Influence of salvianolic acid B on expressions of TGF-β1/Smad signaling pathway related proteins in human lung fibroblasts and its mechanism

Objective To investigate the influence of salvianolic acid B on the expressions of TGF-β1/Smad signaling pathway related proteins in human lung fibroblasts,and to explore the mechanism of the inhibitory effect of Sal B on TGF-β1-induced lung fibroblast activation.Methods The human embryonic lung fibroblasts(MRC-5)were cultured in vitro and randomly divided into control group(the cells were cultured with DMEM without TGF-β1or Sal B),Sal B group(the cells were cultured with 10μmol·L-1 Sal B),TGF-β1group(the cells were cultured with 10μg·L-1 TGF-β1),and TGF-β1(10μg·L-1)+ Sal B(10μmol·L-1)group.The protein levels of p-Smad2,p-Smad3,TβRⅠ,and Smad7in the fibroblasts in various groups were detected by Western blotting method.Results Compared with control group,the expression levels of p-Smad2,p-Smad3,and TβRⅠproteins in TGF-β1group were significantly increased(P0.05),and the expression level of Smad7protein was decreased(P0.05).Compared with control group,the expression levels of p-Smad2,p-Smad3,TβRⅠ,and Smad7proteins in lung fibroblasts in Sal B group had no significant change(P0.05).Compared with TGF-β1group,the expression levels of p-Smad2,p-Smad3,and TβRⅠin TGF-β1+ Sal B group were descended(P0.05),and the expression level of Smad7was increased(P0.05).Conclusion Sal B could suppress the TGF-β/Smad signaling pathway in lung fibroblasts and to inhibit the TGF-β1-induced lung fibroblast activation.