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

The role of plants in the treatment of disease and enhancement of production in animals in South African rural communities is poorly documented. Rapid Rural Appraisal (RRA) methods were employed to describe the use of ethnoveterinary medicinal plants in cattle by Setswana-speaking people in the Madikwe area of the North West Province of South Africa. Information was gathered from key spokespersons through individual interviews, group interviews, guided field walks and observations. Ethnoveterinary uses in cattle of 46 plant species representing 24 families were recorded. Plants were used in 84 % of the total number of ethnoveterinary remedies. These plants were used alone (64 %) or in mixtures (36 %) for 43 indications. The most important indications for the use of ethnoveterinary remedies were retained placenta, diarrhoea, gallsickness, fractures, eye inflammation, general ailments, fertility enhancement, general gastrointestinal problems, heartwater, internal parasites, coughing, redwater and the reduction of tick burdens. Plant materials were prepared in various ways including, infusion (36 %), decoction (33 %), infusion or decoction (13 %), ground fresh material (6 %), sap expressed from fresh material (3 %), charred (2 %) and dried (1 %). Unprocessed, fresh material was used in 6 % of remedies. The most common dosage form was a liquid for oral dosing (83 %). Other dosage forms included, drops, licks, ointments, lotions and powders. Liquid remedies for oral dosing were administered using a bottle. The study indicated that Setswana-speaking people in the North West Province have a rich heritage of ethnoveterinary knowledge, which includes all aspects of ethnoveterinary medicinal plant use. The impact of ethnoveterinary medicinal plant use on medicinal plant population densities was also assessed through a comparison of the medicinal plant densities inside and outside the Madikwe Game Reserve. Belt transects were used in a stratified trial design to record plant densities. No statistically significant differences in medicinal plant densities that could be attributed to medicinal plant use, were found. / Dissertation (MSc)--University of Pretoria, 2000. / Paraclinical Sciences / Unrestricted

Diabetes mellitus is becoming an increasing concern all over the world. Many people especially in poor communities have been using medicinal plants to treat diabetes and its complications. Much work has been done to find scientific evidence to support the use of medicinal plants in many cases with good evidence to support the traditional use. There has been an increase in research on the use of botanicals for either the treatment and/or management of diabetes in many parts of the world. To start this study an informal survey on plant species used to treat diabetes was carried out with local inhabitants and herbal traders in the Newcastle region (KwaZulu Natal). The plant species were chosen based on their wide use by traditional healers and local inhabitants. The efficacy of the selected plant (Senna alexandrina, Cymbopogon citrates, Cucurbita pepo, Nuxia floribunda, Hypoxis hemerocallidea and Cinnamomum cassia) used to treat diabetes mellitus by traditional healers in KwaZulu Natal province of South Africa was evaluated under controlled laboratory conditions. With the exception of Senna alexandrina and Nuxia floribunda, there has been some independent evidence of the efficacy of these plant species In this study three relevant in vitro and semi in-vivo assays were selected to test the efficacy of different extracts on alpha amylase (carbohydrate digestive enzyme) activity, alpha glucosidase (glucose absorption) activity and islets of Langerhans insulin secretory activity. Hexane, ethyl acetate, acetone and methanol extracts were examined and screened for their phytochemical properties and activity in the selected assays Alpha amylase inhibitory assay Not all extracts of the plant species had α-amylase enzyme inhibitory activity. The acetone extracts of C. pepo and H. hemerocallidea had enzyme inhibition less than that of acarbose positive control (EC50 = 1.82, 0.92 and 0.56 mg/ml respectively). The other plant species that had substantial α-amylase inhibitory activity was the methanol extracts of C. citratus and C. cassia (EC50 = 0.313 and 0.12 mg/ml respectively), ethyl acetate extracts of C. citratus and N. floribunda (EC50 = 1.20 and 1.60 mg/ml respectively). The hexane extracts of C. cassia (0.72 mg/ml), N. floribunda (0.88 mg/ml), C. pepo (0.70 mg/ml) and S. alexandrina (0.083 mg/ml) all had α-amylase inhibitory activity.The best activity was present in the intermediate polarity extracts. If these more apolar plant extracts are not toxic or do not have negative side effects they may be much more efficient than acarbose in managing α-amylase activity. Alpha glucosidase inhibitory assay In contrast to the alpha amylase activity, the inhibitory activity of the non-polar (hexane and ethyl acetate) plant extracts was in general higher than that of polar extracts. With the methanol and acetone extracts the inhibitory activity varied from no activity in the methanol extract of C. cassia to highly active methanol extract of C. pepo (70.3%) and acetone extract of H. hemerocallidea (84.35%). Among the plants studied C. cassia and N. floribunda (bark) had the highest inhibitory activity in the hexane and ethyl acetate extracts, the acetone extract of H. hemerocallidea had the highest inhibitory activity. The hexane crude extracts ofN. floribunda and C. citratus had very high inhibitory activity at the highest concentration tested (1 mg/ml). The ethyl acetate crude extracts of all the plant species used in this study had an inhibitory activity above 90% against α-glucosidase at 1 mg/ml. When compared to acarbose all the plant species used in this screening study had good activity against the α-glucosidase enzyme with the exception of the methanol extract of C. cassia. The inhibitory activity of hexane and ethyl acetate extracts was close to that of the positive control. If the more non-polar plant extracts are not toxic or do not have negative side effects (not tested) it appears that they may be more or less efficient than acarbose in managing α-glucosidase activity. Islets of Langerhans as a target site Only with the H. hemerocallidea acetone extract was there an increase in insulin secretion of 2.5 mIU/L (Table 8) at 8 ug/ml. With all the other extracts the insulin levels were less than 0.2 mIU/L. The positive controls of acarbose and glibenclamide at a concentration of 1 mg/ml stimulated insulin secretion to 11.5 and 19.8 mIU/L respectively. In comparison, the positive controls acarbose and glibenclamide control produce a 5-8 fold greater increase in insulin secretion although the exposure was at a 100-fold higher concentration. This would indicate that the H. hemerocallidea acetone crude extract contains a very potent secretogogue compound. It is possible that higher concentrations of the other plant extracts may also have led to stimulation of insulin production. If the more non-polar plant extracts are not toxic or do not have negative side effects and are biologically available, it appears that they may be much more efficient than acarbose and glibenclamide in managing insulin secretion. Conclusion The best overall activity was observed in the non-polar and intermediate solvents (hexane and ethyl acetate). Although the organic extracts had good activity, it does not explain the use of aqueous extracts by traditional healers because water extracts were not active in the assays. The activity of the C. pepo acetone leaf extract and N. floribunda ethyl acetate bark extract is the first reported evidence of activity with regard to diabetes mellitus. From the in vitro results, it can be concluded some extracts of all the traditionally used species have some merit in the management of diabetes mellitus type II, as suggested by the ethnomedicinal leads. In may be worthwhile following up on this work by isolating the compounds responsible for the biological activities. / Dissertation (MSc)--University of Pretoria, 2010. / Paraclinical Sciences / unrestricted

