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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

Pharmacological investigation of some trees used in South African traditional medicine.

Eldeen, Ibrahim Mohamed Suliman. January 2005 (has links)
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.
52

Micropropagation and medicinal properties of Barleria greenii and Huernia hystrix.

January 2009 (has links)
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.
53

Biological activity of traditional medicinal plants used against venereal diseases in South Africa.

Buwa, Lisa Valencia. January 2006 (has links)
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.
54

Pharmacology and phytochemistry of South African traditional medicinal plants used as antimicrobials.

Fawole, Olaniyi Amos. January 2009 (has links)
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.
55

Understanding Tsonga tradicional [i.e. traditional] medicine in the light of Jesus' healings..

Titoce, Isaias Paulo. January 2002 (has links)
Religion and culture always go together. From the very first day a new person is brought out into this world, s/he starts learning how to live with her or his people, and starts learning their beliefs and values. The person grows up with this knowledge, and it forms a part of his/her life. These beliefs and values are unquestionable from the perspective of that person. They are accepted as natural and normative. If s/he, for example, is brought up in a culture in which kneeling is a form of showing respect, s/he will internalise this, and will always kneel when the act of showing respect is required. For another person who is brought lip in a different culture where standing lip, for example, is regarded as the way of showing respect, kneeling or sitting before a respected individual or occasion can be regarded by a such person as an impoliteness. As we can see, cultural values are subjective, and they are appropriate for the people of a specific culture in which they were fashioned and accepted as normative. What often happens is that when two different cultures meet there is a collision between them, and what often happens is that the one which is supported by power smashes the other and imposes its normative rules on it. When Christianity came to Africa, it was full charged by European way of viewing the world, and in its worldview, anything which was not within the European cultural nornlative frame, was something to get rid of Consciously or unconsciously, Christianity was used as a powerful tool for the West's cultural domination over Africans. The Church demonised African culture, and regarded it as a prototype of anti-Christianity. To become Christians, Africans were required to forsake their life style and assimilate the Western style of living. Things such as drums, xylophones, which were part of African culture, were associated with the demons and thus banned from the lives of the "faithful" African Christians. The memorial ceremonies, which were held for our ancestors, were understood as being a form of idolatry, whereas the church's memory of the saints was regarded as something very Christian. And, if the African culture and practices were abominable for the Western Christian missionaries, its traditional health care system was seen as the ultimate manifestation of the evil. [t is with the desire of reclaiming the legitimacy of African traditional health care system for Africans that 1 set out to examine healing from a cross-cultural perspective, and above all healing in the Bible, and specially Jesus' healings in order to see what is abominable with African traditional medicine. / Thesis (M.Th.)-University of Natal, Pietermaritzburg, 2002.
56

Seed germination and medicinal properties of Alepidea species.

Mulaudzi, Rofhiwa Bridget. January 2009 (has links)
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.
57

In vitro bulb induction in Eucomis zambesiaca Baker.

Cheesman, Lee. January 2009 (has links)
Eucomis L’ Hér. is a genus of 10 species that fall within the Hyacinthaceae family. Eucomis zambesiaca Baker is a summer-blooming bulbous geophyte occurring from northern South Africa to Malawi. Eucomis species are used in southern African traditional medicine for the treatment of various ailments, in particular, pain and inflammation. As a result, the bulbs are heavily harvested for trade in South Africa’s traditional ‘muthi’ markets. Over-collection of Eucomis species has seriously depleted natural populations and now Eucomis plants are among the 15 scarcest medicinal species to be traded. Micropropagation is a useful technique for rapid clonal multiplication of plant material which could potentially yield useful secondary metabolites as well as alleviate the pressure on the wild plant populations. The in vitro induction of storage organs is especially beneficial as it can limit the loss of plants during acclimatization as bulblets are hardier than shoots or plantlets. The aim of this research was to determine optimal growth conditions for bulblet induction of Eucomis zambesiaca. The effect of environmental and physiological parameters on the initiation and growth of bulblets was investigated. These included the effect of temperature, photoperiod, various carbohydrates at different concentrations and combinations as well as various plant growth regulators. Maximum number of bulblets per explant was obtained at 20 °C, with an average of three bulbs p er leaf explant. The average bulblet mass was 57 mg, which was significantly higher than bulblets formed at other tested temperatures. An 8 h light regime was the optimum photoperiod. The highest mean number of bulblets (1.4 per leaf explant) developed under the 8 h photoperiod and the bulblets that formed were large in size. They had a mean bulb diameter of 3.4 mm and a mean bulb weight of 42 mg. Different carbohydrates such as fructose, sucrose and glucose were tested at concentrations of; 1, 3, 6, 9 and 12%. Fructose at a concentration of 3% was found to produce the best results. An average of 1.2 bulbs formed per explant. The mean bulb diameter was 3.4 mm and mean bulb weight was 56.6 mg. Plant growth regulators (GA3, IAA, IBA, NAA, BA, zeatin, iP and others) were tested at concentrations of 1, 2 and 5 mg/L. 1 mg/L IBA was found to be the optimum hormone treatment for bulblet induction. Bulblets were large, had good leaves and well established roots. Medium supplemented with 1 mg/L IBA produced bulblets that had an average bulb diameter of 4.36 mm and a mean bulblet weight of 79.1 mg. Bulblets grown in vitro were transferred to vermiculite and placed in a misthouse to acclimatize. After 2 months the plantlets were transferred to pots containing a sand:soil mixture of 1:1 and placed in a greenhouse. There was a 80 to 90% survival rate. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2009.
58

Pharmacological evaluation of some central nervous system effects of Cotyledon Orbiculata.

