Background: 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.

Materials and Methods: 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.

Results: 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.

Conclusions: Our results suggest that DM induces apoptosis in Purkinje cells which is subsided by oleuropein.