Figure 1. Melatonin treatment enhances the proliferation of CHRF cells. The maximum action concentration was 200 nM (n=6). Cell proliferation was assessed by (A) cell counts, (B) survival rate and (C) XTT assay at 24 h, 48 h and 72 h after administration of melatonin treatment. Normal, CHRF cells incubated with 10% FBS; Control, CHRF cells incubated with 0.5% FBS. Two-way ANOVA (with a Tukey multiple comparison test) was employed to test for significance. * p < 0.05, ** p < 0.01 vs control group.