• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 106
  • 20
  • 2
  • 1
  • 1
  • Tagged with
  • 139
  • 139
  • 139
  • 139
  • 49
  • 48
  • 37
  • 36
  • 27
  • 24
  • 23
  • 23
  • 18
  • 17
  • 17
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
91

Ethnobotanical study of plants from Pondoland used against diarrhoea.

Madikizela, Balungile. January 2012 (has links)
Diarrhoea and related diseases are the most common causes of death in children, especially from developing countries, killing about 1.5 million children under the age of five yearly. In South Africa, diarrhoea is the third leading cause of death. This condition results from food and water sources infected with Campylobacter spp., Escherichia coli, Salmonella spp., Shigella spp., Giardia intestinalis and Cryptospondium parvum amongst others. Diarrhoea spreads through faeces-contaminated water. Hence, infection is more common when there is a short supply of clean drinking and cooking water. Waterborne diseases are common in rural communities of Bizana because the majority of rural dwellers depend largely on water from unprotected sources. Most of the pathogens that cause diarrhoea have developed resistance to several antibiotics. Therefore there is a need for new and safe antidiarrhoeal drugs. Most people in developing countries use traditional medicine to treat all kinds of diseases including diarrhoea and South Africa is no exception. Each cultural group in South Africa has different medical solutions for the prevention and curing of the same disease. The people from Pondoland (AmaMpondo), around Bizana have a strong tradition of using medicinal plants for the cure and prevention of several conditions including diarrhoea. Although several researchers have conducted different types of studies in many parts of South Africa to evaluate the efficacy of traditional medicine used in the treatment of diarrhoea, there is, however, still a lot of undisclosed data that should be collected. The aims of this research were to record and collect medicinal plants that are used for treating diarrhoea in Bizana, Pondoland in the Eastern Cape and evaluate them for their pharmacological properties. An ethnobotanical approach is one of several methods that have been useful in selecting plants for pharmacological research, yielding better results than other plant selection methods. Using questionnaires, this approach was used to record plants that are used for treating diarrhoea in Bizana for testing in pharmacological assays. From the completed questionnaires, nine plants were selected for bioassays based on their higher frequency index, and the fact that the plants have never been evaluated against diarrhoea causing-microorganisms. The study revealed 34 plant species belonging to 21 families as being used in treatment of diarrhoea in the study area. Psidium guajava was the most mentioned plant species. The dried, ground plant materials were each extracted non-sequentially using petroleum ether (PE), dichloromethane (DCM), 70% ethanol (EtOH) and water. Among all the extracts, 70% ethanol yielded the highest quantity of crude extract. The extracts were each evaluated for their antibacterial, anti-inflammatory and genotoxicity properties. For the antibacterial activity, the following diarrhoea causing microorganisms were used: Gram-positive Staphylococcus aureus and Gram-negative Campylobacter jejuni, E. coli and Shigella flexneri. A microdilution assay (for S. aureus, E. coli and S. flexneri) and the disk diffusion technique (for C. jejuni) were used for antibacterial testing. The extracts were also evaluated for their ability to inhibit cyclooxygenase (COX-1 and -2) enzymes. Genotoxicity was evaluated using the Salmonella microsome assay without S9 metabolic activation. Three strains of Salmonella typhimurium TA98, TA1535 and TA1537 were used. The evaluated plant extracts showed a broad spectrum of inhibitory activity with MIC values ranging from 0.098-12.5 mg/ml and mean zone inhibition percentage ranging from 0-73%. The best activity was exhibited by DCM extracts of Rapanea melanophloeos, EtOH extracts of Ficus craterostoma and Maesa lanceolata with MIC values of 0.098 mg/ml and EtOH extracts of Searsia chirindensis with 73% mean zone inhibition percentage. The inhibitory activity against COX-1 enzyme was higher than COX-2, with 19 plant extracts for the former and 7 for the latter. The highest inhibition of COX-1 was shown by EtOH extracts of F. craterostoma and the DCM extract of S. chirindensis at 100%. Highest percentage COX-2 inhibition was shown by water extracts of F. craterostoma and DCM extracts of Tecoma capensis with 99.5% and 99.0% respectively. None of the tested plant extracts were mutagenic, at all concentrations tested against all tester strains of the bacteria. The results of this study demonstrate that people still have a rich and diverse pool of knowledge concerning the uses of plants against diarrhoea. The data also show that plants form part of the cultural heritage of the communities in Pondoland. Therefore it is important to urgently save the people’s cultural heritage by recording the existing knowledge and confirming therapeutic uses of plants through scientific methods. This will prevent the information from vanishing together with the ageing knowledge holders. In light of the fact that the evaluated plants were selected based on their ethnobotanical use for treating diarrhoea, the activities reported here goes a long way in adding value to the plants used as part of traditional medicine. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2012.
92

