Pelargonium sidoides DC. (Geraniaceae) root extracts are used in the Eastern Cape Province of South Africa as a traditional medicine for the treatment of respiratory tract and gastro-intestinal infections. Ethanolic extracts are used globally as herbal treatments for bronchitis, asthma and as an immune system booster. Despite documented exploitation of wild populations by illegal harvesters, this species has not been awarded a protected status. The high level of harvest in the years preceding this study prompted this investigation of the prospects for sustainable root harvest through wild harvest and greenhouse cultivation. A novel method was developed for the purification of umckalin, a bioactive constituent in root extracts, such that the root umckalin concentrations of wild and cultivated plants could be quantified by HPLC. As part of the cultivation experiments, the concentration of umckalin in roots was measured for plants across part of the species’ distribution range in the Eastern Cape Province. This survey revealed that root umckalin concentrations were inversely related to the average annual rainfall of the collection site (r² = 0.94, p = 0.007) and directly related to soil pH (r² = 0.97, p = 0.002). Thus, the possibility of inducing high umckalin concentrations in greenhouse-cultivated plants was investigated by subjecting plants to rapid and prolonged water stress treatments. Two leaf applied hormone treatments (cytokinin and gibberellin) and a root competition treatment with a fast growing annual (Conyza albida) were also investigated based on the potential function of umckalin in P. sidoides plants. These five treatments did not significantly affect root umckalin concentrations compared to well-watered controls. The results of further experiments suggested that umckalin production may have been influenced by the geographical origin and genetics of plants rather than environmental variation. Following wild harvest experiments, the regrowth of replanted shoots from which a standard proportion of the root was harvested showed that water availability affected shoot survival but not root regrowth rate. Regrowth rates were low, questioning the viability of wild harvest. In contrast, greenhouse cultivated plants showed ca. six times greater growth rates, supporting the cultivation of roots to supply future market demand.

The commercialisation of natural resources such as medicinal plants is a strategy that is increasingly being employed by poor people in developing countries such as South Africa, as a means of generating an income. Increasing economic hardship and a lack of employment opportunities in the formal sector of the economy has led to many urban dwellers seeking alternative means of meeting their everyday livelihood needs. Although the contribution of natural resources to subsistence economies is widely recognised, there are few studies that have examined the significance of the trade in medicinal plants to the livelihoods of poor and marginalised people. Thirty informal street traders were interviewed to investigate the role of the medicinal plant trade in sustaining the livelihoods of the traders who operate in the informal sector of the Nelson Mandela Bay Municipality, South Africa. The findings of the research indicate that the sale and collection of medicinal plants is an activity which is exploited by people with limited resources, few skills, little or no education and often without any other source of household income. Middle-aged women from impoverished, single income households dominated the trade. Although income from the trade is modest, it contributed substantially to the total household cash income of the traders. Other benefits of the trade included independence and having a sense of purpose in life, as the traders felt that they were not only helping their families but also the wider community. However, without the income from the trade, many of the traders and their families would be destitute and thus the medicinal plant trade is vital to the wellbeing of these people.

