Curcumin induced apoptosis is mediated through oxidative stress in mutated p53 and wild type p53 colon adenocarcinoma cell lines

Curcumin has anti-oxidant, anti-cancer and anti-carcinogen property. Our laboratory had previously reported that, curcumin treatment induces reactive oxygen species (ROS) generation in HT-29 cell line, an effect contradictory to its anti-oxidant property. This study evaluates the role of p53 in curcumin mediated ROS generation and cell death. Curcumin induced ROS was determined by 2',7'-dichlorofluorescein and apoptosis by Hoechst33342/PI staining in HT-29 and HCT-116 cell lines. ROS generation occurs within 1 hour of 40 mu M curcumin treatment and a reduction was observed by third hour in HCT-116 insinuating p53 involvement. N-acetyl cysteine (NAC) pre-treatment effectively quenched ROS and inhibited membrane potential loss in HT-29, but less effective in HCT-116. Mitochondrial membrane potential loss is evident with 10 and 40 mu M curcumin in HCT-116 and at 40 mu M curcumin in HT-29. Total p53 protein level increase was observed by 24 hours in HCT-116 upon NAC pre-treatment. Our results indicate that curcumin induces ROS mediated cell death in colon adenocarcinoma cell lines and may be mediated via p53.