D'urbanised tradition : the restructuring and development of the muthi trade in Durban.

Nesvag, Stein Inge. January 1999 (has links)
This thesis is about the history of the muthi trade (the African traditional medicine trade) since it was introduced to Durban. "D'Urbanised Tradition" refers to the way the tradition surrounding muthi was urbanised in Durban, and how it has been viewed as a 'de-urbanising' element in the city. The thesis deals with the changes, over the past 100 years, to the tradition of muthi trading that were brought about both by actors 'within' the trade - what I refer to as 'restructuring of tradition' - and by interventions from 'external' forces (the state, the biomedical lobby and the conservationist lobby) - what I have termed 'the development of tradition'. Whereas many studies present (Zulu) tradition as something static, this study of "D'Urbanised tradition" focuses on change and process - why and how these changes to tradition have occurred. It comprises an analysis of how the dialectic between change and continuity within the muthi trade has been negotiated by strategic actors throughout the twentieth century. Emphasis is on the economic and political potentials of tradition and traditional medicine, and focus will be on changes in the muthi trade in Durban, using the Russell Street Muthi Market in the 1990s as a case study. Although 'restructuring' and 'development' are kept separate in this thesis, they denote interrelated processes whereby active agents strategically use tradition to achieve their ends. It is argued that the traditions surrounding muthi have been manipulated both as economic as well as political tools by the various vested interests in the trade. The thesis deals with one of the largest and most important sectors of South Africa's informal economy, and provides a historical analysis and case study of the strategies used by both traders and outside institutions involved in the trade. This is done by using the paradigm of 'tradition'. / Thesis (M.A.)-University of Natal, Durban, 1999.
93

Response of the endangered medicinal plant : Siphonochilus aethiopicus (Schweif) B.L. Burt. to agronomic practices.

