• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 18
  • 8
  • 1
  • Tagged with
  • 32
  • 32
  • 10
  • 7
  • 7
  • 7
  • 7
  • 6
  • 6
  • 6
  • 6
  • 5
  • 5
  • 5
  • 5
  • 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.
1

The use of 'dry sex' traditional medicines by Zambian women

Mbikusita-Lewanika, Mbololwa January 2002 (has links)
No description available.
2

Evaluation of a phytogenic product from two western herbal medicines to replace an antimicrobial growth promoter in poultry production

Van Heerden, Ilse 06 October 2010 (has links)
Antimicrobial growth promoters (AGPs) are substances that are added to feed in sub-therapeutic levels in intensive animal production to improve weight gain and conversion of feed (FCR) into body mass. AGPs have been used widely as growth promoters in broiler and pig production under high-density growth conditions. Despite the observed efficacy, the use of AGPs has been criticized due to its possible role in the development of antibiotic resistance in human pathogens. Directive 183/2003 of the European Parliament, issued in 2003, banned of the use of all antibiotic agents as growth promoters in the European Union from 2006. The new context caused an increase in the search for alternative growth promoters. The aim of this study was to produce a commercially viable prophylactic antibacterial phytogenic product from Ginkgo biloba and Hypericum perforatum with a low potential to develop resistance, as an alternative to AGPs in poultry production. The first objective of this study based on earlier results of the Phytomedicine Programme, was to evaluate the activity and potentize extracts from Ginkgo biloba and Hypericum perforatum for optimal activity against relevant bacterial pathogens. Extracts of ethyl acetate (EA), hexane, dichloromethane (DCM) and acetone (in order of activity) from a direct extraction procedure of powdered G. biloba leaves were active against Enterococcus faecalis, Staphylococcus aureus and Clostridium perfringens. The EA, hexane and DCM extracts were 2 to 3 times more active than the acetone extract (average total activity 1728 ml/g dry extract for the 3 pathogens). The DCM-, EA-, acetone- and hexane extracts (in order of activity) from the direct extraction procedure from H. perforatum were only active against C. perfringens with the first three extracts having a total activity of between 1026 and 1333 ml/g dry material and the hexane extract a total activity of 333 ml/g dry material. The spectrum of activity of G. biloba corresponds to that of Zn-bacitracin, which is commonly used an antibiotic growth promoter in the poultry industry. The second objective in this study was to combine extracts or fractions of extracts of G. biloba and H. perforatum to optimise activity against selected bacterial pathogens. A synergistic effect could be observed when combining a ratio of 1:5 of G. biloba: H. perforatum (hexane extracts) or 1:15 (acetone extracts) against E. faecalis while only an indifferent (neutral) effect was observed against C. perfringens. After elucidation of the quantitative and qualitative aspects involved in the antimicrobial activity, the major antibacterial compound from G. biloba was isolated and characterized as ginkgolic acid (C17:1). It was also determined whether activity against E. faecalis and C. perfringens in an extract or fraction of and extract of G. biloba can be attributed only to ginkgolic acid or whether synergism or other interactions also play a role in the antibacterial activity. It was shown that synergistic interactions are at play between constituents in the hexane and EA fraction, with the last mentioned fraction not containing any ginkgolic acid. These results support the use of the whole extract as opposed to isolated compounds as antimicrobial agents against pathogenic organisms. Two important pharmacodynamic parameters were investigated i.e. resistance development to a hexane extract and the isolated ginkgolic acid from G. biloba against E. faecalis and secondly the time-kill dynamics of this hexane extract over 24 h against E. faecalis. The bactericidal nature of the hexane extract from G. biloba as well the absence of decreased susceptibility to this extract (and the isolated ginkgolic acid) in the resistance studies against E. faecalis indicate that this extract has potential to be exploited as a alternative to AGPs in the poultry industry. The final objective was to determine the effect of extracts of G. biloba alone or in combination with H. perforatum extracts on the performance of broiler chickens over a 35 day period. The effect of these extracts on C. perfringens in the intestine of broilers was also investigated. No significant differences were found with relation to any of the production parameters studied (FCR, live weight or % survival) although a trend towards more favourable European Performance Efficiency Factor index values were observed for treatments containing G. biloba (5% improvement) or a combination of G. biloba and H. perforatum (2.1% improvement) compared to the untreated control. Similarly, Zn-Bacitracin resulted in a 5.5% improvement compared to the untreated control. There was a general trend (not statistically significant, P=0.05) towards a reduction in C. perfringens scores in the feed supplemented with G. biloba- in combination with H. perforatum extract which can probably be ascribed to the direct antimicrobial effect. The rate of colonization was however too low to cause infection probably due to lack of virulence of the C. perfringens challenge and the absence of predisposing factors due to the hygienic growth conditions used. It is necessary for an effective disease model to be developed in order for the efficacy of any new treatment method to be properly evaluated. Such a model will require a much higher incidence of disease and reproducibility than was achieved in this project. The safety of using extracts of G. biloba with ginkgolic acid as the prime antibacterial compound was considered. The active dose was at least 42 times lower than safe dosage recommended in the literature. The combination of extracts of G. biloba and H. perforatum holds promise as a potential growth promoter in poultry production. Better results may be achieved if potentized extracts are used and compared with Zn-Bacitracin and a negative control under industrial growth conditions where the birds are stressed and natural infections would take place. Copyright / Thesis (PhD)--University of Pretoria, 2009. / Paraclinical Sciences / unrestricted
3

