Preliminary Exploration of the Effect of Panax notoginseng Saponins on Macrophage M1 Polarization and Its Mechanism

Abstract

OBJECTIVE To observe the effects of Panax notoginseng saponins (PNS) on the ratio of macrophage M1 polarization and inflammatory factor TNF-α, and preliminarily explore its relationship with regulating the expression of GAS6/MERK pathway. METHODS The single culture of THP-1-derived macrophages and Transwell co-culture system of THP-1-derived macrophages and HFLS-RA were established respectively. LPS+IFN-γ induced the polarization of macrophage M1. Then the cells were divided into control group and PNS intervention groups (5, 10, 20 μg·mL-1). After adding PNS for 48 h, the optimal concentration of PNS was selected by CCK-8 method. The ratio of macrophage M1 polarization was detected by flow cytometry. The expression levels of TNF-α, MERTK receptor and GAS6 ligand were detected by qPCR. The secretion levels of TNF-α and GAS6 were detected by ELISA. Total protein and phosphorylation of MERTK receptor were detected by Western blot. RESULTS In the single culture of THP-1-derived macrophages, 5-20 μg·mL-1 PNS could significantly inhibit macrophages M1 polarization and up-regulate MERTK expression. In Transwell co-culture system, 5-20 μg·mL-1 PNS could also significantly inhibit M1 polarization and up-regulate the expression of MERTK. Compared with the single culture system, 5 μg·mL-1 PNS could significantly up-regulate the secretion level of GAS6 in HFLS-RA, and the phosphorylation level of MERTK was significantly up-regulated after 5 and 10 μg·mL-1 PNS treatment. CONCLUSION Certain concentrations of PNS can significantly inhibit the ratio of macrophage M1 polarization induced by LPS+IFN-γ and the expression level of inflammatory factor TNF-α, and its mechanism may be related with regulating the expression of GAS6/MERK pathway.