Hartzell, James Francis. January 2011 (has links)
This study examines field cropping constraints for domestication of an endangered, wild medicinal plant, Siphonochilus aethiopicus, (Schweif.) B.L. Burt. Extensive literature review and careful observations of plant growth behavior during two years of crop trials overturned several long-held but erroneous claims that have consistently appeared in the scholarly literature, and revealed previously undocumented plant growth characteristics. S. aethiopicus (Schweif.) B.L. Burt. is a rhizomatous corm, not a rhizome. Field growth observations demonstrated clearly that the false stem and leaves grow continuously from emergence in September to senescence in April-May; the corm retains its tuberous roots during winter senescence, and is genetically preprogrammed to shoot in September. Flowers may emerge throughout the growing season (not only initially prior to shoot emergence), typical leaf count is 11-15, not 6-8 as previously reported, numbers that remain constant even when the plant height increases by 20-30% under shade, and leaf distichy is independent of the sun’s course and is unaffected by mother corm orientation. S. aethiopicus proved to be unusually resistant to common field diseases and pests, and resilient to severe hail. The responses of S. aethiopicus were tested in a series of field trials to the effects of levels of compost, field spacing, size of planting material, addition of biocontrol agents, different degrees of shading, and factorials of the macronutrients Nitrogen, Phosphorous and Potassium. Spacing-Composted chicken litter combinations were tested in 2005-2006 in factorial combination with Spacing at 15 cm-4.5 kg ha-1, 20 cm-7.5 kg ha-1, 30 cm-10 kg ha-1, and 40 cm-15.5 kg ha-1, and these treatments were randomized with 4 Corm planting sizes (height by base diameter in mm): Small (S, 12.38 mm x 12.6 mm), Medium Small (MS, 29.65 mm x 27.93 mm), Medium Large (ML, 38.48 mm x 37.78 mm) and Large (L, 52.37 mm x 44.10 mm). 2005-2006 ANOVA tests showed significant differences between Spacing-Compost and Corm Size for the total harvest biomass measure, with 30 cm and 40 cm spaces better than 15 cm spacing, and Corm Size MS, ML and L all better than S, and ML better than MS. Total Corms harvested per block and ii Survival Percentage were similarly significant for Corm Size, but not Spacing. Corms smaller than the Small criteria were raised separately, under optimal conditions in a nursery. In a separate 2005-2006 Compost-only trial ANOVA tests did not find significant differences between compost levels. In 2006-2007 we tested Spacing separately at 5, 10, 15, 20, 30 and 40 cm between planted corms in each plot. We tested Compost levels separately, with 0, 5, 10 and 15 kg ha-1 compost per plot. In 2006-2007 only the ML and L sizes were used in an even mix. There were no significant differences between treatments due to high experimental error, but measurement across all production parameters showed a clear trend towards best performance at spacing between 20 and 40 cm. Overall the results from the Spacing, Compost-level and Corm Size trials suggest that 30 cm is perhaps the optimal field spacing, higher compost levels tend to give better results, and the ML and L corm sizes perform better in open-sun field trials. These parameters are recommended for further field studies and production. The effects of two commercial strains of Trichoderma spp were tested at recommended doses applied to S. aethiopicus. T. harzianum Strain B77 was used as a drench at planting in comparison with a Control and a fungicide in 2005-2006. There were no significant differences between treatments for Harvested Biomass or Survival Percentage. B77 did perform significantly better than the Fungicide in the Total Corm measurement, but neither treatment was significantly different from the Control. In sum, there was a weak trend towards a greater number of output corms as a result of the application of the biocontrol agent. In both 2005-2006 and 2006-2007 we tested T. harzianum Strain kd applied as a drench at planting, with a second drench at 4 weeks. In 2006-2007 there were no significant differences between treatments, but the trend was towards better performance as a result of the drench at planting only. In 2005-2006 open field trials had shown that S. aethiopicus is susceptible to sunburn and Erwinia soft rot when grown in the full sun. Therefore, we tested the effect of various shadecloth densities and colours on production performance in 2006-2007. Treatments were Control (full sun), 40% White (TiO2) (23% shade), 40% Grey (28-30% shade), Light Black (40%), Medium Black (50%), Dark Black (80%), and Red (40%). There were no significant differences between treatments, but the trends indicated that the Control (full sun) and Dark Black (80% shade) performed the worst. Colour of shade did not appear to be important, and plants under all the shadecloths with 40-50% shade grew best. In a factorial trial different levels of Nitrogen, Phosphorous, and Potassium (NPK)were tested, over two seasons. Four levels of each input were used: N at 0 (Control), 40 kg ha-1 (N1), 80 kg ha-1 (N1), and 120 kg ha-1 (N3). P levels were 0 (Control) 60 kg ha-1 (P1) ,120 kg ha-1 (P2) and 200 kg ha-1 (P3). K levels were 0 (Control), 100 kg ha-1 (K1), 200 kg ha-1 (K2), and 400 kg ha-1 (K3). In 2005-2006 there were no significant differences between treatments. In 2006-2007 data there were significant results for Nitrogen only within each repetition. However, significance disappeared when combining across repetitions. We then ran a Bootstrap re-sampling analysis of both 2005-2006 and 2006-2007 data (data were analyzed separately because of different plot sizes and corm numbers in the two years), looking at the optimal level of each macronutrient tested against all combinations of the other two. Though significant results were obtained for each individual level of each macronutrient against the others in combination, the difference between the confidence intervals was not significant. However, there was a clear trend: the optimum N levels were between 40 and 80 kg ha-1; optimum P level was 0 (the Control) and optimum K levels were between 100 and 200 kg ha-1. Tests of handling during harvest, storage, and planting yielded additional useful information for small scale commercial farmers. The optimal harvest time is May, when the false stem and leaves are senescing and yellow, but still upright and visible. Harvest is facilitated by moistening the soil to minimize breaking off of tuberous roots, with simple field washing to remove compacted soil highly recommended. Harvested corms and tuberous roots should be stored under air-restricted, cool conditions because the tuberous roots contain high moisture and will shrivel quickly when left exposed to air, and excessively dried corms will eventually die. Senesced mother corms should be discarded at harvest. Corms are genetically preprogrammed to shoot, so should be planted in September in soft soil, with 1-2 cm of soil coverage. The studies provide a framework for developing the basic agronomy for the domestication and commercial crop production of an endangered medicinal plant species. / Thesis (M.Sc.Agric.)-University of KwaZulu-Natal, Pietermaritzburg, 2011.
94

