Thesis (Ph.D (Plant Physiology) --University of Limpopo, 2006 / Refer to document / National Research Foundation and ARC (Nelspruit)

This quantitative study seeks to determine the impacts of harvesting three plant species traditionally used for wound healing during circumcision. Three localities where these plant species occur have been identified. The population size for each species was determined and an assessment of the extent of harvesting was determined through repeated assessment of marked plants. A significant harvest of these species resulted in the unsustainable use of our natural resources. Out of 25 Boophone disticha plants marked, only one plant was remaining after two circumcision seasons. The Brunsvigia grandiflora and Scadoxus multiflorus populations monitored disappeared completely, with no single marked plant found after two circumcision seasons. Growth rates of wild populations of Boophone disticha and cultivated Brunsvigia grandiflora and Scadoxus multiflorus plants were determined. The seedling bulbs of Brunsvigia grandiflora grew significantly more slowly at less than 0.6 cm per year, while Scadoxus multiflorus grew faster at over 1 cm per year. A model for population dynamics of the three plant species was designed which showed that the plants are being harvested before they even flower. It is therefore recommended in this study that a conservation plan for these plant species must be done to save the little that is left in the wild before they become critically endangered.

The post-harvest physiology of nine frequently used indigenous southern African medicinal plants was investigated, in particular the effects of storage time and accelerated ageing on the biological activity and chemical constituents of these plants. Water, ethanol and hexane extracts of fresh plant material as well as material that had been stored in dry form in paper bags at room temperature for 90 days (short-term) were tested. Three bioassays, the COX-1 anti-inflammatory assay, nematode anthelmintic assay and minimum inhibitory concentration anti-bacterial assay, were used to determine biological activity. Thin layer chromatography of all the plant extracts were used to determine changes in chemical composition. The plants tested were Alepidea amatymbica Eckl. & Zeyh., Leonotis leonurus (L.) R. Br., Drimia robusta Bak., Vernonia colorata (Willd.) Drake, Scilla natalensis Planch., Eucomis autumnalis (Mill.) Chitt. subsp. autumnalis, Bowiea volubilis Harv. ex Hook. f., Helichrysum cymosum (L.) D. Don and Siphonochilus aethiopicus (Schweinf.) B. L. Burtt. Only those plants, which are known to exhibit a particular biological activity either traditionally or scientifically, were tested in the relevant bioassays. Of the plant extracts tested for anthelmintic activity only the water extracts showed activity and very little change in activity was observed after storage. Of the plant extracts tested for anti-inflammatory activity the ethanol extracts generally yielded highest activity. S. natalensis and B. volubilis both showed an increase in cyclooxygenase inhibition (anti-inflammatory) activity after storage whereas S. aethiopicus, H. cymosum, D. robusta and V. colorata showed a loss in activity after storage. The anti-inflammatory activity of E. autumnalis did not change. The water extracts of plants tested for antibacterial activity showed no activity, whereas the ethanol extracts generally showed an increase in activity. The TLC fingerprints indicated that there was chemical break-down during storage in certain species. These corresponded to the changes in biological activity. Alepidea amatymbica, Eucomis autumnalis, Helichrysum cymosum, Leonotis leonurus, Siphonochilus aethiopicus and Vernonia colorata were investigated further as to the effect of one year's storage (long-term storage) on their chemical composition and biological activity. Similar trends to that of the 90-day storage were observed. Activity gained in plants that were stored for 90 days was retained after a year of storage. Elevated temperature and humidity (55 C and 100% relative humidity) were used to accelerate the ageing process of Alepidea amatymbica, Leonotis leonurus and Vernonia colorata plant material. Again changes in the chemical composition and biological activity were observed, and the extent of these changes was greater than those in the stored material. The compounds responsible for the cyclooxygenase inhibition in the ethanolic extracts of Alepidea amatymbica leaf material appear to be stable and were not affected by the conditions of the accelerated ageing procedure (55 C and 100% humidity for seven days), but the root material lost activity, as did the leaf material of Leonotis leonurus. The leaf material of Vernonia colorata showed a slight (8%) increase in cyclooxygenase inhibition activity. The response of the plant material to accelerated ageing with respect to antibacterial activity varied with plant species. Alepidea amatymbica root material and Vernonia colorata leaf material appear to be stable whereas the other plant materials lost activity after prolonged (25 days) ageing. / Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 2003.

