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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.
41

Avaliação dos efeitos citotóxicos, genotóxicos, mutagênicos, antigenotóxicos, antimutagênicos e anticarcinogênicos do Lupinus albus em camundongos Mus musculus /

Oliveira, Jaqueline Aparecida de. January 2013 (has links)
Orientador: Maria Aparecida Marin-Morales / Banca: Grasiela Dias de Campos Severi-Aguiar / Banca: Elaine Cristina Mathias da Silva Zacarin / Resumo: O uso de plantas medicinais é uma prática muito antiga e utilizada pela maioria dos povos em todo o mundo. Lupinus albus (L. albus), conhecido popularmente como tremoço branco, vem sendo usado na medicina popular, em forma de sementes cruas, como regulador de níveis de glicemia e colesterol. Embora descrito na literatura que suas proteínas e alcaloides isolados têm potencial para isto, não se tem qualquer informação científica em relação à eficiência de suas sementes cruas. O objetivo deste trabalho foi avaliar os possíveis efeitos, citotóxicos, genotóxicos e antigenotóxicos, mutagênicos e antimutagênicos, carcinogênicos e anticarcinogênicos e também o potencial imunomodulador do extrato aquoso de sementes cruas de L. albus, por meio de ensaios de micronúcleo em medula óssea, Focos de criptas aberrantes em cólon, contagem diferencial de leucócitos, níveis de glicemia e colesterol do soro de camundongos da espécie Mus musculus, bem como determinar e quantificar, por meio de cromatografia gasosa, alcaloides e ácidos graxos desse extrato. Foi avaliado nos camundongos seus efeitos nas concentrações equivalente a 3 sementes/dia (como utilizado na medicina popular) e 9 sementes/dia. A análise fitoquímica do extrato revelou a presença do alcaloide lupanina, dos ácidos graxos oleico, linoleico, palmítico e esteárico. Porém não foi possível observar, por meio de ensaios bioquímicos, os efeitos hipoglicêmicos de L. albus em ambos os protocolos seguidos. Foi observado que os níveis de colesterol apresentaram melhora, para o protocolo com administração da DMH. No ensaio de MN em medula óssea, não foi observado efeito citotóxico, porém foi possível observar efeito genotóxico e mutagênico para o extrato testado na concentração maior no tratamento sub-crônico. Foram também observados efeitos antigenotóxico e... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The use of medicinal plants is a very old practice, used by most of the people around the world. Lupinus albus (L. albus), popularly known as white lupine, has been used in popular medicine in form of raw seeds, as a regulator of blood glucose and cholesterol. Although literature describes that their isolated proteins have the this potential, there is no scientific information regarding the efficiency of their raw seeds. The aim of this study was to evaluate the possible genotoxic, antigenotoxic, mutagenic, antimutagenic, anticarcinogenic and carcinogenic effects, and also the immune modulatory potential of aqueous extract of raw seeds of L. albus, by means of bone marrow micronucleus, aberrant crypt foci in colon, leukocyte counting, blood glucose and serum cholesterol levels of mice Mus musculus, as well as to determine and quantify alkaloids and fatty acids of these extracts, by gas chromatography. The effects of concentrations equivalent to 3 seeds/day (as used in popular medicine) and 9 seeds/day were evaluated in mice. Chemical analysis of the extract showed the presence of the alkaloid lupanine and oleic, linoleic, palmitic and stearic fatty acids. However, according to biochemical assays, it was not possible to observe hypoglycemic effects of L. albus in both followed protocols. It was observed that cholesterol levels showed an improvement in the protocol using DMH. No cytotoxic effects were observed in the MN assay in bone marrow, but genotoxic and mutagenic effects were recorded in highest concentration of the tested extract. Antigenotoxic and antimutagenic effects were also observed, demonstrating a preventive action for the two concentrations tested due to the promotion of harm reduction for pre-extract treatment. When the extract of L. albus was administered simultaneously with DMH, a reduction in damage was... (Complete abstract click electronic access below) / Mestre
42

The impacts of harvesting circumcision amaryllids from the Eastern Cape Province, South Africa

