EPC-K1 attenuates peroxynitrite-induced apoptosis in cerebellar granule cells

Apoptosis induced by peroxynitrite in cultured cerebellar granule cells was confirmed morphologically by chromatin condensation and biochemically by DNA laddering. A 30 min exposure to peroxynitrite (10 mu M) initiated oxidative stress, which caused the formation of thiobarbituric acid-reactive substances (TBARS) and the alteration of cell membrane fluidity. Peroxynitrite treatment also caused ATP decrease and thus activated the apoptotic program. Pre-treating cells with antioxidant EPC-K1 (L-ascorbic acid 2-[3,4-dihydro-2,5,7,8-tetramethyl-2-(4,8, 12-trimethyltridecyl)-2H-1-benzopyran-6-yl-hydrogen phosphate] potassium salt), a new water-soluble derivative of vitamin C and vitamin E, attenuated oxidative injury and prevents cells from apoptosis. The results suggest that EPC-KI might be used as a potential therapeutic agent for diseases associated with NO/ONOO--mediated neuronal injury.