukhanje and Amahlathi) in the Eastern Cape Province of South Africa to investigate their perceptions on meat quality and safety, together with challenges faced by meat handlers during the distribution of meat from the abattoir to retailers. The microbiological profile and physico-chemical quality of red meat at different stages of the abattoir to retail outlets in the distribution chain were also determined. Swabs (n=216) and meat samples (n=450) were collected from beef, pork and mutton carcasses during the loading process of carcasses into trucks at the abattoir, when offloading carcasses at the supply points and during marketing. Physico-chemical qualities such as colour (L* - lightness, b* - redness and a* - yellowness) and meat pH measurements were taken at each point. To determine the microbiological profiles of the carcasses, four microbiological parameters were considered: Total bacteria count (general bacteria), coliform count (related to hygiene and indicator for pathogens), Escherichia coli (Gram-negative pathogen) and Staphylococcus aureus (Gram-positive pathogen). Two types of packaging (vacuum and overwrapping) were used to determine their effect on shelf-life and microbiological quality of red meat under the normal marketing conditions over a storage duration of 15 days. The results from the study showed low awareness of consumers about the pathogenic diseases which arise from meat. A strong significant association (p ˂ 0.05) between educational status and awareness on meat safety was observed. Most of the consumers perceived that quality goes beyond safety such that 35.6 percent of the respondents indicated that they did not have a problem with consuming spoiled meat, whilst the remaining 64.4 percent indicated that they would r eject spoiled meat. Although retailers indicated that they take meat safety into consideration in their shops, 92 percent of the retailers revealed that they do not perform microbial assessment of meat in their shops. A series of loading and off-loading, temperature fluctuations, environmental temperatures and ques during offloading were reported as the major challenges during transportation of carcasses from the abattoir to the supply points. The microbial counts were significantly (p<0.05) higher in samples from the commercial abattoir than in those from the communal abattoir. Escherichia coli was the predominant microbial contaminant in the samples from both abattoirs. When following the chain, total bacterial count (TBC), coliform count (CC) and the levels of E. coli contamination increased progressively between the loading and the off-loading points (5.1 to 7.9 log10 CFU/cm2; 5.0 to 5.6 log10 CFU/cm2 and 2.7 to 3.7 log10 CFU/cm2, respectively). The storage period, meat type, distance during transportation and temperature were found to have a significant impact on the microbial levels during the distribution of carcasses. Distribution stage had a significant effect (p<0.05) on some of the physico- chemical meat quality attributes and differences in the lightness (L*) and redness (a*) values between the loading, off-loading and display points were observed. Consumers perceived retailer class as one of the factors influencing meat quality, but according to the instrumental measurements retailer class did not have a significant effect on physico-chemical meat quality. However, distance and storage duration significantly (p<0.05) affected (L*) and (a*) values in the meat during distribution chain. Vacuum and overwrapping packaging significantly affected (p<0.05) the shelf life of meat. Therefore, it was concluded that post-slaughter handling during the distribution chain affects the physico- chemical, microbiological and shelf-life of meat.