Nombewu, Nomatile January 2014 (has links)
This quantitative study seeks to determine the impacts of harvesting three plant species traditionally used for wound healing during circumcision. Three localities where these plant species occur have been identified. The population size for each species was determined and an assessment of the extent of harvesting was determined through repeated assessment of marked plants. A significant harvest of these species resulted in the unsustainable use of our natural resources. Out of 25 Boophone disticha plants marked, only one plant was remaining after two circumcision seasons. The Brunsvigia grandiflora and Scadoxus multiflorus populations monitored disappeared completely, with no single marked plant found after two circumcision seasons. Growth rates of wild populations of Boophone disticha and cultivated Brunsvigia grandiflora and Scadoxus multiflorus plants were determined. The seedling bulbs of Brunsvigia grandiflora grew significantly more slowly at less than 0.6 cm per year, while Scadoxus multiflorus grew faster at over 1 cm per year. A model for population dynamics of the three plant species was designed which showed that the plants are being harvested before they even flower. It is therefore recommended in this study that a conservation plan for these plant species must be done to save the little that is left in the wild before they become critically endangered.
43

Bioactivity and chromatographic profiles of the selected medicinal plants against candida albicans

Mulaudzi, Takalani Millicent 17 July 2015 (has links)
MSc (Botany) / Department of Botany
44

Chemical investigation of isihlambezo or traditional pregnancy-related medicines.

Brookes, Kathleen Bridget. January 2004 (has links)
This study was undertaken to redress the scant knowledge regarding the chemistry and mode of action of pregnancy-related traditional medicines, or isihlambezo (Zulu), which are used by 60 to 80% of women in South Africa. The three selected plants are among the six most frequently cited species from the approximately 90 used by traditional healers. The purpose of the study was to identify components which could cause uterine contractions, those with nutritional value for the foetus and mother, and those with any toxic effects. Plant root extracts were purified via silica gel column chromatography and bioassays were carried out on the fractions, using isolated rat uterine tissue. Purified compounds were identified via spectral techniques, and some were characterised by comparison to authentic standards using HPLC, and others by matching their GC-MS spectra to library standards. Thirty-eight compounds were identified in total, the majority of these being novel to the species concerned. Those isolated from Combretum kraussii were 1 sitosterol, 2 combretastatin, 3 3',4-tri-O-methylellagic acid, 4 combretastatin B-1, 5 combretastatin A-1, 6 3,3'-di-O-ellagic acid lactone, 7a ellagic acid lactone, 7b ellagic acid, 8 and 9 a mixture of combretastatin B-1 and A-1 glucosides, 10 and 11 partly characterised glucosides of ellagic acid. Those isolated from Gunnera perpensa were 12 3',4-tri-methylellagic acid, 13 ellagic acid lactone, 14 1,1'-biphenyl-4,4'-diacetic acid, 15 p-hydroxybenzaldehyde, 16 Z-methyl lespedezate, 17 and 18 partly characterized higher glucosides of Z-methyllespedezate. Those isolated rom Rhoicissus tridentata were 19 (-)-epigallocatechin, 20 (+)-gallocatechin, 21 procyanidin B3, 22 procyanidin B4, 23 (+)-catechin hydrate, 24 (+)-mollisacacidin, 25 (+)-epicatechin, 26 fisetinidol-(4a-8) catechin, 27 (-)-fisetinidol, 28 fisetinidol-(4b-8)catechin, 29 gallic acid, 30 epicatechin-3-0-gallate, 31 partly characterized hydrogel of glucose, 32 sitosterol, 33 sitosterolin, 34 y-sitosterol, 35 oleanolic acid, 36 lupen-3-one, 37 20-epi-y-taraxastananol and 38 triacontanol. The compounds with the greatest in vitro uteroactivity were predominantly proanthocyanidins or phenolic glucosides. It is proposed that effects of phenolic glucosides could be due to the interaction of the sugar moiety as well as the phenolic moiety with the receptor site in muscle tissue. The corresponding phenolic aglycones isolated were only moderately uterotonic, or unreactive by comparison. Non-polar compounds such as sitosterol and sitosterolin showed minimal enhancement of the uterine response at low concentrations, and inhibition at higher concentrations. Aqueous root extracts of the plants were all found to be non-toxic according to cell-viability tests using monkey vero cells and human fibroblasts. Extracts are therefore considered safe for human consumption, although it is recommended that Rhoicissus tridentata be used with caution because it showed the lowest cell viability of the three species, and uterine hyperstimulation has been attributed to this species, as well as CNS depression and respiratory arrest. Ions which could be nutritionally beneficial in pregnancy, calcium, iron, and phospate, were present in low in aqueous extracts. Levels of calcium and potassium ions were considered to be too low to directly stimulate uterine muscle. Proanthocyanidins, combretastatins, ellagic acid derivatives and phytosterols, with health-promoting properties, were also identified. / Thesis (Ph.D.)-University of KwaZulu-Natal, Durban, 2004.
45

Bioprospecting the flora of southern Africa : optimising plant selections.

