Sclerocarya birrea (marula, Anacardiaceae) is a highly-valued indigenous tree in most parts of sub-Saharan Africa because of its medicinal and nutritional properties. The marula tree is adapted to the semi-arid conditions that characterise most parts of sub-Saharan Africa and renders them unsuitable for conventional crop agriculture. The unique nutritional properties of marula and its high tolerance to dry conditions provide opportunities for its development into a plantation crop. On the other hand, the demand for marula plant parts, mainly the bark and roots as medicinal remedies, poses a great threat to wild populations. In the long term, the growing demand of marula products in the food, pharmaceutical and cosmetic industries will not be sustainable from wild populations alone. Plant tissue culture technologies can be useful for in vitro manipulation and mass propagation of the plant in the process of domestication and conservation. The aims of the project were to determine the optimum conditions for seed germination, in vitro propagation and plant regeneration, and to evaluate the potential bioactivity of secondary metabolites from its renewable plant parts as an alternative option in the conservation of S. birrea. An ex vitro seed germination study indicated that after-ripening and cold stratification are critical factors. Cold stratification (5 °C) of marula nuts for 14 days improved germination (65%) as compared to non-stratified nuts (32%). Direct shoot organogenesis was achieved from leaf explants through the induction of nodular meristemoids on Murashige and Skoog (MS) (1962) medium and woody plant medium (WPM) supplemented with 6-benzyladenine (BA) in combination with naphthalene acetic acid (NAA), indole-3-butryric acid (IBA) and indole-3-acetic acid (IAA). Induction of nodular meristemoids from 86% of the leaf cultures was achieved on a MS medium with 4.0 ìM BA and 1.0 ìM NAA. High levels (78–100%) of induction were also achieved on WPM with different concentrations of BA (1.0–4.0 ìM) and IBA (1.0–4.0 ìM). The highest conversion of nodular meristemoids into shoots on MS initiation medium was only 22% for 4.0 ìM BA and 1.0 ìM NAA. This was improved to 62% when nodular clusters were cultured in MS liquid medium. Histological studies revealed high numbers of unipolar meristematic buds developing from globular nodules. These embryo-like structures have in the past been mistaken for true somatic embryos. The initiation of high numbers of nodular meristemoids per explant provides potential for automated large-scale clonal propagation in bioreactors, in vitro phytochemical production and the development of synthetic seed technology, similar to somatic embryogenesis. Plant regeneration through nodule culture has potential for application in mass micropropagation and plant breeding of S. birrea. Adventitious shoot and root induction are important phases in micropropagation. Plant growth regulators play an important role in these developmental processes, and the type and concentration used have major influences on the eventual organogenic pathway. Three auxins (IAA, IBA and NAA) and four aromatic cytokinins (6-benzyladenine, meta-topolin, meta-topolin riboside, and meta-methoxytopolin riboside) were evaluated for their potential to induce adventitious shoot and root formation in S. birrea shoots, hypocotyls and epicotyls. Among the evaluated cytokinins, the highest adventitious shoot induction (62%) was achieved on MS medium supplemented with meta-topolin (8.0 ìM). The lowest adventitious shoot induction (2.5%) was obtained on MS basal medium containing 2.0 ìM meta-methoxytopolin riboside. The highest adventitious shoot induction for hypocotyls was 55% on MS medium supplemented with 8.0 ìM meta-topolin. For the tested auxins, IBA induced adventitious rooting in 91% of shoots at a concentration of 4.0 ìM after 8 weeks in culture. However, the in vitro rooted plants only survived for two weeks when transferred ex vitro. A temperature of 25 °C and 16-h photoperiod were optimum for adventitious root induction. Stomatal density (number per mm2) on the abaxial leaf surfaces was higher for the 16-h photoperiod treatment (206.6 ± 15.28) compared to that for a 24-h photoperiod (134.6 ± 12.98). Normal mature stomata with kidney-shaped guard cells and an outer ledge over the stomatal pore were observed for in vitro plants growing under a 16-h photoperiod. Total phenolic content, proanthocyanidins, gallotannins, flavonoids, and antioxidant activities of S. birrea methanolic extracts were evaluated using in vitro bioassays. Methanolic extracts of the young stem bark and leaves contained high levels of these phytochemicals. Sclerocarya birrea young stem extracts contained the highest levels of total phenolics (14.15 ± 0.03 mg GAE g-1), flavonoids (1219.39 ± 16.62 ìg CE g-1) and gallotannins (246.12 ± 3.76 ìg GAE g-1). Sclerocarya birrea leaf extracts had the highest concentration of proanthocyanidins (1.25%). The EC50 values of the extracts in the DPPH free radical scavenging assay ranged from 5.028 to 6.921 ìg ml-1, compared to ascorbic acid (6.868 ìg ml-1). A dose-dependent linear curve was obtained for all extracts in the ferric-reducing power assay. All the extracts exhibited high antioxidant activity comparable to butylated hydroxytoluene based on the rate of â-carotene bleaching (89.6 to 93.9%). Sclerocarya birrea provides a source of secondary metabolites which have potent antioxidant properties and may be beneficial to the health of consumers. Sclerocarya birrea young stem and leaf ethanolic extracts exhibited high bioactivity (MIC < 1.0 mg ml-1) against both Gram-positive (Bacillus subtilis and Staphylococcus aureus) and Gram-negative (Escherichia coli and Klebsiella pneumoniae) bacteria. The highest activity (MIC = 0.098 mg ml-1 and total activity = 1609.1 ml g-1) was recorded for young stem extracts against B. subtilis. The highest activity (MIC = 1.56 mg ml-1 and MFC = 1.56 mg ml-1) in the antifungal assay against Candida albicans was observed for young stem ethanolic extracts. Sclerocarya birrea extracts had moderate acetylcholinesterase (AChE) inhibition activity. The dichloromethane (DCM) and methanol (MeOH) fractions exhibited dose-dependent acetylcholinesterase inhibitory activity. The highest AChE inhibitory activities were from leaves (DCM fraction, IC50 = 0.1053 mg ml-1) and young stems (MeOH fraction, IC50 = 0.478 mg ml-1). High inhibitory activity against cyclooxygenase (COX-1 and COX-2) enzymes was observed. All extracts and fractions showed high COX-1 enzyme inhibition (90.7-100%). Petroleum ether (PE) and dichloromethane fractions also exhibited high inhibition against COX-2 enzyme (77.7-92.6%). The pharmacological activities observed suggest that S. birrea renewable plant parts (leaves and young stems) provide a substantial source of medicinal secondary metabolites. Based on these results, plant part substitution can be a practical conservation strategy for this species. / Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2009.

