Medicinal bulbs form part of the diversified flora in South Africa. The plants are used extensively in South African traditional medicine in the treatment of various ailments. Due to the ever-increasing demand and the unrestricted collection of medicinal plants from the wild, many of these slow growing bulbous plant species are driven into over-exploitation and extinction. The main parts collected for use are the underground bulbs, leading to the destructive harvesting of the whole plant. This form of plant harvesting poses threats to the long term sustainability of these plant resources from their natural habitats. Sustainable harvesting of these plants should be within the limits of their capacity for self-renewal. However, this seldom occurs with the often inconsiderate medicinal plant gatherers. Conservation of these plants is therefore necessary. A strategy that would take into consideration the sustainable harvesting and perhaps simultaneously provide similar medicinal benefits, would be the substitution of bulbs with leaves of the same plant. This study was aimed at evaluating the seasonal pharmacological and phytochemical properties in bulbs/corms and leaves of medicinal bulbs with a view of promoting the substitution of bulbs with leaves in traditional medicinal use. Four medicinal bulbous plants, Tulbaghia violacea, Hypoxis hemerocallidea, Drimia robusta and Merwilla plumbea were evaluated for the pharmacological and phytochemical properties in their bulbs/corms and leaves in spring, summer, autumn and winter seasons, with a view of promoting the use of leaves as a conservation strategy. Dried plant materials were sequentially extracted with petroleum ether (PE), dichloromethane (DCM), 80% ethanol (EtOH) and water in each season. The extracts were tested for activities against Gram-positive (Bacillus subtilis and Staphylococcus aureus), Gram-negative (Escherichia coli and Klebsiella pneumoniae) bacteria and the fungus Candida albicans using the in vitro microdilution assays to obtain minimum inhibitory concentrations (MIC) and minimum fungicidal concentrations (MFC). The four plant species were also evaluated for their ability to inhibit cyclooxygenase (COX-1 and COX-2) enzymes. Spectrophotometric methods were used to evaluate saponin and phenolic contents of samples from the four plant species in each season. Antibacterial activity was fairly comparable between bulbs/corms and leaves of H. hemerocallidea, T. violacea, and M. plumbea, with at least one extract showing some good activity (MIC < 1 mg/ml) in most of the seasons. Bulb extracts of D. robusta did not show good antibacterial activity while the leaf extracts showed good activity (0.78 mg/ml) against B. subtilis in spring, summer, and autumn and S. aureus (0.78 mg/ml) in autumn. The best antibacterial activity was recorded in winter, with MIC values as low as 0.195 mg/ml from the DCM bulb extracts of T. violacea against K. pneumoniae and S. aureus and PE corm extracts of H. hemerocallidea (0.195 mg/ml) against B. subtilis. Good antibacterial activity from water extracts were only recorded from corm extracts of H. hemerocallidea in summer, autumn and winter, H. hemerocallidea leaf extracts in autumn and winter, and M. plumbea bulb extracts in autumn. The leaf extracts of all the screened plant species demonstrated good fungicidal activity in autumn, with H. hemerocallidea corm water extracts recording an MFC value as low as 0.39 mg/ml. The leaf extracts of H. hemerocallidea (water), D. robusta (DCM) and M. plumbea (DCM) had good MFC values of 0.78 mg/ml each, in spring. The DCM leaf extracts of T. violacea also showed good fungicidal activity (0.78 mg/ml) in summer, while corm water extracts of H. hemerocallidea had an MFC value of 0.39 mg/ml in winter. There were no fungicidal activities recorded from all the bulb extracts in all the seasons. All the PE and DCM extracts in all the tested plant samples recorded between moderate (40-70%) and high (> 70%) COX-1 and COX-2 inhibition levels across all seasons. The EtOH corm extracts of H. hemerocallidea also demonstrated moderate to high inhibitory activity against COX-1 enzyme across all seasons. Bulb and leaf extracts of T. violacea showed selective inhibitory activity for COX-2 enzyme in all the seasons. The highest COX inhibitory levels were recorded in COX-2 from the PE leaf (spring) and bulb (autumn) extracts of T. violacea, with both recording 100% inhibitory activity. Phytochemical analysis revealed higher total phenolic compounds in bulbs/corms and leaves of all the analysed plant species, to be either higher in spring or winter. Plant material collected in autumn had the least levels of total phenolics. An almost similar trend to that of total phenolics was observed for flavonoids, gallotannins and condensed tannins in most plant samples, with higher levels either in spring or winter. Total saponins were consistently higher in winter than in the other seasons in all the screened plant species. There were in some cases, relationships between the peaks in the levels of some phytochemical compounds and the observed levels of bioactivity in different assays. The results obtained from this study demonstrate that the leaves of the screened plant species may substitute or complement bulbs in the treatment of certain ailments in traditional medicine. Thus, plant part substitution can be sustainably utilised in the conservation of these plant species while retaining the same medicinal benefits. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2010.

