Plasma antioxidant status in healthy smoking and non-smoking men.

Human serum contains many different antioxidants which may be important in the maintenance of an antioxidant status. The aim of this study was to evaluate the relationship between lipid peroxidation and total plasma antioxidant capacity in healthy smoking and non-smoking young and elderly subjects. Plasma concetrations of alpha-tocopherol, beta-carotene and ascorbic acid were detected by HPLC. Additionally, in the in vitro experiments, the effects of exogenous compounds (ascorbic acid, uric acid, Trolox) on total ferric reducing activity of plasma were tested. We demonstrated that total antioxidant capacity of plasma obtained from healthy non-smoking young subjects was significantly higher than plasma antioxidant capacity of smoking elderly subjects. The concentration of thiobarbituric acid-reactive substances (TBARS) (p < 0.001) in young non-smoking volunteers was lower than that in young smokers. The concentration of TBARS in elderly non-smoking volunteers was lower than in elderly smokers. Plasma concentrations of alpha-tocopherol, beta-carotene and ascorbic acid were significantly lower in elderly smokers than in elderly non-smokers of same age. No difference in plasma levels of alpha-tocopherol, beta-carotene and ascorbic acid were found in 22-year-old smoking and non-smoking subjects. In vitro addition of ascorbic acid, uric acid, or Trolox to plasma samples significantly increased their total antioxidant capacity. Decrease of FRAP values and increase of TBARS concentra-' tions is a significant physiologic condition of aging process. Supplementation of antioxidants could be useful for the enhancement of plasma antioxidant status (Tab. 1, Fig. 3, Ref: 35).