The in vitro and in vivo anti-flammatory properties and cytotoxicity of extracts of Euphorbia hirta

Ekpo, Okobi Eko 22 January 2009 (has links)
Asthma is considered one of the most common respiratory complaints in the world today but a medical cure for this condition is currently not available. The use of herbal medicines to treat asthma has however been reported and Euphorbia hirtais one such herb. The alkaloids, flavonoids, glycosides, sterols, tannins and triterpenoids in E. hirta appear to exert the anti-asthma effects reported. In the first part of this study, the aqueous, acetone, dichloromethane and hexane extracts of E. hirta were evaluated for their effects on the lysosomal membrane integrity, cell viability and cell number of MRC-5 cell-line using the NR/MTT/CV assay. Hydrocortisone was used as a pharmaceutical control. The differences between the effects of the different extracts were investigated and the effects of the extracts were compared with hydrocortisone. Results obtained showed that hydrocortisone was relatively toxic to the MRC-5 cells whereas all four extracts studied showed very limited cytotoxic effects, with the aqueous extracts generally exhibiting the least effects. In the second part of this study, the effects of the aqueous E. hirta extract on the blood coagulation system and general airway wall microstructure and ultrastructure were investigated using the BALB/c mouse asthma model. Hydrocortisone was also used as a pharmaceutical control. Parameters studied included inflammatory cell population in peripheral blood and their migration into the lung parenchyma; platelet aggregation and fibrin fibre morphology; fibroblast and mucous cell proliferation; alveolar cell numbers, lamellar body formation as well as filopodia formation. The animal weights were continuously being monitored throughout the study. Results from the animal studies showed that the aqueous extract of E. hirta had limited effects on changes in the animal weights and did not cause fragility of blood fibrin fibres nor change the integrity and morphology of the platelets in the mice as seen in those treated with hydrocortisone. E. hirta extracts also significantly reduced the number of active inflammatory cells (especially neutrophils, eosinophils and basophils); restored the histological alterations observed in respiratory structures studied and had diverse, dose-dependent beneficial ultrastructural effects like reduction of smooth muscle hypertrophy, inhibition of macrophages into the airway parenchyma, among others. The final judgment and conclusion of this study was that the aqueous E. hirta extract did not show cytotoxic effects and could be used for the treatment of asthma in the BALB/c mice at doses ranging 25-62.5mg/kg. Further research leading to clinical trials is recommended after testing the potency of equivalent doses of this extract in other animal asthma models. / Thesis (PhD)--University of Pretoria, 2008. / Anatomy / PhD / Unrestricted
4

