Inhibitory effects of indole [alpha]-lipoic acid derivatives on nitric oxide production in LPS/IFN[gamma] activated RAW 264.7 macrophages

Alpha-lipoic acid ([alpha]-lipoic acid) is a potent antioxidant compound that has been shown to possess anti-inflammatory effects. RAW 264.7 macrophages produce various inflammatory mediators such as nitric oxide, IL-1[beta], IL-6 and TNF-alpha upon activation with LPS ( Lipopolysaccharide) and IFN[gamma] (interferon gamma). In this study, the effect of 12 synthetic indole [alpha]-lipoic acid derivatives on nitric oxide production and iNOS (inducible nitric oxide synthase) protein expression in LPS/IFN[gamma] activated RAW 264.7 macrophages was determined. Cell proliferation, nitric oxide levels and iNOS protein expression were examined with thiazolyl blue tetrazolium blue test, griess assay and western blot, respectively. Our results showed that all of the indole [alpha]-lipoic acid derivatives showed significant inhibitory effects on nitric oxide production and iNOS protein levels (p