The human immunodeficiency virus (HIV) is one of the most common and dreaded diseases of the 21th century. Today, the disease is still spreading with increasing incidence. “Since the beginning of the epidemic, almost 75 million people have been infected with the HIV virus and about 36 million people have died of HIV. Globally, 35.3 million [32.2–38.8 million] people were living with HIV at the end of 2012” (http://www.who.int/gho/hiv/en/). Several studies have been conducted on herbs under a multitude of ethnobotanical grounds. The use of medicinal plants for the management of HIV has become a common practice especially, in the Eastern Cape Province of South Africa (Wilfred Otang Mbeng, 2013 PhD thesis, UFH). At the beginning of this programme, an ethnomedicinal survey of plants used for the management of HIV infection was carried out in targeted areas of the Province and information on the names of plants, the parts and the methods of preparation were collected. The survey revealed that 18 species representing 12 families were found to be commonly used for the management of HIV, as well as other opportunistic diseases such as tuberculosis, diabetes mellitus, sores, high blood pressure, etc. Carpobrotus edulis was selected for this research because it was the most frequently used in the Province. The foliar micro morphological contents of the plant, its phytochemical and antioxidant activity, in vitro antimicrobial activity, inhibitory effect against HIV-1 protease and reverse transcriptase, mechanisms of action and cytotoxicity were investigated. In terms of the foliar micro morphological contents in plants, an electron microscopy scanning (SEM) was completed. Investigation revealed that both glandular tricomes and calcium oxalate crystals (CaOX) were observed. Consequently, it is hypothesized that the bioactive therapeutic compounds secreted by C. edulis may be produced in the glandular trichomes. An investigation of phytochemical content of the plant extracts (C. edulis) was completed using four solvent extracts (hexane, acetone, ethanol and water). Results of the phytochemical analysis showed that proanthocyanidins (86.9 ± 0.005%) where highest in the aqueous extract with phenolics at 55.7 ± 0.404% in acetone extract, tannin at 48.9 ± 0.28% in ethanol extract, while the hexane extract had the highest levels of flavonoids (0.12 ± 0.05%) and flavonols (0.12 ± 0.05%). Antioxidant studies of the various extracts revealed that aqueous and ethanol extracts were found to be the best solvents for antioxidant activity in C. edulis leaves. GC-MS analysis of the essential oil from C. edulis leaves revealed that the essential oil contained at least 28 compounds. These included, in order of abundance: Oxygenated monoterpenes (36.61%); fatty acids esters (19.25%); oxygenated diterpenes (19.24%); monoterpenes (10.6%); sesquiterpenes (3.58%); and diterpenes (1.43%). Similarly, a GC-MS analysis of the crude hexane, acetone and ethanol extracts from C. edulis leaves identified a total of 59 compounds. Of the 59 compounds, 12 major phyto-metabolites that are active against infectious diseases were identified. To comfirm the potential use of C. edulis to treat infectious disease, antifungal activity of the crude essential oil extract and the four solvent extracts were tested against Candida albicans, Candida krusei, Candida glabrata, Candida rugosa and Cryptococcus neoformans strains. The essential oil extract was found to be the most active against all the fungal strains tested and performed better than the four extracts used various solvents used to extract (hexane, acetone, ethanol and water) the C. edulis leaves were tested for antibacterial and anti HIV-1 reverse transcriptase (RT) activity. The results indicated that both gram-positive and gram-negative isolates were inhibited by the extracts (hexane, acetone and ethanol) but antimicrobial activity was observed for the water extract. The lowest minimum inhibitory concentration values were obtained for the ethanol extract, followed by acetone and hexane extracts. No inhibition of HIV-1 reverse transcriptase was observed for any of the leaf extracts, even up to concentrations of 16 mg/ml. The potential inhibitory activities of the various solvent extracts against HIV-1 protease were evaluated at four different concentrations (16, 1.6, 0.16 and 0.016 mg/ml). Results indicated that the water extract showed almost 100% inhibition of HIV-1 protease activity, with an IC50 of 0.86 mg/ml leaf extract. Other solvent extracts (hexane, acetone and ethanol) however, did not show any inhibition activity above that observed for the DMSO control. The metabolic components in the water extract were subjected to LC-MS/MS analysis, which identified at least 91 compounds present in the water extract. Further studies involving the molecular modelling need to be carried out to confirm the inhibitory potential of these compounds. The cytotoxicity of the water extract of C. edulis leaves was also screened using human Chang liver cells at concentrations ranging bewteen 0.005 mg/ml and 1 mg/ml. Results indicated that the water extracts were not toxic. In conclusion the results from this study support the use of water extracts of C. edulis leaves by traditional healers to treat HIV infections and have identified possible mechanisms of action of the water extracts of C. edulis.

