The effects of catechin on superoxide dismutase activity and its gene expression in pheochromocytoma cells

Background. Overexpression of manganese superoxide dismutase (MnSOD) cDNA via plasmid transfection leads to growth inhibition in vitro and in vivo in various human cancers. Polyphenolic compounds such as catechin isolated from tea bush Camellia sinensis has been shown to have anticancer effect in vitro. This study evaluated the effect of catechin on the MnSOD activity and mRNA level of pheochromocytoma cells (PC-12). Methods. PC-12 cells were incubated with different concentrations of catechin at short-term (2 days) and long-term (7 days) in Dulbecco modified Eagle medium. The activity of superoxide dismutase (SOD) was measured and its mRNA was assayed by Northern blotting. Results. After incubation for 2 days, catechin slightly but significantly increased the activity of copper/zinc superoxide dismutase (CuZnSOD). However, it did not show any significant effect at 7 days. The MnSOD activity showed significant changes in both short-term and long-term. The amount of mRNA also showed similar changes. Conclusions. Catechin is a natural antioxidant which has been shown to have antitumor effect in basic and epidemiological studies. The present data suggest that catechin can increase MnSOD gene expression in PC-12, which might have beneficial effect in tumor prevention.