Effect of vitamin E supplementation on dichlorvos-induced toxicity in the hippocampus of male albino rat

Background
The hippocampus is a brain structure that plays important roles in the acquisition of new memories. Dichlorvos or 2,2-dichlorovinyl dimethyl phosphate (DDVP) is an organophosphate compound that is toxic to the hippocampus. Vitamin E is an antioxidant.
Aim
To evaluate the potential ameliorating effect of vitamin E supplementation on dichlorvos (DDVP)-induced toxicity in the hippocampus of male albino rat.
Materials and methods
In total, 40 male-adult rats aged 3 months were divided into five groups: group A (control): they received no treatment. Group B (treated): DDVP given at a dose of 2.5 mg/kg body weight/day for 4 weeks. Group C (protective): DDVP at the same previous dose cotreated with vitamin E at a dose of 200 mg/kg body weight/day for 4 weeks. Group D (therapeutic): DDVP given at the same previous dose for 4 weeks. Post-DDVP administration, rats were further treated with vitamin E at the same previous dose for another 4 weeks. Group E (rehabilitated): DDVP given at the same previous dose for 4 weeks. Post-DDVP administration, rats were further treated with distilled water for another 4 weeks. For each group, brains of rats were processed for light microscopy (gallocyanin chrom alum stain).
Results
Group B (treated) showed degenerative changes in the hippocampal principal cells. Group C (protective), showed improvement of cells more or less similar to control. Group D (therapeutic) showed improvement of cells near to control. Group E (rehabilitation) showed marked deterioration of cells in comparison with control.
Conclusions
DDVP had a toxic effect on rat hippocampus, that did not improve by rehabilitation. Vitamin E was found to be necessary for amelioration of the hazards of DDVP toxicity and its protective effect is more obvious than its therapeutic effect.