The crisis of newly emerging diseases and the resistance of many pathogens to currently used drugs, coupled with the adverse side-effects of many of these drugs have necessitated the continuous search for new drugs that are potent and efficacious with minimal or no adverse side-effects. The plant kingdom is known to contain many novel biologically active compounds, many of which could potentially have a higher medicinal value when compared to some of the current medications. Indeed, the use of plants in traditional medicine, especially in African communities, is gaining more importance due to their affordability and accessibility as well as their effectiveness. Exponential population growth rates in many developing countries has resulted in heavy exploitation of our plant resources for their medicinal values. In addition, plant habitat destruction arising from human developmental activities has contributed to the fragmentation or loss of many plant populations. Owing to these factors, many plant species with horticultural and/or medicinal potential have become either extinct or are threatened with extinction. These threatened species cut across different taxonomic categories including shrubs, trees and succulents. Without the application of effective conservation strategies, the medicinal and/or horticultural potential of such threatened species may be totally lost with time. The extinction of such species could lead to the loss of potential therapeutic compounds and/or genes capable of being exploited in the biosynthesis of new potent pharmaceutical compounds. / Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2009.

The rhizomes of Alepidea amatymbica and Alepidea natalensis are used for medicinal purposes. Because of the increase in demand for these plants the species is becoming scarce. As the seed biology of neither species is well defined, conditions as well as treatments required for optimum germination and vigour were studied. Seeds were exposed to various physical factors such as varying light and temperature conditions and cold stratification, sowing depth and seed storage. The effects of smoke-water, butenolide (3-methyl-2H-furo [2, 3-c] pyran-2-one) a novel smoke compound and chemical substances (gibberellins, kinetin and KNO3) were also tested in order to improve seed germination. Alepidea amatymbica and A. natalensis achieved the highest seed germination (72.5% and 80%, respectively) at 25 °C under a 16 h photoperiod with a mean germination time (MGT) of 18 and 12 days, respectively. Phytochrome studies showed that A. natalensis requires light for germination. Cold stratification (5 °C) for 14-28 days significantly improved the percentage germination of both species (> 90%) compared to non-stratified seeds (control) at 25 °C under a 16 h photoperiod. Sowing A. amatymbica and A. natalensis seeds at a depth of 0.5 cm resulted in higher percentage germination compared to 2.5 cm. The highest emergence rate for A. amatymbica was 40% at a sowing depth of 0.5 cm and the lowest emergence rate was 3% at 2.5 cm. Six months storage of A. natalensis seeds at room temperature (25 ± 2 °C) showed maximum germination (99%) with a MGT of 9 days. Smoke-water treatment of A. amatymbica seeds significantly enhanced germination from 72% to 91%. Smoke and butenolide at 10 °C and 25 °C promoted germination of A. natalensis seeds in a 16 h photoperiod. Smokewater application significantly improved both germination and seedling vigour of A. natalensis. GA3 (10-8 M) was the best treatment for achieving maximum percentage germination of A. natalensis seeds. Antibacterial (two Gram-positive bacteria: Bacillus subtilis, Staphylococcus aureus and two Gram-negative bacteria: Escherichia coli, Klebsiella pneumoniae), antifungal (Candida albicans), anti-inflammatory (COX-1 and -2) and genotoxicity tests (Ames test) were carried out on petroleum ether (PE), dichloromethane (DCM), 80% ethanol (EtOH) and water extracts of the two Alepidea species. Water