2002 Volume 48 Issue 1 Pages 65-68
Recently we reported that the supplementation of vitamin B6 to low vitamin B6 diet caused suppression in colon tumorigenesis and cell proliferation of azoxymethanetreated mice in a dose-dependent manner among 1, 7, and 14mg pyridoxine HCl/kg diet (J Nutr 131: 2204-2207, 2001). To examine the mechanism of the anticolon tumor effect of vitamin B6, male ICR mice were fed the diet containing 1, 7, 14, and 35 mg pyridoxine HCl/kg diet for 22 wk and simultaneously given a weekly injection of azoxymethane for an initial 10 wk. The supplementation of vitamin B6 to a low vitamin B6 diet (1 mg pyridoxine HCl/kg) suppressed the levels of colonic 8-hydroxyguanosine and 4-hydroxynonenal and in-ducible nitric oxide synthase protein. The results suggest that the preventive effect of vita-min B6 against colon tumorigenesis is at least in part mediated by reducing oxidative stress and nitric oxide production.