The use of traditional medicine is a popular practice in South Africa especially among rural dwellers due to several reasons such as availability of natural products, cultural beliefs, preference of natural products to synthetically derived drugs and the high cost of modern drugs. Traditional healers in South Africa play key roles in administering treatment for all sorts of ailments using plants. The aim of this study was to evaluate the efficacy of seven selected medicinal plants that are used in traditional medicine to treat stomach-related ailments for their pharmacological and phytochemical properties. Plant material was extracted sequentially with ethyl acetate (EtOAc), ethanol (EtOH) and water. The extracts were evaluated for their antimicrobial activities using the microdilution technique against two Gram-positive (Enterococcus faecalis ATCC 19433 and Staphylococcus aureus ATCC 12600) bacteria and a Gram-negative (Escherichia coli ATCC 11775) bacterium. A modified microdilution technique was used to screen for antifungal activity against a yeast-like fungus (Candida albicans ATCC 10231). Only the EtOAc extract of Tetradenia riparia demonstrated good antibacterial activity against the Gram-negative E. coli, all the other extracts that were active only showed good antibacterial activity against the two Gram-positive (E. faecalis and S. aureus) bacteria with MIC values <1 mg/ml. None of the extracts that exhibited good inhibitory activity showed corresponding bactericidal activity against the bacterial test strains, suggesting that the observed activity were all inhibitory. Good antifungal activity with an MIC value <1 mg/ml was observed in only 5 extracts, and none of the extracts exhibited corresponding fungicidal activity. The in vitro colorimetric assay for anthelmintic activity against Caenorhabditis elegans revealed that almost all the extracts possessed moderate to high anthelmintic properties. The EtOAc extract of T. riparia had the best activity at MLC value of 0.004 mg/ml. The anti-inflammatory activity of the plant extracts was tested using the cyclooxygenase assays to determine their inhibitory potential against COX-1 and COX-2 enzymes. All the EtOAc extracts demonstrated both COX-1 and COX-2 inhibitory activity in the range of 50.7 ± 2.4 to 99.5 ± 0.5%. Apart from the EtOH extracts of C. multicava that showed high inhibitory activity against both COX-1 and COX-2, all the other EtOH extracts were COX-2 selective. Aqueous extracts exhibited poor inhibitory activity against both COX-1 and COX-2 enzymes with the exception of T. riparia and Coddia rudis that showed good inhibitory activity (69.1 ± 0.9 and 92.65 ± 0.7%) against COX-1 and COX-2 respectively. The standard plate incorporation assay for the Ames test was carried out to determine the potential genotoxic effects of the plant extracts and this revealed that all the extracts were non-mutagenic towards Salmonella typhimurium tester strains TA98, TA100 and TA1537 without metabolic activation. However, further studies incorporating metabolizing enzymes are needed to confirm the safe use of the studied plants. Phytochemical analysis revealed relatively high amounts of total phenolics, gallotannins and flavonoids in all the evaluated plants. Total and steroidal saponins were detected in only two plant samples, Canthium spinosum and Cassinopsis ilicifolia (bark). These findings present useful information on the types of bioactive compounds that could be responsible for the pharmacological activities observed among some of the plant extracts. The results obtained in this study showed different levels of pharmacological activities among all the evaluated medicinal plants which provide scientific validation for their use in traditional medicine as antimicrobial agents. Phytochemical analysis provides valuable information for further study that will be aimed at isolation and identification of the bioactive principles in the evaluated plant species. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2011.

