Schistosomiasis is an important public health issue for rural communities located near,or around slow moving water bodies in the tropical and subtropical areas. Successful control of the disease involves multifaceted approaches, which include snail control, environmental sanitation, health education and chemotherapy. Although snail control might be an effective method of controlling schistosomiasis, there has been a general lack of control initiatives, largely due to the cost of available molluscicides. Plants offer a wide array of compounds which, on extraction, may show molluscicidal activity. If molluscicidal compounds that occur in indigenous plants can be extracted using local labour and simple technology, then there should be culturally acceptable and inexpensive molluscicides. The aim of this study was, therefore, to screen some Zulu medicinal plants for molluscicidal activity. We have also attempted to isolate the active chemical compounds from such plants. Aqueous and methanolic crude extracts of ten (10) Zulu medicinal plants, used for different medicinal and domestic purposes, were screened for molluscicidal activity on Biomphalaria pfeifferi and Bulinus africanas snails reared in the laboratory during the time of bioassay. Bayluscide® (niclosamide) was used as a positive control for comparison, while de-chlorinated tap water was used as the negative control. Six of the plants were not active against the snails. Extracts from four of the plants demonstrated weak to moderate molluscicidal activities. These plants are: (i) Sclerocarya birrea stembark, (ii) Psidium guajava (hybrid) leaves, (iii) Leonotis leonurus aerial parts and (iv) Ekerbegia capensis stem-bark. The LC50 values of the plant extracts were 78 ppm, 100 ppm, 398 ppm and 600 ppm respectively. Of the 4 plants that showed molluscicidal activity, S. birrea aqueous and methanol extracts were the most active against the snails, with LC50 values of 82 ppm and 78 ppm respectively. For the other plant extracts, only the methanolic extracts showed activity. Brine shrimp toxicity assay was performed with all the active extracts. Psidium guajava showed 10% survival of the shrimps at 1000 ppm, whereas no survival was observed for the other plant extracts at this concentration (1000 ppm). The results obtained in this study indicate that further studies have to be conducted, especially with S. birrea extracts, whose both aqueous and methanolic extracts showed significant activity against the snails. / Thesis (M.Med.Sc.)-University of Durban-Westville, 2002.

The herbal medicine trade is thriving in KwaZulu Natal with an ever-increasing number of people harvesting and trading in indigenous plants, especially those species with medicinal and/or magical properties. The number of plants harvested has increased whereas the size of the plants collected has decreased, resulting in low recruitment into wild populations. As a result of these two factors, species diversity has decreased. To this end, the aim of these investigations was to establish micropropagation protocols for the selected species i.e. Bowiea volubilis, Haworthia_ limifolia and Cryptocarya latifolia. In addition, hardening-off protocols were also developed. The bulbous plant, Bowiea volubilis, was propagated via organogenesis using the inflorescence stem. Bulblet formation occurred directly without an intervening callus phase. Bulblets were produced on explants on Linsmaier and Skoog (1965) (LS) medium containing 30 g.r' sucrose and either I mg.r' BAP and I mg.r' 2,4-D or 1 mg.r' BAP and 1 mg.r' NAA. Shoots and roots were induced upon transfer to the basal medium devoid of plant growth regulators. Regenerated plantlets were successfully hardened-off. Haworthia limifolia, a succulent, was propagated via direct somatic embryogenesis using leaf material. Embryo formation was induced on a modified Murashige and Skoog (1962) (MS) medium containing 20 g.r' sucrose and 1 - 5 mg.r' 2,4-D. secondary embryogenesis occurred when the explants were transferred to the basal medium supplemented with activated charcoal and devoid of growth hormones. Healthy plantlets, produced from secondary embryos, were transferred to pots and acclimatised to greenhouse conditions. A large proportion of the plantlets regenerated were vitrified and as a result, this problem was addressed by changing the medium composition or culture environment. Silica gel, when placed in the culture vessel, was the best treatment for reversal of the vitrified condition. The establishment of leaf and nodal segment cultures of Cryptocarya latifolia required extensive investigation of sterilants to reduce fungal contamination. Several fungicides were tested and a successful sterilisation protocol was established. A number of media were tested for the induction of dormant axillary buds and multiplication of shoots. The best medium for both bud induction and proliferation was MS medium containing 30 g.r1 sucrose and 1 mg.r1 BAP and 0.01 mg.r1 NAA. Callus cultures were established on MS medium containing 30 g.r1 sucrose and 3 mg.rl 2,4-D. These calli, however, were non-embryogenic. Application of the established protocols and future research strategies are discussed. / Thesis (M.Sc.)-University of Natal, 1995.

