Study on the mechanism of action of Saussurea involucrata injection in regulating the “GLUT1/HK2” glucose metabolism pathway affecting macrophage polarization

Objective To investigate the mechanism by which Saussurea involucrata injection (SII) mitigates rheumatoid arthritis through modulation of macrophage polarization via glucose metabolism reprogramming.Method Bone marrow-derived monocytes (BMDMs) were isolated from rats and cultured as the control group. Lipopolysaccharide (LPS)-induced BMDMs, representing polarized M1 macrophages, served as the model group. M1 macrophages were treated with 0.06mM 2-DG and 2 mg/mL SII. Glucose, lactate, NAPDH, and ATP levels were quantified using commercial kits. Western blotting assessed protein expression of GLUT1、HK2, PFKFB3, and IDH2. Flow cytometry measured CD86 (M1 macrophage marker) and CD206 (M2 macrophage marker) expression. ELISA determined levels of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-1β), inducible nitric oxide synthase (iNOS), interleukin-10 (IL-10), transforming growth factor-β (TGF-β), and arginase-1 (Arg-1) in cell supernatants.Result Compared with the normal group, glucose consumption increased, enzyme expression levels of the key enzymes of glycolysis GLUT1, HK2 and PFKFB3 increased, IDH enzyme activity was significantly reduced, ATP production was decreased, and lactic acid levels were increased, and increased the M1-type macrophage surface membrane molecule CD86+ promoted the expression of IL-6, TNF-α, and iNOS pro-inflammatory factors, and decreased the M2-type macrophage surface membrane molecule CD206+ inhibited the expression of TGF-β, IL-10, and Arg-1 anti-inflammatory cytokines. Compared with the model group,2-DG and SII glucose consumption decreased in all dose groups, the expression of GLUT1、HK2 and PFKFB3 decreased, the expression of IDH enzyme activity was up-regulated, the level of ATP effective production was increased, and the level of lactic acid decreased, decreased expression levels of pro-inflammatory factors IL-1β, TNF-α, and iNOS by decreasing the M1 type macrophage surface membrane molecule CD86+, and increased expression of anti-inflammatory cytokines TGF-β, IL-10, and Arg-1 by increasing the M2 type macrophage surface membrane molecule CD206+ promoting TGF-β, IL-10, and Arg-1.Conclusion Saussurea involucrata injection alleviates inflammatory response by correcting macrophage polarization through glucose metabolism reprogramming.