Differential Inhibitory Effects of Salvianolic Acids on Activation of Rat Hepatic Stellate Cells by Platelet-Derived Growth Factor

Platelet-derived growth factor (PDGF) induces cell proliferation together with oxidative stress. The present study investigated the effects of salvianolic acid A (Sal A) and B (Sal B) on the PDGF-induced signaling cascades in hepatic stellate cells (HSCs). HSC-T6, a rat hepatic stellate cell line, was stimulated with PDGF (10 ng/mL). The inhibitory effects of Sal A and B on oxidative stress-related signaling pathways were assessed in vitro. The protein levels were measured by Western blotting. FACS analysis was applied to detect the thioredoxin (Trx) level. Sal A and B showed different inhibitory abilities on the PDGF-related pathway. Sal A inhibited 70-kDa ribosomal S6 kinase (p70(s6k)) and associated proteins. Sal B attenuated PDGF-induced c-jun-N-terminal kinase (JNK), p38, and PKC-delta phosphorylations. Both Sal A and B diminished the activation of PKD, Trx, hemeoxygenase (HO)-1, and Nrf2. Taken together, our results showed that Sal A and B attenuated PDGF-induced ROS formation in HSCs, possibly through different signaling pathways.