Yu Gan Long Ameliorates Hepatic Fibrosis by Inhibiting PI3K/AKT, Ras/ERK and JAK1/STAT3 Signaling Pathways in CCl4-induced Liver Fibrosis Rats.

Yu Gan Long (YGL) is a Chinese traditional herbal formula which has been reported to attenuate liver fibrosis for many years and we have explored its anti-fibrotic mechanism through blocking transforming growth factor (TGF-β) in the previous study. But the mechanisms associated with platelet-derived growth factor (PDGF)-BB remain obscure. In this study, we further investigated the mechanism of YGL reducing carbon tetrachloride (CCl4)-induced liver fibrosis in rats. Our results showed that YGL suppressed CCl4-induced upregulation of collagen IV (Col IV), type HI precollagen (PCHI), hyaluronuc acid (HA) and laminin (LN), which are implicated in liver fibrosis. Also, YGL reduced the α-smooth muscle actin (α-SMA) expression, which acts as the indicator of liver fibrosis. Furthermore, YGL decreased the serum levels of hepatic stellate cell (HSC) mitogen PDGF-BB and inflammation cytokines, including TNF-α, IL-1β, IL-6. Markers involved in liver fibrosis, such as Ras, p-Raf-1, p-ERK1/2, p-JNK, p-P38, p-PI3K, p-AKT, p-JAKl, p-STAT3 were downregulated significantly after treatment with YGL. Our results indicated that YGL ameliorated CCl4-induced liver fibrosis by reducing inflammation cytokines production, and suppressing Ras/ERK, PI3K/AKT, and JAK1/STAT3 signaling pathways, which provided further evidence towards elucidation of the anti-fibrotic mechanism of YGL.