Oxidative Stress Mediated Hippocampal Neuron Apoptosis Participated in Carbon Disulfide-Induced Rats Cognitive...

Occupational exposure to carbon disulfide (CS₂) exhibits central nervous systems toxicity. But the mechanism is unclear. The present study was designed to investigate the relationship between the CNS damage and cognitive dysfunction caused by CS₂, and eventually reveal the possible oxidative-related mechanism of hippocampus pathological changes in CS₂ exposed rats. Male Wistar rats were administrated with CS₂ at dosage of 200, 400 and 600 mg/kg for consecutive 20 days, respectively. Cognitive performances were evaluated by Morris water maze tests. Thionin and immunohistochemical analysis were used to investigate the hippocampal neuron damage, and the expression of apoptosis related proteins (cleaved-caspase 3, Bax and Bcl-2) were detected to explore the possible mechanisms of neuronal loss. Oxidative stress parameters were checked by commercial assay kits. Rats exposed to CS₂ displayed cognitive dysfunction manifested as decreased spatial learning ability and memory lesion. Pathological changes and significant neuron loss were observed in hippocampus, especially in CA1 and CA3 sub-regions. Mitochondria-dependent apoptosis pathway was implicated in the CS₂-induced neuronal loss which was demonstrated by the up-regulation of cleaved-caspase 3 and Bax accompanied with down-regulation of Bcl-2. Furthermore, extensive oxidative stress induced by CS₂ was also revealed by the measurement of ROS, RNS, MDA, GSH&GSSG and antioxidant enzymes (CAT, T-SOD, and GSH-Px). Our study suggested that oxidative stress mediated hippocampal neuron apoptosis might play an important role in CS₂ induced CNS damage and cognitive dysfunction.