Thesis (M.Sc. (Biochemistry)) -- University of Limpopo, 2013 / Diabetes mellitus is one of the fast growing chronic metabolic disorders throughout the world. It has become a life threatening disease and health burden. So far it can only be managed with commercial therapeutic agents, proper diet and exercise. People particularly from developing countries use medicinal plants to treat this condition. According to WHO, about 80% of the population in developing countries are dependable on medicinal plants. This prompted many researchers to explore the effectiveness and safety of these plants. In the current study ten medicinal plants were randomly chosen, screened for antidiabetic activity by testing their ability to inhibit α-amylase and α-glucosidase enzymes. The plants were tested using in vitro assays. The finely powdered leaves of each plant were extracted with hexane, chloroform, acetone and ethyl acetate. Phytoconstituents of each plant extracts were analyzed using both qualitative and quantitative methods. All plant extracts tested positive for phenols, flavonoids and all negative for starch. Their compounds were better separated in the TEA mobile system on the TLC plates. All plant extracts had more of total phenolics ranging between 0.1-400 GAE/mg than total flavonoids and condensed tannins. Antioxidant activity of the plant extracts was tested quantitatively at various concentrations using DPPH. Most plant extracts were able to scavenge the radicals produced by DPPH at highest concentration of 2.5 mg/mℓ. Not all plant extracts with the highest number of total phenolics had the highest antioxidant activity. For antidiabetic in vitro assays, plant extracts inhibited various percentages of both α-amylase and α-glucosidase activity at concentrations ranging between 0.019- 2.5 mg/mℓ. The best overall activity against both enzymes was observed in acetone and ethyl acetate plant extracts. Cassia abbreviata and Helinus integrifolius were even more active than acarbose which was used as positive control. These plant extracts inhibited both the enzymes in a dose dependent and non-competitive manner. Seeing that both extracts of C. abbreviata and H. integrifolius were consistent when inhibiting both enzymes, they were further evaluated for their effect on glucose uptake by the C2C12 muscle and H-II-4-E liver cells. All the plant extracts tested were able to increase glucose uptake in the muscle cells. However optimal increase was seen in the liver cells when treated with 250 µg/mℓ of acetone and ethyl acetate extracts of C. abbreviata. The cytotoxicity effects of both acetone and ethyl acetate of C. abbreviata and H. integrifolius was tested using the xCelligence system on RAW 264.7 cells. Different cell indexes were obtained after treating the cells with different concentrations (0.05,0.1 and 0.25 mg/mℓ) of each plant extracts respectively. The system was run for three days but the toxic effects of plant extracts were analyzed for the first ten hours. The results obtained shows that cell index decreased as the concentration of the plant extracts was increased. All the plant extracts were less toxic as compared to positive control, Actinomycin D. The leaves of H. integrifolius were further exhaustively extracted with hexane, dichloromethane, acetone, ethyl acetate and methanol respectively. Since the DCM extracts yielded the highest mass in quantity, it was further used for isolation of active compounds. Column chromatography and bioassay guided fraction led to isolation of a mixture of triterpenes identified as α and β-amyrin. The structure was elucidated using nuclear magnetic resonance technique. The inhibitory capability of the isolated compound against α-amylase enzyme was less than the crude extract which inhibited more than 50% of the activity at a concentration of 1 mg/mℓ.Based on the enzymes assays and cell culture work it can be concluded that C. abbreviata and H. integrifolius species are the best inhibitors of carbohydrate digesting enzymes, and therefore be used to manage postprandial hyperglycemia in the people with type 2 diabetes. However more work still need to be conducted for further isolation of more active compounds.

Thesis (MA. (African Languages)) -- University of Limpopo, 2012 / Ngudo ino yo sengulusa ndeme ya u thusa ṅwana ho sedzwa nḓila ya Tshivenḓa, sa izwi maitele aya a tshi khou ngalangala musalauno. Ngudo iyi yo sumbedza uri u thusiwa hu kha ḓi vha hone naho mathusele a hone o fhambana, sa izwi zwi tshi bva kha thendelano ya muṱa. Ho wanala uri kha muthuso hu shumiswa vhathu vhofhambanaho u fana na vhomaine, vhakegulu, vhafunzi kana ha tou rengwa mishonga ine ya shumiswa kha u thusa ṅwana. Ngudo yo dovha ya sumbedza mvelelo mmbi dza u sa thusa ṅwana na mvelelo mbuya dza u thusa ṅwana.

