Anti-Inflammatory Effect of Ethanolic Extract from Polyopes affinis through Suppression of NF-κB and MAPK Activation in LPS-Stimulated RAW 264.7 Cells

In this study, the anti-inflammatory effect of Polyopes affinis ethanol extract (PAEE) was investigated using LPS-stimulated RAW 264.7 cells and a croton oil-induced ICR mice model. Treatment with PAEE significantly reduced production of nitric oxide (NO) and pro-inflammatory cytokines [interleukin (IL)-6, tumor necrosis factor (TNF)-α, and IL-1β] in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. PAEE treatment also reduced expression of inducible NO synthase, cyclooxygenase-2, nuclear factor-κB, and mitogen-activated protein kinases in LPS-stimulated RAW 264.7 cells. In the croton oil-induced ear edema test, application of PAEE (10∼250 mg/kg body weight) reduced ear edema in a dose-dependent manner, and PAEE treatment at 50 mg/kg body weight showed similar inhibitory effects compared with prednisolone (10 mg/kg body weight). Histological analysis revealed reduced dermal thickness and lower number of infiltrated mast cells. These results suggest that PAEE might be used as a promising anti-inflammatory agent for inhibition of LPS-induced inflammation and ear edema formation.