Medicinal plants have been used as traditional medicine in the treatment of numerous human diseases for thousands of years in many parts of the world. In the developing world, especially in rural areas, herbal remedies continue to be a primary source of medicine. Scientifically, medicinal plants have proven to be an abundant source of biologically active compounds, many of which have already been formulated into useful therapeutic substances or have provided a basis for the development of new lead molecules for pharmaceuticals. Antibiotic resistance, undesireable side effects and expences associated with the use of combination therapy in the treatment of Helicobacter pylori infections have generated a considerable interest in the study of medicinal plants as potential sources of new drugs against this organism. The high complexicity of bioactive compounds accumulated in plants coupled with their broad antimicrobial activity may make it difficult for pathogenic organisms, including H. pylori to acquire resistance during treatment. This study therefore evaluates the antimicrobial potential of selected South African medicinal plants employed in the treatment of H. pylori-related infections, and the subsequent isolation of the plant active principles. An ethnobotanical survey of plants used in the treatment of H. pylori-related infections was conducted in the study area. Crude extracts of Combretum molle, Sclerocarya birrea, Garcinia kola, Alepidea amatymbica and 2 Strychnos species were screened against 30 clinical strains of H. pylori and 2 standard control strains (NCTC 11638 and ATCC 43526). In the preliminary stages of this study, ethyl acetate, acetone, ethanol, methanol and water extracts of the plants were tested against H. pylori by agar well diffusion and micro broth dilution methods. The plant crude extracts that exhibited anti-H. pylori activity with a iv percentage susceptibility of 50 percent and above were considered for the rate of kill assays and the most active crude extracts selected for bio-assay guided isolation of the active ingredient. Preliminary fractionation of the crude extract was achieved by thin layer chromatography (TLC) using different solvent combinations; hexane/diethylether (HDE), ethyl acetate/methanol/water (EMW) and chloroform/ethyl acetate/formic acid (CEF) in order to determine the most suitable combination for column chromatography (CC) and subsequent testing by indirect bioautography. The extract was then fractionated in a silica gel column using previously determined solvent combinations as eluent. Active fractions obtained from column chromatography separations were further fractionated and the compounds identified by gas chromatography/mass spectrometry (GC/MS) analysis. All the plants exhibited antimicrobial activity against H. pylori with zone of inhibition diameters ranging from 0 - 38 mm and minimum inhibitory concentration (MIC) values ranging from 0.06 - 5.0 mg/mL. The most active plant extracts were the acetone extract of C. molle with a percentage susceptibility of 87.1 percent, acetone and aqueous extracts of S. birrea (71 percent each) and the ethanolic extracts of G. kola (53.3 percent). Except for the aqueous extract, these extracts also exhibited a strong bactericidal activity against H. pylori at different concentrations. TLC analysis revealed the presence of 9 components in the acetone extract of S. birrea with the EMW solvent system as opposed to 5 and 8 with HDE and CEF respectively. Bioassay-guided isolation led to the identification of 52 compounds from the acetone extract of S. birrea with n-octacosane being the most abundant (41.68 percent). This was followed by pyrrolidine (38.91 percent), terpinen-4-ol (38.3 percent), n-eicosane (24.98 percent), cyclopentane (16.76 percent), n-triacontane (16.28 percent), aromadendrene (13.63 percent) and α-gujunene (8.77 percent). Terpinen-4-ol and pyrrolidine demonstrated strong antimicrobial activity against H. pylori at all concentrations tested. These results may serve as preliminary scientific validation of the ethnomedicinal uses of the above mentioned plants in the treatment of H. pylori-related infections in South Africa. Terpinen-4-ol and pyrrolidine could be considered for further evaluation as therapeutic or prophylactic agents in the treatment of H. pylori-related infections. However, further investigations would be necessary to determine their toxicological properties, in-vivo potencies and mechanism of action against H.pylori

Garcinia kola is one of the plants used in folklore remedies for the treatment of microbial infections. Bacterial resistance to commonly used antibiotics has necessitated the search for newer and alternative compounds for the treatment of drug resistant microbial infections. This study focuses on the bioactivity of G. kola seeds on Streptococcus pyogenes (ATCC 49399), Staphylococcus aureus (NCTC 6571), Plesiomonas Shigelloides (ATCC 51903) and Salmonella typhimurium (ATCC 13311), organisms which can cause illnesses from mild to severe with potentially fatal outcomes. The crude ethyl acetate, ethanol, methanol, acetone and aqueous extracts were screened by agar-well diffusion method and the activities of the extract were further determined by Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) assays. The inhibition zones ranged from 0 - 24 mm, while MIC and MBC of the extract ranged between 0.04 - 1.25 mg/mL and 0.081 - 2.5 mg/mL respectively. Chloroform/ Ethyl Acetate/ Formic acid (CEF) solvent system separated more active compounds followed by Ethyl Acetate/ Methanol/ Water (EMW) and Benzene/ Ethanol/ Ammonium Hydroxide (BEA). The extracts were fractionated by Thin Layer Chromatography (TLC). Bioautography was used to assess the activity of the possible classes of compounds present in the more active extracts. Column chromatography was used to purify the active compounds from the mixture while Gas Chromatography-Mass Spectrometry (GC-MS) was used to identify the phyto components of the fractions. The MIC of the fractions ranged between 0.0006 - 2.5 mg/mL. CEF 3 (F3), CEF 11 (F11) and CEF 12 (F12) revealed the presence of high levels fatty acids Linoleic acid, 1, 2-Benzenedicarboxylic acid and 2, 3-Dihydro-3, 5-dihydroxy-6-methyl, respectively. The results obtained from this study justify the use of this plant in traditional medicine and provide leads which could be further exploited for the development of new and potent antimicrobials.

