Preventive Effects of Salvianolic Acid B on Transforming Growth Factor-β1-Induced Epithelial-to-Mesenchymal Transition of Human Kidney Cells

Epithelial-mesenchymal transition (EMT) is an important mechanism in kidney fibrosis. While Salvianolic acid-B (Sal 13) has been well appreciated to show a protective effect of tissue fibrosis, the objective of this study was to investigate the influence of Sal B on the transdifferentiation of renal tubular epithelial cells. Human kidney proximal tubular cell line (HK-2) was used as the proximal tubular cell model and EMT was induced with 5 ng/ml of human tranforming growth factor (TGF)-beta 1. The effects of the Sal B on cell morphology were observed by phase contrast microscopy, and the possible mechanisms were studied by immunocytochemistry and real-time reverse transcription-polymerase chain reaction. Our results revealed that Sal B could inhibit TGF-beta 1-induced myofibroblast phenotype and restored the epithelial morphology in a dose-dependent manner. It was partially through modulating alpha-smooth muscle actin (SMA) increase and E-cadherin reduction. These observations strongly suggest that Sal B is a potent inhibitor of TGF-beta 1-induced EMT and might be a promising agent for treating tubulointerstitial fibrosis.