title: Compound Astragalus and Salvia miltiorrhiza extract inhibits cell proliferation, invasion and collagen synthesis in keloid fibroblasts by mediating transforming growth factor-β / Smad pathway.
abstract: BACKGROUND
  The transforming growth factor (TGF)-β/Smad pathway plays a key role in keloid development. We have previously demonstrated that compound Astragalus and Salvia miltiorrhiza extract (CASE) inhibits liver fibrosis and reduces invasion capacity of HepG2 cells by mediating the TGF-β/Smad pathway. We therefore hypothesize that CASE may also exert antifibrotic effects in keloids by mediating the TGF-β/Smad pathway.
  
  
  OBJECTIVE
  To investigate the effects of CASE on cell proliferation, invasion and collagen synthesis in keloid fibroblasts, and to explore the effects of CASE on the TGF-β/Smad signal pathway in order to elucidate its mechanisms of action.
  
  
  METHODS
  The inhibitory effects of CASE on keloid fibroblasts were evaluated. Cell proliferation was studied by MTT assay; cell invasion was observed utilizing Transwell invasion chambers; and collagen synthesis in keloid fibroblasts was measured by (3) H-proline incorporation assay. Expression of proteins induced by TGF-β1 and their intracellular localization in keloid fibroblasts were investigated by Western blot and immunofluorescence, respectively. Plasminogen activator inhibitor-1 (PAI-1) transcriptional activity was measured by real-time reverse transcription-polymerase chain reaction.
  
  
  RESULTS
  CASE significantly inhibited cell proliferation induced by newborn bovine serum as well as collagen synthesis and cell invasion induced by TGF-β1 in keloid fibroblasts, while it showed weak effects on normal fibroblasts. The phosphorylation of Smad2/3 was markedly reduced by CASE treatment, while CASE exhibited stronger inhibitory effects on linker region phosphorylation (pSmad2L and pSmad3L) compared with effects on C-terminal region phosphorylation (pSmad2C and pSmad3C). In addition, CASE blocked formation of Smad2/3/4 complexes and their nuclear translocation, but upregulated Smad7 expression in a dose-dependent manner. PAI-1 mRNA and protein levels were also suppressed by CASE treatment.
  
  
  CONCLUSIONS
  These results suggest that CASE exhibits inhibitory effects on cell proliferation, invasion and collagen synthesis in keloid fibroblasts, and its mechanisms of action may involve the TGF-β/Smad pathway.
authors.affiliation: Department of Pharmacology and Institute of Natural Medicine, Anhui, China.
authors.forename: S
authors.initials: S
authors.lastname: He
authors.forename: Y
authors.initials: Y
authors.lastname: Yang
authors.forename: X
authors.initials: X
authors.lastname: Liu
authors.forename: W
authors.initials: W
authors.lastname: Huang
authors.forename: X
authors.initials: X
authors.lastname: Zhang
authors.forename: S
authors.initials: S
authors.lastname: Yang
authors.forename: X
authors.initials: X
authors.lastname: Zhang
mesh_terms: D000328:Adult; D000818:Animals; D002417:Cattle; D049109:Cell Proliferation / Q000187:drug effects*; D003094:Collagen / Q000096:biosynthesis*; D004305:Dose-Response Relationship, Drug; D004365:Drugs, Chinese Herbal / Q000494:pharmacology*; D005260:Female; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D007627:Keloid / Q000378:metabolism / Q000473:pathology; D008297:Male; D008875:Middle Aged; D010766:Phosphorylation; D027561:Salvia miltiorrhiza; D044967:Serum; D015398:Signal Transduction / Q000187:drug effects; D051899:Smad2 Protein / Q000378:metabolism*; D016212:Transforming Growth Factor beta / Q000378:metabolism*; D053773:Transforming Growth Factor beta1 / Q000494:pharmacology; D055815:Young Adult
chemical_list: C543477:Astragali compound; D004365:Drugs, Chinese Herbal; C497782:SMAD2 protein, human; D051899:Smad2 Protein; D016212:Transforming Growth Factor beta; D053773:Transforming Growth Factor beta1; D003094:Collagen