Behavioral effects and oxidative status in brain regions of adult rats exposed to BDE-99.

Polybrominated diphenyl ethers (PBDEs) are used as flame retardants. Although developmental neurotoxicity of PBDEs has been already investigated, little is still known about their potential neurotoxic effects in adulthood. In this study, we assessed the oxidative damage in brain sections and the possible behavioral effects induced by exposure to 2,2',4,4',5-pentabromodiphenyl ether (BDE-99). Adult male rats (10/group) received BDE-99 by gavage at single doses of 0, 0.6 or 1.2mg/kg/body weight. Forty-five days after exposure, the following behavioral tests were conducted: open-field activity, passive avoidance and Morris water maze. Moreover, cortex, hippocampus and cerebellum were processed to examine the following oxidative stress (OS) markers: reduced glutathione (GSH), oxidized glutathione (GSSG), glutathione reductase (GR), glutathione peroxidase (GPx), glutathione-S-transferase (GST), superoxide dismutase (SOD), catalase (CAT) and thiobarbituric acid reactive substances (TBARS). In cerebellum, BDE-99 significantly decreased SOD, CAT and GR activities at the highest BDE-99 dose. A decrease in CAT and SOD activities was also observed in cortex and hippocampus, respectively. In the behavioral tests, no BDE-99 effects were observed, while histopathological examination of the brain regions was normal. The current results show that the brain antioxidant capacity is affected by BDE-99 exposure, mainly in cerebellum. Oxidative damage could be a mechanism for BDE-99 neurotoxicity in adult rats.