Pharmacological evaluation of some central nervous system effects of Cotyledon Orbiculata.

Kabatende, Joseph January 2005 (has links)
The use of traditional medicine through the use of medicinal plants in Africa and especially in South Africa has long been considered an important characteristic of people's daily lives and socio-cultural heritage. Cotyledon Orbiculata is among the medicinal plants that are used by South African traditional practitioners for the treatment of epilepsy and painful conditions such as corns, warts, toothache, earache, boils and various other ailments. However, the claim of therapeutic successes of medicinal plants by traditional medicine practitioners are hardly subjected to scientific scrutiny. This study therefore, investigated the anti-epileptic property of Cotyledon Orbiculata by studying the effects of the methanol extract of the plant against chemically induced seizures by pentylenetetrazole, picrotoxin, bicuculline and N-methyl-DL-aspartic acid in mice. The study also investigated the analgestic effects of Cotyledon Orbiculata by studying the effect of the plant extract on pain induced by acetic acid and hot plate thermal stimulation.
95

Investigation of antidiabetic properties, mechanisms of action and toxicology of Strychnos Henningsii (GILG) bark

Oyewole, Oyedemi Sunday January 2011 (has links)
The apparent reversal of trend from modern drugs to herbal medicine is partly due to the fact that synthetic drugs have always shown adverse reactions and other undesirable side effects. Hence, the use of medicinal plants for the treatment of diseases such as diabetes is very common especially in the rural areas. Majority of these plants are used based on the experience and indigenous knowledge without identification of the therapeutic agents. There is enormous wealth of medicinal plants in the world yet many of them have not been discovered or studied scientifically to substantiate their ethno-medicinal usages. Ethnobotanical study has been the method often used to search for locally important plant species for the discovery of crude drugs with low side effects. An ethnobotanical survey was conducted on the medicinal plants commonly used for the management of diabetes mellitus in Nkonkobe Municipality, Eastern Cape of South Africa. Information was obtained through structured questionnaire administered to traditional healers and herbalists in the region. The study revealed 15 species of plants belonging to 13 families. Strychnos henningsii and Leonotis leonorus among others were repeatedly mentioned by the traditional healers as the two mostly used plants for the management of diabetes mellitus. The infusion and decoction of the roots, leaves and barks of these plants are the methods of preparation. The antioxidant potential of aqueous bark extract of S. henningsii was investigated both in vivo and in vitro using spectroscopic method. The antioxidant activity of the extract against hydrogen peroxide (H2O2), 2,2′-azinobis[3-ethylbenzothiazoline6-sulfonic acid] diammonium salt (ABTS), as well as reducing power was concentration dependent. The extract exhibited lower and average scavenging activities against 1,1diphenyl2picrylhydrazyl (DPPH) and nitric oxide (NO) radicals with IC50 value of 0.739 and 0.49 mg/ml respectively. The administration of the plant extract at 250, 500 and 1000 mg/kg significantly increased the activities of the antioxidant enzymes in the hepatotoxic rats induced with carbon tetrachloride. On the other hand, the stem bark extract had lower effect on lipid peroxidation level except at the dose of 250 mg/kg. The effect of oral administration of S. henningsii extract was evaluated in normal Wistar rats for 28 days. The observed result indicated non- toxic effect of sub-acute administration of plant extract to the animals except at certain doses. This is because, there was no apparent damage to some haematological and biochemical parameters used in assessing organ specific toxicity. However, the alterations observed on platelet, white blood cells and its differentials imply parameter and dose selective toxicity when repeatedly consumed on daily basis at the doses investigated. This study also investigated the antidiabetic activities of the extract at the doses of 125, 250 and 500 mg/kg body weight in diabetic rats induced with streptozotocin -nicotinamide for 15 days. The extract appreciably (P <0.05) reduced the blood glucose level, feed and water intake while the best result was obtained at 250 mg/kg. Similarly, the level of triacylglycerol at the three doses investigated was significantly decreased. In addition, the glucose tolerance was reduced to near normal level after 90 min at certain doses. The clinical significance of the extract on some biochemical and haematological parameters lessen both hepatic and renal damages. Anaemic condition in diabetic animals was also improved after plant extract administration. However, no significant effect was observed in white blood cells and some of its differentials. The extract demonstrated strong glucose utilization in 3T3-L1 cells with a response of 278.63 percent of the control at 12.5μg/ml while that of Chang liver cells was 103.54 percent. The cytotoxicity result revealed non toxic effects of the extract to both cell lines. Treatment of 3T3 L1 cells with the extract did not reduce lipid accumulation. The extract inhibited the activity of α- glucosidase and α- amylase in a concentration dependent manner with IC50 values of 38 μg/ml and 60.9 μg/ml respectively. The percentage protein antiglycation of S. henningsii was 18.4, 38.2 and 61.2 perceent for 0.25, 0.5 and 1 mg/ml respectively while aminoguanidine a known inhibitor of protein glycation was 87.2 percent at 1 mg/ml. The FRAP assay values of the extract was 357.05 μmol Fe (II)/g. The findings from this study support the folkloric usage of this plant for the management of diabetes mellitus in the region.
96

