[Mechanism of Bushen Huoxue Formula in regulating endometrial oxidative stress and fibrosis].

Intrauterine adhesion(IUA) is a common gynecological disease that is difficult to treat, and there is a lack of specific effective drugs and measures to prevent endometrial fibrosis. In this study, the mechanism of endometrial oxidative stress and fibrosis regulation was studied in an IUA rat model constructed by Bushen Huoxue Formula intervention of mechanical injury combined with infection. A total of 72 SPF SD female rats aged 8-10 weeks were randomly divided into blank control group, model control group, low-dose, medium-dose, and high-dose groups of Bushen Huoxue Formula, and estrogen groups. The rats in the estrous cycle of the model control group and the positive control group were simulated with surgical injury and infection, and the sham operation group was treated with on-off abdominal treatment. After successful modeling, the model control group was administered intragastrically with purified water of 15 μL·g~(-1) every day. The low-dose group was administered intragastrically with Bushen Huoxue Formula of 7.8 g·kg~(-1); the medium-dose group was administered intragastrically with Bushen Huoxue Formula of 15.6 g·kg~(-1), and the high-dose group was administered intragastrically with Bushen Huoxue Formula of 31.2 g·kg~(-1). The estrogen group was administered intragastrically with estradiol valerate of 4.2 mg·kg~(-1). After continuous intervention for 28 days, all rats were deprived of water and killed to collect blood and tissue. Hematoxylin-eosin(HE) staining calculated the number of uterine glands; Masson staining calculated the area of uterine collagen fibers. Combined with HE and Masson staining, semi-quantitative scores were performed on the degree of endometrial fibrosis. Immunohistochemistry was performed to detect the vascular endothelial growth factor(VEGF), stromal cell-derived factor-1(SDF-1), and transforming growth factor-β1(TGF-β1) expression in rats' uterine tissue. Enzyme-linked immunosorbent assay(ELISA) dected angiopoietin 1(IFN-γ), interleukin-1α(IL-1α), TGF-β1, tumor necrosis factor-α(TNF-α), collagen type Ⅳ(Ⅳ-Col), leukemia inhibitory factor(LIF), superoxide dismutase(SOD)、glutathione peroxidase(GSH-Px);The mRNA expressions of Smad2, Smad3, adisintegrin and metalloproteinase(ADAM17) and TGF-β1 were determined by qPCR. Notch and ADAM17 protein expression in rat uterus were determined by Western blot. The results showed that the area of uterine fibrosis was significantly reduced and the conditions of edema and adhesion were effectively alleviated after high-dose intervention of Bushen Huoxue Formula. The levels of inflammatory factors and Ⅳ-Col were significantly decreased, and the levels of LIF and antioxidant enzymes were significantly increased. The mRNA expressions of Smad2, Smad3, ADAM17 and TGF-β1 were significantly down-regulated. Immunohistochemical results showed that Bushen Huoxu Formula could effectively increase the positive expression of SDF-1 and reduce the positive expression of VEGF and TGF-β1. Western blot results showed that the protein expressions of Notch and ADAM17 in high-dose, medium-dose and low-dose of Bushen Huoxu Formula groups were significantly down-regulated in a dose-dependent manner. These results suggest that Bushen Huoxue Formula may inhibit fibrosis process through ADAM17/Notch signaling pathway, suggesting that Bushen Huoxuet Formula is one of the potential therapeutic methods for IUA.