A biochemical study of the antidiabetic and anticogulant effects of Tulbaghia Violacea
- Authors: Davison, Candice
- Date: 2010
- Subjects: Medicinal plants -- South Africa , Diabetes -- Alternative treatment -- South Africa , Violaceae -- Therapeutic use -- South Africa , Anticoagulants (Medicine) , Plants -- Analysis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10311 , http://hdl.handle.net/10948/1523 , Medicinal plants -- South Africa , Diabetes -- Alternative treatment -- South Africa , Violaceae -- Therapeutic use -- South Africa , Anticoagulants (Medicine) , Plants -- Analysis
- Description: Secondary metabolites derived from plants, especially those used by traditional healers, are at the forefront of new drug development in combating diseases such as cancer and diabetes. Garlic is employed in indigenous medicine all over the world for the treatment of a variety of diseases. Dietary garlic has been recognized for its beneficial health effects. In particular, garlic consumption has been correlated with (i) reduction of risk factors for cardiovascular diseases and cancer, (ii) stimulation of immune function, (iii) enhanced detoxification of foreign compounds, (iv) hepatoprotection, (v) antimicrobial effects, (vi) antioxidant effects, and most importantly (vii) its hypoglycemic and anticoagulant properties. Due to these beneficial properties, garlic and its closely related genera which includes Tulbaghia violacea, may be useful as coadjuvant therapy in the treatment of type 2 diabetes and some of its physiological complications. The aim of this study was to determine if T. violacea has antidiabetic and anticoagulant properties. This was performed in vitro using both aqueous and organic extracts of the roots, leaves and bulbs. An organic extract was able to improve glucose-stimulated insulin secretion (GSIS) in INS-1 pancreatic β-cells and glucose uptake in Chang liver cells. The BO extract had no effect on the glucose uptake in 3T3-L1 an adipose cell line and reduced glucose utilisation in C2C12, a skeletal muscle cell line. Some of the properties displayed by T. violacea in this study are consistent with those found in similar studies with garlic extracts. It was observed that the BO extract increased the membrane potential and Glut-2 expression in INS-1 cells cultured at hyperglycemic levels, however, at normoglycemic levels a reduction was observed. The oxygen consumption increased at both glycemic levels due to treatment with the BO extract. Platelets were exposed to the extracts to determine their effects upon platelet aggregation, adhesion and protein secretion. Since the BO extract displayed the highest potential at inhibiting platelet aggregation and adhesion. A rat model was used in ex vivo studies to determine if the extract exhibited the same effect in a physiological model. It was noted that the BO extract exhibited a higher degree of inhibition on platelet aggregation and adhesion than the positive control, aspirin. The BO extract reduced clotting times in the prothrombin time (PT) test, but prolonged the clotting time in the actived partial thromboplastin time (APTT) assay in the ex vivo model; however, it had no affect on these clotting assays in the in vitro model using human blood. The BO extract increased the D-dimer and Fibrinogen-C levels in the in vitro model, but had no effect on the D-dimer concentrations and lowered the Fibrinogen-C levels in the ex vivo model. The active compounds in the extract remain to be elucidated.
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- Date Issued: 2010
A chemical investigation of Tulbaghia Violacea
- Authors: Burton, Stephanie Gail
- Date: 1990
- Subjects: Liliaceae , Plants -- Analysis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4528 , http://hdl.handle.net/10962/d1015725
- Description: Tulbaghia violacea, a member of the family Alliaceae is indigenous to the Eastern Cape and is widely used as a herbal remedy for various febrile and gastro-enteric ailments, particularly in young children. Adverse effects, and even fatalities, have been reported following treatment with the plant extract. The project has involved synthesis of model compounds, chromatographic analysis of flavonoid and other constituents of the plant, and examination of the volatile components. Some fifteen flavones were synthesised as chromatographic models and in the course of this work, the development of a new method for synthesis of carboxylic anhydrides was completed. Use of the flavone standards permitted identification of the flavonols kaempferol and quercetin in hydrolysed glycosidic plant extracts. In addition, several sugars were identified, viz., D-glucose, D-fructose, L-arabinose and D-galactose as free sugars, and D-glucose, D-galactose , 1-rhamnose, D- fucose, D-xylose, 1-arabinose and D-fructose as glycosidic sugars, by g.l.c. and g. c. - m. s. analysis of derivatives of isolated sugar mixtures. The presence in the plant extracts of steroidal saponins was also demonstrated. The sulphur compounds, 2,4,5,7-tetrathiaoctane-2,2-dioxide and 2,4,5,7-tetrathiaoctane were isolated from the plant and characterised spectroscopically. This result, together with analysis of volatiles from the plant, has led to a proposal concerning the nature and origin of sulphur compounds in Tulbaghia violacea, showing close correlation with the sulphur compounds in Allium species. Investigation of the biological activity of Tulbaghia violacea extracts showed bacteriostatic activity, particularly of extracts which had not been heated, and which had been prepared from mature plants. Treatment of isolated smooth muscle preparations with Tulbaghia violacea extracts indicated the presence of a β-adrenergic agonist having an inhibitory effect on normal muscle contraction. The results of the investigations indicate that while there may be some basis for use of the plant as an antibacterial, or to treat colic, the adverse effects, caused possibly by the sulphur compounds and/or steroidal saponins present, may override the beneficial effects.
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- Date Issued: 1990
A critical study of the determination of molybdenum in plant material
- Authors: Gore, William Tompson
- Date: 1961
- Subjects: Molybdenum , Plants -- Analysis , Spectrophotometry , Polarography
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4477 , http://hdl.handle.net/10962/d1012071 , Molybdenum , Plants -- Analysis , Spectrophotometry , Polarography
- Description: 1. Polarographic and spectrophotometric methods for the determination of molybdenum were reviewed. 2. The inclusion of salicylaldoxine in several supporting electrolytes was examined with a view to developing a polarographic procedure, suitable for routine analyses, which did not necessitate a preliminary time-consuming separation stage. A stable molybdenum wave was obtained from an electrolyte having a composition similar to the test solution obtained after the wet digestion of plant material. The height of the wave was found to be, over an optimum range, independent of the reagent concentrations. The wave was however distorted by a maximum, which rendered it unsuitable for quantitative analytical application. 3. The spectrophotometric procedure for molybdenum using thiocyanate is virtually specific and was examined critically. Modifications were found to improve the sensitivity of the procedure, and the stability of the chromatic compound. 4. The modified spectrophotometric procedure is recommended for the routine determination of molybdenum in plant material.
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- Date Issued: 1961
A critical study of methods for the determination of zinc in soils and plant materials
- Authors: Eve, Desmond John
- Date: 1955
- Subjects: Soils -- Zinc content , Soils -- Analysis , Plants -- Analysis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4468 , http://hdl.handle.net/10962/d1011770 , Soils -- Zinc content , Soils -- Analysis , Plants -- Analysis
- Description: Although it is only fairly recently that the importance of trace elements in plant nutrition has been established, enormous advances have been made in this field of research and numerous publications of considerable scientific and economic importance, dealing with the subject, have appeared. The physiological functions of zinc in promoting plant growth have not all been satisfactorily identified as yet. There are indications, however, that zinc acts as a catalyst or regulator in plant metabolism. It appears too, that the element plays some role in chlorophyll formation. Zinc deficiency is associated with leaf chlorosis and a general collapse of v ital processes. The analysis of leaves and soils has become an essential part of the study of the nutritional diseases of plants and it is imperative that accurate and reliable methods of analysis should be available. Intro. p. 1.
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- Date Issued: 1955