[Effect of acupoint thread-embedding on macrophage polarization of epididymis adipose tissue in obese mice].

OBJECTIVE: To observe the effect of acupoint thread-embedding at "Zusanli" (ST 36) and "Fenglong" (ST 40) on the macrophage polarization of epididymis adipose tissue in obese mice, and to explore the action mechanism of acupoint thread-embedding on weight control. METHODS: Among 30 male C57BL/6 mice, 10 mice were randomly selected and fed with normal diet, and the remaining 20 mice were fed with high-fat diet to establish the obesity model. Sixteen mice with successful obesity model were randomly divided into a model group and an acupoint thread-embedding group, 8 mice in each group. Eight mice were selected from mice which were fed with normal diet as the normal group. On the next day of successful modeling, acupoint thread-embedding was performed at "Zusanli" (ST 36) and "Fenglong" (ST 40) in the acupoint thread-embedding group, once every 10 days for 4 times. The body weight was recorded at 0, 8, 16, 24, 32, 40 days into intervention; the level of glucose metabolism was compared after intervention; the level of lipid metabolism and weight of epididymal adipose tissue were compared at the end of the intervention; the mRNA expression of M1 and M2 macrophage-related cytokines interleukin-10 (IL-6), monocyte chemoattractant protein-1 (MCP-1), tumor necrosis factor-α (TNF-α) and interleukin-10 (IL-10) were detected by real-time PCR; the mRNA and protein expression of M1 macrophage labeled inducible nitric oxide synthase (iNOS) and M2 macrophage labeled arginase-1 (Arg-1) were detected by real-time PCR and Western blot. RESULTS: Compared with the normal group, the body weight at 0, 8, 16, 24, 32, 40 days into intervention in the model group was increased (P<0.05); the results of glucose tolerance test at 0, 30, 60, 120 min and insulin tolerance test at 0, 30, 60, 90, 120 min in the model group were higher than those in the normal group (P<0.05); the levels of total cholesterol and triacylglycerol in the model group were significantly higher than those in the normal group (P<0.001, P<0.01); the weight of epididymal adipose tissue in the model group was significantly higher than that in the normal group (P<0.001); the mRNA expression of IL-6, MCP-1, TNF-α and iNOS was increased (P<0.05, P<0.01, P<0.001), that of IL-10, Arg-1 was decreased (P<0.01), the protein expression of iNOS was up-regulated (P<0.01), and that of Arg-1 was down-regulated (P<0.001). Compared with the model group, the body weight at 16, 24, 32, 40 days into treatment in the acupoint thread-embedding group was reduced (P<0.05); the results of glucose tolerance test at 30, 60, 120 min and insulin tolerance test at 30, 60 min in the acupoint thread-embedding group were lower than those in the model group (P<0.05); the levels of total cholesterol and triacylglycerol in the acupoint thread-embedding group were significantly lower than those in the model group (P<0.01, P<0.05); the weight of epididymal adipose tissue in the acupoint thread-embedding group was significantly lower than that in the model group (P<0.01); the mRNA expression of IL-6, MCP-1, TNF-α and iNOS was reduced (P<0.05), that of IL-10, Arg-1 was increased (P<0.05), the protein expression of iNOS was down-regulated (P<0.05), and that of Arg-1 was up-regulated (P<0.01). CONCLUSION: Acupoint thread-embedding at "Zusanli" (ST 36) and "Fenglong" (ST 40) may play a role in weight control by regulating the polarization of macrophages.