Phenolic compounds from Chaenomeles speciosa alleviate inflammation in lipopolysaccharide-treated RAW264.7 macrophages via the NF-κB and MAPK pathways

Chaenomeles speciosa(Sweet)Nakai cultivated widely in temperate regions possesses anti-inflammatory properties,however,the underlying molecular mechanisms remain not fully understood.In this study,a purified phenolic extract of C.speciosa rich in chlorogenic acid,procyanidin B1 and catechin(determined by HPLC-Q-TOF-MS/MS)exhibited dose-dependent anti-inflammatory effects on lipopolysaccharide(LPS)-treated RAW264.7 macrophages.The extract at 30μg/mL was most potent and enabled most cells in normal morphology under LPS stimulation without causing cytotoxicity.The extract suppressed the levels of nitric oxide(NO),tumor necrosis factor-α(TNF-α),interleukin-6(IL-6)and interleukin-1β(IL-1β),and the mRNA and protein expressions of nitric oxide synthase(iNOS)and cyclooxygenase-2(COX-2).The mechanisms underlying such anti-inflammatory actions included the regulation of phosphorylation of related proteins to monitor the expressions of inflammatory mediators and genes in the nuclear factor kappa-B(NF-κB)and mitogen-activated protein kinase(MAPK)signaling pathways.Therefore,the phenolic extract from C.speciosa is a desirable anti-inflammatory agent for inflammatory conditions to meet the rising demand for natural and cost-effective therapeutics.