title: Tiliroside, the major component ofAgrimonia pilosaLedeb ethanol extract, inhibits MAPK/JNK/p38-mediated inflammation in lipopolysaccharide-activated RAW 264.7 macrophages.
abstract: In the present study, thein vivoanti-inflammatory activity ofAgrimonia pilosaLedeb (AP) ethanol extract was confirmed in experimental animal models, including xylene-induced ear edema in mice and carrageenan-induced paw edema in rats. Tiliroside, the major component of AP extract, was isolated and purified by high-performance liquid chromatography. The anti-inflammatory mechanism of tiliroside was then examined using lipopolysaccharide (LPS)-activated RAW 264.7 macrophage cells. An MTT assay was used to determine cytotoxicity and a Griess assay was used to determine nitric oxide (NO) production. Concentration levels of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were determined by enzyme-linked immunosorbent assay. Protein expression levels of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), phosphorylated (p)-extracellular signal-regulated kinase (ERK) 1/2, p-c-Jun N-terminal kinases (JNK), p-p38 and inhibitor of κB-α were detected by western blot analysis. AP ethanol extract was revealed to inhibit xylene-induced ear edema in mice and carrageenan-induced paw edema in rats. Tiliroside significantly suppressed the overproduction of NO (P<0.01), but revealed no notable inhibition of the release of TNF-α and IL-6. In addition, tiliroside significantly downregulated the elevated expression levels of iNOS and COX-2 induced by LPS (P<0.01). The phosphorylation of JNK and p38 proteins were also significantly inhibited (P<0.01), however, tiliroside exhibited no obvious inhibition on the phosphorylation of ERK 1/2 and the degradation of IκB-α protein. In conclusion, the anti-inflammatory molecular mechanism of tiliroside may involve the downregulation of iNOS and COX-2 protein expression levels, and the inactivation of mitogen-activated protein kinase (MAPK)/JNK, in addition to the MAPK/p38 signaling pathway.
authors.affiliation: Key Laboratory of Molecular Pharmacology and Drug Evaluation, Ministry of Education of China, School of Pharmacy, Yantai University, Yantai, Shandong 264005, P.R. China.
authors.forename: Xin
authors.initials: X
authors.lastname: Jin
authors.affiliation: Department of Rehabilitation Medicine, Yantai Yu-Huang-Ding Hospital, Yantai, Shandong 264000, P.R. China.
authors.forename: Shiqing
authors.initials: S
authors.lastname: Song
authors.affiliation: Key Laboratory of Molecular Pharmacology and Drug Evaluation, Ministry of Education of China, School of Pharmacy, Yantai University, Yantai, Shandong 264005, P.R. China.
authors.forename: Jing
authors.initials: J
authors.lastname: Wang
authors.affiliation: Key Laboratory of Molecular Pharmacology and Drug Evaluation, Ministry of Education of China, School of Pharmacy, Yantai University, Yantai, Shandong 264005, P.R. China.
authors.forename: Qingzhen
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: Tianjin State Key Laboratory of Modern Chinese Medicine, School of Chinese Materia Medica, Tianjin University of Traditional Chinese Medicine, Tianjin 300193, P.R. China.
authors.forename: Feng
authors.initials: F
authors.lastname: Qiu
authors.affiliation: Key Laboratory of Molecular Pharmacology and Drug Evaluation, Ministry of Education of China, School of Pharmacy, Yantai University, Yantai, Shandong 264005, P.R. China.
authors.forename: Feng
authors.initials: F
authors.lastname: Zhao
keywords: Agrimonia pilosa Ledeb; cyclooxygenase-2; inducible nitric oxide synthase; mitogen-activated protein kinase; tiliroside