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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.
431

An appraisal of homoeopathic proving methodology as a bridge between the indigenous and rationalist-scientific understandings of medicinal plants : the case of Strychnos henningsii

Ross, Ashley Hilton Adrian January 2011 (has links)
Submitted in fulfillment of the requirements of the Degree of Doctor of Technology: Homoeopathy, Durban University of Technology, 2011. / Aim This study sought to appraise homoeopathic proving methodology as a bridge between the indigenous and rationalist-scientific understandings of medicinal plants through a detailed exploration of the relationships existing between data derived from respective paradigmatic explorations of a single African traditional medicinal plant, Strychnos henningsii [Red bitterberry]. Methods The data derived from the implementation of a triple-blind, placebo-controlled homoeopathic proving methodology, on 32 healthy human subjects (50 percent placebo), using the bark of Strychnos henningsii in the 30CH potency, were evaluated for internal consistency and coherence, and subsequently compared to data derived from a phytochemical analysis of the crude bark sample, and translated data derived from semi-structured mothertongue interviews of eight Zulu traditional healers. The proving data took the form of subjective journal data and the results of four objective blood measures of erythrocyte sedimentation rate (ESR), redand white blood cell indices, and liver functions. The subjective data were evaluated in terms of defined inclusion criteria and presented in standard materia medica and repertory formats, and tabulations of objective data were subjected to independent statistical analysis, using repeated-measures ANOVA and profile plots. The crude bark sample was analysed in terms of the presence of strychnine and other indole alkaloids, using highperformance liquid chromatography-mass spectrometry, and interview data related to the indigenous understanding and application of Strychnos henningsii within the traditional African medical paradigm, were audiovisually recorded, collaboratively translated, and independently verified. ABSTRACT iii Qualitative data processing and analysis was effected with the aid of NVivo® software, and a range of comparative analyses were effected with the aid of Radar® homoeopathic software, materia medica references and the Mappa Mundi elemental theory model. Results The proving yielded 581 subjective symptoms, covering a broad range of physical and mental disease manifestations, and nine statistically-significant treatment effects within the objective data set. These included elevation of ESR and changes in two red blood cell indices, four white blood cell indices and two liver function indices. The two proving data sets were demonstrated to show high levels of correlation, although these correlations were not demonstrable for all provers. The phytochemical analysis confirmed the presence of between two and five strychnine-related compounds (excluding strychnine itself), and the field interview data served to confirm all except two documented traditions of use, as well as identifying a number of novel indications and application of Strychnos henningsii bark. The comparative analyses demonstrated the integrity of homoeopathic proving methodology as a mode of scientific investigation, and significant and widespread overlaps of proving symptomatology with both the pharmacology and toxicology of strychnine, and the physical and metaphysical understanding and application within the traditional African medical paradigm. Conclusions Homoeopathic proving methodology was discussed in terms of the evident degree of overlap with the indigenous and rationalist-scientific paradigms, and the incomplete nature of the homoeopathic ‘totality’. A number of recommendations were made for future cross-paradigmatic research. / Durban University of Technology. Postgraduate Development and Support Directorate.
432

Phytochemical isolation of compounds from the plant sceletium tortuosum

Setshedi, Itumeleng Bridgette 02 1900 (has links)
Traditionally, Sceletium tortuosum has been used as a medicine and for social and spiritual purposes. The genus is distributed in the south-western parts of South Africa. This project phytochemically analysed and characterised Sceletium plant extracts and determined if any extract showed anti-malarial properties. Extracts were prepared in ethanol and methanol and various compounds were purified using column chromatography with hexane and ethyl acetate as mobile phase. The structure of isolated compounds, including mesembrine, pinitol, sucrose, mesembrenone and obtusalin, was confirmed using NMR. The Plasmodium Lactate dehydrogenase assay was used to screen all extracts and mesembrine to show that four extracts showed antimalarial activity with activity values ranging between 1.47 μg/ml and 7.32 μg/ml, well below the 10 μg/ml cut off value. The study recommends extracting compounds from fresh plant material and further research as to anti-malarial activity of compounds isolated from Sceletium tortuosum / Life & Consumer Sciences / MSc. (Life Sciences)
433

Chemopreventive properties of South African herbal teas, rooibos (Aspalathus linearis) and honeybush (Cyclopia spp) : mechanisms against skin carcinogenesis