MSc (Botany) / Department of Botany / See the attached abstract below

Text in English / The introduction of the New Growth Path (NGP) and the New Industrial Policy Framework (NIPF) have created an opportunity for the industrialisation of indigenous medicinal and aromatic plants (MAPs Amarula (Sclerocarya birrea), Buchu (Agathosma betulina), and Pelargonium (Pelargonium sidoides) for job creation and economic development in South Africa. The aim is to create a locally sustainable industry which creates jobs as well as improvement of the balance of payments. The National Growth Plan highlights some of the opportunities for industrialization as well as creation of decent jobs. There is increasing pressure on the harvesting of wild indigenous medicinal and aromatic plants (MAPS). The establishment of a local pharmaceutical and nutraceutical industry for processing MAPS remains a challenge in South Africa and many low income countries. The objective of this study was to assess the challenges and their impact looking at particular species, Amarula, Buchu and Pelargonium by using structured focus group interviews with users in communities and businesses in KwaZulu Natal Province, Eastern Cape and the Western Cape. More data/information was also collected from key stakeholder companies including desk-top reviews. Data/information was analysed using the SPSS computer programme and the Atlas software to summarize data and the results. Graphs and tables were used where necessary. The qualitative research reported on some qualitative assessments and challenges facing the establishment of medicinal and aromatic plants in South Africa. Comparative findings from BRICS were also reported. The results of the study indicated that there is continuous exploitation of several medicinal plant species, for plant trade, from the wild and substantial loss of their habitat. The research identifies a number of challenges such as: poor standards for raw materials, lack of research and development linking industry driven revenues, demand exceeding supply, regulatory risk, community risk, lack of understanding of judicious agronomic practices, ethical challenges, liquidity risk as well as political instability fail to attract foreign direct investments. The research concludes that for the establishment of a viable local pharmaceutical industry, iii beverage industry and nutraceutical industry with sustainable harvesting, there are serious hegemonic challenges which will require multi-stakeholder analysis. However, for the South African (SA) industry to be competitive, detailed feasibility studies need to be done comparing SA with other BRICS countries. There is also a need for the Research and Development to be strengthened. It must also be linked into industrial development in the industry. Furthermore there is a need to initiate the incentivizing of the pharmaceutical manufacturing to lower the cost of setting up the businesses in the industry and lessen the need to harvest from South African forests. Furthermore there is a need for programmes of production so that key species are given opportunity for cultivation and the attention they deserve to preserve these depleting resources. / Agriculture and  Animal Health / M.Sc. (Agriculture)

Text in English / The introduction of the New Growth Path (NGP) and the New Industrial Policy Framework (NIPF) have created an opportunity for the industrialisation of indigenous medicinal and aromatic plants (MAPs Amarula (Sclerocarya birrea), Buchu (Agathosma betulina), and Pelargonium (Pelargonium sidoides) for job creation and economic development in South Africa. The aim is to create a locally sustainable industry which creates jobs as well as improvement of the balance of payments. The National Growth Plan highlights some of the opportunities for industrialization as well as creation of decent jobs. There is increasing pressure on the harvesting of wild indigenous medicinal and aromatic plants (MAPS). The establishment of a local pharmaceutical and nutraceutical industry for processing MAPS remains a challenge in South Africa and many low income countries. The objective of this study was to assess the challenges and their impact looking at particular species, Amarula, Buchu and Pelargonium by using structured focus group interviews with users in communities and businesses in KwaZulu Natal Province, Eastern Cape and the Western Cape. More data/information was also collected from key stakeholder companies including desk-top reviews. Data/information was analysed using the SPSS computer programme and the Atlas software to summarize data and the results. Graphs and tables were used where necessary. The qualitative research reported on some qualitative assessments and challenges facing the establishment of medicinal and aromatic plants in South Africa. Comparative findings from BRICS were also reported. The results of the study indicated that there is continuous exploitation of several medicinal plant species, for plant trade, from the wild and substantial loss of their habitat. The research identifies a number of challenges such as: poor standards for raw materials, lack of research and development linking industry driven revenues, demand exceeding supply, regulatory risk, community risk, lack of understanding of judicious agronomic practices, ethical challenges, liquidity risk as well as political instability fail to attract foreign direct investments. The research concludes that for the establishment of a viable local pharmaceutical industry, iii beverage industry and nutraceutical industry with sustainable harvesting, there are serious hegemonic challenges which will require multi-stakeholder analysis. However, for the South African (SA) industry to be competitive, detailed feasibility studies need to be done comparing SA with other BRICS countries. There is also a need for the Research and Development to be strengthened. It must also be linked into industrial development in the industry. Furthermore there is a need to initiate the incentivizing of the pharmaceutical manufacturing to lower the cost of setting up the businesses in the industry and lessen the need to harvest from South African forests. Furthermore there is a need for programmes of production so that key species are given opportunity for cultivation and the attention they deserve to preserve these depleting resources. / Agriculture and  Animal Health / M. Sc. (Agriculture)

