Oleuropein Attenuates Deltamethrin-induced Apoptosis in Rat Cerebellar Purkinje Neurons

Deltamethrin (DM) is a synthetic pyrethroid insecticide that can elicit neurotoxicity, and lead to apoptosis. There is accumulating evidence that oleuropein (OE) has anti-apoptotic effect. This study aimed at determining the DM toxicity and anti-apoptotic effect of OE pretreatment in cerebellar Purkinje neurons. Rats were randomly divided into four groups as follow: DM treated group (12.5 mg/kg; single dose), OE treated group (20 mg/kg per day), DM plus OE treated group, and vehicle group. Sections of cerebellum were taken 24 hours after deltamethrin injection and studied for histopathological and immunohistochemistry assessments. Further characteristics of degeneration in Purkinje neurons were observed in DM group compared with DM plus OE group. Compared with DM group (9.56±1.69), the positive staining for Bax in Purkinje neurones decreased in DM plus OE group (2.99±0.50) but upper than OE (0.72±0.15) and vehicle (0.57±0.03) groups. Compared with DM group (0.50±0.05), the positive staining for Bcl-2 in Purkinje neurons increased in DM plus OE group (3.29±0.18) but lower than OE (4.38±0.80) and vehicle (5.87±1.93) groups. Our results suggest that DM induces apoptosis in Purkinje cells which is subsided by oleuropein.