Assessment of plants used for the treatment of cattle wounds and myiasis in Amatola Basin, Eastern Cape Province, South Africa

Soyelu, Oluseyi Temitope January 2010 (has links)
No description available.
97

Effects of micronutrients on growth and quality of bush tea (Athrixia phylicoides DC)

Maedza, Khathutshelo Vuwani 20 April 2016 (has links)
Bush tea (Athrixia phylicoides DC.) is a herbal beverage and medicinal plant indigenous to South Africa. A trial was conducted to determine the effect of micronutrients on the plant growth and quality of bush tea. The trial was laid out in a completely randomized block design with five replicates. Treatments consisted of single applications of Zinc (Zn), Copper (Cu), Boron (Bo), Iron (Fe) and Magnesium (Mg) at three levels (50ml/l, 100ml/l and 150ml/l) and a combination of all micronutrients. A control treatment with no spray was also included. Leaf analysis was conducted using Varian Liberty series II instrument. Total polyphenols were determined using the Folin Ciocalteau method and tannins were determined using Vanillin HCl method. Bush tea samples (one leaf per sample) were analysed using head space solid phase micro-extraction gas chromatography (HS-SPME-GC-MS). Results of this study demonstrated that application of micronutrients increased the total polyphenols, tannins and total flavonoids in bush tea, with most of the increase in total polyphenols (77.5-93.7 mg/g) occurring in combination B + Zn + Fe + Cu + Mg treatment, increase in tannins (87.3-99.5 mg/g) occurring in copper treatment and increase in total flavonoids (164.6-176.6 mg/g) occurring in mixture (B + Zn + Fe + Cu + Mg) treatment. Results also show a significant increase in the quality and plant growth of bush tea. Five major compounds were identified (>80% identification probability) namely alpha-pinene, beta-pinene, myrcene, beta-caryophyllene and caryophyllene oxide. Linear relationship between percentage leaf tissues and treatments levels of micronutrients in bush tea was also observed. Boron and copper treatments showed strong linear correlation with a positive relationship between treatments levels and leaf percentage. Therefore, for improved total polyphenols content in bush tea leaves, a combination of (B + Zn + Fe + Cu + Mg) is recommended. Tannin content in bush tea leaves were significantly increased at Cu50 ml/l, Cu100 ml/l and Cu150 ml/l. For improved total flavonoids content in bush tea leaves, a combination of foliar spray of (B + Zn + Fe + Cu + Mg) is recommended. The LC-MS observations from the study showed no significant qualitative difference between control and micronutrient treatments with these treatments showing similar number of peaks. There was a significant quantitative difference between control and where magnesium peaks applied at adequate rates at (50 ml/l and 100 ml/l) and combination of (B + Zn + Fe + Cu + Mg) applied at (10 ml/l and 20 ml/l) / Agriculture, Animal Health and Human Ecology / M. Sc. (Agriculture)
98