extracts of A. natalensis rhizomes exhibited high activity (MIC values of 0.78 mg/ml) against the four bacterial strains. High activity was also observed in the PE and DCM leaf extracts of the same plant against the Gram-positive bacteria. The PE and DCM extracts of A. amatymbica rhizomes exhibited the best activity (MIC values of 0.39 mg/ml) against Bacillus subtilis. The rest of the extracts showed low activity (MIC values >1 mg/ml). All the extracts showed activity against Candida albicans, with A. natalensis leaf extracts exhibiting the highest antifungal activity with MIC values of 0.88, 0.20 and 0.78 mg/ml for PE, DCM and EtOH, respectively. EtOH extracts had inhibition less than 40% for both A. natalensis and A. amatymbica. All the PE extracts showed higher inhibitory activity for COX-2 than for COX-1. PE and DCM extracts had percentage inhibitions above 70% in both COX-1 and COX-2 assays. The Ames test for genotoxicity revealed that none of the plant extracts were genotoxic to the Salmonella TA98 tester strain. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2009.

Traditional medicine in South Africa is part of the culture of the people and has been in existence for a long-time. Although animal components form part of the ingredients used, plant material constitutes the major component. South Africa is endowed with vast resources of medicinal and aromatic plants which have been employed for treatment against various diseases for decades. A large number of South Africans still depend on traditional medicine for their healthcare needs due to its affordability, accessibility and cultural importance. Helminth infections are among the variety of diseases treated by traditional healers. These infections are regarded as neglected tropical diseases (NTDs) due to their high prevalence among the economically disadvantaged living in rural areas in different regions of the world. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2009.

Este trabalho é o resultado de uma pesquisa exploratória por meio de metodologia qualitativa, de análise documental, da Política Nacional de Plantas Medicinais e Fitoterápicos com base no modelo dos Fluxos Múltiplos de John Kingdon para análise de políticas públicas. Foi efetuada revisão dos modelos de análises de políticas públicas e analisados os antecedentes da formação da agenda das políticas públicas farmacêuticas e o processo de formação da agenda e formulação da Política referida. Foram identificados os atores envolvidos, os conceitos, os problemas e as soluções apresentados, o fluxo político que as colocou na agenda governamental e seu processo de formulação, assim como os empreendedores e a ocorrência de janelas de oportunidades. E assim objetivando avaliar as possibilidades de sua implementação em relação as suas diretrizes de desenvolvimento científico e tecnológico no estado do Rio Grande do Sul, as dicotomias e ambigüidades presentes no processo. A partir da análise discutiram-se aspectos a superar e aperfeiçoar a fim de que sejam alcançados seus propósitos. / This work is the result of a exploratory research, by qualitative methodology, documental analysis, of National Policy of Medicinal Plants and Phytomedicines, based on Multiple Streams Model, by John Kingdon, for public policies analyses. It was made a review of policy analysis models and analyzed the preceding facts of agenda setting of pharmaceuticals public policies and the agenda setting and formulation process of the policy. The actors involved, the concepts, the problems and solutions presented, the political stream of governmental agenda and its formulation process, also the policy entrepreneurs, and policy windows. So, evaluating the possibilities of its implementation, relative to the scientific and technological development in the state of Rio Grande do Sul, the dichotomies and ambiguities in the process. To assume that analysis, we discussed aspects to overcome and improve with the intention to reach their purposes.

