Ascorbate and Alpha-Tocopherol Mitigate Toxic Pathological Changes in Adult Wistar Rats Exposed to Cypermethrin

Excessive and uncontrolled use of pyrethroids such as cypermethrin (CYP) for pest control in Nigeria can adversely affect humans. This study investigated the oxidative stress response to cypermethrin exposure as well as the therapeutic effect of ascorbate and alpha-tocopherol when administered singly or co-administered. Additionally, the lungs and heart of the exposed animals were histologically assessed for cypermethrin-induced cytopathic changes. Twenty-five adult male Wistar rats weighing between 180 – 200g were randomly assigned to five groups of five animals each. Group I was the unexposed control group, while Group II was the exposed untreated group that was orally administered Cypermethrin at a dose of 10mg/kg/bw. Group III – V was given cypermethrin at standard doses of 10mg/kg/bw, and orally administered with ascorbate (5000mg/kg/bw), alpha-tocopherol (3000mg/kg/bw) and co-administration of ascorbate and alpha-tocopherol (5000mg/kg/bw and 3000mg/kg/bw) respectively. Animals were euthanized after 28 days, and samples were processed for histological and biochemical studies. The results showed elevated malondialdehyde (MDA) levels with a concurrent marked decrease in superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT) activities (p<0.05) in the cypermethrin-exposed untreated rats, while histopathological findings revealed inflammation and congestion in the organs studied. The co-administrative treatment with ascorbate and alpha-tocopherol better restores biochemical parameters than their single administration. Conclusively, co-administration of ascorbic acid and alpha-tocopherol ameliorates cypermethrin-induced oxidative damage better than single administration, which may be due to their synergistic antioxidant properties.