Geniposide inhibits hepatic fibrosis and hepatic stellate cell activation through blocking the TGF-β1/Smad signaling pathway / 生理学报

ABSTRACT

The purpose of this study was to investigate the effect of Geniposide on hepatic fibrosis and activation of hepatic stellate cells (HSCs) and to explore possible underlying mechanism. Human HSCs (LX-2) were treated with 5 ng/mL transforming growth factor-β1 (TGF-β1), followed by co-culture with Geniposide at various concentrations (0, 1, 2.5, 5, 10, 20, 40, 60, 80, 100 μmol/L). Cell viability was determined by MTT assay. Then, LX-2 cells were divided into control, TGF-β1 (5 ng/mL) and TGF-β1 + Geniposide (20 μmol/L) groups, and the gene and protein expression of collagen I, fibronectin, α-smooth muscle actin (α-SMA), p-Smad2 and p-Smad3 was detected by qPCR and Western blot, respectively. BALB/c mice were treated with CCl4 (25%, 1 mL/kg) to generate a model of hepatic fibrosis (CCl4 group), and the control group and CCl4 + Geniposide group were administered with olive oil and CCl4 + 40 mg/kg Geniposide, respectively. After 4 weeks of treatment, the liver function and serum hepatic fibrosis indexes of mice were detected, histological observation was performed by HE and Masson staining, and α-SMA expression in the tissue was analyzed by immunohistochemistry. Western blot was utilized for the determination of the protein expression of α-SMA, TGF-β1, p-Smad2 and p-Smad3. The results showed that Geniposide inhibited LX-2 cell proliferation. In addition, Geniposide significantly downregulated the gene and protein expression of collagen I, fibronectin and α-SMA and the expression of TGF-β1/Smad signaling-related proteins induced by TGF-β1 in vitro. Histological observations showed that Geniposide significantly inhibited CCl4-induced hepatic fibrosis, HSC activation and expression of TGF-β1/Smad signaling-related proteins in mice. In summary, Geniposide prevents the hepatic fibrosis and HSC activation possibly through the inhibition of the TGF-β1/Smad signaling pathway.