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- Date Issued: 2015
Effects of natural antioxidants and thermal treatment on quality of meat from Bonsmara and non-descripts cattle
- Authors: Falowo, Andrew Bamidele
- Date: 2015
- Subjects: Meat -- Preservation Antioxidants Meat -- Microbiology
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/2589 , vital:27906
- Description: The broad objective of this study was to determine the effects of natural antioxidants and thermal treatment on quality of meat from Bonsmara and non-descript cattle. A survey was conducted among 222 consumers in Alice (Fort Hare University community), Eastern Cape Province to determine the level of their awareness on application of antioxidants as preservatives in meat and meat products during storage. Representative samples of Muscularis longissimuss thoracis et lumborum and liver were collected from each carcass of Bonsmara (n=40) and non-descript (n=40) cattle reared on natural pasture to determine the effect of natural antioxidants and thermal treatment on their quality. The results from the survey revealed that 51.35 percent of the respondents had not heard about the use of antioxidant as preservatives in meat products. However, among the remaining respondents (48.65 percent) that were aware of antioxidant and its use as preservative, about 19 percent knew of natural antioxidants, 35 percent synthetic antioxidants while 46 percent had knowledge of both. The results further revealed that the majority of the respondents (82 percent) that had knowledge of natural antioxidants were concerned about the use of synthetic antioxidants in meat and meat products due to their health consequences. The in vitro antioxidant and antibacterial analyses of Bidens pilosa and Moringa oleifera leaf extracts revealed that they contain rich bioactive compounds. Furthermore, the addition of leaf extracts from Moringa oleifera (ML, 0.05 and 0.1 percent w/w) and Biden pilosa (BP, 0.05 and 0.1 percent w/w) to ground raw beef as a natural antioxidant were found to improve the physicochemical, oxidative stability and microbiological qualities of meat compared to the control (meat without extract) and BHT treatment (0.02 percent w/w) during 6 days storage at 40 C. Cattle breed did not have much effect on colour parameters. However, the overall pH of ground beef treated with extracts showed lower values than control and BHT treated beef. Also, ground beef samples containing extracts exhibited (P < 0.05) better colour stability, especially higher redness (a* values), than the control. The formation of TBARS in beef samples treated with extracts was significantly (P < 0.05) lower than the control and BHT treatment. The antibacterial assay of the extracts revealed an appreciable broad spectrum activity against the tested bacteria and microbial counts in ground beef samples compared to control and BHT group. Ground beef treated with plant extracts exhibited lower microbial and lactic acid bacterial counts (P < 0.05) at day 0 and 3 than control samples. Moreover, it was observed that application of sous vides thermal method did not significantly affect the fatty acids and mineral loss in beef and liver across the treatments. However, the total concentration of MUFA was lower in raw liver (20.11±2.38 - 21.08±1.23 percent) than in beef (40.22±1.90 - 42.53±1.29 percent), while total PUFA content were higher in liver (30.73±2.60 - 31.11±1.19 percent) than in beef samples (10.13±3.36 - 11.02±2.74 percent) (p < 0.05). The results also revealed that liver samples from Bonsmara and non-descript cattle had a higher percentage of intramuscular fat content of 4.67 ± 0.53 percent and 4.44 ± 0.53 percent respectively, and fat free dry matter of 27.51 ± 1.05 percent and 25.73 ± 1.05 percent, respectively, than the beef samples (p < 0.05). The concentrations of Mg (52.80±0.22 - 53.70±0.02mg/100g) and Zn (8.90±0.15 - 19.60±0.15mg/100g) were higher in beef than liver samples. The level of Ca (17.00±0.17 - 17.50 ± 0.17mg/100g) in liver was higher than that of beef samples. It was concluded that most consumers preferred the use of natural antioxidants in meat products than synthetic antioxidants due to their health risk. The effectiveness of M. oleifera and B. pilosa leaf extracts on meat quality also revealed that these plants are promising candidates as natural preservatives and their application should be considered in the meat industry. Lastly, findings from this study showed that application of the sous vide technique could protect meat products from nutritional loss during thermal treatment.
