Gallic acid ameliorates endometrial hyperplasia through the inhibition of the PI3K/AKT pathway and the down-regulation of cyclin D1 expression

Background: Gallic acid (GA) is an organic compound with phenolic properties that occurs naturally and can be found in Guizhi Fuling capsules, showcasing a wide range of biological functionalities. Purpose: The objective of this study was to examine the influence of GA on endometrial hyperplasia (EH) and elucidate its underlying mechanism. Methods: Initially, the induction of EH was achieved by administering estradiol to mice via continuous subcutaneous injection for a duration of 21 days. Concurrently, GA treatment was administered, and subsequently, the uterine tissue structure was assessed using hematoxylin and eosin (H &E) staining. Following this, the proliferation of human endometrial cells treated by GA was determined utilizing the CCK-8 method. Furthermore, network pharmacology and single-cell-RNA-seq data were employed to identify the target of GA action. In addition, we will employ immunofluorescence (IF), immunohistochemistry (IHC), flow cytometry, western blot and RT-qPCR methodologies to investigate the impact of GA on the expression level of cyclin D1, PI3K, p-PI3K, AKT, p-AKT. Results: GA treatment ameliorated histopathological alterations in the uterus and suppress proliferation. Estradiol stimulation can activate the PI3K/AKT pathway, leading to up-regulation of cyclin D1 expression, whereas GA treatment results in down-regulation of its expression. Conclusions: The expression of cyclin D1 is down-regulated by GA through the inhibition of the PI3K/AKT pathway, effectively mitigating estradiol-induced EH in mice.