Effect of Chinese patent medicine Kunling Pill on endometrial receptivity: A clinical trial, network pharmacology, and animal-based study.

Although pregnancy success rates are raised with assisted reproductive technology, it still cannot meet clinical demands. Kunling Pill (KLP), a traditional Chinese medicine, is widely used in various gynecological disorders, particularly in improving fertility and pregnancy rates. However, the underlying mechanism of how KLP affects pregnancy outcomes remains unclear. This study aimed to explore the effects and mechanisms of KLP on endometrial receptivity. Firstly, a retrospective trial was conducted to validate the efficacy of KLP on repeated implantation failure (RIF) patients. The result indicated a significant increase in the proportion of live birth in KLP group (30.56%) compared to the control group (16.89%). Secondly, network pharmacology methods predicted the active components and network targets of KLP. Endometrial receptivity is closely associated with the activation of inflammatory factors, predicting the function of KLP on the immune system. The estrogen and apoptotic signaling pathways were also highlighted in the gene ontology enrichment analysis. Thirdly, a decreased endometrial receptivity model was established by controlled ovarian hyperstimulation (COH) in female C57BL/6 mice, divided into the COH and KLP groups. Normal female mice are as control group. In vivo, KLP administration could increase endometrial thickness and the number of endometrial glands and pinopodes. In the endometrium, KLP supplementation upregulated the expressions of estrogen receptor α, progesterone receptor, endothelial nitric oxide synthase, and integrin αVβ3 in the murine uterus and reduced serum levels of estrogen and progesterone. KLP regulated the uterine immune cells and inhibited cell apoptosis in the ovary via Bcl-2/Bax/caspase-3 pathway. In conclusion, KLP administration raised the live birth rate in RIF patients to optimize medication regimens, mainly because KLP ameliorated impaired endometrial receptivity.