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- Date Issued: 2015
Evaluation of the quality indices of the final effluents of two wastewater treatment plants in buffalo City Metropolitan Municipality in the Eastern Cape Province
- Authors: Osuolale, Olayinka O
- Date: 2015
- Language: English
- Type: Thesis , Doctoral , PhD (Microbiology)
- Identifier: vital:11292 , http://hdl.handle.net/10353/d1021079
- Description: Waste waters can be sources of pollution to surface water and the environment with severe implications for public health. Most treatment plants in the Buffalo City Municipality in the Eastern Cape Province discharge their treated effluent into the surface waters which directly and indirectly impacts on the quality of surface waters in the region. The objective of this study was to determine the microbiological and physicochemical qualities of the final effluents of two wastewater treatment plants in the Buffalo City Municipality in the Eastern Cape Province of South Africa over a period of 12 months (September 2012 to August 2013). The qualities of the final effluents of WW-Ama Wastewater Treatment Plant with respect to phosphate (3.9 mg/l - 20.6 mg/l), free chlorine (0.05 mg/l - 0.71 mg/l), chemical oxygen demand (COD) (4.7 mg/l - 211 mg/l), and faecal coliform (0 - 2.92 × 104 CFU/100 ml) were not in compliance with the permissible limits set for effluent discharged to surface water by South Africa guidelines for effluent discharge. Other physicochemical parameters like biological oxygen demand (BOD) (2.2 mg/l - 9.0 mg/l), total dissolve solid (TDS) (253 mg/l - 336.3 mg/l) and turbidity (4.8 NTU - 43.20 NTU) with no SA regulatory set limits were compared to other regulatory standards and they do not comply with the limits. Also, at the second WWTP’s, the WW-Dim Treatment Plant effluent quality for free chlorine (0.06 mg/l - 7.2 mg/l), BOD (0.1 mg/l - 7.4 mg/l), and turbidity (4.02 NTU - 24.3 NTU) also did not comply. For microbiological qualities, counts of presumptive E. coli and Vibrio ranged between 0 - 2.92 × PROFESSOR ANTHONY I. OKOHAntibiogram of the bacterial isolates were determined using the disk diffusion method. A total of 107 confirmed E. coli and 100 confirmed Vibrio spp. were used for this assay. Results of antibiotic sensitivity test revealed that 63.6% of the E. coli isolates were resistance to ampicillin while 49.5% were resistant to tetracycline and cephalothin. The least resistances were observed against gentamicin (3.7%) and cefotaxime (1.9%). No resistance was observed against meropenem. For the Vibrio spp, resistance was most frequently observed against tetracycline (38%) ampicillin (26%), chloramphenicol (16%), cefotaxime (14%), trimethoprim-sulfamethoxazole (13%) and the least resistance observed was against ciprofloxacin (1%). This study demonstrates that poorly treated wastewater effluent can be a source of eutrophic water with high nutrient levels and pathogenic bacteria and enteric viruses as well as antibiotic resistance determinants that could impact negatively on human health. The finding of this study also suggests that WWTPs have to be properly monitored and controlled to ensure compliance to set guidelines. This could be attained through the application of appropriate treatment processes, which will help to minimize possible dangers to public environment health.
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- Date Issued: 2015
Implication of tillage, texture and mineralogy on the sieving efficiency, physical-based soil organic matter and aggregate stability of some soils in the Eastern Cape
- Authors: Peter, Prince Chinedu
- Date: 2015
- Subjects: Tillage Soil management -- South Africa -- Eastern Cape Soil physics -- South Africa -- Eastern Cape , Soil structure -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/2710 , vital:28058
