Beta-carotene as antioxidant

Objective: Beta-carotene has been shown to exhibit a good radical-trapping antioxidant activity in vitro. We were interested to see if dietary β-carotene in combination with various intake levels for vitamin A would also inhibit lipid peroxidation. Design: Sixty male Wistar rats received vitamin A (as retinyl palmitate) for 14 weeks in the diet (40000, 4000 and 400 IU/kg food). In the last 5 weeks one half of each group received β-carotene (50 mg/kg food). Lipid peroxidation (induced by 10 μM Fe2+ and 0.2 mM ascorbate) was measured ex vivo in liver microsomes. Results: The β-carotene-treated group had similar β-carotene levels in liver microsomes (3.4 nmol per mg protein) as the other group, irrespective of vitamin A intake. No difference in lipid peroxidation was seen between the groups with different β-carotene and vitamin A diets. Conclusion: Beta-carotene is not effective in vitro as antioxidant in liver microsomes of rats fed β-carotene with various intakes of vitamin A. Chemicals/CAS: Antioxidants; Ascorbic Acid, 50-81-7; beta Carotene, 7235-40-7; Ferrous Compounds; Glutathione, 70-18-8; retinol palmitate, 79-81-2; Vitamin A, 11103-57-