Please read the abstract in the dissertation Copyright 2002, University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. Please cite as follows: Rakuambo, NC 2002, The traditional use of medicinal plants to treat erectile dysfunction and the isolation of their bioactive compounds, MSc dissertation, University of Pretoria, Pretoria, viewed yymmdd < http://upetd.up.ac.za/thesis/available/etd-03122012-172112 / > E12/4/140/gm / Dissertation (MSc)--University of Pretoria, 2002. / Plant Science / unrestricted

Thesis (Ph. D.)--University of California, San Diego, 2009. / Title from first page of PDF file (viewed July 9, 2009). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references (p. 369-389).

BACKGROUND: Ethnobotanical knowledge continues to be important for treating illness in many rural communities, despite access to health care clinics and pharmaceuticals. However, access to health care clinics and other modern services can have an impact on the distribution of medical ethnobotanical knowledge. Many factors have been shown to be associated with distributions in this type of knowledge. The goal of the sub-analyses reported in this paper was to better understand the relationship between herbal remedy knowledge, and two such factors, age and social network position, among the Yucatec Maya in Tabi, Yucatan. METHODS: The sample consisted of 116 Yucatec Maya adults. Cultural consensus analysis was used to measure variation in herbal remedy knowledge using competence scores, which is a measure of participant agreement within a domain. Social network analysis was used to measure individual position within a network using in-degree scores, based on the number of people who asked an individual about herbal remedies. Surveys were used to capture relevant personal attributes, including age. RESULTS: Analysis revealed a significant positive correlation between age and the herbal medicine competence score for individuals 45 and under, and no relationship for individuals over 45. There was an insignificant relationship between in-degree and competence scores for individuals 50 and under and a significant positive correlation for those over 50. CONCLUSIONS: There are two possible mechanisms that could account for the differences between cohorts: 1) knowledge accumulation over time; and/or 2) the stunting of knowledge acquisition through delayed acquisition, competing treatment options, and changes in values. Primary ethnographic evidence suggests that both mechanisms may be at play in Tabi. Future studies using longitudinal or cross-site comparisons are necessary to determine the whether and how the second mechanism is influencing the different cohorts.

published_or_final_version / abstract / Chemistry / Doctoral / Doctor of Philosophy

published_or_final_version / Biological Sciences / Doctoral / Doctor of Philosophy

published_or_final_version / abstract / Biological Sciences / Doctoral / Doctor of Philosophy

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