- Description: Soil structure and its associated physical properties are essential soil components. Soil texture and mineralogy are inherent soil properties that influence soil management. This study assessed the implication of tillage, texture and mineralogy on soil sieving, aggregate stability indices and physical fractions of organic matter in soils of Eastern Cape Province of South Africa. An Iris FTLVH – 0200 digital electromagnetic sieve shaker (Filtra Vibraciόn SL Spain), was used to determine settings for sieving efficiency. Mean weight diameter (MWD), water stable aggregate (WSA), state of aggregation (SA), dispersion ratio (DR), water dispersible clay (WDC), clay dispersion ratio (CDR), clay flocculation index (CFI), and potential structural deformation index (PSDI) were aggregate stability indices evaluated to check for sensitivity in evaluating aggregate stability of soils under two tillage systems and physical fractions of carbon and nitrogen in soils of Eastern Cape Province. The T4I3P2 and T4I4P3 settings were sensitive under tillage and T4I1P4, T3I4P3 and T4I4P3 were sensitive under mineralogical considerations for sieving efficiency. The total carbon in soils under conventional tillage (CT) was 17.7 g/kg and in soils under no tillage (NT) it was 15.8 g/kg. The total carbon content in the clay fraction of soils under CT was 24.1 percent higher than the total carbon content in the clay fraction of soils under NT. The total nitrogen content in the clay fraction of soils under CT was 5.4 percent higher than the total nitrogen content in the soils under NT. The total carbon in the sandy loam (SL) textured soils was 17.4 g/kg and in the sandy clay loam (SCL) textured soils it was 17.1 g/kg. The total nitrogen in SL soils was 3.7 g/kg and in SCL soils it was 3.7 g/kg. The clay fraction had higher total carbon than other fractions in Sl and SCL soils. The higher values of nitrogen were observed in the silt fraction for SL soils and clay fraction for SCL soils. The total carbon in the soils dominated with kaolinite was 17.3 g/kg and in quartz dominated soils the value was 16.9 g/kg. The total nitrogen in the soils dominated with kaolinite was 3.7 g/kg and in the soils dominated with quartz the value was 3.7 g/kg. For soils under NT the WDC was 135.8 g/kg and for soils under CT it was 139.7 g/kg. The ASC was 72.5 for soils under NT and 92.0for soils under CT. The DR was 0.9 for soils under NT and 0.8 for soils under CT. The CFI was 0.5 for soils under NT and 0.5 for soils under CT. The CDR was 0.5 for soils under NT and 0.5 for soils under CT. The MWDw was 1.6 mm for soils under NT and 1.4 mm for soils under CT. The MWDd was 4.0 mm for soils under NT and 4.0 for soils under CT. The percent WSA > 0.25 mm was 61.7 percent for soils under NT and 56.2 percent for soils under CT. The PSDI was 55.2 percent for soils under NT and 61.15 percent for soils under CT. The SA was 43.2 percent for soils under NT and 37.89 percent for soils under CT. The WDC was 125.7 g/kg for SCL soils and 151.4 g/kg for SL soils. The CDR was 0.5 for both SCL and SL soils. The DR was 0.9 for SCL soils and 0.8 for SL soils. The CFI was 0.5 for both SCL and SL soils. The ASC was 56.2 g/kg for SCL soils and 115 g/kg for SL soils. The MWDw was 1.5 mm for SCL soils and 1.4 mm for SL soils. The MWDd was 3.6 mm for SCL soils and 3.6 mm for SL soils. The percent WSA > 0.25 mm was 53.0 percent for SCL soils and 62.5 percent for SL soils. The PSDI was 59.2 percent for SCL soils and 59.7 percent for SL soils. The SA was 33.6 percent for SCL soils and 45.2 percent for SL soils. The WDC was 313.3 g/kg for kaolinitic soils and 120.7 g/kg for quartz dominated soils. The CDR was 0.5 for kaolinitic soils and 0.5 for quartz dominated soils. The DR was 0.9 for kaolinitic soils and 0.8 for quartz dominated soils. The CFI was 0.5 for kaolinitic soils and 0.5 for quartz dominated soils. The ASC was 110.0 g/kg for kaolinitic soils and 101.7 g/kg for quartz dominated soils. The WSA > 0.25 mm was 57.3 percent for quartz dominated soils and 68.4 percent for kaolinitic soils. The MWDw was 1.6 mm for quartz dominated soils and 0.8 mm for kaolinitic soils. The MWDd was 3.6 mm for quartz dominated soils and 3.4 mm for kaolinitic soils. The PSDI was 56.3 for quartz dominated soils and 76.0 for kaolinitic soils.