MSc (Microbiology) / Department of Microbiology / BACKGROUND: Medicinal plants form an important part of the Southern African cultural heritage. Indigenous populations, for example the Vha-Venda people, tend to use medicinal plants in formulations rather than western medicines for health and survival. In order to certify and give scientific credibility to the use of medicinal plants formulations used by Vha-Venda people for the treatment of diseases, several assays were carried out. The present study was aimed at assessing phytochemical content, antimicrobial, antioxidant and cytotoxic activities of four indigenous Venda medicinal plants in a formulation and compare their activity with each plant used individually. METHODS: Peltophorum africanum (roots), Pterocarpus angolensis (bark), Terminalia sericea (roots) and Ximenia caffra (roots) were collected from the Thohoyandou area. The collected plant parts were extracted with methanol and water respectively. Individual plant extracts and Five designed formulations were tested for their antimicrobial activity against Staphylococcus aureus ATCC 25923 (Methicillin Resistant), Staphylococcus aureus ATCC 33591(Methicillin Susceptible), beta lactamase producing Klebsiella pneumonia (ATCC 700603) and extended spectrum beta lactamase producing E. coli (ATCC 35218), four clinical isolates of Candida spp and Cryptococcus neoformans using the Broth dilution method. Minimum bactericidal concentration (MBC) of the extracts was determined by culturing the contents of minimum inhibitory concentration (MIC) on nutrient agar. Similarly, minimum fungicidal concentration (MFC) was also determined by culturing contents of MIC in sabouraud dextrose agar (SDA). Extracts were further assessed for their total phenolic content, total flavonoid content and Qualitative phytochemical analysis. The antioxidant ability of the plants extracts and formulations to scavenge free radical DPPH was also determined. The plant formulations were assessed for their anti-HIV activity using the reverse transcriptase colorimetric assay kit. Cytotoxicity against human lymphatic endothelial cells (HLEC) was determined using MTT assay. RESULTS: Methanolic and aqueous extracts of T. sericea exhibited the best antifungal and antibacterial activities whilst P. angolensis and X. caffra showed poor activities. Methanolic plant formulations showed good activities compared to aqueous formulations. However, Fractional Inhibition Concentration Index showed that there was 1 synergistic interaction, 25 additive interactions and 14 antagonistic interactions between the plant extracts. The methanolic formulation 3 showed the best overall phenolic content at 11.85±0.109 mgGAE/g whilst aqueous X. caffra extract showed the least content at 4.546±0.104 mgGAE/g. Higher total flavonoid contents were seen in methanolic formulation 4 at 2.75±0.02 mgQE/g. Qualitative phytochemical analysis revealed the presence of flavonoids, phenolics, terpenoids, tannins, saponins and steroids in 80% of the tested plant extracts and formulations. All plant extracts and formulations exhibited good antioxidant activity against DPPH. The methanolic formulation showed the best antioxidant activity with IC50 of 0.094 ± 0.33μg/ml. For anti- HIV inhibition, all formulations at 200μg/ml exhibited higher percentage of HIV-1 reverse transcriptase inhibition with methanolic mixture 3 being the best overall at 97.5% activity whilst aqueous mixture5 was the least active with 63.03% inhibition activity. Moreover, the best anti-HIV activity at 100μg/ml was exhibited by methanolic mixture 3 at 71% inhibition. Furthermore, aqueous X. caffra, mixture 2 inhibited 26% and 51% at 12.5mg/ml and 3.125mg/ml respectively. Peltophorum africanum and mixture 5 inhibited 34%, 54% and 43% at 3.125mg/ml, 6.25mg/ml and 12.5 mg/ml respectively of Human Lymphatic Endothelial cells growth. CONCLUSIONS: The results from the study indicated that most of the commonly used traditional medicinal Plants in the Venda region when mixed together have merit for use in traditional medical practice as they have shown good antimicrobial activities, good antioxidant xviii activities, good phytochemical activities and good cell proliferation activity. However some formulations showed antagonistic interaction against bacteria. Some Individual medicinal plants showed toxicity at higher concentrations against immune cells. Whereas formulations promoted cell proliferation, therefore, the use of such individual plants in the treatment of infections should be highly monitored as they may pose a health threat to normal immune cells. Generally, plants are potential pharmacological agents which needs to be preserved and harvested with care. / NRF

