To investigate the effect of Yunkang Oral Liquid on preventing lipopolysaccharide(LPS)-induced abortion and regulating immune tolerance in mice,sixty normal ICR mice were randomly divided into normal group,model group,Yunkang Oral Liquid high,middle and low dose groups and progesterone group.Abortion model was established by tail vain injection of LPS(0.1μg/mouse)on the 7th day of pregnancy.Since the first day of pregnancy,the same volume of distilled water,Yunkang Oral Liquid at the dose of 36,18 and 9 m L·kg~(-1)·d~(-1),and progesterone at the dose of 0.038 g·kg~(-1)·d~(-1)were given in corresponding groups.The mice were sacrificed at the 9th day of pregnancy,and the embryo loss of each group was calculated.The levels of Th1 type cytokines(TNF-α,IFN-γ)and Th2 type cytokines(IL-4,IL-10)in uterus homogenate were detected by ELISA.HE staining was performed to examine the histopathological changes in the decidua.The expression levels of CD14,F4/80 in macrophages of uterus were detected by immunohistochemistry.Western blot was used to investigate the protein expression of TLR4,MyD88 and NF-κB in uterine decidua.In our study,all Yunkang Oral Liquid groups could significantly reduce the embryo absorption rate of mice,while high dose group can significantly increase the levels of IL-10 and IL-4;both medium and high dose groups can significantly decrease TNF-α,and IFN-γlevelsin the uterus of model mice,reduce the protein expression of NF-κB,MyD88 and TLR4 in uterine decidua tissue.Various treatment groups could reduce the counts of F4/80,CD14 macrophages and decrease expression area in uterine tissue.Our results showed that Yunkang Oral Liquid could prevent LPS-induced abortion,and the mechanism may be associated with inhibiting the TLR4/MyD88/NF-κB signaling pathway and regulating the balance of Th1/Th2 immune factors,which could improve the endometrial receptivity of mice,and promote the development of decidua and implantation of embryo.
Keywords: NF-κB signaling pathway; Yunkang Oral Liquid; lipopolysaccharide(LPS); maternal-fetal immune tolerance; threatened abortion.