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- Date Issued: 2015
Isolation, characterisation of terpenoids and biosynthesis of silver nanoparticles of acacia mearnsii de wild and acacia Karroo Hayne and their Bioassays
- Authors: Avoseh, Opeyemi Nudewhenu
- Date: 2015
- Language: English
- Type: Thesis , Doctoral , PhD (Chemistry)
- Identifier: vital:11355 , http://hdl.handle.net/10353/d1021292
- Description: Great wealth of traditional knowledge about the use of plants had been transferred from generation to generations leading to the present day drug discovery and invention of new scientific methods of isolation, purification and identification. With the discovery of new diseases and drug-resistant organisms, there is no other source or deposit of lead compounds or drugs than the plant kingdom. As a result of this, about 25% of the current drug administered owe their origin to plant sources with the view to reduce the carcinogenic effect of synthetic drugs. Volatile terpenoids among other broad spectrum of natural product had been implicated to show high therapeutic properly. In the present study, selected locally-used medicinal plants were exploited for the presence of potent bioactive compounds and ability to form nanoparticles with distinctive property for use as chemoprotective agent against inflammation, tumors, cancer and other chronic diseases. Acacia mearnsii De Wild and Acacia karroo Hayne studied in this report are known to be invasive species with no proper regulation to conserve and preserve them. However, ethnopharmacology report of these plant species in the Southern Africa region reveals that they are good antiseptic, anti-diarrhea, anti-inflammation and a forage for livestock. These plants were subjected to volatile extraction protocol of some parts of the plants (stem and leaves) followed by examination of the anti-inflammation capacity of the extracts using an animal model. In addition, the bye-product (hydrosol) from the stem bark of each species possess a high reducing and stabilizing property leading to synthesis of silver nanoparticles, followed by investigation of the anti-inflammation potential of the synthesized silver nanoparticles using animal model. The volatile oils of the leaves and stem bark of Acacia mearnsii De Wild obtained by hydro-distillation were analyzed by Gas Chromatography-Mass Spectrometry (GC-MS). Twenty, Thirty-Eight, Twenty-nine and Thirty-Eight components accounting for 93.8%, 92.1%, 78.5% and 90.9% of the total oils of the fresh, dry leaves and fresh, dry stem bark respectively. The major components of the oil were octadecyl alcohol (25.5%) and phytol (10.5%); cis-verbenol (29.5%); phytol (10.1%) and phytol (23.4%) for the fresh leaves, dried leaves, and fresh stem, dry stem bark respectively. Oral administration of essential oils at the dose of 2% showed significant (p<0.05) anti-inflammatory properties in the albumin induced test model in rats. Oils from the fresh leaves and dry stems inhibited inflammation beyond 4 h post treatment. Furthermore, the chemical composition of the essential oils obtained by hydro-distillation from the leaves and stem bark (dry and fresh) of Acacia karroo Hayne, analysed by GC-MS, shows that hexanal (10.67%) and ß-ionone (9.74%) were dominant in the dried leaves, β-pinene (14.30%), and (Z)-2-Hexen-1-ol (10.21%) in the fresh leaves while Octacosane (10.59%) and phytol (23.38%) were dominant in the dry and fresh stem respectively. The anti-inflammation ability of these oils after an albumin-induced inflammation on wistar rats, shows a significant effect at the 1st h of treatment with a significance of P< 0.01 for all part plants, while the fresh leaves shows further inhibitory activities at the 2nd h of analysis. Silver nanoparticles (AgNPs) were successfully synthesized from AgNO3 through a green route using the aqueous extract (hydrosols) of Acacia mearnsii De Wild and Acacia karroo Hayne as reducing agent and as well as capping agent. The Acacia-mediated AgNPs were characterized with the use of UV-vis absorption spectroscopy, Fourier Transform Spectroscopy (FT-IR), Transmission electron microscope (TEM), Scanning Electron Microscope (SEM), Energy Dispersive Spectroscopy (EDX), and X-ray Diffractometry (XRD). A spherical, 10-40 nm diameter silver nanoparticles were synthesized with very low level of stability for the AMDS and the AKDS-AgNPs. In addition, nociceptive activity with a mice rat reveals higher inhibition at the neurogenic phase for the AKDS-AgNPs, while AMDS-AgNPs exhibited a high inhibition at the inflammatory phase. The potent anti-inflammatory activity of essential oils of A. mearnsii De Wild and A. karroo Hayne hereby confirmed its traditional use in treating various inflammatory diseases, while the inflammatory studies on the synthesized AgNPs reveals a very active compound which can be used as a potent opioid or non-steroidal anti-inflammatory drug (NSAID).