Influence of environmental parameters on efficacy of herbal medicines

Netshiluvhi, Thiambi Reuben 06 May 2012 (has links)
It is evident that herbal medicines continue to be the mainstay of healthcare systems and source of livelihoods of many local communities in South Africa and other developing countries. As a result, there is an overwhelming dependence on medicinal products harvested from natural populations. This dependence has led to local extinction of some important medicinal plants that include Warburgia salutaris and Cassine transvaalensis in South Africa. Cultivation has great potential to relieve the pressure on natural populations. However, some traditional practitioners and scientists believe that cultivation may weaken medicinal properties and that increased secondary metabolites may form only under stress conditions, respectively. This is certainly true in some cases especially where infections with pathogens, browsing by herbivores or competition takes place in nature. It is however not clear how true this is with environmental stresses. The overall aim of this study was to evaluate to what degree different environmental conditions influenced antimicrobial and antioxidant activities of plants cultivated outside their natural environment. In order to address the aim of the study, exploratory and in-depth studies were undertaken. The exploratory study comprised long-lived Combretum collinum Fresen. (Combretacea), Terminalia sericea Burch. ex DC. (Combretaceae) and Sclerocarya birrea (A. Rich.) Hochst. (Anacardiaceae). Short-lived herbaceous Tulbaghia violacea Harv. (Alliaceae) and Hypoxis hemerocallidea Fish, C.A.Mey,&Avé- Lall, (Hypoxidaceae), were included as part of the exploratory study. The in depth studies were further undertaken, also with short-lived herbaceous Leonotis dysophylla Benth. (Lamiaceae), Bulbine frutescens (L.) Willd. (Asphodelaceae) and T. violacea. Acetone leaf extracts of all plants were studied for antimicrobial activity against bacteria (Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Enterococcus faecalis) and fungi (Candida albicans, Cryptococcus neoformans and Aspergillus fumigatus). Extracts were also studied for antioxidant activity against Trolox and L-ascorbic acid standard oxidants using 2,2’-azinobis-(3-ethyl-benzothiazoline-6-sulfonic acid) (ABTS) and 2,2- diphenyl-2-picryl-hydrazyl (DPPH) free radicals, respectively. The exploratory study tested the effect of different rates of annual rainfall (≥870 mm/year, 651 mm/year and 484 mm/year) on the antibacterial activity of C. collinum, T. sericea and S. birrea growing in nature. The minimum inhibitory concentration (MIC) of acetone extracts of air-dried leaves was determined by using microplate serial dilution technique. Thin layer chromatography (TLC) and bioautography determined chemical constituents and antibacterial activity of extracts, respectively. The majority of extracts had low MIC values, which indicated good antibacterial activity against test bacteria (MIC of 240 μg/ml - 60 μg/ml). Leaf extracts of C. collinum and S. birrea against S. aureus (range of 390 – 100 μg/ml), E. coli (310 -70 μg/ml) and P. aeruginosa (520 - 70 μg/ml) had antibacterial activity increased significantly with low rate of annual rainfall. However, extracts of T. sericea against P. aeruginosa (240 - 100 μg/ml) and E. faecalis (150 - 820 μg/ml) had antibacterial activity significantly increased and decreased, respectively. Extracts of C. collinum and S. birrea against E. faecalis as well as T. sericea against S. aureus and E. coli did not show any clear correlation between activity and different rates of annual rainfall. Inconsistent results suggest that other factors in nature such as genetic variability, age difference, pathogens, herbivores or allelopathy (competition) might have influenced the antibacterial activity of extracts. The results indicate that the antimicrobial activity of plants growing in nature may be highly variable. In order to eliminate possible effect of those factors common in nature, another exploratory study was undertaken using clone T. violacea and H. hemerocallidea of similar age (Chapter 3). Plants were grown under controlled conditions that included irrigation with 1000 ml of distilled water in intervals of 3, 14 and 21 days outside natural environment. Dry mass of all plants was reduced significantly (P≤0.05) with watering interval of 21 days, which indicated the effect of water stress. Air-dried leaves of all plants were finely ground and extracted with acetone. Extracts had good antibacterial activity as attested by low MIC values (< 1 mg/ml) across watering intervals. Differences in the antibacterial activity of the extracts against test bacterial between water treatments were not statistically significant (P≤0.05). Furthermore, there was no clear correlation between the activity of extracts and water treatments in terms of the MIC and total activity values or chemical constituents. The results in general suggest that cultivation under optimal watering intervals may not necessarily weaken the biological activity of extracts. To complement the above findings, in depth studies were also undertaken with clone L. dysophylla, T. violaceae and B. frutescens of similar age growing under controlled conditions outside natural environment. The studies determined the influence of a wide range of water (50 ml – 500 ml) and temperature (15°C and 30°C) treatments on antibacterial, antifungal and antioxidant of extracts. With the exception of a crassulacean acid metabolism (CAM) plant, B. frutescens, transpiration, dry mass and leaf areas of the other two plants were reduced significantly (P 0.05) under high temperature of 30°C and lowest water supply of 50 ml. Acetone leaf extracts had some biological activity. Differences in the majority of antibacterial and antifungal activities of extracts between water and temperature treatments were not statistically significant. With the exception of the influence of temperature, the majority of the antioxidant activity of extracts was almost similar between water treatments. However, the significant reduction of the antioxidant activity of all extracts under high temperature of 30°C was indicative of great sensitivity to high temperatures. The overall findings suggest that the biological activity of plants is more likely to vary widely in nature than under controlled conditions outside the natural environment. This is an indication that natural environment cannot always guarantee high and stable biological activity. As a result, beliefs by some traditional practitioners and scientists that cultivation weakens medicinal properties and good secondary metabolites form only under stress, respectively, cannot be widely substantiated. Therefore, the study encourages cultivation of medicinal plants. It has potential to optimise yield of biomass production, and ensure uniform and quality biological activity as well as reduce misidentification. / Thesis (PhD)--University of Pretoria, 2012. / Paraclinical Sciences / unrestricted
5

