Abstract
The effect of fatty acid unsaturation on the antioxidant ability of beta-carotene and alpha-tocopherol to inhibit azobis-isobutyronitrile AIBN)-induced malondialdehyde (MDA) formation is investigated in a hexane solution. A positive correlation is shown between the fatty acid unsaturation and MDA production in homogeneous solutions. Both beta-carotene and alpha-tocopherol act as chain-breaking antioxidants in our model, effectively suppressing AIBN-induced MDA formation. When alpha-tocopherol is added to fatty acid solutions, a lag phase of about 30 min is observed and a propagation phase is produced at a rate dependent on the degree of unsaturation and similar to that observed in the absence of the antioxidant. A specific inhibition of initiation phase by alpha-tocopherol is confirmed by its total consumption after 30 min of incubation with AIBN. On the other hand, when beta-carotene is added, a lag period is not observed and the inhibition of propagation phase progressively increases in relation to the degree of fatty acid unsaturation. These data present different antioxidant roles for beta-carotene and alpha-tocopherol in AIBN-induced lipid peroxidation and suggest that beta-carotene can be a very effective antioxidant in highly unsaturated membranes, such as those enriched with n-3 polyunsaturated fatty acids (PUFA).
Lingua originale | English |
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pagine (da-a) | 943-948 |
Numero di pagine | 6 |
Rivista | FREE RADICAL BIOLOGY & MEDICINE |
Stato di pubblicazione | Pubblicato - 1995 |
Pubblicato esternamente | Sì |
Keywords
- beta-carotene
- fatty acid unsaturation