Douwes, Errol. January 2005 (has links)
Focused procedures which streamline and optimise plant prioritisation and selection in bioprospecting have the potential to save both time and resources. A variety of semiquantitative techniques were assessed for their ability to prioritise ethnomedicinal taxa in the Flora of Southern Africa (FSA) region. These techniques were subsequently expanded upon for application in plant selection for the Novel Drug Development Platform bioprospecting programme. Least squares regression analyses were used to test the hypothesis that ethnomedicinal plant use in southern Africa is strictly random, i.e. no order or family contains significantly more medicinal plants, than any other order or family. This hypothesis was falsified revealing several 'hot' plant orders. The distribution of southern African ethnomedicinal taxa was investigated, and revealed low ethnomedicinal plant usage in the Western Cape and Northern Cape. The historical settlement of Bantu tribes in the eastern regions of southern Africa was one explanation for this discrepancy. Growth forms of ethnomedicinal taxa in 'hot' orders (identified in the regression analysis) were analysed. The results indicated no clear preferences across orders, but rather a preference for particular growth forms in certain orders. With respect to distribution, endemism and Red Data List status of ethnomedicinal taxa, the Western Cape had the greatest proportion of endemics and Namibia had the highest proportion of Red Data Listed ethnomedicinal taxa. With respect to chemotaxonomy, the Asteraceae contained the highest proportion of terpenoids, the Rubiaceae the highest proportion of alkaloids and the Fabaceae the highest proportion of flavonoids. The predictive value of regression analyses was tested against an existing analysis of anti-malarials and the subsequent in vitro bioassays on Plasmodium falciparum. In particular, the ability of these analyses to identify plants with anti plasmodial IC50 values of [less than or equal to] 10 [micro]g/ml was assessed. Most species in 'hot' genera showed comparatively good antiplasmodial activities (IC50 [less than or equal to] 10 [micro]g/ml). Plant candidates were prioritised for screening anti-tuberculosis, anti-diabetes and immune-modulatory compounds, using a weighting system based on; their ethnomedicinal application, chemotaxonomic potential, frequency in ethnomedicinal trade, association with the relative disease, toxicity, Red Data status, indigenous or endemic status, and family selection in ethnomedicine (identified through regression analyses). Other taxa were short-listed due to their presence in biodiversity hotspots where few ethnomedicinal plant use records are documented, and still others were incorporated due to their taxonomic association with efficacious exotic allies. Statistical analyses of the weighting processes employed were not possible in the absence of screening results which are due only in December 2006. The legislation governing bioprospecting in South Africa is discussed and several recommendations are presented to minimise negative impacts on the industry. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2005.
46

Botany in medieval and Renaissance universities

Reeds, Karen. January 1991 (has links)
Thesis (Ph. D.)--Harvard University, 1975. / "Annex: 'Renaissance humanism and botany, ' Annals of science 33 (1976), 519-542 [and] 'Publishing scholarly books in the sixteenth century, ' Scholarly publishing, April 1983, 259-274." Includes bibliographical references (p. 261-283) and index.
47

Botany in medieval and Renaissance universities

Reeds, Karen. January 1991 (has links)
Thesis (Ph. D.)--Harvard University, 1975. / "Annex: 'Renaissance humanism and botany, ' Annals of science 33 (1976), 519-542 [and] 'Publishing scholarly books in the sixteenth century, ' Scholarly publishing, April 1983, 259-274." Includes bibliographical references (p. 261-283) and index.
48

The distribution patterns, utilisation and conservation of Sclerocarya birrea (A. RICH.) HOCHST, SUBSP. CAFFRA in two villages of the Limpopo Province, South Africa

Mocheki, Tebogo Allison 05 1900 (has links)
MSc (Botany) / Department of Botany / See the attached abstract below
49

Bark in traditional healthcare in KwaZulu-Natal, South Africa : usage, authentication and sustainability.

