Agrimonolide from Agrimonia pilosa suppresses inflammatory responses through down-regulation of COX-2/iNOS and inactivation of NF-κB in lipopolysaccharide-stimulated macrophages

Background: Agrimonolide from Agrimonia pilosa showed a strong anti-inflammatory activity, and the present study aims to reveal potential mechanisms on molecular level explaining its anti-inflammatory effect. Hypothesis/Purpose: To investigate the mechanism of anti-inflammatory activity of agrimonolide. Study design: Anti-inflammatory activity of agrimonolide in cells was applied. Methods: Anti-inflammatory activity of agrimonolide isolated from Agrimonia pilosa was evaluated using lipopolysaccharide (LPS) stimulated RAW 264.7 cell models. The productions of IL-1 beta, IL-6, TNF-alpha and NO were determined by ELISA and nitrite analysis, respectively. The expressions of iNOS and COX-2 were measured by western blotting and RT-PCR analysis. Results: The pre-treatment with agrimonolide significantly reduced the levels of pro-inflammatory cytokines (IL-1 alpha, IL-6, and TNF-alpha), as well as attenuated the expression of iNOS and COX-2 in LPS-stimulated macrophages. Furthermore, agrimonolide inhibited the activation of JNK and p38 MAPKs and decreased the activation of JAK-STAT and NF-kappa B in LPS-stimulated macrophages. Conclusion: The present study suggested that agrimonolide exerted anti-inflammatory activity, at least in part, via suppressing LPS-induced activation of JAK-STATs and p38 MAPKs signaling pathway. (C) 2016 Elsevier GmbH. All rights reserved.