Anti-proliferative and cytotoxic effects of saffron in HCT116 p53 wildtype and HCT116 p53 −/− cells. MTT viability test showing the HCT116 p53 wildtype and HCT116 p53 −/− cells untreated (ctrl) or treated with different concentrations of saffron (0.25 to 4.0 mg/ml) for 24 and 48 h (A and B). The MTT data shown are performed in triplicates. Cell numbers were measured using the crystal violet technique after saffron treatment for 24 and 48 h (C and D). Results are means ± s.d. (n = 3). (*, Saffron treatment was statistically significant against the control for P < 0.05). (#, Saffron treatment was statistically significant in HCT116 p53 wildtype against HCT116 p53 −/− cells for P < 0.05).