Grace, Olwen Megan. January 2002 (has links)
Healthcare in South Africa is polarised between western and traditional African systems of therapy. The latter is consulted by the majority of the population and therefore plays an integral role in the delivery of healthcare to South Africans. Traditional medicines are primarily plant products with long storage lives, among which the dominance of bark is typical of southern African traditional healthcare systems. Expansion of the traditional healthcare sector during the twentieth century, in response to rising consumer demands, stimulated a lucrative trade in medicinal plants that is centred in KwaZulu-Natal. Since herbal medicines are sourced almost exclusively from indigenous vegetation, harvesting pressures exerted on the indigenous flora to meet demands for traditional medicines have rendered such resources non-sustainable. Although trees comprise a small fraction of South African medicinal plant species, bark from them constitutes a substantial proportion of the plant products used medicinally. Trees are among the most threatened medicinal plants in South African due to their limited abundance, the ecological sensitivity of the vegetation in which they occur, and destructive methods of commercial bark harvesting that frequently take place within protected areas. In KwaZulu-Natal, bark is harvested primarily from forests that occupy an extent of only 0.1 % in the province. Conservation of economically valuable tree species is particularly problematic since data necessary for the establishment of sustainable usage systems are absent or inaccessible. Alternatives to in situ conservation for renewable bark resources include propagation, multi-use timber systems and reintroduction of locally extinct species. To facilitate appropriate management of bark resources, there is a need for specialist publications and consolidated data with which sustainable usage levels may be determined. The importance of bark in South African traditional healthcare is poorly reflected by the ethno botanical literature. In this study, 180 bark species used in traditional healthcare in KwaZulu-Natal were inventoried from thorough literature surveys, but this number is anticipated to be a conservative reflection of actual statistics. Where trade data were recorded in the literature, they indicated intensive exploitation of bark resources in KwaZulu-Natal and throughout South Africa, but conservation and management data were lacking for 72 % of the species inventoried. A number of problems were encountered in the literature, of which vague information and the documentation of local vernacular nomenclature were the most troublesome. Despite the importance of traditional medicine, the country's political history led to the prevailing situation, where the traditional healthcare sector is largely unregulated. Coupled with increasingly limited availability of medicinal plants, the quality and appropriate use of traditional medicines is negatively affected by growing numbers of inadequately trained practitioners, herbalist retailers and plant gatherers. Possibilities of misidentification or purposeful adulteration of medicinal bark products therefore lead to concerns for patient safety, since dried bark is difficult or impossible to identify. Whilst bark characters are useful for field identifications, many useful diagnostic characters are lost through desiccation, and anatomy and morphology of bark are variable. Additionally, medicinal bark products used in KwaZulu-Natal, and their identification, are largely undocumented. This study focussed on eight bark species used medicinally in the province, elected by an esteemed traditional medical practitioner as having problematic identity. Monograph-type characterisation profiles were drawn up for reference specimens collected from various localities, and their medicinal bark products traded under vernacular names recorded in the literature. In the absence of standardised traditional medicines, there is a need for reliable and affordable methods for their authentication. Phytochemical bark characters identified by Thin Layer Chromatography (TLC) have proved useful in chemotaxonomic studies, and the technique is widely used for herbal drug authentication. TLC was tested here for authentication of medicinal bark products from the aforementioned study species. Three reference samples of each species were collected, and TLC-generated fingerprints compared. At the intraspecific level, TLC was useful in confirming the relationship of ethanol and hexane bark extracts, but was less meaningful in distinguishing between fingerprints of different species. Three medicinal bark products of each study species were purchased and fingerprints compared to a reference. The technique proved useful in confirming the identity of several medicinal bark products. Authentication of medicinal bark products may be useful in toxicology cases and in the accurate documentation of their trade. This research identified a complexity of issues surrounding the use of bark in traditional healthcare in KwaZulu-Natal, and indeed South Africa. A multi-faceted approach is required to secure their sustainability. Critical, however, to factors such as effective conservation and regulation of the traditional healthcare sector, is recognition of the importance, and documentation, of traditional bark medicines. The integrity of traditional healthcare, and the future of the South African flora, hinge upon the sustainable use of medicinal products such as bark. / Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 2002.
50

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.

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