Orange juice vs vitamin C: effect on hydrogen peroxide-induced DNA damage in mononuclear blood cells.
The intake of fruits rich in vitamin C seems to increase the antioxidant defence of the organism. However, it is still not clear whether vitamin C alone is responsible for this effect. The aim of the present investigation was to study the effect of the intake of a single portion of blood orange juice (BOJ, 300 ml, providing 150 mg vitamin C) on mononuclear blood cell (MNBC) DNA damage, compared with a drink supplemented with the same amount of vitamin C (C-drink) or sugars (S-drink). Seven young healthy subjects were randomised in a repeated-measures design in which they received each drink on different occasions, 2 weeks apart. Blood samples were collected at baseline, every hour for 8 h, and at 24 h after the intake of each drink. Vitamin C was analysed at each time point by HPLC, whereas H2O2-induced MNBC DNA damage was evaluated at 0, 3 and 24 h by means of the comet assay. Plasma vitamin C concentration increased similarly following BOJ or C-drink intake and was not affected by the S-drink. DNA damage significantly decreased 3 h after BOJ intake (about 18 %; P < 0.01) and remained constant at 24 h (about 16 %; P < 0.01). No effect of the C-drink and S-drink was observed. In conclusion, the intake of a single portion of BOJ provided an early protection of MNBC against oxidative DNA damage; however, the protective effect of BOJ was not explained by vitamin C alone, thus other phytochemicals could be involved.
Guarnieri
Serena
S
Department of Food Science and Microbiology, Division of Human Nutrition, University of Milan, 20133 Milan, Italy. serena.gaurnieri@unimi.it
Riso
Patrizia
P
Porrini
Marisa
M
D000328:Adult; D000975:Antioxidants / Q000494:pharmacology; D001205:Ascorbic Acid / Q000097:blood / Q000494:pharmacology*; D001628:Beverages / Q000032:analysis*; D002957:Citrus; D004249:DNA Damage / Q000187:drug effects*; D005260:Female; D005504:Food Analysis / Q000379:methods; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology; D007963:Leukocytes, Mononuclear / Q000187:drug effects*; D018384:Oxidative Stress / Q000187:drug effects
D000975:Antioxidants; D006861:Hydrogen Peroxide; D001205:Ascorbic Acid