Huangqi-Danshen Decoction Against Renal Fibrosis in UUO Mice via TGF-β1 Induced Downstream Signaling Pathway

Background: Huangqi-Danshen decoction (HDD) is a Chinese medicinal herb pair with good efficacy in treating chronic kidney disease, but its mechanism needs to be clarified. Aim: To uncover the underlying mechanism of HDD antagonizing renal fibrosis through network pharmacology (NP) analysis and experimental validation. Materials and Methods: The chemical components of water extract of HDD were analyzed by combining the ultra-high performance liquid chromatography coupled with Q-Exactive mass spectrum analysis (UHPLC-QE-MS) and HERB database. NP was used to identify core common targets of HDD components and renal fibrosis. Subsequently, male C57BL/6 mice were divided into Sham, unilateral ureteral obstruction (UUO) and UUO+HDD groups. Renal function, histopathology, Western blotting, and immunohistochemistry analyses were used to evaluate the protective effect of HDD on UUO mice. The effects of HDD on signaling pathways were validated in both UUO mice and transforming growth factor-β1 (TGF-β1)-induced HK-2 cells. Results: By combining UHPLC-QE-MS analysis and HERB database, 25 components were screened in HDD extract. There were 270 intersection targets of the 25 components and renal fibrosis. Based on their scores in protein-protein interaction analysis and degree values in component-pathway-target triadic network, 6 core common targets of the 25 components and renal fibrosis were identified, namely phosphoinositide 3-kinase (PI3K), signal transducer and activator of transcription 3 (Stat3), non-receptor tyrosine kinase Src (Src), epidermal growth factor receptor (EGFR), matrix metalloproteinase 9 (MMP9), and MMP2. HDD ameliorated renal tubular damage and collagen deposition and downregulated fibrosis-related proteins expression in UUO mice. Furthermore, HDD was demonstrated to reduce PI3K, Stat3, Src, EGFR, and MMP2 expressions, and enhance MMP9 expression in the kidney of UUO mice and in TGF-β1-induced HK-2 cells. Conclusion: HDD can alleviate renal fibrosis which may be related to regulating the expression of essential proteins in the epithelial-mesenchymal transition and extracellular matrix production/degradation signaling pathways.