Thesis (M.Sc. (Biochemistry )) --University of Limpopo, 2007 / Refer to document / The Cannon Collins Trust Fund and the National Research Foundation

This study sought to establish some ofthe problems that occur during a consultation process between a healthcare worker and a patient, such as intangible and tangible verbal/nonverbal communication problems. Tangible nonverbal problems refer to eye contact, gestures, body posture and facial expression. Tangible verbal problems refer to voice tone/attitude and language and intangible to race, age, gender, education and culture. It was made clear that the problems involved in the consultation process were, in the main, common to other fonns of communication such as that between a reference librarian and a client, customer, visitor or user. The factors that hindered communication were investigated by means of semi-structured interviews and questionnaires. The sample population was made up of 100 black isiZulu speaking females and seven healthcare workers of a heterogeneous background. The perception ofthe respondents in relation to the above-named factors (language, age, gender, attitude, culture, education, gestures and postures) was sought. The analysis of the results obtained showed that some of the significant factors that are a problem in communication include voice tone/attitude, eye contact, sitting position, gestures, facial expression and language. Patients, for the sake ofeffective concentration and free flow ofinfonnation, preferred healthcare workers who were polite, had a cheerful demeanour and who sat still and straight up (not looking around or standing). This is noted because the majority of the patients acknowledged such healthcare workers and were not satisfied with those who behaved otherwise. For example, in relation to previous consultations (irrespective of the Clinics), out of the 70 respondents who encountered problems, 61 (87%) in despair cited cases of rudeness, of which the majority of such cases related to African healthcare workers. Culture also mattered, when seen in terms of people being able to speak the same language and understand one another, with respect to the contextual meaning of words. As far as eye contact was concerned, it was apparent that adjustments had been made. For example, it was discovered that although it is the Zulu culture to avoid eye contact, especially between the young and the old, Zulu people have come to accept eye contact in a crosscultural South Africa. Their acceptance was also seen as due to the advantages ofeye contact. This was made clear by the fact that ofthe 90 (91%) respondents who acknowledged the fact that the healthcare workers maintained eye contact during the consultation process, 87 (97%) said it was polite as it gave them the assurance that the healthcare workers were paying attention to what they were saying. Among the socio-demographic variables investigated, the gender of the healthcare worker emerged as one ofthe important predictors of effective communication. This is because the majority of the respondents indicated feeling freer with someone of the same gender groupmg. Certain recommendations were made which were considered vital in improving not only the consultation process but any other form of communication, including that between a reference librarian and a client. The main recommendations were that the healthcare workers be polite and endeavour to speak the main language as the patients. Due to the fact that some healthcare workers hurry during consultation, it was recommended that more staff be employed. / Thesis (M.I.S.)-University of Natal, Pietermaritzburg, 2000.

South Africa is home to a wide diversity of cultural groups, all of which utilize the flora for a variety of purposes. This is true with regard to traditional medicine systems which are similar to those of the rest of Africa south of the Sahara, with diviners (sangomas) and herbalists (inyangas) as the key health providers. In addition, the Country is rich in plant diversity with some 30 000 species of flowering plants - almost one tenth of the worlds recorded higher plants. This incorporates a large diversity of plants including trees, shrubs, herbs, bulbs and corms. The adverse effects of traditional medicinal plants and natural products are not well documented in the literature. Recently, many plants used as food or in traditional medicine have been shown to be potentially mutagenic using in vitro assays. Thus, the scientific evaluation of traditional medicine and medicinal plants is very important to validate claims made on safety and efficiency of such usages. After a survey