4,4’-Dimethoxy Chalcone Improves Insulin Sensitivity In Highfat Diet-induced Mice

Obesity and type 2 diabetes are now generalized as "diabetes" because obesity is an important risk factor for the increase in type 2 diabetes.The rising prevalence of obesity and diabetes not only causes severe psychological and physical stress on patients and caregivers,but also brings a huge burden on healthcare systems.At present,although the drugs for clinical treatment of diabetes can effectively relieve symptoms,there are more or less deficiencies.Therefore,it is urgent to develop more effective and safe drugs.4,4’-dimethoxychalcone(DMC)is a kind of flavonoids.It has been shown that DMC can prolong lifespan,slow down the aging of cultured human cells and protect mice from long-term myocardial ischemia.Meanwhile,autophagy induced by DMC is necessary for different species to play a protective role.However,the role of DMC in glucose and lipid metabolism has not been reported.This study investigated the function and effect of DMC in improving insulin sensitivity,and further provided new ideas for the development of drugs for the treatment of obesity and diabetes.Objective:To investigate the effect of DMC on insulin sensitivity in mice fed with high-fat and to explore its mechanism.Methods:1.At the animal level,wild type C57/BL 6 mice fed on high-fat diet were divided into two groups: control group and experimental group.The experimental group was intraperitoneally injected with 0.5 mg/kg DMC every other day,while the control group was injected with DMSO.The food intake and body weight of mice were recorded every week.At the sixth week,glucose tolerance test(GTT),insulin tolerance test(ITT)and sodium pyruvate tolerance test(PTT)were measured.2.At the tissue level,liver,epididymal adipose tissue(e WAT),subcutaneous adipose tissue(i WAT)and brown adipose tissue(BAT)were measured.The morphological changes of liver and e WAT were observed by HE staining.The infiltration of macrophages was detected by immunohistochemistry.RNA transcriptome sequencing was used to detect the transcriptome sequence of e WAT.The m RNA levels of Acc,Fasn,Srebp-1c,Il-6 and i Nos genes in e WAT were detected by RT-q PCR.The protein expression level of FASN in e WAT was detected by Western Blot.The biochemical indexes of ALT,AST,TBA,TC,TG,HDLC,LDL-C in blood and ALT,AST,TBA,FFA,TC,TG in liver were detected.3.At the cellular level,RAW264.7 cell were divided into three groups:(1)Control group:DMEM complete culture medium;(2)LPS(100 ng/m L)and INF-γ(20 ng/m L)induced the differentiation of RAW264.7 into M1 proinflammatory type.(3)DMC experimental group:Based on the experimental conditions of LPS / INF-γ induction,DMC(1m M)was given,and the cells were co-incubated for 12 h,then the cells were collected.The genes of Il-6,i Nos and Arg-1 in the cells were detected by RT-q PCR.Result:1.Compared with the control group,there was no difference in body weight and food intake of DMC mice after administration.ITT showed that insulin levels in DMC mice were improved(P<0.05),there was no significant difference in GTT and PTT.2.HE staining of e WAT showed that there were infiltration of inflammatory cells in the control group,and the infiltration of inflammatory cells were significantly reduced in the DMC group.F4/80 immunohistochemical staining indicated that the inflammatory cells were macrophages.3.DMC inhibited the expression of genes related to fatty acid synthesis in e WAT.4.DMC inhibited the m RNA expression of Il-6 and i Nos,and promoted the expression of Arg-1 in RAW264.7 cell.5.There were no changes in the histological morphology of liver and no difference in hepatic and blood biochemical indexes between DMC group and control group.Conclusion:DMC improved insulin sensitivity of mice fed on high-fat diet by inhibiting fatty acid synthesis and reducing the infiltration of M1 macrophages in e WAT.