Effects of dietary supplementation of α-tocopherol on plasma glutathione and DNA repair activities Journal Article


Authors: Hu, J. J.; Roush, G. C.; Berwick, M.; Dubin, N.; Mahabir, S.; Chandiramani, M.; Boorstein, R.
Article Title: Effects of dietary supplementation of α-tocopherol on plasma glutathione and DNA repair activities
Abstract: In a randomized double-blind trial of alpha-tocopherol (vitamin E), we investigated the effects of alpha-tocopherol supplementation on lipid- and water-soluble antioxidants in plasma and DNA repair activities in peripheral mononuclear leukocytes, Baseline levels of antioxidants and DNA repair activities were assessed twice before alpha-tocopherol intervention: on day 1 (visit 1) and day 3 (visit 2). During the second visit, participants were randomized to receive one of three dosages of alpha-tocopherol, 15, 60; or 200 mg/day for 4 weeks, The same biochemical measurements as at baseline were repeated twice after intervention: on day 17 (visit 3) and day 31 (visit 4), A total of 31 healthy volunteers were eligible for the study, completed all four visits and were included in the final data analysis, At baseline, no appreciable differences of dietary intake of vitamin E and plasma alpha-tocopherol were observed among the three dosage groups, In general, supplementation of alpha-tocopherol for 2-4 weeks resulted in a dose-dependent increase of plasma level of alpha-tocopherol (compared to baseline); significant increases of plasma alpha-tocopherol at visits 3 and 4 were observed in the two higher dosage groups, 60 and 200 mg, but not in the lowest dosage group, 15 mg, At visit 4 (but not visit 3), plasma glutathione levels were significantly elevated (compared to baseline) in the two higher dosage groups, 60 and 200 mg, but not in the lowest dosage group, 15 mg, In addition, there was an increase in the lipid protection ratio by supplementation of cy-tocopherol for 2-4 weeks in the two higher dosage groups, 60 and 200 mg, but not in the lowest dosage group, 15 mg, in general, there were no consistent effects of alpha-tocopherol on DNA repair activities in peripheral mononuclear leukocytes after being adjusted for baseline DNA repair activities, Results from this study demonstrate the interrelationship between alpha-tocopherol and other antioxidants in plasma; total plasma antioxidants can be modulated by short-term dietary supplementation of alpha-tocopherol.
Keywords: risk; oxidative stress; retinol; polyps; damage; cells; inhibition; vitamin-e; thiols; cancer
Journal Title: Cancer Epidemiology Biomarkers and Prevention
Volume: 5
Issue: 4
ISSN: 1055-9965
Publisher: American Association for Cancer Research  
Date Published: 1996-04-01
Start Page: 263
End Page: 270
Language: English
ACCESSION: WOS:A1996UE61500004
PROVIDER: wos
PUBMED: 8722217
Notes: Article -- Source: Wos
Citation Impact
MSK Authors
  1. Marianne Berwick
    120 Berwick
  2. Somdat   Mahabir
    15 Mahabir