Effects of S/B remedy containing Scutellaria baicalensis and Bupleurum scorzonerifolfium on hepatic interleukin-6 related signal transducer and activator of transcription 3 activation in mice through cell-cell interaction

Biol Pharm Bull. 2011;34(5):727-33. doi: 10.1248/bpb.34.727.

Abstract

Signal transducer and activator of transcription 3 (STAT3) plays an important role in regulating interleukin 6 (IL-6) related growth control of the liver. Our previous study demonstrated that a mixture containing Scutellaria baicalensis and Bupleurum scorzonerifolfium (S/B remedy) modulated the growth of hepatocytes during liver regeneration after 2/3 partial hepatectomy. The aim of this study was to investigate whether S/B remedy induced mouse hepatic STAT3 activation directly in hepatocytes or indirectly via non-parenchymal cell-hepatocyte interaction. Direct S/B remedy effects were studied using primarily isolated hepatocytes; while C57BL/6J mice were used to study indirect effects of S/B remedy using gadolinium chloride to deplete Kupffer cells' function. The results showed that S/B remedy and its active constituents did not directly activate growth-related signaling in primarily isolated hepatocytes. However, S/B remedy induced STAT3 and subsequently suppressor of cytokine signaling (SOCS3) activation in mouse liver and increased serum IL-6 level in a dose-dependent manner, which could be partially blocked by pretreatment with gadolinium chloride. Oligonucloetide microarray analysis from S/B remedy-treated peripheral blood leukocytes demonstrated an up-regulation of IL-6 gene expression. We conclude that S/B remedy did not directly induce STAT3 activation in vitro, but induced hepatic IL-6 related STAT3 activation through non-parenchymal cell-hepatocyte interaction in vivo. The results provide important information on the molecular mechanisms of S/B remedy for treatment of human liver diseases.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Base Sequence
  • Blotting, Western
  • Bupleurum / chemistry*
  • DNA Primers
  • Liver / drug effects*
  • Liver / metabolism
  • Mice
  • Mice, Inbred C57BL
  • Plant Extracts / pharmacology*
  • Reverse Transcriptase Polymerase Chain Reaction
  • STAT3 Transcription Factor / drug effects*
  • STAT3 Transcription Factor / metabolism
  • Scutellaria baicalensis / chemistry*

Substances

  • DNA Primers
  • Plant Extracts
  • STAT3 Transcription Factor
  • Stat3 protein, mouse