| Insulin resistance(IR) is an important pathogenesis of type ? diabetes(T2DM).Various factors lead to the reduction of glucose uptake and utilization by insulin-like target organs,which in turn triggers hyperglycemia.Therefore,studying the mechanism of insulin resistance and developing drugs to improve insulin resistance have become one of the current hot spots in the prevention and treatment of diabetes.Variety of plant flavonoids have good biological effects in this regard.As one of them,the flavonoids of echinops latifolifius tausch also have a variety of similar physiological functions.However,there are currently no domestic and foreign reported studies on the effect of flavonoids of echinops latifolifius tausch on insulin resistance.In order to explore the improvement by the flavonoids of echinops latifolifius tausch on insulin resistance in type ? diabetes model of mice and its mechanism,present research optimized the extraction process of flavonoids from echinops latifolifius tausch(ELTF)by response surface analysis.The effects of ELTF on corresponding gene expressions in muscle tissues were detected by RT-PCR and Wester blot through in vitro experiments with insulin-resistant mice C2C12 skeletal muscle cell models,and in vivo experiments with high-fat and high-sugar+streptozotocin experimental insulin resistance mice models of type ? diabetes.1 The optimized extraction process of ELTF:absolute ethanol as extraction liquid,the extraction time is 120 min,the material-to-liquid ratio is 1:50,the extraction temperature is 65?,and the experimental yield is 7.18%.2 The alcohol extract of echinops latifolifius tausch is filtered through 5kDa hollow cellulose membrane,extracted with ethyl acetate for 3 times;extraction with n-butanol with equal volume of water for 3 times;ethanol rinse with polyamide powder through 30-80 mesh filter,and the purity of ELTF is 84.8%.3 Horse serum was used to differentiate mouse C2C12 myoblasts for 4 days to obtain C2C12 skeletal muscle cells;within the maximum safe concentration,palmitic acid induces insulin resistance in mouse C2C12 skeletal muscle cells at an optimal concentration of 0.2 mmol/L.4 Using CCK-8 method to evaluate the maximum safe concentration of ELTF for 24h is 200 ?g/mL;after testing for 24 h with different dose of ELTF,it can significantly increase the sugar consumption of C2C12 skeletal muscle cells of insulin resistant mice compared with the model group(P<0.05)5 ELTF increased the mRNA expression of AMPK,GLUT4,IRS-1,Ppary,PI3 Knase p85 from mouse C2C12 skeletal muscle cells compared with the model group(P<0.05).Compared with the model group,ELTF each-dose group showed a significant increase for AMPK expression(P<0.05),ELTF low-dose groups showed a significant increase for GLUT4 expression(P<0.05),ELTF each-dose group showed a significant increase for IRS-1 Expression level(P<0.05),ELTF low dose groups showed a significant increase for Ppary expression(P<0.05),ELTF low dose group showed a significant increase for PI3 Knase p85 expression(P>0.05).6 The experimental type ? diabetes mice were treated with ELTF for 28 days.Compared with the blank control group,the weight of mice from the experimental type ? diabetes model group was significantly reduced(P<0.05),and the weight of mice from groups treated with high,medium,and low dose of ELTF and metformin group all reduced,among which there is a significant reduce in the high and low dose-treated groups(P<0.05).Compared with the blank control group,the blood glucose of mice from the diabetes model group,the groups treated with high,medium,and low dose of ELTF,and the metformin treated group all increased with significant differences(P<0.05);compared with the model group,the blood glucose of mice from the positive drug group and groups treated with high,medium and low dose of ELTF was significantly reduced(P<0.05).Compared with the blank control group,the content of TC,TG and LDL in the diabetes model group was significantly increased(P<0.05),and the content of HDL was not significantly reduced(P>0.05);compared with the diabetes model group,the content of TC,TG,LDL and HDL changed with no significance(P>0.05).7 Compared with the model group,ELTF increased the mRNA expression of AMPK,GLUT4,IRS-1,Ppar?,PI3 Knase p85 in skeletal muscle from mice of type ? diabetes modele(P<0.05).Compared with the model group,the ELTF high-dose group showed a significant increase for the AMPK expression(P<0.05),the ELTF low,and high-dose groups showed a significant increase for GLUT4 expression(P<0.05),and the ELTF each-dose group showed a significant increase for the expression of IRS-1(P<0.05),ELTF low dose groups showed a significant increase for the expression of Ppary(P<0.05),and ELTF high dose group showed a significant increase for the expression of PI3 Knase p85(P>0.05).Conclusion:The optimized extraction process of ELTF:absolute ethanol as extraction liquid,the extraction time is 120 min,the material-to-liquid ratio is 1:50,the extraction temperature is 65?,and the experimental yield is 7.18%.ELTF can significantly increase the sugar consumption of C2C12 skeletal muscle cells in mice with insulin resistance induced by palmitic acid.ELTF can improve the blood lipids of type ? diabetes model mice,lower the blood sugar of type ? diabetes model mice,and effectively improve the insulin resistance status of type ? diabetes model mice.ELTF can improve skeletal muscle cell insulin resistance and type ? diabetes model mice insulin resistance by regulating genes and proteins related to AMPK signaling pathway. |
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