Leonotis leonurus: the anticoagulant and antidiabetic activity of Leonotis leonurus

Mnonopi, Nandipha January 2010 (has links)
Commercial marrubiin, aqueous and organic extracts of Leonotis leonurus were tested in vitro for their anticoagulant and antiplatelet activities. The aqueous extract inhibited platelet aggregation by 69.5 percent (100 μg/mL), while the organic extract (100 μg/mL) and marrubiin (5 μg/mL) showed 92.5 percent and 91.6 percent inhibition, respectively, by inhibiting the binding of fibrinogen to glycoprotein IIb/IIIa receptor in a concentration dependent manner. The extracts significantly prolonged activated partial thromboplastin time compared to untreated plasma controls. Fibrin and D-Dimer formation were drastically decreased. The extracts and marrubiin concentration-dependently inhibited calcium mobilization induced by collagen and thrombin. The formation of thromboxane A2 was also significantly reduced by both the extracts and marrubiin. Protein secretion and platelet adhesion were significantly reduced by both the extracts and marrubiin. The organic extract and marrubiin showed a more pronounced effect than the aqueous extracts in all the in vitro assays. The ex-vivo animal model confirmed the results obtained in vitro. Similar to the in vitro studies, activated partial thromboplastin time clotting time was prolonged by marrubiin and the number of aggregated platelets were significantly reduced relative to aspirin. The findings reflect that marrubiin largely contributes to the organic extract's anticoagulant and antiplatelet effect in vitro. INS-1 cells were cultured under normo- and hyperglycaemic conditions. Marrubiin and the two Leonotis leonurus extracts were screened for anti-diabetic activity in vitro. The stimulatory index of INS-1 cells cultured under hyperglycaemic conditions was significantly increased by 60 percent and 61 percent (p<0.01; n=5) in cells exposed to the organic extract (10 μg/mL) and marrubiin (500 ng/mL), respectively, relative to the normoglycaemic conditions. The gene expression of insulin was significantly increased by 76.5 and 71 percent, and of glucose transporter-2 by 93 and 92.5 percent for marrubiin and the organic extract, respectively, under the same conditions stipulated above (p<0.01; n=4). The extract and marrubiin similarly showed an increase in respiratory rate under hyperglycaemic conditions. Marrubiin increased insulin secretion, HDL-cholesterol, while it decreased total cholesterol, LDL-cholesterol and the atherogenic index in the in vivo rat model.
99

Biological activities of medicinal plants traditionally used to treat Septicaemia in the Eastern Cape, South Africa

