Ascorbic acid does not increase the oxidative stress induced by dietary iron in C3H mice.
Iron is a potent prooxidant that can induce lipid peroxidation. Ascorbic acid, a potent antioxidant, has prooxidant effects in the presence of iron in vitro. We investigated whether ascorbic acid and iron co-supplementation in ascorbic acid-sufficient mice increases hepatic oxidative stress. C3H/He mice were fed diets supplemented with iron to 100 mg/kg diet or 300 mg/kg diet with or without ascorbic acid (15 g/kg diet) for 3 wk. Liver iron concentration, malondialdehyde (MDA), glutathione (GSH), glutathione S-transferase (GST), glutathione peroxidase (GPx), superoxide dismutase (SOD), and catalase (CAT) were measured. High dietary iron increased liver iron concentrations slightly (P < 0.05), whereas it dramatically increased hepatic MDA (P < 0.0001). Ascorbic acid increased MDA but only in mice fed the low-iron diet (P < 0.05). The high-iron diet reduced GPx (P < 0.0001), CAT (P < 0.0005), SOD (P < 0.05), and GST (P < 0.005) activities regardless of ascorbic acid supplementation. In contrast, ascorbic acid reduced GPx (P < 0.0001) and CAT (P < 0.05) activities only in mice fed the low-iron diet. In conclusion, ascorbic acid supplementation can have prooxidant effects in the liver. However, ascorbic acid does not further increase the oxidative stress induced by increased dietary iron.
Premkumar
Kumpati
K
Department of Internal Medicine, Division of Gastroenterology and Hepatology, University of California Davis, Davis, CA, USA.
Bowlus
Christopher L
CL
D000818:Animals; D000975:Antioxidants / Q000633:toxicity*; D001205:Ascorbic Acid / Q000633:toxicity*; D004305:Dose-Response Relationship, Drug; D005260:Female; D019266:Iron, Dietary / Q000633:toxicity*; D008099:Liver / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D008297:Male; D051379:Mice; D008809:Mice, Inbred C3H; D010084:Oxidation-Reduction; D018384:Oxidative Stress / Q000187:drug effects*
D000975:Antioxidants; D019266:Iron, Dietary; D001205:Ascorbic Acid