LPS로 자극된 RAW 264.7 cell에서 개민들레 (Hypochoeris radicata L.) 꽃 에틸아세테이트 분획물의 염증 억제 효과

Abstract

In this study, in order to evaluate the usefulness of Hypochoeris radicata L. as anti-inflammatory resource, the anti-inflammatory effects of it's extracts was investigated in lipopolysaccharide (LPS)-induced RAW 264.7 cells. We first examined the inhibitory effect of 80% EtOH extracts from different parts (flower, leaf, root, aerial part and whole plant) of H. radicata L. on nitric oxide (NO) production in LPS-stimulated RAW 264.7 cells. The flowers extract of H. radicata L. showed strong inhibitory effect against the production of NO, and solvent fractions (ethylacetate, H20) were obtained from H. radicata L. flowers. Almong then, ethylacetate fraction of H. radicata L. flower (HRF-EA) inhibited production of pro-inflammatory mediators such as NO, inducible NO synthase (iNOS), prostaglandin E2 (PGE2), and cyclooxygenase-2 (COX-2) and cytokines such as tumour necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6 in LPS-stimulated RAW 264.7 cells. To further examine the mechanism responsible for the inhibition of iNOS and COX-2 expression by HRF-EA, we examined the effect of HRF-EA on LPS-induced nuclear factor-κB (NF-κB) activation and the phosphorylation of mitogen-activated protein kinases (MAPKs). HRF-EA inhibited LPS-induced NF-κB activation by inhibition of IκB-α degradation and p50 phosphorylation. Further, the phosphorylation of MAPKs such as p38, ERK and JNK was suppressed by HRF-EA in a concentration-dependent manner. These results suggest that HRF-EA may inhibit LPS-induced production of inflammatory markers by blocking NF-κB activation and MAPKs phosphorylation. Also, The chemical constituents of the HRF-EA were further analysed by HPLC and found to include luteolin (70 mg/g). Thus, HRF-EA have the potential for use in anti-inflammatory resource.