Magcwebeba, Tandeka Unathi 12 1900 (has links)
Thesis (PhD)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: The present study employed a two-phased approach to investigate the possible mechanisms involved in the chemopreventive properties of rooibos (Aspalathus linearis) and different honeybush species (Cyclopia spp.) in vitro. In the first phase, the effect of unfermented methanol and aqueous herbal tea extracts against the growth parameters (cell viability, proliferation and apoptosis) of normal (CRL 7761); premalignant (HaCaT); and malignant (CRL 7762) skin cells was evaluated and compared to green tea extracts. The predictive potential of polyphenol content (total polyphenol and flavanol/proanthocyanidins) and antioxidant properties (ABTS; ORAC; FRAP and LPO) in the biological activity of extracts in cells was also assessed. Of the herbal teas, the methanol extract of rooibos was the most active and it inhibited the growth of skin cells presumably by inducing mitochondrial dysfunction via membrane depolarisation. At lower concentrations, this activity was associated with inhibition of cell proliferation that was selective for cancer cells whilst higher concentrations induced apoptosis that was more prominent in premalignant cells. The strong antioxidant properties of the extracts implicated the role of pro-oxidative polyphenol/iron interactions involving monomeric flavonoids and polymeric proanthocyanidins in the cytotoxic effects of rooibos. The strong relationship between total polyphenolic and flavanol/proanthocyanidins content, antioxidant properties and reduction of cell viability indicated that these parameters (polyphenols and antioxidant properties) can serve as predictive tools for the cytotoxic effects of rooibos in vitro. The aqueous extracts of honeybush species, although weaker, displayed similar effects to rooibos extracts in cells with C. genistoides being the most effective at selectively inhibiting the proliferation of cancer cells whilst the pro-apoptotic activity of C. subternata and C. intermedia was more prominent in premalignant cells. The underlying mechanisms are also likely to result from pro-oxidative mechanisms resulting from polyphenol/iron interactions that mainly involve polymeric flavanol-like proanthocyanidin compounds in honeybush. In contrast, the methanol extracts exhibited weaker cytotoxic effects and protected cancer cells from going into apoptosis. The cytoprotective effects of honeybush species are possibly mediated by the major monomeric compounds such as mangiferin and hesperidin through antioxidant mechanisms that result in reduction of oxidative stress. Due to the possible dual role of the monomeric and polymeric compounds in the honeybush extracts, the total polyphenolic content of these herbal teas may not be a good indicator of biological activity in vitro. However, as aqueous extracts displayed high flavanol/proanthocyanidins content and exceptional activity in the ABTS assay, these parameters may be considered as indicators of cytotoxicity. On the other hand, methanol extracts, particularly from the xanthone-rich species (C. genistoides and C. longifolia) which exhibited the weakest cytotoxic effects, were more active in the ORAC thus this assay may be a useful predictor for cytoprotective activity. In the second phase, an in vitro UVB/HaCaT model which used IL-1α as a biomarker for early inflammation was developed and validated with known anti-inflammatory compounds, dexamethasone and ibuprofen. It was used to determine the specific mechanisms involved in the modulatory effects of the herbal tea extracts against inflammation. Rooibos extracts and the aqueous extract of honeybush enhanced the cytotoxic effects of UVB in the model and exhibited indirect anti-inflammatory effects as they removed icIL-1α containing cells via apoptosis. In contrast, methanol extracts of honeybush exacerbated icIL-1α by protecting UVB stimulated cells from undergoing apoptosis. In conclusion, methanol extract of rooibos and aqueous extracts of honeybush species may be useful in protecting the skin after UVB exposure. These herbal tea extracts may block initiation and delay the promotion stage during skin carcinogenesis by removing premalignant cells via apoptosis and preventing onset of inflammation. In contrast, due to their cytoprotective effects, methanol extracts of honeybush may be more effective at preventing oxidative stress