Does the taste matter? Taste and medicinal perceptions associated with five selected herbal drugs among three ethnic groups in West Yorkshire, Northern England

Pieroni, Andrea, Torry, Bren January 2007 (has links)
In recent years, diverse scholars have addressed the issue of the chemosensory perceptions associated with traditional medicines, nevertheless there is still a distinct lack of studies grounded in the social sciences and conducted from a cross-cultural, comparative perspective. In this urban ethnobotanical field study, 254 informants belonging to the Gujarati, Kashmiri and English ethnic groups and living in Western Yorkshire in Northern England were interviewed about the relationship between taste and medicinal perceptions of five herbal drugs, which were selected during a preliminary study. The herbal drugs included cinnamon (the dried bark of Cinnamomum verum, Lauraceae), mint (the leaves of Mentha spp., Lamiaceae), garlic (the bulbs of Allium sativum, Alliaceae), ginger (the rhizome of Zingiber officinale, Zingiberaceae), and cloves (the dried flower buds of Syzygium aromaticum, Myrtaceae). The main cross-cultural differences in taste perceptions regarded the perception the perception of the spicy taste of ginger, garlic, and cinnamon, of the bitter taste of ginger, the sweet taste of mint, and of the sour taste of garlic. The part of the study of how the five selected herbal drugs are perceived medicinally showed that TK (Traditional Knowledge) is widespread among Kashmiris, but not so prevalent among the Gujarati and especially the English samples. Among Kashmiris, ginger was frequently considered to be helpful for healing infections and muscular-skeletal and digestive disorders, mint was chosen for healing digestive and respiratory troubles, garlic for blood system disorders, and cinnamon was perceived to be efficacious for infectious diseases. Among the Gujarati and Kashmiri groups there was evidence of a strong link between the bitter and spicy tastes of ginger, garlic, cloves, and cinnamon and their perceived medicinal properties, whereas there was a far less obvious link between the sweet taste of mint and cinnamon and their perceived medicinal properties, although the link did exist among some members of the Gujarati group. Data presented in this study show how that links between taste perceptions and medicinal uses of herbal drugs may be understood as bio-cultural phenomena rooted in human physiology, but also constructed through individual experiences and culture, and that these links can therefore be quite different across diverse cultures.
6

A cytotoxic diterpenoid from Croton membranaceus, the major constituent of anticancer herbal formulations in Ghana

