Fullerene and omega-3 and omega-6 fatty acids on fish brain antioxidant status

The carbon nanomaterial fullerene (C(60)) can act as anti or pro-oxidant. The aim of this study was to evaluate, in cell suspensions of carp brains (Cyprinus carpio, Cyprinidae), the effect of C(60) after a pre-treatment with polyunsaturated fatty acid (PUFAs) such as omega-3 (docosahexaenoic acid, DHA) and omega-6 (linoleic acid, LA). Assays consisted of a pre-treatment with PUFA (48 h) and then exposure to C(60) (2 h). Cell viability and total anti-oxidant capacity did not differ (p > 0.05). A reduction (p < 0.05) was observed in reactive oxygen species (ROS) and thiobarbituric acid reactive substances (TBARS) concentration in fish brain cells pre-exposed with PUFA groups and then exposed or not with C(60). An antioxidant effect of C(60) was evident since in control group (cells not pre-exposed to PUFA), a significant (p < 0.05) reduction of intracellular ROS concentration was observed, although this reduction was not enough to reduce the TBARS levels. Cysteine levels presented a reduction (p < 0.05) in all groups exposed to C(60). For glutathione (GSH), an increase (p < 0.05) was registered in cells exposed to C(60) without PUFAs pre-treatment and in the C(60) group pre-treated with DHA. Overall C(60) appears to play an antioxidant role that is modulated by PUFA, taking into account its effects on intracellular ROS concentration and MDA levels. Results also suggest that C(60) influences GSH synthesis, as showed for the augmented levels of this antioxidant and also for the lowering of the intracellular cysteine concentration.