Kabatende, Joseph January 2005 (has links)
The use of traditional medicine through the use of medicinal plants in Africa and especially in South Africa has long been considered an important characteristic of people's daily lives and socio-cultural heritage. Cotyledon Orbiculata is among the medicinal plants that are used by South African traditional practitioners for the treatment of epilepsy and painful conditions such as corns, warts, toothache, earache, boils and various other ailments. However, the claim of therapeutic successes of medicinal plants by traditional medicine practitioners are hardly subjected to scientific scrutiny. This study therefore, investigated the anti-epileptic property of Cotyledon Orbiculata by studying the effects of the methanol extract of the plant against chemically induced seizures by pentylenetetrazole, picrotoxin, bicuculline and N-methyl-DL-aspartic acid in mice. The study also investigated the analgestic effects of Cotyledon Orbiculata by studying the effect of the plant extract on pain induced by acetic acid and hot plate thermal stimulation.
59

Investigation of antidiabetic properties, mechanisms of action and toxicology of Strychnos Henningsii (GILG) bark

Oyewole, Oyedemi Sunday January 2011 (has links)
The apparent reversal of trend from modern drugs to herbal medicine is partly due to the fact that synthetic drugs have always shown adverse reactions and other undesirable side effects. Hence, the use of medicinal plants for the treatment of diseases such as diabetes is very common especially in the rural areas. Majority of these plants are used based on the experience and indigenous knowledge without identification of the therapeutic agents. There is enormous wealth of medicinal plants in the world yet many of them have not been discovered or studied scientifically to substantiate their ethno-medicinal usages. Ethnobotanical study has been the method often used to search for locally important plant species for the discovery of crude drugs with low side effects. An ethnobotanical survey was conducted on the medicinal plants commonly used for the management of diabetes mellitus in Nkonkobe Municipality, Eastern Cape of South Africa. Information was obtained through structured questionnaire administered to traditional healers and herbalists in the region. The study revealed 15 species of plants belonging to 13 families. Strychnos henningsii and Leonotis leonorus among others were repeatedly mentioned by the traditional healers as the two mostly used plants for the management of diabetes mellitus. The infusion and decoction of the roots, leaves and barks of these plants are the methods of preparation. The antioxidant potential of aqueous bark extract of S. henningsii was investigated both in vivo and in vitro using spectroscopic method. The antioxidant activity of the extract against hydrogen peroxide (H2O2), 2,2′-azinobis[3-ethylbenzothiazoline6-sulfonic acid] diammonium salt (ABTS), as well as reducing power was concentration dependent. The extract exhibited lower and average scavenging activities against 1,1diphenyl2picrylhydrazyl (DPPH) and nitric oxide (NO) radicals with IC50 value of 0.739 and 0.49 mg/ml respectively. The administration of the plant extract at 250, 500 and 1000 mg/kg significantly increased the activities of the antioxidant enzymes in the hepatotoxic rats induced with carbon tetrachloride. On the other hand, the stem bark extract had lower effect on lipid peroxidation level except at the dose of 250 mg/kg. The effect of oral administration of S. henningsii extract was evaluated in normal Wistar rats for 28 days. The observed result indicated non- toxic effect of sub-acute administration of plant extract to the animals except at certain doses. This is because, there was no apparent damage to some haematological and biochemical parameters used in assessing organ specific toxicity. However, the alterations observed on platelet, white blood cells and its differentials imply parameter and dose selective toxicity when repeatedly consumed on daily basis at the doses investigated. This study also investigated the antidiabetic activities of the extract at the doses of 125, 250 and 500 mg/kg body weight in diabetic rats induced with streptozotocin -nicotinamide for 15 days. The extract appreciably (P <0.05) reduced the blood glucose level, feed and water intake while the best result was obtained at 250 mg/kg. Similarly, the level of triacylglycerol at the three doses investigated was significantly decreased. In addition, the glucose tolerance was reduced to near normal level after 90 min at certain doses. The clinical significance of the extract on some biochemical and haematological parameters lessen both hepatic and renal damages. Anaemic condition in diabetic animals was also improved after plant extract administration. However, no significant effect was observed in white blood cells and some of its differentials. The extract demonstrated strong glucose utilization in 3T3-L1 cells with a response of 278.63 percent of the control at 12.5μg/ml while that of Chang liver cells was 103.54 percent. The cytotoxicity result revealed non toxic effects of the extract to both cell lines. Treatment of 3T3 L1 cells with the extract did not reduce lipid accumulation. The extract inhibited the activity of α- glucosidase and α- amylase in a concentration dependent manner with IC50 values of 38 μg/ml and 60.9 μg/ml respectively. The percentage protein antiglycation of S. henningsii was 18.4, 38.2 and 61.2 perceent for 0.25, 0.5 and 1 mg/ml respectively while aminoguanidine a known inhibitor of protein glycation was 87.2 percent at 1 mg/ml. The FRAP assay values of the extract was 357.05 μmol Fe (II)/g. The findings from this study support the folkloric usage of this plant for the management of diabetes mellitus in the region.
60

Assessment of plants used for the treatment of cattle wounds and myiasis in Amatola Basin, Eastern Cape Province, South Africa

Soyelu, Oluseyi Temitope January 2010 (has links)
No description available.

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