Alzheimer’s disease (AD) is a complex neurodegenerative disorder with limited treatment options. Previous research has shown that metabolism of the platelet activating factor (PAF) family of lipid second messengers is impaired in AD. While PAFs are known to exacerbate glutamate excitotoxicity, signal tau hyperphosphorylation, and mediate amyloid β neurotoxicity, it is not yet clear whether cognitive decline can be ascribed to activation of the G-protein-coupled PAF receptor (PAFR). Here, I assessed whether loss of PAFR would alter Morris water maze performance in the TgCRND8 (Tg) mouse model of AD. I show that learning is impaired in Tg PAFR+/+ but not in Tg PAFR-/- mice. Together, these findings suggested that blocking PAFR-mediated glutamate overload or inhibiting PAF-synthesizing enzymes are two relevant therapeutic strategies. As traditional medicine is a major form of health care in regions like Mesoamerica, I conducted an ethnobotanical survey of medicinal plants used by Q’eqchi’ Maya healers of southern Belize to treat symptoms relevant to AD. I collected a total of 22 plants, 19 of which were identified to the species level. None of the plant extracts used for symptoms of AD were neurotoxic when tested on cerebellar granule neurons (CGNs). I found that extracts of Margraviaceae gentlei and Gonzalagunia panamensis protected CGNs from glutamate-induced excitotoxicity, in vitro, and Peperomia hirta inhibited sPLA2 activity. These results demonstrate a pharmacological basis for Q’eqchi’ Maya traditional medicine used to treat symptoms relevant to AD, and highlight several plants with potential for future development into natural products for the treatment of AD.

The purpose of this research was to investigate what traditional healing practices African immigrants are using and have ceased to use, during the process of resettlement into Canadian society. An additional purpose was to investigate the participants' reasons for using or not using their traditional healing practices. One aim of the study was to provide information about these traditional differences and the ways in which professionals in the social service sector acknowledged African immigrants and have been helpful to them. Another aim of the study was to identify whether, and in what ways, professionals have been helpful. The study is important not only for social workers and human service professionals, but also for African immigrants themselves as well as for African immigrant community groups within Victoria. The African immigrants' traditional practices and the ways in which they adapt and resettle into the new society remain unknown in the literature. Perhaps, the African immigrants common challenges and their unique traditional approach to resettlement into the Canadian society have not yet captured the full attention of social work and human service professionals. This study was grounded in structural theory, migration theory, settlement theory and adaptation theory in order to draw theoretical understanding of the relationship between immigrants resettlement process and their experiences. The research was qualitative and exploratory. It included a participatory interview design. Twenty African immigrants from five different regions of Africa participated in the study. Two distinct traditional practices were identified (i.e. material tradition and non material tradition) which are the foundation of African immigrants traditional healing practices. This research has found that the use or abstention of traditional healing practices in re-settlement depends on the participants reasons for migration. There were distinct differences in the use or non-use of traditional healing practices between those who planned (economic), and those who were forced (political) to migrate / Arts, Faculty of / Social Work, School of / Graduate

