cytochrome-c-t and 5-hydroxyindole

5-Hydroxyindole (5HI), a metabolite of tryptophan, is involved in learning and memory, central neuron system regulation, and anti-oxidant activity. However, its protective action in mitochondrial function is not clear. Here, we tested whether 5HI protects against tert-butylhydroperoxide (t-BHP)-induced oxidative damage and mitochondrial dysfunction in human fibroblast cells. 5HI significantly suppressed t-BHP-induced cytotoxicity as determined by intracellular reactive species generation, lipid peroxidation, glutathione depletion, and peroxynitrite (ONOO(-)) generation. In addition, 5HI reduced t-BHP-induced DNA condensation. Pretreatment with 5HI significantly restored mitochondrial membrane potential (Deltapsim), suggesting that it protected cells against t-BHP-induced apoptosis. Western blot analysis also revealed that 5HI markedly inhibited cytochrome c release and caspase-3 activation, but not caspase-9 activation. Our data suggest that 5HI protects cells by attenuating oxidative stress and consequently protects against mitochondrial dysfunction.

Topics: Apoptosis; Caspase 3; Caspase 9; Cell Line; Cytochromes c; DNA Damage; Fibroblasts; Glutathione; Humans; Indoles; Lipid Peroxidation; Membrane Potential, Mitochondrial; Mitochondria; Oxidative Stress; Peroxynitrous Acid; Reactive Oxygen Species; tert-Butylhydroperoxide