of the available ethnobotanical literature, ten trees used in South African traditional medicine were selected. These species were: Acacia niolotica subspecies kraussiana, Acacia sieberiana, Albizia adianthifolia, Combretum kraussii, Faidherbia albida, Ficus sur, Prunus africana, Salix mucronata, Terminalia sericea and Trichilia dregeana. Plant parts including leaf, root and bark were collected from each of the selected trees (exceptions were Albizia adianthifolia, Faidherbia albida, Terminalia sericea and Prunus africana) and extracted using ethyl acetate, ethanol and water individually to ensure the extraction of compounds over a wide range of polarities. The extracts (in total, 78) were screened for antibacterial, anti-inflammatory (COX-1 and COX-2) and antiacetylcholinesterase activities and investigated for their potential mutagenic effects using the Ames test. Antibacterial activity was detected using the disc-diffusion and microdilution assays. The extracts were tested against Gram-positive bacteria: Bacillus subtilis, Staphylococcus aureus, Micrococcus luteus and Gram-negative bacteria: Escherichia coli and Klebsiella pneumoniae. Of the 78 different plant extracts 111 tested (final amount of plant material was 1 mg per disc), 84% showed activity against Gram-positive bacteria. From this percentage, 20% also showed activity against Gram-negative bacteria. The best inhibition was observed with ethyl acetate and ethanol root extracts of Terminalia sericea against both Gram-positive and Gram-negative bacteria. In the micro-dilution assay, 55% of the plant extracts showed minimum inhibitory concentration (MIC) values ~ 1.56 mg/ml against Gram-positive and/or Gram-negative bacteria. The ethyl acetate bark extract of Acacia sieberiana and the root and bark ethyl acetate extracts of Acacia nilotica inhibited bacterial growth of both Gram-positive and Gram-negative bacteria at concentrations ~ 0.8 mg/ml. The aqueous leaf extracts of Acacia sieberiana had a low MIC value (0.3 mg/ml) against Gram-negative Kleibsiella pneumoniae and the ethyl acetate extracts of the root inhibited growth of Escherichia coli with an MIC value of 0.1 mg/ml. However, these two extracts showed no activity in the disc-diffusion assay. The MIC values of the neomycin (control) were 0.8 I-Ig/ml and 3.1 I-Ig/ml against Kleibsiella pneumoniae and Escherichia coli respectively. In the anti-inflammatory test, 70% of the plant extracts from different plant parts (leaf, root, bark) of the tree investigated showed strong inhibition in both the CQX-1 and CQX-2 bioassays. The CQX-2 inhibitory effects of aqueous extracts were generally lower when compared to the organic solvent extracts. However, water extracts of Acacia nilotica was an exception (~ 90%). In the acetylcholinesterase inhibitory test, 21% of the plant extracts were active at concentrations ~ 1 mg/ml using the micro-plate assay. The lowest IC50 value was 0.04 mg/ml obtained with an ethanol bark extract of Combretum kraussii. The IC50 value of the galanthamine (positive control) was 2 I-IM. None of the investigated plants showed any potential mutagenic effects with Salmonella typhymurium strain TA 98 using the Ames test. Using bioassay-guided fractionation, anolignan B was isolated from the ethyl acetate root extract of Terminalia sericea. Antibacterial activity of anolignan B was determined using the microdilution assay. The compound possessed activity against both Gram-positive and Gram-negative bacteria. The lowest MIC value (3.8 IJg/ml) was observed with Staphylococcus aureus. MIC value of the neomycin was 1.5 IJg/ml. Anti-inflammatory activity of anolignan B was detected using the CQX-1 and CQX-2 bioasays. The compound showed strong inhibitory activity against CQX-1 and weaker activity against CQX-2. The ICso values were 1.5 mM and 7.5 mM with CQX-1 and CQX-2 respectively. The ICso values of indomethacin were 0.003 mM and 0.186 mM against CQX-1 and CQX-2 respectively. There were no potential mutagenic effects showen by anolignan B against Salmonella typhimurium strain TA 98 in the Ames test. Isolation of anolignan B from Terminalia species and the antibacterial and anti-inflammatory activities observed in this work have not been reported previously and could therefore be recorded as novel biological activities for this compound. These results also support the idea that the use of ethnobotanical data can provide a valuable short cut by indicating plants with specific uses which might likely be sources of biologically active chemicals. / Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2005.

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.

