α-Lipoic Acid Enhances Reduced Glutathione,Ascorbic Acid,and α-Tocopherol in Aged Rats

Abstract

It is hypothesized that a reduction in the level of antioxidants with age leads to an impairment in the quenching of free radicals, which in turn increases the risk of succumbing to age-associated disorders. Male albino rats of Wistar strain (both young and aged rats) were treated with lipoic acid for 7 and 14 days. Analyses were carried out in blood, liver, kidney, and brain for lipid peroxidation, reduced glutathione, ascorbic acid, and α-tocopherol. The levels of reduced glutathione, and vitamins C and E were found to be lowered in aged rats, whereas the level of lipid peroxidation was found to be high. After intraperitoneal administration of lipoate (a thiol antioxidant) to the aged rats, a time-dependent reduction in the level of lipid peroxidation and elevation in the levels of reduced glutathione, and vitamins C and E were observed. From our observations, we conclude that lipoic acid, a dithiol, normalizes lipid peroxidation and prevents the oxidation of reduced glutathione, possibly through recycling mechanisms, thereby maintaining normal metabolic function. Thus, lipoic acid supplementation could be beneficial in minimizing age-associated disorders where free radicals are the major cause.