Dioscin alleviates BDL- and DMN-induced hepatic fibrosis via Sirt1/Nrf2-mediated inhibition of p38 MAPK pathway

Toxicol Appl Pharmacol. 2016 Feb 1:292:19-29. doi: 10.1016/j.taap.2015.12.024. Epub 2015 Dec 30.

Abstract

Oxidative stress is involved in hepatic stellate cells (HSCs) activation and extracellular matrix overproduction. We previously reported the promising effects of dioscin against CCl4-induced liver fibrosis, but its effects and mechanisms on BDL- and DMN-induced liver fibrosis remain unknown. The results in the present study indicated that dioscin significantly inhibited HSCs activation and attenuated hepatic fibrosis in rats. Furthermore, dioscin markedly up-regulated the levels of sirtuin 1 (Sirt1), HO-1, GST, GCLC and GCLM via increasing the nuclear translocation of nuclear erythroid factor 2-related factor 2 (Nrf2), which in turn inhibited mitogen-activated protein kinase 14 (p38 MAPK) phosphorylation and reduced the levels of COL1A1, COL3A1, α-SMA and fibronectin. These results were further validated by knockdown of Sirt1 and Nrf2 using siRNAs silencing, and abrogation of p38 MAPK using SB-203580 (a p38 MAPK inhibitor) in HSC-T6 and LX-2 cells. Collectively, our findings confirmed the potent effects of dioscin against liver fibrosis and also provided novel insights into the mechanisms of this compound as a candidate for the prevention of liver fibrosis in the future.

Keywords: Dioscin; Hepatic fibrosis; Nrf2; Oxidative stress; Sirt1; p38 MAPK.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Bile Ducts / injuries
  • Dimethylnitrosamine / toxicity*
  • Diosgenin / analogs & derivatives*
  • Diosgenin / pharmacology
  • Diosgenin / therapeutic use
  • Dose-Response Relationship, Drug
  • Hepatic Stellate Cells / drug effects
  • Hepatic Stellate Cells / metabolism
  • Humans
  • Ligation
  • Liver Cirrhosis / chemically induced
  • Liver Cirrhosis / drug therapy
  • Liver Cirrhosis / metabolism*
  • MAP Kinase Signaling System / drug effects
  • MAP Kinase Signaling System / physiology
  • Male
  • NF-E2-Related Factor 2 / biosynthesis*
  • Rats
  • Rats, Sprague-Dawley
  • Rats, Wistar
  • Sirtuin 1 / biosynthesis*
  • p38 Mitogen-Activated Protein Kinases / antagonists & inhibitors
  • p38 Mitogen-Activated Protein Kinases / metabolism*

Substances

  • NF-E2-Related Factor 2
  • Nfe2l2 protein, rat
  • dioscin
  • p38 Mitogen-Activated Protein Kinases
  • Sirt1 protein, rat
  • Sirtuin 1
  • Diosgenin
  • Dimethylnitrosamine