Protective effect of l-carnosine against 12-O-tetradecanoylphorbol-13-acetate- or hydrogen peroxide-induced apoptosis on v-myc transformed rat liver epithelial cells

Apoptotic processes have been associated with cancer and neurodegenerative diseases such as Alzheimer’s disease, Parkinsonʹs disease etc. β-Alanyl-l-histidine (l-carnosine), occurring abundantly in skeletal muscles has been suggested to possess antioxidative activity. We investigated whether l-carnosine prevents 12-O-tetradecanoylphorbol-13-acetate (TPA)- or hydrogen peroxide (H2O2)-induced apoptosis involving mitochondria in the v-myc transformed rat liver epithelial cells (WB-myc cells). l-Carnosine prevented both TPA- and H2O2-induced DNA fragmentation, the loss of mitochondrial membrane potentials and blocked the release of cytochrome c into cytosol. Subsequently, the cleavages of poly (ADP-ribose) polymerase were significantly reduced in l-carnosine-treated cells. However, western blotting analysis revealed that p53 protein level did not change for 12 h after TPA- and H2O2-treatment. Therefore, these results suggested that l-carnosine, an antioxidant, protected both H2O2- and TPA-induced apoptosis through mitochondrial pathways.