Sesame oil protects against permethrin-induced memory decline and oxidative stress in the hippocampus of Wistar rats

Permethrin is a synthetic pyrethroid commonly used for the control of insect pests. It is neurotoxic at high doses and its exposure has been associated with tremor, salivation, paresthesia, depressed reflexes and nerve damage, in animal studies. Sesame seed oil is derived from the seeds of the flowering sesame plant, known for its beneficial antioxidative and anti-inflammatory properties. This study investigated the possible ameliorative effects of Sesame seed oil on permethrin-induced neurotoxicity. A total of 16 male Wistar rats were divided into four groups: the control group given standard rat feed, permethrin (PER) group treated with 100 mg/kg permethrin, sesame seed oil (SO) group administered with 5 ml/kg SO and SO+PER group co-treated with SO and PER, all for 14 days. The rats were assessed for memory and spatial learning and thereafter anesthetized and sacrificed after 14 days of treatment. The hippocampus was excised from the brain and processed for tissue histology, histochemistry and immunohistochemistry, using haematoxylin & eosin stain, cresyl fast violet stain and antibody against ionised calcium binding adaptor molecule 1 (for microglial expression) respectively. Oxidative status was assessed using glutathione peroxidase (GPx) and superoxide dismutase (SOD) enzymes as biomarkers. Results revealed that permethrin caused memory deficits, varying degrees of disruption of the normal hippocampal microarchitecture, microglial activation and depletion of endogenous antioxidants. On the other hand, these activities were either prevented or minimised in the rats that received sesame seed oil intervention. Our findings revealed that sesame seed oil is both anti-oxidative and anti-inflammatory and capable of mitigating permethrin-induced hippocampal neurotoxicity.

Key Words: Sesame seed oil, Permethrin, memory deficits, oxidative stress, neuroinflammation