Throughout the history of mankind, many infectious diseases have been treated with plant extracts. Venereal infections are one such group and are regarded as conditions that are highly responsive to traditional treatment. Aqueous, ethanol and ethyl acetate extracts of 13 plants used in South Africa for the treatment of venereal diseases were screened for in vitro antibacterial, antifungal, mutagenic and antimutagenic activities. Antibacterial activity was evaluated using the disc-diffusion and microdilution assays to determine the minimal inhibitory concentration (MIC) values of the extracts. The extracts were tested against the Gram-positive bacteria Bacillus subtilis and Staphylococcus aureus, and the Gram-negative bacteria Escherichia coli and Klebsiella pneumoniae. Among the plants tested, Gunnera perpensa, Harpephyllum caffrum, Hypoxis latifolia and Ledebouria ovatifolia showed the best antibacterial activity. The aqueous rhizome extract of Gunnera perpensa displayed good activity against Gram-negative bacteria with an MIC value of 0.78 mg/ml, and against S. aureus (0.78 mg/ml). Aqueous and ethanol extracts of H. caffrum bark were active against both Gram-positive and Gram-negative bacteria. Hypoxis latifolia aqueous corm extracts exhibited very good MIC values against K. pneumoniae (0.78 mg/ml), E. coli and S. aureus (1.56 mg/ml). Ethanol and ethyl acetate bulb extracts of Ledebouria ovatifolia displayed good activity against Bacillus subtilis bacteria with MIC values of 0.78 mg/ml and 0.39 mg/ml respectively. Antifungal activity was evaluated using the microdilution bioassay. Good activity was shown by the ethanolic bark extracts of Bersama lucens and Harpephyllum caffrum against Candida albicans. Only in the case of Harpephyllum caffrum did aqueous extracts have activity against Candida albicans. In the Ames test, all plant extracts showed a negative genotoxic response except for ethanol and ethyl acetate bulb extracts of Cyrtanthus obliquus which induced mutations in TA98. Moderate antimutagenic activity was observed with the ethyl acetate extract of G. perpensa and the ethanolic extract of H. latifolia. High antibacterial and antifungal activity detected with Harpephyllum caffrum bark extracts resulted in an investigation on seasonal and geographical variation of this inhibitory activity. Seasonal variation in antibacterial and antifungal activities was investigated in order to determine the best collection time to ensure potential high medicinal activity in plant preparations. The highest inhibitory activity was detected with plant material collected in June and December 2003, with a decline in activity when collections were made in September 2004. The chemical profiles of TLC chromatograms were compared and little variation was found, particularly in the case of plant material obtained from the Botanic Garden of the University of KwaZulu-Natal and a 'Muthi' Shop in Pietermaritzburg. Identification of active compounds from G. perpensa and H. caffrum was not successful due to insufficient amounts of isolated fractions. / Thesis (Ph.D.)-University of KwaZulu-Natal, 2006.

Among all the major infectious human diseases, gastro-intestinal infections caused by microbial pathogens are a major cause of morbidity and infant death in developing countries, largely due to inadequate sewage disposal and contaminated water. Traditional health practitioners in South Africa play a crucial role in providing health care to the majority of the population. Many plants are locally used by South African traditional healers to treat microbial infections related to gastro-intestinal tracts. Ethnopharmacological and ethnobotanical studies using traditional knowledge as a selection strategy has given priority to certain plants for isolation and identification of plant novel bioactive compounds. Pharmacological and phytochemical studies of the investigated twelve medicinal plant species (from 10 families) extensively used as antimicrobials against gastro-intestinal infections was necessary to validate the use of the plants. Furthermore, to provide sufficient preliminary information for the isolation and identification of active compounds that are present in the investigated plants. Plant parts were sequentially extracted using petroleum ether (PE), dichloromethane (DCM) and 70% ethanol (EtOH). Cold water and boiled (decoction) extracts of the plant materials were prepared non- sequentially. Among the extracts, EtOH yielded the highest amount of plant substances. A total number of 85 extracts were evaluated for antibacterial activity, 80 for antifungal activity, 64 for anti-inflammatory activity, and 27 biologically active extracts were tested for genotoxicity. The microdilution method was used to determine the minimum inhibitory concentration values in the antibacterial assay against two Gram-negative bacteria (Escherichia coli ATCC 11775 and Klebsiella pneumoniae ATCC 13883) and two Gram-positive