Multiple protective mechanisms of alpha-lipoic acid in oxidation, apoptosis and inflammation against hydrogen peroxide induced toxicity in human lymphocytes

The naturally antioxidant and coenzyme, alpha-lipoic acid (α-LA), has gained considerable attention regarding different functions and therapeutically effective in treating oxidative stress-associated diseases in the human body. This study was designed to examine the protective effect of α-LA against H 2 O 2 -induced oxidative stress and apoptosis in human lymphoid cells. Human peripheral blood lymphocytes were preincubated with α-LA and then exposed to H 2 O 2 . After that, the viability of the cells, rate of apoptosis, oxidative stress biomarkers such as reactive oxygen species (ROS) and level of lipid peroxidation (LPO), and also tumor necrosis factor-α (TNF-α) were studied. Pretreatment of lymphocytes with α-LA, dramatically enhanced viability of the cells and decreased apoptosis. Investigation of caspases gives a clear picture of the mechanism by which α-LA decreases ROS and causes a reduction in apoptosis through caspase-9-dependent mitochondrial pathway. Furthermore, α-LA dose dependently decreased oxidative stress by a reduction in level of LPO, and the dose of 1000 µM indicates a significant decrease ( p