Withagulatin A inhibits hepatic stellate cell viability and procollagen I production through Akt and Smad signaling pathways

Abstract

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 μmol/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 μmol/L) inhibited transforming growth factor-β (TGF-β) stimulated type I procollagen gene expression, which was attributable to the suppression of TGF-β 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.

Plumbagin protects liver against fulminant hepatic failure and chronic liver fibrosis via inhibiting inflammation and collagen production

“…It was also observed that plumbagin sharply inhibited other signals, such as pSTAT3, NF-κB/p65, and Akt/mTOR in LX-2 cells (Figure 6B ), which all are involved in inflammation and liver fibrosis [ 21 – 25 ]. In addition, NF-κB/p65 activation in RAW 264.7 cells was decreased by plumbagin ( Supplementary Figure 1 ).…”

“…The Akt/mTOR pathway correlates HSC survival and proliferation [ 22 – 24 ]. Activated Akt is a key survival factor that directly phosphorylates mTOR, which ultimately stimulates HSC proliferation [ 25 ]. STAT3 actively promotes HSC activation [ 37 , 38 ].…”

Characterization of the conversion between CD133+and CD133-cells in colon cancer SW620 cell line

“…Cell proliferation was measured by standard sulforhodamine B (SRB) assays 27 and the optical density (OD) value was read at 515 nm using a multi-well spectrophotometer (VERSAmax, Molecular Devices). The growth inhibition rate was calculated as (OD 515control -OD 515agents )/OD 515control × 100%.…”

Inhibition Effect of Physalis angulata Leaf Extract on Viability, Collagen Type I, and Tissue Inhibitor of Metalloproteinase 1 (TIMP-1) but Not Plasminogen Activator Inhibitor-1 (PAI-1) of Keloid Fibroblast Culture

“… 25 A study on withagulatin A isolated from P. angulata L showed inhibition of TGF-β stimulated type I procollagen gene expression in primary hepatic stellate cells isolated from normal livers of male Sprague Dawley rats, which was attributable to the suppression of TGF-β stimulated SMAD2 and SMAD3 phosphorylation. 26 The expression of keloid procollagen 1 mRNA increased 35 times compared to preputium fibroblast. 6 Excessive collagen formation in keloid is the target therapy for keloid.…”