Divya Dattaprasad, Vickram, Kashinath Rattihalli Thirumalarao
BACKGROUND Major actions of insulin include glucose uptake, utilization and storage as well as protein and fat synthesis. Diabetes mellitus (DM) is a metabolic disease mainly results due to insulin deficiency or failure in insulin action. Plant extracts have been used as medicine for DM since ancient times. The allium plants’ active principles are found to be mainly disulfides and sulfoxides and their hypoglycaemic values are well established. Our earlier studies with a low molecular weight thiol, 3-mercapto-1-propanol (thiopropanol), have shown insulin-like actions in isolated liver tissues of alloxan diabetic rats. A study was undertaken to assess the insulin-like actions of thiopropanol disulfide (TPDS) prepared from thiopropanol. MATERIALS AND METHODS Male Swiss albino rats weighing 200-250 g were employed. Alloxan monohydrate was used to induce diabetes. Optimum dosage of TPDS was determined. Six normal and six diabetic rats were sacrificed on the 31st day of the study. Extracted liver tissues were divided into three groups namely- normal, control alloxan diabetic and TPDS-exposed alloxan diabetic groups. Levels of liver tissue glucose, glycogen, lactate, pyruvate, total thiol groups, alanine, total amino acid nitrogen (AAN) as well as activities of hexokinase (HK), glucose-6-phosphate dehydrogenase (G6PD), alanine transaminase (ALT) and aspartate transaminase (AST) were estimated. Per hour glucose utilization, lactate production, pyruvate production and amino acid utilization were calculated. RESULTS The results showed significant increase (p<0.001) in glucose utilization, lactate production, pyruvate production, total thiol groups, AAN, alanine, HK activity and G6PD activity, and significant decrease (p<0.001) in activities of ALT and AST in TPDSexposed alloxan diabetic liver slices as compared to control alloxan diabetic liver slices. CONCLUSION TPDS undergoes sulfhydryl cleavage like any other disulfide to produce its corresponding thiol component which is responsible for the increased glucose utilization.
