3. Electronic Theses and Dissertations (ETDs) - All submissions
Permanent URI for this communityhttps://wiredspace.wits.ac.za/handle/10539/45
Browse
3 results
Search Results
Item The chemotaxonomy and biological activity of salvia stenophylla ( lamiaceae ) and related taxa(2003-10-13) Gono-Bwalya, AngelaSalvia stenophylla Burch, ex Benth. (Lamiaceae) is a perennial aromatic herb, which is widespread in the high altitude areas of the central and eastern parts of South Africa and also occurs in southwest Botswana and central Namibia. It is closely related to Salvia runcinata L. f. and Salvia repens Burch, ex Benth., with which it forms a species complex. The most recent revision of southern African Salvia species is that by Codd (1985). In this revision, the most important characters used in delimiting the three taxa were corolla size, calyx size and trichome density. As a result of intergrading morphological characters, the specific limits between the three taxa are not clear and positive identification of typical material is often difficult. Taxonomic delimitation through use of chemical characters was therefore the principle objective of this study. The taxa represented in this species complex are known in folk medicine and plant extracts have been used in the treatment of urticaria, body sores, and stomach ailments and as a disinfectant. S. stenophylla is reported to contain a-bisabolol, a compound that has anti-inflammatory properties. Based on the traditional uses of these plants and the international use of a-bisabolol to develop active cosmetic products, establishing a scientific rationale for the known uses was an important secondary objectiveItem Indigenous Salvia species : an investigation of their pharmacological activities and phytochemistry(2008-09-26T07:03:36Z) Kamatou, Guy Paulin PoungoueThe genus Salvia belongs to the family Lamiaceae and encompasses 900 species worldwide of which 26 are found in southern Africa and many of them are used in local traditional medicine. However, the phytochemistry and pharmacological activities of the South African species have not been extensively investigated. The leaf trichome morphology that may be used to distinguish species was investigated with the scanning electron and light microscopy. Both glandular (capitate or peltate) and non-glandular trichomes were identified in all species. The essential oils were isolated by hydro-distillation and analysed by GC and GC-MS methods. The oil yield was relatively low and ranged from 0.004 (S. radula) to 0.50% (S. muirii) (w/w). Major components identified include α-pinene, 1,8-cineole, linalool, limonene, myrcene, β-caryophyllene, spathulenol, β-caryophyllene oxide, viridiflorol, δ-3- carene and α-bisabolol. High performance liquid chromatography analysis was used to identify phenolic compounds in 17 solvent extracts. Betulafolientriol oxide was detected in all species. Rosmarinic acid was only absent in S. verbenaca, while S. garipensis and S. radula were the only species which lacked oleanolic acid/ursolic acid. Various in vitro biological activities were investigated. Nearly all the solvent extracts displayed anti-oxidant activity with IC50 values ranging from 1.61 to 74.50 μg/ml using the DPPH· radical, while the IC50 values ranged from 11.88 to 69.26 μg/ml with the ABTS·+ radical. The solvent extract of S. schlechteri was three times more active than vitamin C. Total phenolic content based on gallic acid equivalents (GAE) revealed the presence of total soluble phenolics in the extract at 45 to 211 mg of GAE dry sample. Almost all the essential oils exhibited promising anti-inflammatory activity (5-lipoxygenase assay) with IC50 values ranging from 22.81 to 77.32 μg/ml. The antimalarial activity was determined using [3H]-hypoxanthine method on the Plasmodium falciparum (FCR-3) strain. The IC50 values of the essential oils ranged from 1.20 to 13.50 μg/ml and were low compared to the solvent extracts (IC50 values ranging from 3.91 to 26.01 μg/ml). Betulafolientriol oxide and salvigenin isolated from S. radula inhibited the growth of malaria parasites with IC50 values of 4.95 and 24.60 μg/ml, respectively. With the exception of S. radula, all the solvent extracts displayed moderate to good activity against Staphylococcus aureus, vii Bacillus cereus, Klebsiella pneumoniae, Escherichia coli and Mycobacterium tuberculosis with the MIC values ranging from 0.03 to 8.00 mg/ml. Four compounds, namely carnosol, 