ABSTRACT
【Objective】 To investigate the effects of naringenin on the polarization of high-glycemic RAW264.7 macrophages and its related mechanism. 【Methods】 The mother solution of NAR was prepared with dimethyl sulfoxide (DMSO), and the log-growth phase macrophage RAW264.7 was pre-tested. DMEM medium with different glucose concentrations (1, 2, 4, 5 and 6 g/L) was used for cultivation for 24 h. Before the experiment, DMEM was diluted into NAR mixture with different final concentrations, and the effect of NAR on RAW264.7 cell activity was detected by CCK-8 method; nitric oxide synthase (NOS) type classification determination of checkerboard induced nitric oxide synthase (iNOS) active filter was used to control the concentration of sugar and high-sugar stimulation. The control group were subdivided into normal control (NG) and osmotic pressure control (NG+M). The high-glucose stimulation group was divided into normal high glucose (HG), high glucose + naringenin (HG+NAR), high glucose + Fasudil (HG+F), and high glucose +C3 transferase (HG+C3). RAW264.7 was cultured for 24 h in each group; the expression levels of supernatant cytokines, namely, interleukin6 (il-6), tumor necrosis factor -α (TNF-α) and interleukin10 (IL-10), were detected by ELISA. Western blotting was used to determine the RhoA/ROCK pathway related proteins, iNOS and Arg-1 protein levels. Type (M1, M2) and proportion (M1/M2) of macrophages were analyzed by flow cytometry. 【Results】 Compared with those in NG group, in HG group RhoA/ROCK pathway-related proteins and iNOS expression were increased, while Arg-1 expression was decreased (P<0.05). The secretion of pro-inflammatory cytokines IL-6 and TNF-α was increased while anti-inflammatory cytokine IL-10 was decreased (P<0.05). The number of M1-type cells and M1/M2 ratio increased (P<0.05). Compared with HG group, RhoA/ROCK pathway related proteins and iNOS expression were decreased in HG+NAR group, HG+F group and HG+C3 group, while Arg-1 expression was increased, IL-6 and TNF- α secretion was decreased, IL-10 was increased, M2-type macrophages were increased, and M1/M2 was decreased (P<0.05). 【Conclusion】 NAR may promote the M2-type differentiation of macrophages stimulated by high glucose by down-regulating RhoA/ROCK signaling pathway.