Apoptosis of rat's ovarian follicle cells induced by triptolide in vivo.

Abstract

This present study aimed to investigate ovarian follicular apoptosis and development in rats administrated with different dosages of triptolide (TR).Thirty healthy female Sprague Dawley rats were randomly divided into 3 groups (n = 10), including placebo group (water and 0.06% Dimethyl Sulfoxide); high dose(HD) group (120 μg/kg.d TR) and low dose (LD) group (60 μg/kg.d TR). Vaginal smear was daily performed to estimate each rat’s estrous cycle, while body weight was measured every 4 days to evaluate rat’s growth pattern and adjust the dosage. Left ovary of each rat was resected and then serial section was performed for follicular classification and counts. Apoptosis was detected with TUNEL assay and then positively-stained follicles were classified and calculated. Compared with the placebo and LD groups, the average estrous cycle was significantly longer in the HD group (p < 0.01). The secondary follicle in both HD and LD groups was significantly more than the control groups (p < 0.05), while there were no significant changes of primordial follicle and antral follicle among three groups. Furthermore, higher proportion of apoptotic follicle in the stage of secondary follicle was found in both HD and LD groups. TR presented dose-dependent inhibition on estrous cycle and apoptosis induction in secondary follicle, which might account for female gonad depression activities. Key words: Triptolide; ovarian follicle; apoptosis; rat.