Water Extract of Samultang Reduces Apoptotic Cell Death by H2O2-Induced Oxidative Injury in SK-N-MC Cells

The purpose of this study was to evaluate the effects of the water extract of Samultang (SMT), a Chinese herb, on apoptotic cell death by H(2)O(2)-induced oxidative stress in SK-N-MC cells. A nuclear fragmentation was observed via fluorescence imaging 12 h after exposure to 30 microM H(2)O(2) and DNA laddering was detected via agarose electrophoresis gel. In addition, increases in sub-G1 phase and cleavage of the PARP protein were observed. However, treatment with SMT for 2 h prior to H(2)O(2) exposure significantly reduced apoptotic cell death induced by incubation with 30 microM H(2)O(2) in SK-N-MC cells. Pre-incubation with water extract of SMT for 2 h prevented the H(2)O(2)-induced decrease in mitochondrial transmembrane potential. SMT also attenuated the increase in caspase-3 activity and the breakdown of PARP protein caused by H(2)O(2)-induced oxidative stress. These results suggest that the water extract of SMT provides inhibition of apoptotic cell death against oxidative injury in SK-N-MC cells.