This study aims to explore the anti-inflammatory and hemostatic effects of the total extract of Clinopodium chinense(TEC), total saponins of C. chinense(TSC), and total flavonoids of C. chinense(TFC) in female rats with abnormal uterine bleeding(AUB), and the possible mechanism. Mifepristone(i.g., 12.4 mg·kg~(-1)) and misoprostol(i.g., 130 μg·kg~(-1)) were used to induce AUB in SD female rats conceiving on the same day. Then the AUB rats were randomized into model group, TEC group, TSC group, TFC group, Yimucao Granules(LG) group, and estradiol valerate(EV) group, with 8 rats in each group. Another 8 non-pregnant female rats were selected as normal group. During the experiment, each group was given the corresponding drug by gavage once a day for 7 days. After the administration, blood and uterine tissue were collected. The uterine bleeding volume was measured by ultraviolet spectrophotometry and the pathological changes of endometrium were observed based on hematoxylin-eosin(HE) staining. In addition, the microvessel density of endometrium was determined by immunohistochemistry, and the content of thromboxane B2(TXB2), 6-keto-PGF_(1α), interleukin-6(IL-6), and tumor necrosis factor-α(TNF-α) in plasma and levels of lutenizing hormone(LH), follicle stimulating hormone(FSH), estradiol(E_2), and progesterone in serum were detected by enzyme-linked immunosorbent assay(ELISA). The mRNA and protein expression of estrogenreceptor α(ERα), progesterone receptor(PR), matrix metalloproteinase(MMP)-2, MMP-9, and vascular endothelial growth factor(VEGF) in uterine tissue was determined by Western blot. Compared with the model group, TEC, TSC, and TFC can reduce uterine bleeding volume, alleviate the pathological damage of endometrium, and increase the microvessel density in endometrium. Moreover, TEC and TSC can significantly raise plasma TXB2 level and ratio of TXB2 to 6-keto-PGF_(1α), and TEC and TFC can significantly reduce the levels of IL-6 and TNF-α. In addition, TEC significantly elevated serum progesterone level and TFC significantly increased serum levels of E_2, FSH, and LH. TSC can significantly raise serum progesterone and FSH levels. In addition, TEC can significantly down-regulate the protein expression of PR, MMP-2, and VEGF and TSC significantly reduced the expression of MMP-9. TFC significantly decreased the expression of PR, MMP-9, and VEGF, and up-regulated the expression of ERα. In conclusion, TEC, TSC, and TFC all show therapeutic effects on AUB, particularly TEC. TSC exerts the effects by enhancing the coagulation function and promoting endometrial repair, and TFC by regulating estrogen levels and reducing inflammatory response. This study reveals the mechanism of C. chinense against AUB and also explains the holistic characteristics of Chinese medicine.
Keywords: Clinopodium chinense; abnormal uterine bleeding; anti-inflammation; endometrial repair; hemostatic effects.