All six plants studied (Senna petersiana, Terminalia sericea, Cassine transvaalensis, Elephantorrhiza burkei, Rauvolfia caffra and Anredera cordifolia) proved to have considerable antibacterial activity. The water extracts of five of the six plants tested, showed activity against Bacillus pumilis, B. subtilis and Staphylococcus aureus respectively. Water extracts from S. petersiana showed a significant antibacterial activity by inhibiting all Gram-positive and two Gram-negative bacteria. A cytotoxicity assay of three plants (S. petersiana, T. sericea and A. cordifolia) on primary vervet monkey kidney ceelsl showed that A. cordifolia was the least cytotoxic extract with an ID50 value of 1.560 mg/ml. Both S. petersian and T. sericea showed an ID50 value of 0.024 mg/ml. Cytotoxicity as determined in this study does not necessarily mean that the active compound which can be isolated from these plants will also be toxic. Antiviral activity of S. petersiana, T. sericea and A. cordifoli crude extracts were investigated against herpes simplex virus type I at the non-toxic concentrations. Both T. sericea and A. cordifoli extracts showed to be non-active against HSV -I, but S. petersiana showed a 20 % reduction in replication of the virus after the sixth day of the experiment. Because of the sensitivity and instability of compounds in the root extract of S. petersiana, it was very difficult to isolate any pure compound. Bioassay-guided fractionation of the seeds of S. petersiana resulted in the isolation luteolin. Its structure was identified and confirmed through spectroscopic methods including IH, BC, UV, HMBC and HMBQ. An antibacterial assay of luteolin isolated from the seeds of S. petersiana showed activity against Baccilus cereus, B. pumilis, Streptococcus aureus and Staphylococcus areus at the concentration of I mg/ml. In the assay to assess the possible antiviral activity of luteolin against herpes simplex type I virus, 50% of the virus was inactivated at the concentration of 250 μg/ml. The results of this study have shown that it is possibl4e that the extracts studied, can provide humankind with valuable agents of potential use in the treatment of herpes and some bacterial species. / Dissertation (MSc ( Plant Physiology))--University of Pretoria, 2006. / Plant Science / unrestricted

Thesis (MSc. (Microbiology)) -- University of Limpopo, 2019 / The emergence of drug resistance to the first line drugs complicates the treatment of tuberculosis (TB), especially in parts of sub-Saharan Africa where accessibility to quality health care is limited. The search for alternative medication has been the centre of research for years due to challenges posed by infectious organisms including drug resistance, lengthy treatment periods and lack of quality health care in developing countries. Stomatostemma monteiroae is used in traditional medicine to treat TB and related symptoms. The aim of this study was to isolate and characterise compounds with antimycobacterial activity from Stomatostemma monteiroae. The plant materials were collected from Ga-Madiga village in Limpopo province of South Africa. Different plant parts namely: leaves, twigs, roots, tuber and tuber-peels were separated, washed, dried and milled to a fine powder. Several solvents (n-hexane, dichloromethane, acetone and methanol) were used to extract the plant material using various extraction methods such as maceration, defatting, and extract enrichment procedure and phytochemical analysis was done using standard chemical tests and thin layer chromatography. The qualitative antioxidant activity was determined by the thin layer chromatography (TLC) based 2,2-diphenyl-1picrylhydrazyl (DPPH) free radical scavenging activity and quantitative antioxidant activity was determined using colorimetric DPPH free radical scavenging and ferric reducing power assay. Antimycobacterial activity of the extracts was assessed using bioautography and micro dilution method tested on Mycobacterium smegmatis (ATCC 1441), Mycobacterium tuberculosis (ATCC 25177) and M. tuberculosis H37Rv (ATCC 27294). The cytotoxic effects of the extracts were evaluated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay on Vero monkey kidney cells. The compounds with antimycobacterial activity were isolated using bioassay-guided fractionation and purified using preparative thin layer chromatography and thereafter identified using NMR spectroscopy to elucidate the structure. Various phytochemical constituents were detected in different plant parts, with the leaves and twigs possessing more of the phytoconstituents analysed. The TLC profile of S. monteiroae indicated that more compounds are non-polar to intermediate in polarity. The antioxidant activity analysis on TLC plates indicated that all the plant parts have low antioxidant activity, this was also confirmed by xxii quantitative tests. The leaves of S. monteiroae had antimycobacterial activity when analysed using bioautography, while other plant parts had no active bands. The minimum inhibitory concentration values were much higher than the positive control