Protective effect of moxibustion preconditioning in rats with premature ovarian insufficiency

Abstract

To observe the effects of moxibustion preconditioning on ovarian function, fertility and ovarian granulosa cell apoptosis in rats with premature ovarian insufficiency (POI), so as to investigate its underlying mechanism in improving POI. Forty-two female SD rats with two complete estrous cycles were randomly divided into control group, model group and pre-moxibustion group, with 14 rats in each group. The pre-moxibustion group was pretreated with mild moxibustion for 14 days before POI model establishment at 1) "Guanyuan" (CV4) and "Zhongwan" (CV12) and 2) bilateral "Shenshu" (BL23) as two sets of acupoints on alternate days, once each day, for 10 min each acupoint. After 14-day mild moxibustion intervention, 75 mg·kg-1·d-1 tripterygium glycoside tablet suspension was administered to rats in the pre-moxibustion group and the model group by gavage, for 14 consecutive days, while equivalent saline was given to rats in the control group in the same way. After modeling, the effect of moxibustion preconditioning on ovarian reserve function was evaluated by the estrous cycles, pregnancy rate and embryo number, morphological changes of ovaries, and serum sex hormone levels. TUNEL staining was used to detect the rate of granulosa cell apoptosis in ovaries. Immunohistochemistry and real time quantitative PCR were used to detect the relative expression of Caspase-3 and Caspase-9 proteins and mRNA levels in ovaries. Compared with the control group, the estrous cycles were disturbed; the pregnancy rate and number of embryos, the wet weight of ovary and ovarian index, the number of total follicles and different level of follicles, serum Estradiol (E2) and anti-mullerian hormone (AMH) levels were all significantly decreased (P<0.01,P<0.05), while the number of atretic follicles, serum follicule-stimulating hormone (FSH) and luteinizing hormone (LH) levels, the number of TUNEL-positive granulosa cells, the expression of ovarian Caspase-3 and Caspase-9 proteins and mRNAs were significantly increased (P<0.01) in the model group. Compared with the model group, the disordered estrous cycles were improved; the pregnancy rate, the embryo numbers, the wet weight of ovary, and the total follicle number and primary follicle number, serum AMH level were significantly increased (P<0.01，P<0.05), while the number of atretic follicles, serum FSH level, the number of TUNEL-positive granulosa cells, expression of ovarian Caspase-3 and Caspase-9 proteins and mRNAs were all significantly decreased (P<0.01,P<0.05) in the moxibustion group. Moxibustion preconditioning could improve ovarian function and improve fertility of POI rats, which may be associated with reducing the apoptosis of ovarian granulosa cells.