Chloroform Extract from Fermented Viola mandshurica Regulates LPS-Induced Inflammation Response in RAW 264.7 Cells by Inhibiting iNOS and COX-2.

Inflammatory is a crucial part of the immune system of body protect it from harmful invaders, such as bacteria, viruses, and other foreign substances. In this study, the effects of chloroform extract of fermented Viola mandshurica (CEFV) on lipopolysaccharide (LPS)-induced inflammatory response in RAW264.7 macrophages were investigated. The CEFV significantly inhibited NO production and reduced the expression of inducible nitric oxide synthase (iNOS) at both protein and mRNA levels in a dose-dependent manner. Also, CEFV decreased PGE2 production, suppressed COX-2 expression, and inhibited the activation of the ERK and JNK pathways but not the p38 pathway. Taken together, CEFV suppressed NF-κB activation, which is a key regulator in the inflammatory response. The main phenolic compounds identified in CEFV were tectoridin, luteolin, resveratrol, and hesperetin. Therefore, in this study, CEFC exhibits potent anti-inflammatory effects by downregulating the production of pro-inflammatory mediators and inhibiting key inflammatory pathway in RAW264.7 cells.