the pro-oxidant, apoptotic and anti-angiogenic effects of selenium supplementation on colorectal tumors induced by 1,2- dimethylhydrazine in balb/c mice

Background: selenium is a mineral that showed both pro- and anti-oxidant activities in various disease models. in this study, we evaluated the anti-tumor effect of selenium against 1,2-dimethylhydrazine (dmh)-induced colorectal cancer in balb/c mice and its effect on apoptosis and angiogenesis.methods: colorectal cancer was induced by subcutaneous injection of dmh (20 mg/kg body weight) in balb/c mice once weekly for 20 weeks. selenium (200 mg/l) was given to dmh plus selenium-treated group in the drinking water for the next 3 months.results: the dmh plus selenium-treated group exhibited significantly lower expression of cloned caudal-type homebox gene -2 (cdx-2) and vascular endothelial growth factor (vegf) but higher caspase-3 expression level at p<0.001 compared to the dmh-treated group. moreover, a decrease in the reduced glutathione content and glutathione peroxidase activity but an increase in the malondialdehyde content were observed at p<0.001. both macroscopic and microscopic examination of the colorectal tissues confirmed the results.conclusions: the anti-tumor effect of selenium against an induced colorectal cancer in mice is attributed to its pro-oxidant, anti-angiogenic and apoptotic effects.