Bayor, M.T., Ayim, J.S.K., Marston, G., Phillips, Roger M., Shnyder, Steven, Wheelhouse, Richard T., Wright, Colin W. January 2008 (has links)
No / Croton membranaceus is used by herbalists and traditional healers in Ghana for the management of various cancers, especially prostate cancers. A methanolic extract of the roots showed cytotoxic activities against two cancer cell lines, and bioassay-guided fractionation of this extract revealed that the cytotoxic activity resided mostly in the ethyl acetate fraction. Six compounds were isolated from this fraction, including a new furano-clerodane diterpenoid (1), for which the trivial name crotomembranafuran is suggested. This compound exhibited an IC50 value of 4.1 microgram/mL (10.6 microM) against human prostate (PC-3) cells, providing some support for the traditional use of C. membranaceus in the treatment of cancers
7

Identificação de planta medicinal baseada em espectrocospia e lógica fuzzy. / Signature of medicinal plant using spectroscopy and fuzzy logic.

Severo, Rosane Beatriz Oliveira 14 December 2009 (has links)
A presente tese de doutorado discorre sobre o método da espectroscopia na região do Infravermelho Próximo, usando Transformada de Fourier (IVP-TF), aplicada à identificação de plantas medicinais, método de análise química qualitativa, que se propõe para o controle de qualidade de fitoterápicos. É apresentado, também, um método computacional, implementado para realizar esta identificação, utilizando modelo e lógica nebulosos (fuzzy). Remete-se a discussão da espectroscopia IVP-TF como um método rápido e de baixo custo, para taxonomia de plantas medicinais brasileiras, bem como promove-se a comparação dos resultados obtidos nos diferentes métodos utilizados. / This doctoral thesis is about the method of Near Infrared spectroscopy using Fourier transform (FT-NIR), applied to identification of medicinal plants, method of the chemical analysis qualitative, which is proposed to the quality control of herbal medicines. It is presented, also, a computational method, implemented to make this identification using fuzzy logic model. Refers to discussion of FT-NIR spectroscopy as a rapid method with low cost for taxonomy of Brazilian medicinal plants, and makes comparison of results obtained in the different methods used.
8

Identificação de planta medicinal baseada em espectrocospia e lógica fuzzy. / Signature of medicinal plant using spectroscopy and fuzzy logic.

Rosane Beatriz Oliveira Severo 14 December 2009 (has links)
A presente tese de doutorado discorre sobre o método da espectroscopia na região do Infravermelho Próximo, usando Transformada de Fourier (IVP-TF), aplicada à identificação de plantas medicinais, método de análise química qualitativa, que se propõe para o controle de qualidade de fitoterápicos. É apresentado, também, um método computacional, implementado para realizar esta identificação, utilizando modelo e lógica nebulosos (fuzzy). Remete-se a discussão da espectroscopia IVP-TF como um método rápido e de baixo custo, para taxonomia de plantas medicinais brasileiras, bem como promove-se a comparação dos resultados obtidos nos diferentes métodos utilizados. / This doctoral thesis is about the method of Near Infrared spectroscopy using Fourier transform (FT-NIR), applied to identification of medicinal plants, method of the chemical analysis qualitative, which is proposed to the quality control of herbal medicines. It is presented, also, a computational method, implemented to make this identification using fuzzy logic model. Refers to discussion of FT-NIR spectroscopy as a rapid method with low cost for taxonomy of Brazilian medicinal plants, and makes comparison of results obtained in the different methods used.
9

A concessão de patentes de medicamentos fitoterápicos no Brasil: uma análise do período 1997-2004 / The granting of patent herbal medicines in Brazil: an analysis of the 1997-2004 period

