Vitamins prevention of diabetic complication: effect of vitamins C and B6 on glycosylated hemoglobin and sorbitol dehydrogenase

ABSTRACT

The experiments were undertaken to assess the role of vitamin C [ascorbic acid] and vitamin B6 [pyridoxine] in relation to sorbitol dehydrogenase activity and glycosylated hemoglobin levels in sorbitol pathway linked neural and vascular dysfunction and nonenzymatic glycosylation in rats with alloxan induced diabetes. Vitamins C and B6 monotherapy were given orally to control and diabetic rats. After 30 days and 45 days of treatment, glycosylated hemoglobin levels were decreased significantly [p <0.05 to 0.001]. Sorbitol dehydrogenase activity in normal rats during vitamin C therapy were increased significantly [p <0.08 to 0.001] from 7 to 9 folds after 30 days and 45 days, respectively. In diabetic rats sorbitol dehydrogenase activity elevated about 2.5 folds. Vitamin B6 increased sorbitol dehydrogenase activity about 7 folds in normal and 3 to 2.5 folds after 30 days and 45 days, respectively, in diabetic rats. These observations together with other evidence, suggested the significant relationship between glycosylated hemoglobin, sorbitol dehydrogenase and intake of vitamin C and vitamin B6. The elevated sorbitol dehydrogenase activity associated with the previously reported sorbitol levels. These vitamins supplementation is effective in individuals with insulin-dependent diabetes mellitus [IDDM]. They may be potentially important in controlling glucose-induced nonenzymatic glycosylation of proteins and, therefore may be a preferable drugs for inhibiting glucose induced nonenzymatic glycosylation, neural and vascular dysfunction