Protective role of vitamin C on spatial memory and oxidative stress alteration during paraquat-induced toxicity in male rats

Paraquat (PQ), is one of the most widely used herbicides all over the world. PQ could induce dopaminergic cell death. Since dopamine involves in memory processing, we investigated the recovery effect of vitamin C on spatial memory along with oxidative stress parameters during PQ induced neurotoxicity in male rats. Rats were divided into five groups (n= 7): control (saline 0.9%), PQ (2.67 and 5 mg/kg), vitamin C (80 mg/kg) plus PQ (2.67), and vitamin C plus PQ (5 mg/kg). The period of intraperitoneal injection (i.p.) was once a day and for 5 consecutive days. The Morris water maze test used for studying the spatial memory. The level of lipid peroxidation (MDA), and activity of antioxidant enzymes; superoxide dismutase (SOD) and catalase (CAT), were determined in the left hemisphere of rats. Results showed that i.p. injection of PQ in both doses, 2.67 mg/kg (P<0.05) and 5mg/kg (P<0.01) significantly decreased the spatial memory. The total SOD activity in PQ-treated groups (2.67 and 5mg/kg) was significantly lower than that of control group (p<0.01). The level of CAT increased, in Vitamin C plus PQ groups in a dose-dependently manner (p<0.05). MDA was significantly increased in PQ-treated group (p<0.01). In PQ-treated groups that were supplemented with vitamin C, SOD activity and lipid peroxidation level were restored to normalcy. Our data revealed that PQ could impair the spatial memory via induction of oxidative stress in the brain tissue. Vitamin C can prevent or diminish the oxidative stress markers in the PQ-treated rats.