rifampicin and the roots (0.31 mg/mL) followed by the leaves (0.83 mg/mL) had lower inhibitory concentrations when tested against M. smegmatis. The MIC values of extracts against TB causing strains varied greatly, the leaves and the roots had even higher MIC value. Toxicity analysis indicated that all plant parts were non-toxic towards Vero cells (LC50 > 0.02 mg/mL). Bioassay-guided fractionation enabled isolation of one antimycobacterial pure compound from the leaves extracts. The isolated compound was identified using NMR and was found to be a sitosterol derivative 8,9-dehydro-4-methyl-24-vinylobtusifoliol. This compound had a noteworthy activity against M. smegmatis. The present study validates the use of S. monteiroae in the treatment of TB related symptoms traditionally. Further studies are required to analyse the cytotoxic effects of the isolated compound and also testing the antimycobacterial activity of the isolated compound on TB causing pathogens. / National Research Foundation (NRF)

Thesis (M. Sc. (Microbiology)) --University of Limpopo, 2019 / Informal street traders and traditional health practitioners at Ga Maja (Limpopo Province) primarily offer consumers semi-processed herbal concoctions that are indicated to have blood-cleansing, immune-boosting, detoxifying, antidiarrheal, antiHIV/AIDS and pain-relieving therapeutic properties. The focus of this study was to validate the pharmacological effects and safety of these herbal concoctions as indicated by the traders. Five herbal concoctions and their medicinal plant recipies used for their preparation were purchased from five independent traders. A laboratory concoction was prepared according to the traders’ instructions. Possible microbial contaminants were identified using Matrix-assisted laser desorption/ionisation time-offlight mass spectrometry and VITEK 2. Nutritional content of the concoctions was determined by a plasma atomic emission spectrophotometer. Qualitative phytochemical analysis was determined using standard chemical tests and thin layer chromatography. Total polyphenol content was quantified calorimetrically. Antioxidant activity was quantified using 2, 2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing power assays. Antimicrobial activities were determined using a broth micro-dilution assay and bioautography. Anti-HIV-1 reverse transcriptase activity was used to determine the antiviral potential of the concoctions. Anti-inflammatory activity was determined using the cyclooxygenase inhibition assays and possible cytotoxic effects of the concoctions were evaluated using MTT cell viability assay. Growth on potato dextrose and nutrient agar plates indicated heavy microbial contamination. Sodium, potassium and zinc were most abundant in the concoctions. The concoctions had similar phytochemical profiles, and together with plant decoctions consisted primarily of polyphenolic constituents. Generally, some plant decoctions had higher antioxidant (EC50: 15.71 – 40.87 µg/mL) and antibacterial (MIC: 0.04 – 0.63 mg/mL) activities. The antimicrobial activities of the concoctions were as a result of synergistic effects of the compounds because no single compound was observed to have antimicrobial activities on the bioautograms. Combination studies showed that the combination of crude decoctions from different plant species resulted in reduced antioxidant, antibacterial and antifungal activities. The laboratory concoction had higher anti-HIV reverse transcriptase activity (EC50: 2.90 µg/mL) than the positive controls used (EC50: 36.65 – 40.90 µg/mL). The concoctions also demonstrated considerable antiinflammatory activity. The lack of standardisation of phytomedicines reduces their xxi pharmacological potential and consistency. However, this study validated the ethnopharmacological use of the different plant species and herbal concoctions towards the treatment of human immune-deficiency virus, pain caused by inflammation, infectious diarrhoea and for immune-boosting. This study also highlighted the complexities associated with combinations of aqueous extracts and the importance of appropriate knowledge on which plant species are to be mixed to enhance their therapeutic properties. Although the concoctions did not exhibit cyctotoxic effects, toxicities may arise from endotoxins produced by the microbial contaminants. Hygienic processing and packaging are essential to ensure that consumers receive quality products that are safe to consume.