Tigloylgomisin P Inhibits Endothelial Inflammation by Regulating the NF-κB and Smad1/5/9 Pathways.

OBJECTIVE: Vascular inflammation contributes to the development of many chronic human diseases. Inflammatory stimuli such as interleukin (IL)-1β or disturbed blood flow trigger endothelial activation, thereby promoting leukocyte recruitment and transmigration through inflammatory signaling pathways. This study aimed to identify novel compounds capable of blocking vascular inflammation, with potential therapeutic applications in vascular inflammatory diseases such as atherosclerosis. METHODS: A natural compound library was screened to identify drug candidates that inhibit IL-1β-induced endothelial inflammation. The anti-inflammatory effects of tigloylgomisin P, one of the hit compounds, were examined in bovine aortic endothelial cells stimulated with IL-1β or oscillatory (disturbed) flow. Endothelial inflammation was assessed by measuring nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) phosphorylation and nuclear translocation, monocyte adhesion to endothelial monolayers, and Smad1/5/9 phosphorylation in vitro. Vascular inflammation in vivo was evaluated in aortas of apolipoprotein E (ApoE) knockout mice treated with tigloylgomisin P using immunohistochemistry. RESULTS: Tigloylgomisin P suppressed IL-1β-induced NF-κB activation and reduced monocyte adhesion. In addition, it inhibited oscillatory shear stress-induced endothelial inflammation mediated by NF-κB activation and Smad1/5/9 phosphorylation. In ApoE knockout mice, administration of tigloylgomisin P decreased inflammatory marker expression in the atheroprone inner curvature of aortic arches. CONCLUSION: These findings suggest that tigloylgomisin P may represent a potential therapeutic agent for vascular inflammatory diseases such as atherosclerosis.