title: Vitamin E supplementation does not alter azoxymethane-induced colonic aberrant crypt foci formation in young or old mice.
abstract: Vitamin E, part of the body's primary lipid-soluble defense against free radicals and reactive oxygen molecules, has been suggested to reduce the risk for some cancers. However, the role of vitamin E in the etiology and prevention of colon cancer, especially in the highest risk group, the aged, is not clear. Thus, this study was conducted to elucidate the effect of vitamin E supplementation on susceptibility to colon cancer by examining azoxymethane (AOM)-induced aberrant crypt foci (ACF) formation, a surrogate biomarker of colon cancer. Young (3-4 mo) and old (19-20 mo) C57BL/6JNIA mice were fed either a control diet (30 mg dl-alpha-tocopheryl acetate/kg diet) or a vitamin E-supplemented diet (500 mg dl-alpha-tocopheryl acetate/kg diet) for 16 wk. After 6 wk of dietary supplementation, young and old mice were injected with saline or AOM weekly for 5 wk to receive the same total dose of AOM (2.2 mg) and killed 10 wk after the first AOM injection. Vitamin E supplementation had no effect on the number of AOM-induced ACF in young or old mice. In addition, vitamin E supplementation did not have an effect on splenocyte interferon-gamma, interluekin-6 and tumor necrosis factor-alpha levels, natural killer cell killing activity or colonic cell proliferation in young or old mice. Thus, alpha-tocopherol does not seem to affect the initiation and early promotion stages of AOM-induced colon carcinogenesis in young or old mice. Whether vitamin E supplementation might be effective in reducing AOM-induced colon tumors is unclear.
authors.affiliation: Jean Mayer U.S. Department of Agriculture Human Nutrition Research Center on Aging at Tufts University, Boston, MA, USA.
authors.forename: Heekyung
authors.initials: H
authors.lastname: Chung
authors.forename: Dayong
authors.initials: D
authors.lastname: Wu
authors.forename: Sung Nim
authors.initials: SN
authors.lastname: Han
authors.forename: Raina
authors.initials: R
authors.lastname: Gay
authors.forename: Barry
authors.initials: B
authors.lastname: Goldin
authors.forename: Roderick E
authors.initials: RE
authors.lastname: Bronson
authors.forename: Joel B
authors.initials: JB
authors.lastname: Mason
authors.forename: Donald E
authors.initials: DE
authors.lastname: Smith
authors.forename: Simin Nikbin
authors.initials: SN
authors.lastname: Meydani
mesh_terms: D000375:Aging / Q000276:immunology*; D000818:Animals; D000975:Antioxidants / Q000008:administration & dosage / Q000494:pharmacology*; D001397:Azoxymethane / Q000633:toxicity*; D002273:Carcinogens / Q000633:toxicity*; D002828:Choristoma; D003110:Colonic Neoplasms / Q000139:chemically induced* / Q000276:immunology; D007371:Interferon-gamma / Q000096:biosynthesis; D015850:Interleukin-6 / Q000096:biosynthesis; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D014810:Vitamin E / Q000008:administration & dosage / Q000276:immunology / Q000494:pharmacology*
chemical_list: D000975:Antioxidants; D002273:Carcinogens; D015850:Interleukin-6; D014810:Vitamin E; D007371:Interferon-gamma; D001397:Azoxymethane