7-O-methylepirosmanol, oleanolic acid and its isomer ursolic acid were isolated from S. chamelaeagnea as the active principles against S. aureus. The solvent extracts of Salvia species were tested for in vitro anticancer activity against human breast adenocarcinoma (MCF-7), colon adenocarcinoma (HT-29) and glioblastoma (SF-268) using the sulforhodamine B assay. The extracts inhibited cell proliferation of all three cell lines to varying degrees, with the IC50 values ranging between 9.69 and 43.65 μg/ml and 8.72 and 59.12 μg/ml against the MCF-7 and SF-268 cell lines, respectively. The IC50 values against the HT-29 cell line ranged from 17.05 to 57.00 μg/ml. The in vitro toxicity profile of 28 samples (17 solvent extracts and 11 essential oils) was evaluated on human kidney epithelial cells using the 3-(4,5-dimethylthiazol-2-yl)-2,5 dimethyl tetrazolium bromide method. The samples displayed some degree of toxicity with IC50 values ranging from 1.79 to 22.9 μg/ml for the essential oils and from 12.12 to 53.34 μg/ml for the solvent extracts. The essential oil composition of S. africana-caerulea, S. africana-lutea and S. lanceolata, collected at the same locality throughout the 2004/2005 growing season, was compared in terms of essential oil yields, chemical composition and biological activities. Mostly quantitative, rather than qualitative variation was observed. Major seasonal fluctuations of certain essential oil compounds were observed in all three species. Variations in biological activities of the solvent extracts over seasons were noted. The biological activities of the solvent extracts of three Salvia species (Salvia africanacaerulea, S. africana-lutea and S. lanceolata) were evaluated in the presence and absence of essential oils. The solvent extract of S. africana-caerulea without essential oil exhibited the best activity against Gram-positive bacteria (MIC value: 0.1 mg/ml), while the solvent extract containing essential oil of S. africana-lutea was the most active against Gramnegative bacteria. The toxicity profile of all three species was significantly higher (P < 0.05) with the solvent extracts containing essential oils. The in vitro biological activities add scientific support to the use of Salvia species in traditional medicine.Item Indigenous Salvia species - an investigation of the antimicrobial activity, antioxidant activity and chemical composition of leaf extracts(2006-11-10T11:30:19Z) Fisher, Vanessa LouiseThe genus Salvia, commonly known as the sages is a member of the mint family (Lamiaceae). In Latin, ‘sage’ means "to save" and the Romans called it "sacred herb". Throughout history it has been used for depression, fever, respiratory infections, women's complaints, sleep inducer, diuretic, gargles and sick room use. The essential oil is reported to have anti-inflammatory, antimicrobial, antioxidant, antiseptic, antispasmodic, astringent, diuretic, antihypertensive and insecticidal properties. Of the 900 species recorded worldwide, 30 are indigenous to South Africa where they are used extensively in traditional healing. The aerial parts of twelve samples were hydrodistilled and the essential oil analysed by GC-MS. The essential oil composition varied quantitatively and qualitatively within the different Salvia species analysed. Linalool was the only compound that was present in all the essential oils. β-caryophyllene and caryophyllene oxide were present in all essential oil with the exception of S. stenophylla. The essential oil as well as methanol and acetone extracts were tested for antimicrobial activity on a number of bacteria and fungi. No species showed activity against Cryptococcus neoformans, Candida albicans nor Alternaria alternata. All test samples studied demonstrated variable degrees of antibacterial activity with the exception of four test samples; S. disermas (methanol and acetone) from the Walter Sisulu Botanical Garden; S. disermas (methanol) from Mossel Bay and S. lanceolata (methanol). Gram-positive organisms were more sensitive to the test samples than the Gram-negative organisms. In general, the extracts were far more active than the essential oils. Thin layer chromatography indicated that all methanol extracts possess antioxidant activity. All methanol extracts contain the antioxidant compound, rosmarinic acid. It is evident that, in addition to rosmarinic acid, other polar and non-polar compounds are present in all Salvia species that also act as antioxidants.