Anti-inflammatory activity of methylene chloride fraction from Glehnia littoralis extract via suppression of NF-κB and mitogen-activated protein kinase activity

Glehnia littoralis (Umbelliferae) has been used traditionally in Korean, Japanese, and Chinese medicine for the treatment of immune-related diseases; however, its anti-inflammatory activity and underlying mechanism remain to be defined. We investigated the anti-inflammatory effect and inhibitory mechanism on inflammation by the methylene chloride fraction from Glehnia littoralis extract (MCF-GLE), which was more effective than Glehnia littoralis extract (GLE). MCF-GLE inhibited 12-O-Tetradecanoyl-phorbol-13-acetate (TPA)-induced inflammation in an inflammatory edema mouse model. Also, MCF-GLE strongly inhibited the releases of nitric oxide (NO), prostaglandin E₂ (PGE₂), tumor necrosis factor-α (TNF-α), and interleukin-1β (IL-1β) and significantly suppressed the mRNA and protein expression of inducible nitric oxide synthase and cyclooxygenase-2 in lipopolysaccharide-stimulated RAW 264.7 macrophage cells in a dosedependent manner. Furthermore, MCF-GLE suppressed NF-κB activation and IκB-α degradation. MCF-GLE also attenuated the activation of ERK and JNK in a dose-dependent manner. These results indicate that MCF-GLE has an inhibitory effect on the in vivo and in vitro inflammatory reaction and is a possible therapeutic agent. Our results suggest that the anti-inflammatory properties of MCF-GLE may result from the inhibition of pro-inflammatory mediators, such as NO, PGE₂, TNF-α, and IL-1β via suppression of NF-κB- and mitogen-activated protein kinases-dependent pathways.