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- Date Issued: 2015
Nutritional value and cultivation requirements of Cleome Gynandra: a wild vegetable growing in the Eastern Cape Province, South Africa
- Authors: Sowunmi, Linda Ifeanyichukwu
- Date: 2015
- Subjects: Ethnobotany -- South Africa -- Eastern Cape Vegetables -- South Africa -- Eastern Cape Nutrition -- South Africa -- Evaluation
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/2600 , vital:27907
- Description: South Africa has wide ranges of plants among which are leafy vegetables growing in the wild. These wild vegetables have been reported to have high nutritive and medicinal potentials. Yet, there is still high prevalence of malnutrition and micronutrients deficiencies among the low income bracket of the population. Effective utilization of wild vegetables has been proposed as part of the solutions to address the problem of dietary deficiencies among the populace. Their importance is mainly as relish to accompany and complement starch based diets. They are also known to serve as supplements for food which have the potential to improve the health status of its consumers in many rural communities. Cleome gynandra L. (Capparaceae) is one of the underutilized species mentioned during asurvey conducted in Nkonkobe municipality of the Eastern Cape Province, South Africa. The plant is an erect annual herb with alternate, palmately compound leaves and its petals are white, pink or lilac. It grows as a weed in this part of the Province and is usually gathered from the wild for food and medicine. It is commonly found on wastes land, road sides and on grass lands. Therefore, this research work was designed to contribute to the possible domestication of this wild vegetable in order to explore the nutritive and therapeutic potentials which would broaden the food base in the Eastern Cape Province. The ultra-micromorphological features of plants have become an essential tool in proper identification and authentication of several plant species. In the light of this, the micromorphology of Cleome gynandra was examined to reveal the micro-morphological characters of the plantand to determine if micro and macro mineral elements are present using energy dispersive x-rays. The present study revealed the epidermal cells of the leaves to be asymmetric in shape with undulating cell walls having four subsidiary cells around the stomata. The leaves have anomocyctic stomata which are more distributed in the abaxial surface than the adaxial surface. The mean length and width of the guard cells in the abaxial surface are 0.09 ± 0.01 mm and 0.08 ± 0.01 mm respectively while that of adaxial surface are 0.1± 0.01 mm and 0.07 ± 0.01 mm respectively. The energy dispersive x-rays (EDXS) micro-analysis of the leaf revealed the presence of phosphorus, manganese, iron, calcium, sodium, magnesium, potassium and zinc as the major constituents of the crystal deposits present in the stomata pores and the mesophyll. C. gynandra was collected from the wild and analysed for its mineral and proximatecomposition using standard analytical methods. The plant showed high levels of sodium, iron, zinc, calcium and potassium while many other macro and micro minerals were moderately present. Amongst the proximate factors investigated, moisture content was found to be 82.1% while crude fibre and protein contents were 39.9 percent and 31.03 percent respectively. Vitamin C was also high (345.3 mg/100g). The anti-nutrients compositions revealed low concentrations of oxalate (7.4 ± 0.4) and phytate (0.6 ± 0.0) mg/100g. The study revealed high nutritive value of the species growing naturally from the wild. Interest in the phenolic compounds has greatly increased recently because these compounds have been implicated in suppressing the risk of degenerative diseases in humans. The pharmacological properties of plants may be related to their antioxidant capacities and hence there was need to investigate the antioxidant potential using aqueous, ethanolic and acetone extracts of different parts of C. gynandra. The quantities of phenols, flavonoids and flavonols were significantly higher (p < 0.05) in both aqueous and ethanol extracts of the leaf while the concentration of proanthocyanidins was higher in the aqueous stem extract compared to other plant parts. The aqueous extract of the different parts exhibited better ABTS, reducing power and NO radical scavenging abilities than ethanol extract.