Due to over-exploitation of commonly-used medicinal plants, mainly from KwaZuluNatal, because of ever-increasing human population growth, many of the useful medicinal plants are becoming depleted in their natural habitats. Some species like Warburgia salutaris, which is currently declared very rare in the KwaZulu-Natal province, appear to be on the verge of extinction. In order to counteract this overexploitation, this study sought to provide information that could help resource users to grow these threatened species through ex situ conservation methods. A short list of heavily utilised medicinal tree specles was selected from the approximately 700 tree species indigenous to KwaZulu/Natal. The criteria considered for short listing were; life form, species scarcity, past population status and part used. A total of 23 species were short listed, but a subset of 12 species was selected based on the availability of fruits and seeds. The aim of short-listing was to work on a manageable number of commonly utilised medicinal tree species. The seed physiology and growth of these species were studied. With the exception of Erythrophleum lasianthum and Curtisia dentata, all of them had a moisture content of 2': 20 % (on a dry mass basis), which is indicative of a recalcitrant behaviour. However, it could not be concluded that these seeds were truly recalcitrant because desiccation sensitivity was not directly assessed. Using the triphenyl tetrazolium chloride (TTC) viability test, most of the seeds of the 12 species seemed to be of good quality. Results of the TTC test for seed viability were similar to results obtained v using direct germination for most species. Results of flotation test for seed viability were different from the results obtained using direct germination for most spcies. The pre-treatment which achieved the highest germination percentage in almost all the seed types was cracking the outer coverings. Cracking pre-treatment appeared to be efficient in enhancing the removal of some substances which might inhibit germination of seeds. Hot water and acid pre-treatments frequently reduced germination. Growth of young seedlings was assessed in terms of stem diameter, height, and leaf area under sun and shade. Seedling growth in terms of stem diameter and height of most species did not show any significant difference. One of the few species which showed statistically significant differences in stem diameter growth was Ekebergia capensis. It was found that 3 out of lO of the species showed statistically significant differences in height growth. Two of the statistically significant differences in height occured on seedlings in the sun while one had statistically significant difference in the 40% shadecloth while 7 did not. Significant differences in leaf area occured on 7 out of lO species. Of these, 4 species had higher growth in the shade than in the sun while 3 had higher growth in the sun than in the shade. Generally, it appears that young developing seedlings establish themselves well under shade environment; this could be because most of the species used in this study are forest species. / Thesis (M.Sc.)-University of Natal, 1996.

Momordica foetida Schum. & Sond. (Cucurbitaceae), locally known as iNtshungu, is widely used by the Zulu people of Natal-KwaZulu for the treatment of a variety of ailments. The dried leaves leaves and stems of this plant was subjected to soxhlet extraction by refluxing with hexane, chloroform and methanol successively. Thin layer chromatography of the chloroform extract of the leaves revealed a multiplicity of compounds. The chloroform extract was further partitioned with sodium hydroxide resulting in an organic and aqueous phase. The organic phase, containing extract A, afforded two compounds, viz. compounds 1 and 2. The basic aqueous fraction was neutralised and re-extracted with chloroform to give extract B, affording five compounds, viz. compounds 3,4,5,6 and 7. Structural elucidation was accomplished by techniques such as IH and 13C NMR spectroscopy, HETCOR, COSY, FTIR and High Resolution Mass Spectrometry. Compounds 1 and 2 were identified as cucurbitane triterpenoids known as momordicines which had been previously discovered in the related species of this plant, Momordica charantia L. The remaining five compounds were identified as novel compounds, although natural derivatives of compounds 6 and 7 had been isolated previously from Momordica charantia L. Compounds 3-7 were each isolated as an epimeric mixture but it was possible to select the resonances corresponding to the major epimer. These five epimers were respectively identified as 5, 19-epoxy-19(R)-hydroxy-25-methoxy-5β- cucurbita-6,23-diene-3β-ol [102], 5,19-epoxy-19(R),25-dihydroxy-5β-cucurbita- 6,23-diene-3β-ol [103], 5,19-epoxy-19(R)-methoxy-25-hydroxy-5β-cucrbita- 6,23-diene-3β-ol [104], 5,19-epoxy-25-methoxy-5β-cucurbita-6,23diene- 3β-ol [105] and 5,19-epoxy-19(R),25-dimethoxy-5β-cucurbita-6,23diene- 3β-ol [106]. Appropriate reactions were performed, where possible, on the compounds isolated in order to confirm their identity. / Thesis (M.Sc.)-University of Natal, Durban, 1994.