Carlos Augusto de Freitas Peregrino 23 May 2006 (has links)
Este trabalho aborda o problema do consumo desenfreado de produtos naturais no Brasil, especificamente de medicamentos fitoterápicos, com suas consequências, discutindo à luz do Direito de Propriedade Industrial e o Direito Sanitário. Procura relacionar o papel e a responsabilidade do INPI e a ANVISA, órgãos diretamente envolvidos na legislação mencionada, para a melhoria da qualidade de produtos fitoterápicos registrados e lançados no mercado brasileiro. Mostra a necessidade de uma reavaliação dos critérios de concessão de patentes para a área analisada por parte do INPI, bem como uma maior aproximação da ANVISA junto à este órgão, de modo que harmonizem estratégias para que a população tenha acesso a medicamentos fitoterápicos seguros e eficazes. Explicita as estratégias d indústria nacional do setor em alavancar suas vendas no mercado, através de projetos de lei que não traduzem com a realidade preconizada pela OMS, para o uso da Medicina Tradicional/Complementar, contrariando a legislação brasileira para o possível registro dos produtos patenteados. Conclui-se que interesses econômicos, ligados à acirrada concorrência no mercado de fitoterápicos e suplementos nutricionais, induzem à concessão de patentes para tais produtos, em detrimento das diretrizes existentes na Lei de Propriedade Industrial brasileira, em critérios de avaliação. / This work approaches the problem of the wild consumption of natural products in Brazil, specifically herbal medicines, with its consequences, discussing to the light of the Right of Industrial Property and the Sanitary Right. It tries to relate the paper and the responsibility of INPI and ANVISA, organs directly involved in the mentioned legislation, for the improvement of the quality of products registered as herbal medicines and thrown in the Brazilian market. It shows the need of a reevaluation of the approaches of concession of patents for the area analyzed on the part of INPI, as well as larger approach of ANVISA close to this organ, so that they harmonize strategies so that the population has access to medications safe and effective herbal medicines. Explicit the strategies of the national industry of the section in it increases its sales in the market, through bills that dont translate with the strategies suggested by Oms, FOR Complementary/Alternative Medicine use, thwarting the Brazilian legislation for the possible registration on the patented products. It is ended that economic interests, linked to the intransigent competition in the herbal medicines market and nutritional supplements, induce to the concession of patents for such products, in detriment of the existent guidelines in the Law of Brazilian Industrial Property, in evaluation approaches.
10

A concessão de patentes de medicamentos fitoterápicos no Brasil: uma análise do período 1997-2004 / The granting of patent herbal medicines in Brazil: an analysis of the 1997-2004 period

Carlos Augusto de Freitas Peregrino 23 May 2006 (has links)
Este trabalho aborda o problema do consumo desenfreado de produtos naturais no Brasil, especificamente de medicamentos fitoterápicos, com suas consequências, discutindo à luz do Direito de Propriedade Industrial e o Direito Sanitário. Procura relacionar o papel e a responsabilidade do INPI e a ANVISA, órgãos diretamente envolvidos na legislação mencionada, para a melhoria da qualidade de produtos fitoterápicos registrados e lançados no mercado brasileiro. Mostra a necessidade de uma reavaliação dos critérios de concessão de patentes para a área analisada por parte do INPI, bem como uma maior aproximação da ANVISA junto à este órgão, de modo que harmonizem estratégias para que a população tenha acesso a medicamentos fitoterápicos seguros e eficazes. Explicita as estratégias d indústria nacional do setor em alavancar suas vendas no mercado, através de projetos de lei que não traduzem com a realidade preconizada pela OMS, para o uso da Medicina Tradicional/Complementar, contrariando a legislação brasileira para o possível registro dos produtos patenteados. Conclui-se que interesses econômicos, ligados à acirrada concorrência no mercado de fitoterápicos e suplementos nutricionais, induzem à concessão de patentes para tais produtos, em detrimento das diretrizes existentes na Lei de Propriedade Industrial brasileira, em critérios de avaliação. / This work approaches the problem of the wild consumption of natural products in Brazil, specifically herbal medicines, with its consequences, discussing to the light of the Right of Industrial Property and the Sanitary Right. It tries to relate the paper and the responsibility of INPI and ANVISA, organs directly involved in the mentioned legislation, for the improvement of the quality of products registered as herbal medicines and thrown in the Brazilian market. It shows the need of a reevaluation of the approaches of concession of patents for the area analyzed on the part of INPI, as well as larger approach of ANVISA close to this organ, so that they harmonize strategies so that the population has access to medications safe and effective herbal medicines. Explicit the strategies of the national industry of the section in it increases its sales in the market, through bills that dont translate with the strategies suggested by Oms, FOR Complementary/Alternative Medicine use, thwarting the Brazilian legislation for the possible registration on the patented products. It is ended that economic interests, linked to the intransigent competition in the herbal medicines market and nutritional supplements, induce to the concession of patents for such products, in detriment of the existent guidelines in the Law of Brazilian Industrial Property, in evaluation approaches.

Page generated in 0.0409 seconds