Anti-inflammatory effects of ononin on lipopolysaccharide-stimulated RAW 264.7 cells

Increasing evidence has shown that ononin, a major isoflavone, has anti-inflammatory effects on lipopolysaccharide (LPS)-induced inflammation. However, the molecular mechanisms underlying the anti-inflammatory effects of ononin are still unclear. In the present study, we investigated these effects and the underlying mechanisms of ononin on LPS-induced inflammatory responses. Mouse RAW 264.7 cells were treated with 1 mu g/mL LPS and 5, 25, 50, 100 or 150 mu M ononin for 18 h. Cell viability was assessed using MIT assays, and the production of nitric oxide (NO), prostaglandin E-2 (PGE(2)) and the pro inflammatory cytokines TNF-alpha, IL-1 beta and IL-6 in cultures was examined by Griess and ELISA analyses. qRT-PCR was performed to detect the mRNA expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX-2). Mitogen-activated protein kinases (MAPKs) and nuclear transcription factor Kappa-B (NF-kappa B) signalling pathway-related proteins were assessed by western blot assays. The results showed that cell viability was not significantly affected by up to 100 mu M ononin. The production of NO, PGE2 and the pro-inflammatory cytokines TNF-a., IL-1 beta and IL-6 in the cultures, the mRNA expression of two major inflammatory mediators, COX-2 and iNOS, and the expression of phosphorylated ERK, JNK, and p38 MAPKs proteins in LPS-treated cells were significantly increased. These changes could be reversed by treatment with ononin in a concentration-dependent manner (P < 0.05). The results suggest that ononin has anti-inflammatory effects on LPS-induced inflammatory responses by inhibiting the NF-kappa B and MAPK pathways and may be a potential treatment for inflammation. (C) 2017 Elsevier Ltd. All rights reserved.