Abstract: Objective: To observe the effect of wild walnut oil on the antioxidant functions in variectomized rats and the apoptosis of hippocampal cells. Methods: Ovariectomized rats were used as elderly animal model and administrated intragastrically with wild walnut oil at various doses (2.4, 1.2, 0.6 g/(kg·d)) for 9 days. The change of serum estradiol (E2) was determined by radioimmunoassay (RIA). The levels of T-SOD and MDA in hippocampus homogenates were determined by biochemical method. The expression of Bcl-2 and Bax in hippocampal dentate gyrus was evaluated by immunohistochemistry, and cell apoptosis in hippocampal dentate gyrus was observed by Hoechst staining. Results: Compared with young rats, the E2 level of ovariectomized rats revealed an obvious decrease (P ＜ 0.01), the T-SOD activity of wild walnut oil group exhibited a dose-dependant increase. Meanwhile, wild walnut oil could result in the reduction of MDA content, increased the expression of Bcl-2 and decreased the expression of Bax in hippocampal dentate gyrus cells. Cell apoptosis of hippocampal dentate gyrus was also inhibited. Conclusion: Wild walnut oil has protective effect against hippocampal cell apoptosis induced by ovariectomization. The mechanism of apoptosis inhibition may be related to the enhanced antioxidant activity and modulated expression of Bcl-2 and Bax.

Key words: walnut oil, ovariectomized rats, hippocamp, apoptosis