Low molecular weight fucoidan from the sporophyll of Undaria pinnatifida suppresses inflammation by promoting the inhibition of mitogen-activated protein kinases and oxidative stress in RAW264.7 cells

Abstract

The suppression of MAPK and oxidative stress could be an important anti-inflammatory mechanism. Fucoidan regulates MAPK activity in several cell lines. However, the mechanism for the anti-inflammatory and oxidative stress effect of low molecular weight fucoidan (LMWF) is poorly understood in RAW264.7 cells. The objective of this study was to examine the critical role of LMWF during LPS-induced inflammation in RAW264.7 cells. To determine the potential role of LMWF, we analysed pro-inflammatory cytokine, transcription factor, inflammation-related and oxidative stress related protein expression in vitro during LPS-induced inflammation in RAW264.7 cells. In this study, we demonstrated the anti-inflammatory effects of LMWF on LPS-induced inflammation in macrophages through the regulation of signalling pathways, including its effect on the attenuation of inflammatory cytokines, such as IL-1β, IL-1 and TNF-α, and the degradation of phosphorylated p38 MAPK, ERK1/2 and JNK. This study also demonstrates that LMWF might block NO as well as the expression of reactive oxygen species (ROS), which subsequently inhibits the iNOS and COX-2 expression induced by LPS. Based on these findings, we suggest that LMWF might have great potential as an external pathogen prevention and intervention agent for inflammatory diseases.