Background: Diazinon (DZN) is an organophosphate insecticide widely utilized in agriculture all over the world and causes many negative effects on plants and animal species, especially on human. The aim of present study was to evaluate the effects of DZN on apoptosis of ovarian follicles in adult rats and to assess the protective role of vit E.

Methods: Thirty adult female Wistar rats were divided into five groups: control group (without any intervention), sham group (received only pure olive oil, as solvent), experimental group 1 (DZN+olive oil, 60 mg/kg), experimental group 2 (vit E, 200 mg/kg), and experimental group 3 (DZN+vit E, the same dosage). All drugs were injected intraperitoneally, except vit E administrated by gavage. The animals were scarified after two weeks and left ovary was used to measure apoptosis of ovarian follicles.

Results: The number apoptotic cells experimental group 1 increased significantly in contrast control group in secondary and graffian follicles (P< 0.001). Administration vit E plus DZN, significantly reduced apoptotic cells compared to DZN group (P< 0.001).

Conclusion: DZN-induced apoptosis in secondary and graffian follicles and vit E inhibited apoptosis induced by DZN. Vit E might have a protective effect on DZN-induced ovarian toxicity.