Protective role of lycopene against PCBs-induced nitrosative stress in cerebral cortex of adult male rats

Polychlorinated biphenyls (PCBs) are known to be putative environmental toxin that produce neurotoxicity and also affect reproductive and endocrine functions. PCBs induce the production of reactive oxygen species (ROS) leading to oxidative stress induced neuronal damage. This study is designed to examine the production of reactive nitrogen species (RNS) by PCB exposure and to validate the alleviating effect of lycopene, a potent dietary anti-oxidant on marker enzymes and protein affected by nitrosative stress induced by PCBs in cerebral cortex of adult male rats. Rats were divided into four groups of six each. Group I rats intraperitoneally (i.p.) administered corn oil (vehicle); group II received lycopene 4mg/kg/bwt (gavage); group III received PCBs (Aroclor 1254) at 2mg/kg bwt (i.p); group IV received lycopene 4mg/kg bwt (gavage) and simultaneously with PCBs 2mg/kg bwt (i.p.). The treatment was given daily for 30 days. Twenty-four hours after the experimental period rats were euthanized. From each rat cerebral cortex tissues was collected and analyzed for mean activities of marker enzymes acetyl cholinesterase (AchE) and creatine kinase (CK). The fate of the mRNA expression of neuronal nitric oxide synthase (nNOS), protein expression of 3-nitro-tyrosine and concentration of nitrite level were analyzed. Results proclaim that PCB induces nitrosative stress in cerebral cortex via RNS production and lycopene acts as a potent anti-oxidant by quenching the RNS thereby reducing the nitrosative stress and protecting from neuronal damage.