Purpose: To evaluate the modulator role of fish oil (FO) on some biochemical changes in the brain of gamma-irradiated rats (RAD).
Material and methods: Male albino rats Sprague Dawley were divided into four groups (n = 10). (i)
Control: received vehicle via gavages during 28 days; (ii) FO: received fish oil (400 mg/kg/day) via gavages during 28 days; (iii) RAD: received vehicle for 7 days before whole body gamma-irradiation with 8 Gy given in four fractions each 7 days apart and continued during the irradiation period; and (iv) FO+ RAD: received FO for 7 days before exposure to the first dose of irradiation and FO treatment was continued during the irradiation period. Animals were sacrificed 24 hours post the last irradiation dose.
Results: A significant increase of malondialdehyde (MDA) and protein carbonyl (CO) content associated with a significant decrease of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) activities and glutathione (GSH) content were recorded in the brain of irradiated rats. Oxidative stress was accompanied by a significant decrease of eicosapentaenoic (EPA) and docosahexaenoic (DHA) levels. Aspartic (Asp) and glutamic (Glu) acid levels were increased. Serotonin level showed a decrease associated with enhanced monoamine oxidase (MAO) activity and increased 5-hydroxyindolacetic acid (5-HIAA) level. FO treatment reduced the severity of radiation-induced oxidative stress, alteration of Asp and Glu levels and serotonin metabolism concomitant with increased EPA and DHA levels.
Conclusion: FO attenuates the severity of radiation-induced biochemical disorders in the brain by counteracting the radiation-induced decrease of EPA and DHA. Further studies are needed concerning the long-term implications of our findings.
Keywords: Fish oil; amino acids; brain; oxidative stress; radiation; serotonin.