- Full Text:
- Date Issued: 2015
Synthesis, characterization & application of visible light responsive nitrogen doped Tio2 and copolymer-grafted asymmetric membranes with ozonolysis for water treatment
- Authors: Mungondori, Henry H
- Date: 2015
- Language: English
- Type: Thesis , Doctoral , PhD (Chemistry)
- Identifier: vital:11350 , http://hdl.handle.net/10353/d1020257
- Description: The use of titanium dioxide for the photo-catalytic removal of organic, inorganic, and microbial pollutants from natural water and wastewater has been considered a very promising technique. The aim of this study was to prepare nitrogen doped titanium dioxide, immobilize it on asymmetric polymeric membranes of poly (methacrylic acid) grafted onto poly (vinylidene difluoride) (PVDF) blended with poly (acrylonitrile) (PAN), and evaluate the photo-catalytic, antimicrobial, and antifouling properties of the membranes. Nitrogen doped titanium dioxide (N-TiO2) nano-particles were prepared by a low temperature sol gel synthesis technique. The modification of TiO2 with nitrogen allows photo-sensitization of the photo-catalyst towards visible light utilization. The N-TiO2 nano-particles were characterized by fourier transform infrared spectroscopy (FT-IR), scanning x-ray photoelectron spectroscopy (SXPS), X-ray diffraction analysis (XRD), diffuse reflectance spectroscopy (DRS), Brunauer Emmett Teller (BET) surface area analysis, and transmission electron microscopy (TEM). The characterizations revealed the presence of the expected functional groups and confirmed successful doping and that the product was visible light responsive. Novel poly (methacrylic acid) grafted onto poly (vinylidene difluoride)/ poly (acrylonitrile) (PMAA-g-PVDF/ PAN) asymmetric membranes were prepared by the dry-wet phase inversion technique. The poly (methacrylic acid) (PMAA) side chains where grafted onto an activated PVDF backbone by reversible addition fragmentation chain transfer (RAFT) polymerization. The photo-catalytic membranes were generated by blending N-TiO2 with the polymer solution before casting the membranes. The membranes were characterized by FT-IR, nuclear magnetic resonance spectroscopy (NMR), scanning electron microscopy (SEM), and thermo-gravimetric analysis (TGA). FT-IR and NMR analyses confirmed successful grafting of MAA chains onto PVDF while SEM confirmed the successful preparation of membranes with asymmetric structure. The efficacy of the photo-catalytic asymmetric membranes was evaluated on the removal of herbicides from synthetic water. Bentazon was easily degraded while atrazine and paraquat were recalcitrant and proved difficult to degrade. The best results were observed with 3 % N-TiO2-PMAA-g-PVDF/ PAN asymmetric membranes on the photo-degradation of bentazon, atrazine and paraquat in water. Significant enhancement in the photo-degradation of the three herbicides was observed when photo-catalytic degradation was coupled with ozonation. Liquid chromatography-mass spectrometry (LC-MS) analysis confirmed the presence of a degradation by-product during the photo-catalytic degradation of bentazon. The photo-catalytic membranes were also evaluated on the photo-catalytic reduction of heavy metals Pb2+ and Fe3+ in water, and the best results were obtained using 1 % N-TiO2-PMAA-g-PVDF/ PAN and 1 % N-TiO2-PAN asymmetric membranes. All prepared photo-catalytic membranes where capable of completely inactivating E. coli ATCC 8739 within 120 minutes of exposure and inactivation rate increased with increasing N-TiO2 photo-catalyst loading. However, there was an indication from the results obtained that N-TiO2 supported on PMAA-g-PVDF/ PAN showed a higher inactivation rate of E. coli ATCC 8739 compared to N-TiO2-PAN and N-TiO2-PVDF membranes. The 1 % N-TiO2-PMAA-g-PVDF/ PAN membranes gave the highest pure water flux (421.83 L/m2h). This increase (PVDF = 30.50 L/m2h, PAN = 73.85 L/m2h) in pure water flux is owedb to PMAA grafting as well as addition of N-TiO2. These modifications resulted in an increased membrane surface hydrophilicity, which promoted permeation of pure water through the membrane structure. A high bovine serum albumin (BSA) rejection (76.5 %) was noted and can be attributed to steric hindrance brought about by PMAA side chains which prevented the bulky BSA molecules from attaching to the membrane surface for PMAA-g-PVDF/ PAN membranes. However, the supporting porous sub-layer of an asymmetric membrane seemed to play a very important role in the overall permeability of a membrane. PVDF membranes are highly hydrophobic hence they gave a very low pure water flux.
