Abstract

Forsythoside (FS) is an active component of Forsythia suspense and exhibit a certain functions, such as, anti-inflammation, anti-bacterial, anti-virus, among others. However, immunomodulation  effects of FS at cell level have been unclear. This work is to investigate the effects of FS on RAW264.7 cells stimulated with lipopolysaccharide (LPS) by detecting the release of cytokines and chemokines, phagocytosis and surface molecule expression. The results showed that the absorbance value of cells in FS groups at medium and high concentration was significantly lower compared with LPS group in terms of 3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium bromide (MTT) assay. There was a marked increase in the release of tumor necrosis factor (TNF)-α and decrease NO production in the experimental groups. FS and LPS-treated RAW264.7 cells strongly exhibited phagocytosic capacity to CFSE-labeled chicken red blood cells, and the number of positive cells expressing MHC-II molecules showed a significant decrease in FS together with LPS groups by flow cytometry analysis. The experiment demonstrated that FS has no significant cytotoxicity at the low concentration, markedly promoted the release of TNF-α and down-expressions of MHC-II surface molecules, and enhanced the phagocytosic capacity of macrophages, whereas inhibited NO production, which suggested that FS has cell immune regulation effect.

Key words: Forsythoside (FS), function, RAW264.7 cells, lipopolysaccharide (LPS).