in skin before UVB exposure. Future studies should focus on the effects of extracts and polyphenolic fractions on the oxidative status of the cells and development of biomarkers of chemoprevention that can be utilised in vivo and in human skin. / AFRIKAANSE OPSOMMING: In hierdie studie word moontlike velkankerwerende eienskappe van rooibos (Aspalathus linearis) en ‘n aantal heuningbos (Cyclopia spp.) spesies deur twee afsonderlike benaderings bestudeer. Die eerste benadering ondersoek die effek van die kruietee op groeiparameters van velselle [lewensvatbaarheid, groei en dood van normale selle (CRL 7761), vroeë kankerselle (HaCaT) en kankerselle (CRL 7762)]. Tydens eksperimente is die moontlikheid om polifenoolinhoud (totale polifenole, en flavanol/proantosianidiene verhouding) en antioksidant-eienskappe te gebruik om die biologiese funksies van die ekstrakte in die selle te voorspel, geevalueer. Die metanolekstrak van rooibos het die groei van selle die effektiefste gestop, moontlik deur depolarisasie van die mitokondriale membraan. By lae konsentrasies van die ekstrak is die groei van kankerselle selektief gestop, terwyl vroeë kankerselle die sensitiefste by hoër konsentrasies was. Die hoë antioksidant-aktiwiteit van die rooibosekstrak kan moontlik ‘n rol speel in die indusering van sitotoksiese effekte in die selle en kan toegeskryf word aan die pro-antioksidant aktiwiteit van die polifenole weens hul interaksie met yster. ‘n Spesifieke funksie word vir die monomeriese flavonoïede en die polimeriese proantosianidiene geïmpliseer. Die sterk verwantskap tussen die totale polifenoolinhoud, flavanol/proantosianidien inhoud en antioksidant aktiwiteit met die verlaging in selgroei, maak hul relevante parameters van die voorspellingsmodel. Die waterekstrakte van heuningbos induseer ook soortgelyke maar swakker effekte met die induksie van kankersel dood, met C. genistoides die selektiefste en C. subternata en C. intermedia die aktiefste spesies wat die groei van die vroeë kanker selle inhibeer. Die onderliggende meganismes betrokke blyk ook aan ‘n pro-oksidant effek toe geskryf te wees, waartydens spesifieke polifenool/yster interaksies betrokke is. In teenstelling met rooibos, beskerm die metanolekstrak van heuningbos kankerselle teen seldood, wat moontlik verband hou met die antioksidant-eienskappe van die hoof monomeriese polifenole, mangiferien/isomangiferien en hesperidien. Vanweë die dubbele rol van die monomeriese polifenole en polimeriese verbindings in heuninghbosekstrakte is die totale polifenol inhoud nie ‘n goeie indikator van die biologiese aktiwiteit in vitro nie. Daarenteen is die flavanol/proantosianien inhoud en die hoë aktiwiteit in die ABTS antioksidanttoets goeie indikators om seldood te voorspel. In teenstelling hiermee het die metanolekstrakte van die xantoon-ryke spesies (C. genistoides en C. longifolia) ‘n baie lae effek op seldood, maar ‘n hoë aktiwitiet in die ORAC toets getoon, wat ‘n goeie rigtingwyser is om die beskermende effek in selle te voorspel. Met die tweede benadering is die anti-inflammatoriese eienskappe en die onderliggende meganismes van die kruietee ondersoek in ‘n UVB/HaCaT selmodel. Intrasellulêre interleukin 1α (IL-1α) is as merker gebruik en die model is geëvalueer deur bekende anti-inflammatoriese verbindings soos dexamethasone en ibuprofin te gebruik. Die metanolekstrak van rooibos en die waterekstrak van heuningbos het die toksiese effek van UVB in die model verhoog deur selle met verhoogde vlakke,van icIL-1α te verwyder deur middel van die induksie van seldood. Die metanolekstrak beskerm die selle teen die oksidatiewe skade wat deur UVB geïnduseer word en verwyder nie selle met hoë IL-1α vlakke nie. Ter opsomming blyk dit dat die metanolekstrak van rooibos en die waterekstrak van heuningbos moontlik gebuik kan word om die vel te beskerm teen die induksie van icIL-1α en sodoende die inisiëring van kanker te blokkeer en ook die promosie van kanker te vertraag. Die beskermende effek van die metanolekstrak kan moontlik aangewend word om die oksidatiewe skade wat deur UVB veroorsaak word teen te werk deur dit aan te wend voordat blootstelling plaasvind. Toekomstige studies behoort verdere karakterisering van die polifenoolsamestelling van die ekstrakte in te sluit en hul effek op die oksidatiewe status en anti-inflammoriese effekte van selle te bepaal ten einde sekere merkers te identifiseer vir vel studies in vivo.
434

