The mechanism of mulberry leaves against renal tubular interstitial fibrosis through ERK1/2 signaling pathway was predicted by network pharmacology and validated in human tubular epithelial cells.

Mulberry leaf was reported that it has antidiabetic activity, although the mechanisms underlying the function have not been fully elucidated. In the present study, the results of network pharmacology suggested that mulberry leaves could regulate key biological process in development of diabetes, and the process implicates multiple signaling pathways, such as JAK-STAT, MAPK, VEGF, PPAR, and Wnt. Then, the research in vitro indicated that mulberry leaves remarkably ameliorated high glucose-induced epithelial to mesenchymal transition, which was characterized with significant reduction of intracellular reactive oxygen species (ROS) levels as well as downregulation of NADPH oxidase subunits NOX1, NOX2, and NOX4, and it was found to be connected with the ERK1/2 signaling pathway in human tubular epithelial cells (HK-2). Moreover, the results of bioinformatics and the dual luciferase report showed that ZEB1 might be a target gene of miR-302a; decreased miR-302a and increased ZEB1 expressions could significantly promote epithelial to mesenchymal transition. However, mulberry leaves could reverse these modulations. Our results demonstrated that network pharmacology could provide a guidance role for traditional Chinese medicine research, and mulberry leaves could be of benefit in preventing high glucose-induced EMT in HK-2 cells, which proved that it was related to the upregulation of miR-302a by targeting ZEB1 and the inhibition of NADPH oxidase/ROS/ERK1/2 pathway.