title: Ascorbic acid does not increase the oxidative stress induced by dietary iron in C3H mice.
abstract: 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.
authors.affiliation: Department of Internal Medicine, Division of Gastroenterology and Hepatology, University of California Davis, Davis, CA, USA.
authors.forename: Kumpati
authors.initials: K
authors.lastname: Premkumar
authors.forename: Christopher L
authors.initials: CL
authors.lastname: Bowlus
mesh_terms: 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*
chemical_list: D000975:Antioxidants; D019266:Iron, Dietary; D001205:Ascorbic Acid