bacteria (Bacillus subtilis ATCC 6051 and Staphylococcus aureus ATCC 12600). A modified microdilution method was used to determine the minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) values in the antifungal assay against Candida albicans. Cyclooxygenase assay was used to evaluate the anti-inflammatory activity of the extracts against cyclooxygenase-1 and -2 (COX-1 and COX-2) enzymes. The plant extracts were screened first at a concentration of 250 ƒÊg/ml per test sample, and then further screened at concentrations of 125 and 62.5 ƒÊg/ml for extracts that inhibited the COX-2 enzyme. The Ames test was used to test for genotoxicity in extracts that showed interesting pharmacological activities using Salmonella typhimurium strain TA98. Among the screened extracts, 25 extracts showed good antibacterial activity with MIC values . 1.0 mg/ml. Dichloromethane extracts exhibited the greatest antibacterial activity, and Gram-positive bacteria were most susceptible. The best antibacterial activity was exhibited by Becium obovatum leaf EtOH extracts with an MIC value of 0.074 mg/ml. A broad spectrum antibacterial activity was observed by leaf extracts of Cucumis hirsutus (PE), Haworthia limifolia (PE), Protea simplex (PE and DCM) and Dissotis princeps (EtOH) against both Gram-negative and Gram-positive bacteria. No interesting antibacterial activity was exhibited by water extracts with the exception of Dissotis princeps water extract with a good antibacterial activity against Gram-positive and Gram-negative bacteria. In the antifungal assay, 6 extracts showed interesting antifungal activity. Protea simplex leaf PE extract showed the best fungicidal activity with an MFC value of 0.014 mg/ml. The best overall antifungal activity was observed in plant EtOH extracts. Some extracts from Agapanthus campanulatus (leaves and roots), Dissotis princeps (leaves), Gladiolus dalenii (corms) and Protea simplex (leaves) showed good activity against Candida albicans. Twenty one extracts inhibited the COX-1 enzyme, while fifteen extracts inhibited the COX-2 enzyme at the lowest screening concentration of 62.5 ƒÊg/ml. The highest COX-1 inhibition at a concentration of 62.5 ƒÊg/ml was exhibited by Diospyros lycioides leaf PE extract (89.1%) while Agapanthus campanulatus root DCM extract showed the highest COX-2 inhibitory activity (83.7%) at the same concentration. In the Ames test, no genotoxicity was observed in any of the extracts, however more tests need to be done to confirm these results. Thin layer chromatograms of the organic solvent plant extracts were developed. The fingerprints of the plant extracts showed colours of bands at different Rf values when viewed under UV254 and UV366 suggesting that the investigated plant species contained different compounds in the extracts. In the quest to understand the source of the plants pharmacological activities, total phenolic compounds including condensed tannins, gallotannins and flavonoids were quantitatively investigated in terms of their amounts in the aqueous methanol extracts of the plants materials using spectrophotometric methods. Alkaloids and saponins were qualitatively determined. The amounts of total phenolics were determined by the Folin Ciocalteu assay, condensed tannins were determined by the butanol-HCl assay, while rhodanine and vanillin assays were used to determine the amounts of gallotannins and flavonoids respectively. Dragendorff reagent was used to detect alkaloids in the plant extracts on thin layer chromatographic plates, while the froth test was employed to detect saponins. Secondary metabolites varied with plant parts and species with Cyperus textilis (leaf) having the highest amounts of total phenolics, condensed tannins and flavonoids. The highest amount of gallotannins was detected in Protea simplex leaf extracts. All the investigated plant materials with the exception of Haworthia limifolia leaf, Protea simplex leaf, Antidesma venosum leaf and Dissotis princeps leaf tested positively to saponins. Alkaloids were detected in Haworthia limifolia leaf (PE and EtOH), Cucumis hirsutus leaf (EtOH), Becium obovatum root (DCM), Protea simplex root and bark (EtOH), Agapanthus campanulatus root (DCM) and leaf (EtOH), Cyperus textilis root (DCM), Vernonia natalensis leaf (PE), Antidesma venosum leaf (PE), Diospyros lycioides leaf (PE) and Dissotis princeps leaf (DCM) extracts. The results obtained from the investigation of the pharmacology and phytochemistry of the plant species used to treat microbial infections related to gastro-intestinal tracts, provide sufficient preliminary information to validate the use of some of the plants in traditional medicine. The information provided might be considered sufficient for further studies aimed at isolating and identifying the active compounds in the plant species, and evaluating possible synergism amongst the isolated compounds. / Thesis (M.Sc)-University of KwaZulu-Natal, Pietermaritzburg, 2009.