Baicalin Ameliorates Experimental Liver Cholestasis in Mice by Modulation of Oxidative Stress, Inflammation, and NRF2 Transcription Factor

Oxid Med Cell Longev. 2017:2017:6169128. doi: 10.1155/2017/6169128. Epub 2017 Jul 5.

Abstract

Experimental cholestatic liver fibrosis was performed by bile duct ligation (BDL) in mice, and significant liver injury was observed in 15 days. Administration of baicalin in mice significantly ameliorates liver fibrosis. Experimental cholestatic liver fibrosis was associated with induced gene expression of fibrotic markers such as collagen I, fibronectin, alpha smooth muscle actin (SMA), and connective tissue growth factor (CTGF); increased inflammatory cytokines (TNFα, MIP1α, IL1β, and MIP2); increased oxidative stress and reactive oxygen species- (ROS-) inducing enzymes (NOX2 and iNOS); dysfunctional mitochondrial electron chain complexes; and apoptotic/necrotic cell death markers (DNA fragmentation, caspase 3 activity, and PARP activity). Baicalin administration on alternate day reduced fibrosis along with profibrotic gene expression, proinflammatory cytokines, oxidative stress, and cell death whereas improving the function of mitochondrial electron transport chain. We observed baicalin enhanced NRF2 activation by nuclear translocation and induced its target genes HO-1 and GCLM, thus enhancing antioxidant defense. Interplay of oxidative stress/inflammation and NRF2 were key players for baicalin-mediated protection. Stellate cell activation is crucial for initiation of fibrosis. Baicalin alleviated stellate cell activation and modulated TIMP1, SMA, collagen 1, and fibronectin in vitro. This study indicates that baicalin might be beneficial for reducing inflammation and fibrosis in liver injury models.

MeSH terms

  • Actins / metabolism
  • Animals
  • Cholestasis / drug therapy*
  • Cholestasis / metabolism
  • Cholestasis / pathology
  • Collagen Type I / metabolism
  • Cytokines / metabolism
  • Disease Models, Animal
  • Flavonoids / pharmacology*
  • Liver / metabolism*
  • Liver / pathology
  • Mice
  • NADPH Oxidase 2 / metabolism
  • NF-E2-Related Factor 2 / metabolism*
  • Nitric Oxide Synthase Type II / metabolism
  • Oxidative Stress / drug effects*
  • Reactive Oxygen Species / metabolism
  • Tissue Inhibitor of Metalloproteinase-1 / metabolism

Substances

  • Actins
  • Collagen Type I
  • Cytokines
  • Flavonoids
  • NF-E2-Related Factor 2
  • Nfe2l2 protein, mouse
  • Reactive Oxygen Species
  • Timp1 protein, mouse
  • Tissue Inhibitor of Metalloproteinase-1
  • baicalin
  • Nitric Oxide Synthase Type II
  • Nos2 protein, mouse
  • Cybb protein, mouse
  • NADPH Oxidase 2