Influence of nourishing yin and tonifying yang sequential therapy combined with Western medicine on TGF-β1/Smads signaling pathway in anovulatory infertility rats with diminished ovarian reserve

Abstract

To explore the influence for combination of nourishing yin and tonifying yang sequential therapy (NYTYST) with Western medicine in treating anovulatory infertility rats with diminished ovarian reserve (DOR) based on TGF-β1/Smads signaling pathway. Methods: A total of 40 female rats were randomly divided into 5 groups, a normal control group, a model group, a Western medicine group, a NYTYST group and a combination group (n=8 in each group). The DOR model was established through orally taking tripterygium pill for continuous 2 weeks. The normal control group and the model group were treated with saline for 10 days. The Western medicine group was treated with hormone replacement therapy (HRT) and ovarian stimulation. The NYTYST group was treated with nourishing yin herbs in proestrus and tonifying yang herbs in late estrus and the combination group was treated with Chinese herb and Western drugs for 10 days. HE staining was used to observe histopathologic changes in ovary. Expression levels of transforming growth factor β1 receptor (TGF-β1R) in rats ovarian were detected by immunohistochemistry. Expression levels of Smad2, Smad3 and Smad7 protein in rat ovarian were detected by Western blot. Results: Compared with the control group, the numbers of developing follicles, mature follicles and corpus luteum were decreased , while atrefic follicles were increased significantly in the model group (P<0.01); the levels of TGF-β1R, Smad2 and Smad3 were decreased significantly, while Smad7 was increased significantly (P<0.01). Compared with the model group, the numbers of developing follicles, mature follicles and corpus luteum, Smad2 and Smad3 expression were increased, while atrefic follicles and Smad7 were decreased significantly in the treatment group (P<0.05 or P<0.01). The numbers of developing follicles and corpus luteum in the combination group was superior to the Western medicine group (P<0.05). Compared with the Western medicine group, the levels of TGF-β1R, Smad2 and Smad3 were increased significantly, while Smad7 was decreased significantly in the combination group (P<0.05 or P<0.01). Conclusion: NYTYST combined with Western medicine can improve the function of ovaries reserve by up-regulation of TGF-β1R, Smad2 and Smad3 while down-regulation of Smad7 in DOR rats.