Oxidative stress and DNA single strand breaks in skeletal muscle of aged rats: role of carnitine and lipoicacid.

The exposure of biological system to various conditions of oxidative stress is the major contributor for aging process. Oxidative stress in turn increases the cellular levels of oxidatively modified proteins, lipids and nucleic acids resulting in a loss of physical activity and metabolic integrity. In this study, we evaluated the role of L-carnitine and DL-alpha-lipoic acid in minimizing oxidant generation and macromolecular damage in skeletal muscle of aged rats. We found that the oxidant generation was increased in aged rat skeletal muscle when compared to young rats. There was a simultaneous increase in the levels of lipid peroxidation, protein carbonyl content and DNA strand breaks in aged rat skeletal muscle. Administration of L-carnitine (300 mg/kg body wt/day) and DL-alpha-lipoic acid (100 mg/kg body wt/day) to aged rats for 30 days, decreased the oxidant generation, lipid peroxidation, protein carbonylation and DNA strand breaks. We concluded that co-administration of carnitine and lipoic acid to aged rats has the potential to prevent oxidative stress mediated macromolecular damage in skeletal muscle of aged rats by their putative role as efficient antioxidants.