MSCAGR (Plant Production) / Department of Plant Production / Indigenous trees play important roles in livelihoods for rural communities. Sclerocarya birrea and Berchemia discolor are indigenous in Africa and are used in rural communities for food and livestock feed, as well as for medicinal and construction purposes. These trees are subject to attack by insects, which can result in lower tree productivity. However, there is no documented information about insects found on both tree species in South Africa. This study investigated the seasonal abundance and diversity of insects on S. birrea and B. discolor in Tshikundamalema Area, Limpopo Province, South Africa. Five trees were selected for each of the two tree species at two sampling sites with different vegetation cover, one site mainly the woodland bushveld while the other site was savannah grasslands. Canopy fogging was used to sample insects. Insect samples were collected at one time point for each of the seasons: summer (February), autumn (May), winter (July) and spring (November). Insects were identified to morphospecies and Simpson’s diversity index was used to compare insect diversity on both trees. Analysis of variance was used to compare the abundance of insects across seasons. The most abundant insects were collected from Coleoptera, followed by Hemiptera, Hymenoptera, Diptera, Lepidoptera and Orthoptera. A total of 3259 insects belonging to the six Orders were collected. All specimens belonging to Coleoptera, Hemiptera and Hymenoptera (3216 in total) were identified to Family level, with a total of 97 morphospecies, belonging to 19 Families. Insects from Diptera, Lepidoptera and Orthoptera were not identified further due to their low numbers. The abundance and diversity of insects were affected by seasons, sites and tree species. The number of insects was high during the spring season with 1782 insects, and summer coming second with 1104 individuals, followed by autumn (238 insects), then winter (92). B. discolor sampled for a great number of insects (1741) as compared to S. birrea (1475). The woodland bushveld (1924 insects) surpassed the savannah grassland (1292 insects) site in terms of the insect numbers sampled. / NRF

See the attached abstract below

MSCAGR ( Plant Production) / Many high valued tree species of medicinal significance in the Limpopo Province, South Africa exhibit seed dormancy, and also contain aromatic oils which inhibit rooting of their stem cuttings. These plant species are under pressure due to human over-exploitation. The main objective of this study was to investigate effects of rooting hormones on the rooting ability that will help in domesticating some of the selected high valued medicinal plants, Elaeodendron transvaalense (bushveld saffron), Brackenridgea zanguebarica (yellow peeling plane), and Warburgia salutaris (pepper-bark tree). Stem cuttings of these plant species were prepared and treated with various concentrations (500, 1000 and 2000 ppm) of IBA, IAA and NAA in different growth media (Natural soil, farm soil and hygromix) at a nursery house. 180 experimental units were sown and arranged in Randomized Complete Block Design (RCBD), each treatment replicated five times and then monitored for a period of three months. Data were only obtained from Brackenridgea zanguebarica as other species dried up two weeks after sprouting. The two variables measured from the experiments were sprouted stems and number of leaves. The data obtained were subjected to analysis of variance and least significant difference (LSD) at 5% probability level was used to compare treatment using STATISTICA software analysis package. The hormone, hormone concentration, growth media and their interactions had effect on sprouted stems and number of leaves produced on Brackenridgea zanguebarica cuttings, with no record of rooting ability. IBA (500 ppm and 1000 ppm) and control (without rooting hormone) showed high significant results with natural soil and farm soil in terms of leaf production compared to the hygromix, which is significantly lower from others. IBA at the various concentrations (500, 1000 and 2000 ppm) and the control gave the highest percentage sprouted stem on both natural soil and farm soil as compared with other hormones at the same / NRF