Is vitamin E a useful agent to protect against oxy radical-promoted lung tumorigenesis in ddY mice?
We have previously reported that oxy radicals can contribute to the enhancing effect of glycerol on 4-nitroquinoline 1-oxide (4NQO)-induced lung tumorigenesis in ddY mice. In this study, we established that feeding high doses of vitamin E to male ddY mice treated with 4NQO plus glycerol could reduce glycerol-enhanced lung tumorigenesis, due to the inhibition of glycerol-induced oxidative stress on the pulmonary nuclei. At 4 weeks after 4NQO injection (10 mg/kg, s.c.), the levels of nuclear thiobarbituric acid reactive substances and oxidative damage to DNA in the lungs of mice treated with 4NQO plus glycerol (5% solution as drinking water) were significantly higher than those in mice treated with 4NQO. The glycerol-induced increase was completely inhibited when a high vitamin E diet was provided for 4 weeks after 4NQO injection. As previously reported, at 23 weeks after 4NQO administration (at the end of this experiment), the 4 week treatment with glycerol enhanced 4NQO-induced lung tumorigenesis in ddY mice. In contrast, the supply of high doses of vitamin E at 4 and 23 weeks after 4NQO injection suppressed glycerol's ability to enhance lung tumorigenesis. These results suggest that vitamin E is useful in protecting against oxy radical-enhanced lung tumorigenesis in mice.
Yano
T
T
Division of Applied Food Research, National Institute of Health and Nutrition, Tokyo, Japan.
Ishikawa
G
G
Ichikawa
T
T
D015112:4-Nitroquinoline-1-oxide; D000818:Animals; D003043:Cocarcinogenesis; D004249:DNA Damage; D004334:Drug Administration Schedule; D005990:Glycerol / Q000494:pharmacology*; D008175:Lung Neoplasms / Q000139:chemically induced / Q000517:prevention & control*; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D010084:Oxidation-Reduction; D013997:Time Factors; D014810:Vitamin E / Q000008:administration & dosage / Q000494:pharmacology*
D014810:Vitamin E; D015112:4-Nitroquinoline-1-oxide; D005990:Glycerol