ABSTRACT
PURPOSE: To investigate the effect of Osthole (OST) on lipopolysaccharide (LPS)-induced macrophage polarization and inflammatory reaction. METHODS: The effect of different concentrations of OST on proliferative activity of RAW264.7 macrophages was examined by CCK-8 method; the effect of OST at different concentrations (6.25, 12.5 and 25 µmol/L) on macrophage polarization and inflammation was investigated by using intracellular reactive oxygen species (ROS) detection kit (DCFH-DA), immunofluorescence staining, q-PCR and flow cytometry. The effects of OST on macrophage polarization and inflammatory responses were investigated by immunoblotting of proteins. Graphpad prism 8.0 software package was used for statistical analysis of the data. RESULTS: CCK-8 results showed that OST was not significantly cytotoxic to RAW264.7 at less than 25 µmol/L, immunofluorescence and q-PCR results showed that OST at 6.25, 12.5 and 25 µmol/L inhibited the expression of inflammatory factors in M1 macrophages, and iNOS, TNF-α, CCR7 were reduced in a concentration-dependent manner, and effectively upregulated the expression of M2 inflammatory factors IL-10, Arg-1 and CD206. Flow cytometry showed that OST effectively inhibited the expression of LPS-induced M1 marker CD86 in macrophages. CONCLUSIONS: OST can regulate lipopolysaccharide-induced M1 macrophages polarization and reduce inflammatory reaction.