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)

Este trabalho é o resultado de uma pesquisa exploratória por meio de metodologia qualitativa, de análise documental, da Política Nacional de Plantas Medicinais e Fitoterápicos com base no modelo dos Fluxos Múltiplos de John Kingdon para análise de políticas públicas. Foi efetuada revisão dos modelos de análises de políticas públicas e analisados os antecedentes da formação da agenda das políticas públicas farmacêuticas e o processo de formação da agenda e formulação da Política referida. Foram identificados os atores envolvidos, os conceitos, os problemas e as soluções apresentados, o fluxo político que as colocou na agenda governamental e seu processo de formulação, assim como os empreendedores e a ocorrência de janelas de oportunidades. E assim objetivando avaliar as possibilidades de sua implementação em relação as suas diretrizes de desenvolvimento científico e tecnológico no estado do Rio Grande do Sul, as dicotomias e ambigüidades presentes no processo. A partir da análise discutiram-se aspectos a superar e aperfeiçoar a fim de que sejam alcançados seus propósitos. / This work is the result of a exploratory research, by qualitative methodology, documental analysis, of National Policy of Medicinal Plants and Phytomedicines, based on Multiple Streams Model, by John Kingdon, for public policies analyses. It was made a review of policy analysis models and analyzed the preceding facts of agenda setting of pharmaceuticals public policies and the agenda setting and formulation process of the policy. The actors involved, the concepts, the problems and solutions presented, the political stream of governmental agenda and its formulation process, also the policy entrepreneurs, and policy windows. So, evaluating the possibilities of its implementation, relative to the scientific and technological development in the state of Rio Grande do Sul, the dichotomies and ambiguities in the process. To assume that analysis, we discussed aspects to overcome and improve with the intention to reach their purposes.

Este trabalho é o resultado de uma pesquisa exploratória por meio de metodologia qualitativa, de análise documental, da Política Nacional de Plantas Medicinais e Fitoterápicos com base no modelo dos Fluxos Múltiplos de John Kingdon para análise de políticas públicas. Foi efetuada revisão dos modelos de análises de políticas públicas e analisados os antecedentes da formação da agenda das políticas públicas farmacêuticas e o processo de formação da agenda e formulação da Política referida. Foram identificados os atores envolvidos, os conceitos, os problemas e as soluções apresentados, o fluxo político que as colocou na agenda governamental e seu processo de formulação, assim como os empreendedores e a ocorrência de janelas de oportunidades. E assim objetivando avaliar as possibilidades de sua implementação em relação as suas diretrizes de desenvolvimento científico e tecnológico no estado do Rio Grande do Sul, as dicotomias e ambigüidades presentes no processo. A partir da análise discutiram-se aspectos a superar e aperfeiçoar a fim de que sejam alcançados seus propósitos. / This work is the result of a exploratory research, by qualitative methodology, documental analysis, of National Policy of Medicinal Plants and Phytomedicines, based on Multiple Streams Model, by John Kingdon, for public policies analyses. It was made a review of policy analysis models and analyzed the preceding facts of agenda setting of pharmaceuticals public policies and the agenda setting and formulation process of the policy. The actors involved, the concepts, the problems and solutions presented, the political stream of governmental agenda and its formulation process, also the policy entrepreneurs, and policy windows. So, evaluating the possibilities of its implementation, relative to the scientific and technological development in the state of Rio Grande do Sul, the dichotomies and ambiguities in the process. To assume that analysis, we discussed aspects to overcome and improve with the intention to reach their purposes.

Please read the abstract in the section 07chapter7 of this document / Thesis (DPhil (Plant Physiology))--University of Pretoria, 2007. / Plant Science / unrestricted

Abstract in English / The number of studies focused on the digital preservation of indigenous knowledge has been growing steadily over the years. Despite the growth in this area of research, there is still a lack of information technology tools that preserve and disseminate indigenous knowledge. Indigenous knowledge has been highlighted as an area that can advance sustainable development, and its preservation is therefore of the utmost importance. Indigenous knowledge is mostly present within older generations, and if it is not preserved, this knowledge will die with its custodians. African communities rely heavily on indigenous medicine. A digital platform needs to be explored that can preserve practices relating to these medicines for future generations. Since indigenous knowledge is dynamic and is constantly evolving, there is a need to explore a digital tool that can highlight this dynamic nature. Current methods of preserving indigenous knowledge of medicinal plants were found to be less than effective and marred by constraints such as space and time. The main objective of this study was therefore to develop a model that could be used to guide the design of a new e-learning system aimed at facilitating the preservation of indigenous knowledge of Namibia’s medicinal plants. In this study, e-learning technology was used to determine the requirements for presenting indigenous knowledge of Namibia’s medicinal plants in such a way as to ensure that individuals can internalise and preserve this knowledge. An interpretivist qualitative approach was followed. Data was collected by conducting a literature review and carrying out a survey. A prototype e-learning system was developed and evaluated based on the collected data. It was found that preserving indigenous knowledge of medicinal plants through e-learning would require, among other things, engagement with the relevant knowledge custodians, leveraging multimedia, and offering content in indigenous languages. / School of Computing / M.Sc. (Computing)