AIM: To investigate the effects of the natural product Withagulatin A on hepatic stellate cell (HSC) viability and type I procollagen production. The potential mechanism underlying the pharmacological actions was also explored. METHODS: The effect of Withagulatin A on cell viability was evaluated in HSC and LX-2 cells using a sulforhodamine B (SRB) assay. Cell cycle distribution was analyzed using flow cytometry. Type I procollagen gene expression was determined using real-time PCR. Regulation of signaling molecules by Withagulatin A was detected using Western blotting. RESULTS: Primary rat HSCs and the human hepatic stellate cell line LX-2 treated with Withagulatin A (0.625-20 micromol/L) underwent a dose-dependent decrease in cell viability, which was associated with S phase arrest and the induction of cell apoptosis. In addition, the natural product decreased phosphorylation of the Akt/mTOR/p70S6K pathway that controls cell proliferation and survival. Furthermore, Withagulatin A (1, 2 mumol/L) inhibited transforming growth factor-beta (TGF-beta) stimulated type I procollagen gene expression, which was attributable to the suppression of TGF-beta stimulated Smad2 and Smad3 phosphorylation. CONCLUSION: Our results demonstrated that Withagulatin A potently inhibited HSC viability and type I procollagen production, thereby implying that this natural product has potential use in the development of anti-fibrogenic reagents for the treatment of hepatic fibrosis.
AIM: To investigate the effects of the natural product Withagulatin A on hepatic stellate cell (HSC) viability and type I procollagen production. The potential mechanism underlying the pharmacological actions was also explored. METHODS: The effect of Withagulatin A on cell viability was evaluated in HSC and LX-2 cells using a sulforhodamine B (SRB) assay. Cell cycle distribution was analyzed using flow cytometry. Type I procollagen gene expression was determined using real-time PCR. Regulation of signaling molecules by Withagulatin A was detected using Western blotting. RESULTS: Primary rat HSCs and the human hepatic stellate cell line LX-2 treated with Withagulatin A (0.625-20 micromol/L) underwent a dose-dependent decrease in cell viability, which was associated with S phase arrest and the induction of cell apoptosis. In addition, the natural product decreased phosphorylation of the Akt/mTOR/p70S6K pathway that controls cell proliferation and survival. Furthermore, Withagulatin A (1, 2 mumol/L) inhibited transforming growth factor-beta (TGF-beta) stimulated type I procollagen gene expression, which was attributable to the suppression of TGF-beta stimulated Smad2 and Smad3 phosphorylation. CONCLUSION: Our results demonstrated that Withagulatin A potently inhibited HSC viability and type I procollagen production, thereby implying that this natural product has potential use in the development of anti-fibrogenic reagents for the treatment of hepatic fibrosis.
Authors: P Skehan; R Storeng; D Scudiero; A Monks; J McMahon; D Vistica; J T Warren; H Bokesch; S Kenney; M R Boyd Journal: J Natl Cancer Inst Date: 1990-07-04 Impact factor: 13.506
Authors: Shimon Reif; Alon Lang; Jeffery N Lindquist; Yutaka Yata; Erwin Gabele; Andrew Scanga; David A Brenner; Richard A Rippe Journal: J Biol Chem Date: 2002-12-26 Impact factor: 5.157