The anticancer mechanisms of polysaccharide peptide (PSP) derived fromthe Chinese medicinal fungus coriolus versicolor

Yang, Xiaotong, 楊曉彤 January 2004 (has links)
published_or_final_version / Zoology / Doctoral / Doctor of Philosophy
435

Traditional Chinese medicinal plants and their endophytic fungi: isolation, identification, and bioassay

Huang, Wuyang., 黃午陽. January 2008 (has links)
published_or_final_version / Biological Sciences / Doctoral / Doctor of Philosophy
436

Identification of Radix Rehmanniae (di huang) as a traditional Chinesemedicine with transcription inhibitory activity of microsomaltriglyceride transfer protein gene

Liu, Ching-chiu., 廖正釗. January 2008 (has links)
published_or_final_version / Chemistry / Master / Master of Philosophy
437

Proteomic profiling of mycelial extract derived from coriolus versicolor and analysis of their anti-tumor effects in human leukemiccells HL-60

Jin, Jing, 金晶 January 2009 (has links)
published_or_final_version / Biological Sciences / Master / Master of Philosophy
438

The formulation and evaluation of rapid release tablets manufactured from Artemisia Afra plant material.

Komperlla, Mahesh Kumar January 2004 (has links)
<p>Infusions, decoctions, alcoholic preparations and other dosage forms of Artemisia afra are frequently used in South African traditional medicine. Generally when these preparations are made without applying good manufacturing practices they do not meet microbial quality control standards, safety and toxicity criteria and encourage poor patients compliance. To overcome the aforementioned disadvantages of traditional dosage forms a sold dosage form, i.e. a table might be recommended. The first objective of this study was to formulate and manufacture a rapid release tablet dosage of Artemisia afra that would contain an amount of plant material equivalent to that found in its traditional liquid dosage forms and that would meet conventional pharmaceutical standards. The second objective was to conduct a pilot study to obtain a preliminary profile of the bioavailability of select flavonoids presents in both the tablet and traditional liquid preparation of Artemisia afra in humans.</p>
439

An assessment of Hypoxis hemerocallidea extracts, and actives as natural antibiotic, and immune modulation phytotherapies.

Muwanga, Catherine January 2006 (has links)
<p>In South Africa, the crude aqueous extract from Hypoxis hemerocallidea is used by AIDS patients to treat opportunistic infections, such as tuberculosis. The rapid emergence of multidrug-resistant tuberculosis, and extreme drug resistant tuberculosis, in recent years, is a major threat to human health. The treatment of TB, nosocomial bacterial infections, and fungal infections is now a clinical challenge, especially in the immuno-compromised individual. There is a dire need for novel antibiotic alternatives with phytotherapies and plant-derived compounds as potentially promising alternatives. The main objective of this study was to investigate the antimycobacterial activity of Hypoxis hemerocallidea, a South African medicinal plant, using Mycobacterium smegmatis.</p>
440

Screening of traditionally used South African medicinal plants against Candida albicans.

Motsei, Mpai Lesego. January 2003 (has links)
Candida species were discovered more than a century ago as a causative organism of oral thrush. In HIV patients, the presence of oral candidiasis has been shown to be the earliest opportunistic infection. Candidiasis lesions associated with HIV infections are primarily a reflection of the specific change of the host's immune response caused by the virus. Studies of AIDS all over the world show that 58-81% of all patients contract a fungal infection at some time during the primordial stage or after developing AIDS and 10-20% have died as a direct consequence of fungal infections. Twenty four South African medicinal plants were screened using a modification of the NCCSL broth microdilution antifungal test against Candida albicans standard strain ATCC 10231 and two clinical isolates from a 5-month- old baby and an adult. This assay was performed in order to find a traditional remedy to treat oral candidiasis. Of all the screened plants Allium sativum L., Glycyrrhiza glabra L., Polygala myrtifolia L. and Tulbaghia violacea L. aqueous extracts were found to have the best activity. Allium sativum and Tulbaghia violacea aqueous bulb extracts had MIC values of 0.56 mgml-1 and 3.25 mgml-1 respectively, whilst Polygala myrtifolia leaf extracts and Glycyrrhiza glabra rhizome extracts had MIC values of 1.56 mgml-1 and 3.25 mgml-1 respectively when tested against the isolate from a 5-month-old baby, which was the most susceptible of the isolates used. All the extracts had higher MIC values against the standard strain (ATTC 10231), which was the least susceptible to the extracts used. Stability testing was performed on fresh aqueous extracts of A. sativum, G. glabra, T. violacea and P. myrtifolia stored at 4°C, 23°C and 33°C over a period of one week, to determine the stability of the extracts in solution. All A. sativum extracts maintained stability for three days in solution, whilst T. violacea extracts remained stable for only two days in solution. TLC fingerprinting of A. sativum and T. violacea extracts indicated the presence of the known antibacterial and antifungal compound allicin. The activity of allicin and other active compounds was observed by using the bioautographic assay, which was performed on these extracts. P. myrtifolia and G. glabra extracts lost stability 24 hours after preparation at all tested temperatures. However, it was clear with the four plant extracts tested that storage of solutions at higher temperatures reduced their activity and stability. The unpleasant taste and smell of A. sativum and G. glabra could however not be masked, since the intake of these two extracts would result in HIV patients being recognised. These two plants where therefore not considered for further investigation. G. glabra and P. myrtifolia are both saponin containing plants. These could be the active constituents responsible for the anticandidal action. G. glabra is known for its biological activity as an antibacterial agent, whilst other Polygala species have been reported to possess antifungal saponins. Although P. myrtifolia and G. glabra are not stable for more than 24 hours, they do not have an unpleasant smell or taste. These plants are therefore further investigated for use as oral mouthwash in clinics and homes. / Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 2003.

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