Chinyama, Robert Fred January 2009 (has links)
Over the past 25 years, there has been a resurgence of worldwide scientific research in the fields of ethnopharmacology. The Western world has acknowledged the continued use of traditional medicines by the majority of third world countries, and the need for novel drug development. Hence, much of the pharmaceutical research in recent years has focused on the ethnobotanical approach to drug discovery (Light et al., 2005). In South Africa, as in most developing parts of the world, traditional herbal medicine still forms the backbone of rural healthcare. The government health services in South Africa provide only western medical care although the majority of the population consult traditional healers for some or all of their healthcare needs (McGaw et al., 2005). Medicinal plants like Harpephyllum caffrum are used as blood purifiers or emetics (Watt and Breyer-Brandwijk, 1962), and also for treating acne and eczema. The antimicrobial activity of this plant can be used to treat septicaemia, which is ranked the sixth leading cause of death among neonates and the eighth leading cause of death for infants through the first year of life (Heron, 2007). In this study, the plants investigated for antimicrobial activity were Harpephyllum caffrum, Hermannia cuneifolia, Chironia baccifera, Rhigozum obovatum, Felicia muricata and Pentzia incana. These plants were tested against ATTC (American Type Culture Collection) strains and microorganisms isolated from clinical isolates of patients suffering from septicaemia. The assay methods used included the agar diffusion method using the Mast multipoint inoculator, the microtitre dilution method were used to determine the minimum inhibitory concentration, thin layer chromatography fingerprints accompanied by bioautographic assay were used to detect the inhibition of bacterial growth by active compounds separated from plant extracts and the Ames test was required to assess the possibility of bacterial mutagenesis upon the exposure to plant extracts which can lead to carcinogenicity. In agar diffusion method, extracts of Harpephyllum caffrum inhibited nine strains of Candida albicans, three species of Acinetobacter and four strains of E.faecalis. Extracts of Hermannia cuneifolia inhibited four strains of B.cereus and three strains of Staphylococcus aureus. Extracts of Chironia baccifera inhibited one strain of Acinetobacter and five strains of E.faecalis. Extracts of plants Rhigozum obovatum, Felicia muricata, and Pentzia incana showed no antimicrobial activity. In the microtitre dilution method used to determine the minimum inhibitory concentration (MIC), the results were different from the agar diffusion method. More activity was observed. Extracts of Harpephyllum caffrum inhibited three strains of E.coli, six strains of S.aureus, three species of Acinetobacter and one strain of Klebsiella pneumonia. Extracts of Hermannia cuneifolia inhibited four strains of B.cereus, three strains of S.aureus, two strains of K.oxytoca and one species of Acinetobacter. Extracts of Chironia baccifera inhibited three strains of S.aureus, one strain of MRSA, one species of Acinetobacter and one strain of S.haemolyticus. The MIC values ranged from 0.049 to 6.25mg/ml. Using the thin layer chromatography fingerprints, bioautography showed the presence of various inhibitory chemical compounds. Methanol and acetone extracts of Harpephyllum caffrum, separated very well and showed various inhibition zones on exposure to Candida albicans, Enterococcus faecalis and Staphylococcus aureus. The different inhibition zones were recorded as Rf In the Ames test (Maron and Ames, 1983) the methanol and acetone extracts of Harpephyllum caffrum and Hermannia cuneifolia were negative which means they were devoid of any mutagenic properties. Methanol extracts of Harpephyllum caffrum showed similar results in the Ames assay as reported by Verschaeve and Van Staden (2008). values ranging from 0.25 to 0.95. The zones indicate the different inhibiting chemical compounds present in the plant. Petroleum ether, ethyl acetate, chloroform and formic acid were the solvents used in the assay in the ratio 8:7:5:1, respectively. Establishing the antimicrobial activity of these plants contribute to the systematic scientific investigation of indigenous South African medicinal plants.
100

Effect of a South African medicinal plant on antiretroviral drug induced abnormalities in rats

Van Gend, Tania Anli January 2008 (has links)
The worldwide AIDS epidemic is known to have had a profoundly negative social, economic and personal impact and has taken a heavy toll on existing health care systems, particularly in developing countries. South Africa is experiencing an HIV epidemic with enormous social and economic consequences. Lopinavir/ritonavir antiretroviral treatment has been accredited with having a significantly positive effect and is a key advance in controlling HIV morbidity and mortality. An indigenous South African medicinal plant, Sutherlandia frutescens, known for its anti-diabetic properties and immune-boosting effects, is used for treating HIV positive patients suffering from opportunistic infections. Despite the use of the medicinal plant extract as homeotherapeutic medication, there is little evidence of toxicity testing that identifies its potential for interaction with antiretroviral drugs. However, scientific data relating to the mechanism through which Sutherlandia frutescens acts on the immune system has not been comprehensively documented. The aim of this study was to investigate lopinavir/ritonavir induced metabolic abnormalities in rats and whether the introduction of a plant extract of Sutherlandia frutescens would counteract the side effects of ARV medication. The results indicated that the rodents did not become insulin resistant, however, biochemical analysis indicated that extended ARV drug treatment would have caused insulin resistance. Significant morphological changes were found in the livers, kidneys and pancreases of rats exposed to the lopinavir/ritonavir. Rats exposed to the Sutherlandia frutescens plant extract showed improved histopathology with minimal abnormalities.

Page generated in 0.3861 seconds