Cucurbitacin-B attenuates CCl4 -induced hepatic fibrosis in mice through inhibition of STAT-3

Chem Biol Drug Des. 2018 Apr;91(4):933-941. doi: 10.1111/cbdd.13160. Epub 2018 Jan 11.

Abstract

Liver fibrosis is a major health concern worldwide. Inhibitors of Signal Transducer and Activator of Transcription 3 (STAT3) have been reported to attenuate experimental liver fibrosis. Therefore, the aim of this study was to investigate the potential ameliorative effect of cucurbitacin-B (Cucu-B) against CCl4 -induced liver fibrosis in mice. Treatment with Cucu-B (5 mg/kg) preserved hepatocellular membrane integrity and amended the metabolic function as indicated by preventing the rise of serum liver function markers. This was confirmed histologically. CCl4 -induced oxidative stress was improved by Cucu-B treatment (1 and 5 mg/kg). Furthermore, Cucu-B treatment ameliorated the fibrotic state as evidenced by inhibiting the rise of hydroxyproline liver content and mitigating the overexpressions of collagen-1α, α-smooth muscle actin (α-SMA) and transforming growth factor beta (TGF-β) as well as the downexpression of matrix metalloproteinase-2 (MMP-2) mRNA. Importantly, STAT3 activity was inhibited by Cucu-B as confirmed by decreased phosphorylation of STAT3 without changing total STAT3 expression. This was substantiated by the reduced Bcl-2 together with increased Bax mRNA expressions with subsequent elevation of Bax/Bcl-2 ratio. In conclusion, Cucu-B hampers CCl4 -induced liver fibrosis in mice. This can be attributed-at least partly-to inhibition of oxidative stress, inflammation and STAT3 signalling.

Keywords: STAT-3; cucurbitacin-B; fibrosis; liver; mice.

MeSH terms

  • Animals
  • Hydroxyproline / analysis
  • Hydroxyproline / metabolism
  • Liver / drug effects
  • Liver / metabolism
  • Liver / pathology
  • Liver Cirrhosis / chemically induced
  • Liver Cirrhosis / pathology
  • Liver Cirrhosis / prevention & control*
  • Male
  • Matrix Metalloproteinase 2 / genetics
  • Matrix Metalloproteinase 2 / metabolism
  • Mice
  • Oxidative Stress / drug effects
  • Phosphorylation / drug effects
  • Protective Agents / chemistry
  • Protective Agents / metabolism
  • Protective Agents / pharmacology
  • Proto-Oncogene Proteins c-bcl-2 / genetics
  • Proto-Oncogene Proteins c-bcl-2 / metabolism
  • STAT3 Transcription Factor / antagonists & inhibitors
  • STAT3 Transcription Factor / metabolism*
  • Signal Transduction / drug effects
  • Transforming Growth Factor beta / genetics
  • Transforming Growth Factor beta / metabolism
  • Triterpenes / chemistry
  • Triterpenes / pharmacology
  • Triterpenes / therapeutic use*
  • bcl-2-Associated X Protein / genetics
  • bcl-2-Associated X Protein / metabolism

Substances

  • Protective Agents
  • Proto-Oncogene Proteins c-bcl-2
  • STAT3 Transcription Factor
  • Stat3 protein, mouse
  • Transforming Growth Factor beta
  • Triterpenes
  • bcl-2-Associated X Protein
  • cucurbitacin B
  • Matrix Metalloproteinase 2
  • Hydroxyproline

Associated data

  • GENBANK/NM_021578.2
  • GENBANK/XM_005257059.3
  • GENBANK/NM_002421.3
  • GENBANK/XM_011250780.1
  • GENBANK/XM_0512835.1
  • GENBANK/NM_ 028301.2