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- Date Issued: 2015
The effects of distance travelled, lairage duration and animal-related factors on pre-slaughter stress indicators, carcass characteristics, nanostructure and technological properties of beef
- Authors: Chulayo, Amanda Yucca
- Date: 2015
- Subjects: Slaughtering and slaughter-houses -- South Africa -- Eastern Cape , Meat -- Quality -- South Africa -- Eastern Cape , Beef -- Quality -- South Africa -- Eastern Cape , Nanostructured materials -- South Africa -- Eastern Cape , Livestock -- Handling -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD (Animal Science)
- Identifier: vital:11835 , http://hdl.handle.net/10353/d1021275 , Slaughtering and slaughter-houses -- South Africa -- Eastern Cape , Meat -- Quality -- South Africa -- Eastern Cape , Beef -- Quality -- South Africa -- Eastern Cape , Nanostructured materials -- South Africa -- Eastern Cape , Livestock -- Handling -- South Africa -- Eastern Cape
- Description: The main objective of the current study was to determine the effect of distance travelled (DT), lairage duration (LDhr) and animal-related factors (animal class, breed, sex) on pre-slaughter stress indicators, carcass characteristics, nanostructure and technological properties of beef. The study was conducted in an Eastern Cape abattoir under the Buffalo City District Municipality. Six genotypes of cattle (Beefmaster, Bonsmara, Brahman, Holstein-Friesian, Non-descript and Nguni) brought for slaughter at the abattoir on different days were used in the study. Slaughter weight (SWT), warm and cold carcass weight (WCW and CCW), fatness and conformation of each animal were measured and recorded. Representative samples of blood plasma and meat quality from the Muscularis thoracis et lumborum (LTL) were collected at slaughter and 24 hours after slaughter, respectively. Heat shock proteins 70kDa (HSPA1A), glucose (GLU), cortisol (CORT), creatine kinase (CK) and lactate dehydrogenase (LDH) were determined from the blood plasma. The representative LTL muscle was used to determine ultimate pH (pHu), lightness (L*), redness (a*), yellowness (b*), meat temperature (Tm), Warner Bratzler Shear Force (WBSF) and histological structure of beef. There were significant effects of distance on pHu, Tm, a*, b*, TL%, CK and LDH. Pearson correlations were observed between distance travelled (DT), creatine kinase (CK), lactate dehydrogenase (LDH), ultimate pH (pHu), colour coordinates (L*, a* and b*) and Warner Bratzler Shear Force (WBSF). Principal component analysis (PCA) revealed that the 1st (pHu), 2nd (Tm) and 3rd (L*) principal components were the critical meat quality attributes. Positive relationships between carcass weights and beef quality characteristics for bovine cattle where the cumulative percentage of the first six principal component`s (PC`s) (SWT, WCW, CCW, DP, pHu and Tm contributed to 93.4 % of the total variance. Significant correlation coefficients between DT (r = 0.15), LDhr (r = 0.29), Ta (r = -0.52), Tm (r = 0.26), L* (r = 0.33), a* (r = 0.32) and WBSF (r = -0.49) were observed. Meat from Brahman (BR), Non-descript (ND) and Nguni (NG) cows had visible skeletal muscle fibres which were thin and long indicating improved tenderness of beef. Exposing animals to longer hours of transportation did not only reduce glucose levels but also increased the expression of HSPA1A and levels of cortisol. The CK and LDH were not related to beef quality. Therefore, CK and LDH can be used as indicators of animal welfare in slaughter cattle but cannot be used to predict the quality of meat. Bulls were the heaviest, although heifers had the highest dressing percentage than cows. Furthermore, the nanostructure of beef indicated that heifers had the best muscle fibres, sarcomere length and visible intercalated discs. The observed nanostructures of Nguni genotype are an indication of tender meat. Beef from heifers of Nguni had visible and tender meat with traces of intramuscular fat while males had shorter sarcomere length and tougher meat.
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- Date Issued: 2015