Stimulating effect of aflatoxin B1 on lipid peroxidation in the in vitro model systems.

Abstract

The prooxidant properties of aflatoxin B1 (AFB1) was evaluated using in vitro model systems. Model system A was based on the peroxidation of phosphatidylcholine (PC) liposomes in the absence or presence of inducers of peroxidation. Model system B was based on the oxidation of linoleic acid. Results showed that incubation of the PC liposomes at 37°C caused peroxidation and PC hydroperoxide (PC-OOH) formation. Inclusion in the system of inducers significantly increased PC-OOH and thiobarbituric acid reactive substances formation and this process was time-dependent. Incorporation of AFB1 in the PC liposomes stimulated lipid peroxidation when the liposomes were incubated in vitro. When lipid peroxidation inducers were included in the system, the prooxidant effect of AFB1 was more pronounced compared with spontaneous lipid peroxidation. Induction of AFB1 in model system B was also associated with increased linoleic acid hydroperoxide formation. As in model system A, AFB1 stimulated lipid peroxidation more effectively in the presence of lipid peroxidation inducers. Inclusion in the system of vitamin E significantly reduced lipid peroxidation but this vitamin was oxidized itself in the presence of AFB1. The results confirm the prooxidant effect of AFB1, suggesting that more attention should be focused on the interactions of aflatoxin with antioxidants.