This study was undertaken as a result of the occurrence of a large number of deaths among the local Black population from the use of herbal medicines prepared from the rootstock of Callilepis laureola known to the Zulus as impila. The salient clinico-pathological features in these cases were hypoglycaemia, centrilobular zonal liver necrosis and acute renal tubular necrosis. The purpose of this study was to investigate fully the clinical, biochemical and pathological aspects of the toxicity produced by Callilepis laureola (impila). The first part of the investigation consisted of an assessment of all cases of death due to acute liver necrosis diagnosed by necropsy at King Edward VIII Hospital, Durban. A review of clinical and necropsy records of 21687 consecutive post-mortems performed on Black patients during a 20 year period showed that acute liver necrosis was the major contributing cause of death in 447 patients. In 263 cases the hepatic lesion was centri lobular zonal necrosis with associated acute tubular necrosis (Group A); while in 184 cases the I iver necrosis was of the massive or submassive type (Group B). A comparative assessment of these two groups as regards necropsy prevalence, age and sex distribution and the clinical, biochemical and pathological findings was undertaken. This study shows that the combination of hypoglycaemia, centri lobular zonal liver necrosis and acute renal tubular necrosis due to Callilepis laureola (impila) poisoning is a distinct clinico-pathological entity and differentiates this group from cases of acute massive and submassive liver necrosis resulting in most cases from fulminant viral hepatitis. In the search for the toxic components of the root of Callilepsis laureola several compounds were isolated. These were atractyloside, carboxyatractyloside, two thymol related oils and a carbohydrate. The thymol related oils as well as the carbohydrate were found to be non-toxic in laboratory rats. The crude methanol extract of the root of Callilepsis laureola, when injected intraperitoneally into laboratory rats, produced centrilobular zonal liver necrosis and acute renal tubular necrosis, the lesions identical to those seen in patients who had died after intake of impila prescribed by witchdoctors and other dispensers of herbal medicines. On the other hand intraperitoneal injections of the purified compound atractyloside caused acute renal tubular necrosis and hypoglycaemia in laboratory rats but failed to produce liver necrosis. Carboxyatractyloside also failed to cause liver necrosis. This indicated that there may be at least two toxins contained in the rootstock of Callilepsis laureola, one causing the liver lesion and the other (atractyloside) causing nephrotoxicity and hypoglycaemia. Repeated attempts at isolating the hepatotoxin have failed; the liver toxin or toxins being lost during the process of extraction and purification. Identification of the hepatotoxin awaits further investigation. It is possible that the liver necrosis may be caused by a metabolite or that it may be a synergistic effect of two or more compounds. / Thesis (MD)-University of Natal, 1983.

This research work is about rituals practice, with specific reference to burning of impepho (an indigenous African Plant) and how this practice excludes women in general. Impepho is an indigenous African plant that, once dried, is burnt in order to communicate with one’s ancestors. Impepho is well-known to the majority of Sub Saharan Africans as it is used to communicate with their ancestors and it is also used by traditional healers to communicate with the deceased. It is used in various ceremonies, as well as in traditional feasts, when chickens, goats or cows are offered to the ancestors. The aim of this study was to find out why women are not allowed to burn impepho. Times have changed to the point that there are now many Zulu households that are headed by women, and these women do in fact burn impepho in order to communicate with their ancestors. This then is the pertinent question: do these women’s requests or prayers go unheard by the ancestors? The study aims to find out from the female participants if they burn impepho in their home or if they still adhere to this male constructed mentality that women should not burn impepho. / Thesis (M.A.)-University of KwaZulu-Natal, Durban, 2012.

In response to an increase in forest destruction, nature conservation agencies in South Africa are beginning to introduce innovative and integrated conservation strategies. This study was established to provide information on resource use in Gxalingenwa State Forest (GSF) and KwaYili State Forest (KSF) on which such conservation initiatives might be based. Local villagers in the area depend on a mix of forest products to meet their livelihood needs, including for example heating, cooking, fencing, building, craft-work and medicine. Large quantities (102.072 tonnes) of plant resources are removed from the GSF and KSF annually by traditional healers and commercial gatherers with commercial gatherers responsible for the largest proportions (88.1 %). However, the total market value of medicinal products to the resource users is higher than the local value, implying that the resource users are not harnessing the full potential of the forest products. Fuelwood, building, fencing and carving also account for a large bulk of materials harvested from the indigenous forests annually. Among several species, Podocarpus falcatus is the most preferred and harvested tree for fuelwood, fencing and building. Despite its high recruitment level, it shows a very unstable population structure. Calodendrum capense is debarked for medicinal uses. It is used locally and its current harvest by commercial gatherers is driven by a huge demand from the 'muti' markets. In KSF, C. capense generally has a low density but also has a relatively good recruitment rate when compared with an unexploited forest. However, the harvesting of immature stems pose a threat to this species. / Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 1999.