EFFECTS OF ACUTE EXERCISE AND ??-CAROTENE ON URINARY 8-HYDROXYDEOXYGUANOSINE EXCRETION LEVELS IN HUMAN 537

Abstract

The purpose of this study was to determine the effects of acute exhaustive exercise and β-carotene supplementation on urinary 8-hydroxydeoxyguanosine (8-OHdG) excretion levels in human. Fifteen untrained male college students (age=19.9 ± 0.2yr, mean ± SE) volunteered to participate. The subjects were ingested with 30 mg of β-carotene/day for 30 days. A double blind design was used with each subject randomly assigned to capsules containing either β-carotene or placebo. Each subjects respectively performed an incremental exercise test to exhaustion on a bicycle ergometer before and after the 30 days β-carotene supplementation period. Urine was analyzed for 8-OHdG, TBARS, hypoxanthine, xanthine, uric acid and creatinine, 1 day before and 3 days after exercise. Plasma all-trans-β-carotene concentrations in theβ-carotene group were significantly higher (19.3 ± 3.0 vs 334.3± 35.4 μg/dl; p<0.01) following ingestion of β-carotene. Urinary excretions of 8-OHdG were unchanged following two exercise tests in placebo subjects. There was no effect of acute exercise to exhaustion on urinary 8-OHdG excretion levels. However, urinary excretions of 8-OHdG before exercise were significantly lower (15.0 ± 1.3 vs 13.0 ± 1.3 nM/g creatinine/day; p<0.05) following ingestion of β-carotene. These data indicate that β-carotene supplementation decreases urinary excretion of 8-OHdG as a marker of oxidative DNA damage, however, acute exercise to exhaustion does not influence urinary excretion of 8-OHdG.