Vitamin B6-mediated suppression of colon tumorigenesis, cell proliferation, and angiogenesis (Review)

This review describes current research on the preventive effect of dietary vitamin B-6 against colon tumorigenesis and its possible mechanisms. Studies in cell culture have demonstrated that high levels of vitamin B-6 suppress growth of some cancer cells. From these studies it has been considered that supraphysiological doses of vitamin B-6 suppress tumor growth and metastasis. However, recent rodent study has indicated that azoxymethane-induced colon tumorigenesis in mice is suppressed by moderate doses of dietary vitamin B-6. Epidemiological studies also support an inverse relationship between vitamin B-6 intake and colon cancer risk. Potential mechanisms underlying the preventive effect of dietary vitamin B-6 have been suggested to include the suppression of cell proliferation, oxidative stress, nitric oxide (NO) synthesis, and angiogenesis. (C) 2003 Elsevier Inc. All rights reserved.