The prevention of oxy radical-mediated lung tumorigenesis in mice by vitamin E.
This work was carried out to estimate the preventive effect of vitamin E on oxy radical-enhanced lung tumorigenesis in ddY mice. We have reported that oxy radicals could be an important factor contributing to the promotive effect of glycerol on 4-nitroquinoline 1-oxide (4NQO)-induced lung tumorigenesis (1). The glycerol-promoted lung tumorigenesis of mice treated with 4NQO was reduced in mice feeding on excessive vitamin E in this study. The levels of nuclear thiobarbituric acid reactive substances (TBARS) and oxidative damage of DNA estimated as DNA single strand breaks (DNA-SSB) were significantly higher in the lungs of mice treated with 4NQO + glycerol than in those treated with 4NQO at 4 weeks after 4NQO administration, This increase was suppressed by the feeding of excessive vitamin E for 4 weeks after 4NQO injection. At 23 weeks after 4NQO injection, the feeding of excessive vitamin E for 4 and 23 weeks after 4NQO injection could cancel the promotive effect of glycerol on lung tumorigenesis. Additionally, the alpha-tocopherol level in serum was related with the degree of lung tumorigenesis at 23 weeks after 4NQO injection. These findings suggest that vitamin E can act as a useful agent to protect mice from oxy radical-promoted lung tumorigenesis.
Ichikawa
T
T
Division of Applied Food Research, National Institute of Health & Nutrition, Tokyo, Japan.
Ishikawa
G
G
Yano
T
T
D015112:4-Nitroquinoline-1-oxide / Q000633:toxicity; D000236:Adenoma / Q000209:etiology / Q000517:prevention & control*; D000818:Animals; D016588:Anticarcinogenic Agents / Q000494:pharmacology*; D002467:Cell Nucleus / Q000187:drug effects / Q000378:metabolism; D005609:Free Radicals / Q000633:toxicity*; D005990:Glycerol / Q000494:pharmacology; D008168:Lung / Q000187:drug effects / Q000648:ultrastructure; D008175:Lung Neoplasms / Q000209:etiology / Q000517:prevention & control*; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D017392:Thiobarbituric Acid Reactive Substances / Q000032:analysis; D014810:Vitamin E / Q000032:analysis / Q000494:pharmacology*
D016588:Anticarcinogenic Agents; D005609:Free Radicals; D017392:Thiobarbituric Acid Reactive Substances; D014810:Vitamin E; D015112:4-Nitroquinoline-1-oxide; D005990:Glycerol