Intervention Research Of Piperine On AMPK Signaling Pathway Upstream Targets In Insulin Resistance C2C12 Myotubes

Objective:Piperine is principal active component of Piper longum L.,which is commonly used in Chinese traditional medicinal and ethnic medicinal.Previous research had proved that piperine improved abnormal glucose metabolism in insulin resistance model rats,3T3-L1 cells and HepG2 cells,up-regulated AMP-activated protein kinase signaling pathway.On the basis of the previous research work,the study established insulin resistance model of C2C12 myotubes,and observed the effect of piperine on glucose metabolism disorder.Then,to further explore the intervention effect of piperine on AMP-activated protein kinase signal pathway upstream targets Adiponectin receptor 1,Liver kinase B1,adaptor protein APPL1 in C2C12 myotubes insulin resistance model,and to illuminate the possible mechanism of piperine on improving insulin resistance.Methods:1.Mouse C2C12 myoblasts were cultured with 2% donor equinum serum for 7-8 days.When differentiated into myotubes,myotubes were divided into normal control group and model groups,insulin resistance model cells were induced by 0.5mM Palmitate Acid for 16 h.And then were divided into model group,metformin group(1mM)and piperine administration groups(2.5,5,10,20,40?M).After treated for 6h,12 h,24h,36 h and 48 h respectively,cell supernatant was used to detecte glucose consumption and to observe the regulation effect of piperine on glucose metabolism disorder in different concentration and time period.2.The cells were collected to detecte the mRNA and protein expression of AMP-activated protein kinase signal pathway upstream targets Adiponectin receptor 1,Liver kinase B1,adaptor protein APPL1 by quantitative polymerase chain reaction and western blot.Results:1.After inducing by Palmitate Acid for 16 h,compared with normal control group,the glucose consumption of model group was significantly reduced.The result showed that C2C12 myotubes insulin resistance cells model was successfully established.2.C2C12 myotubes were intervened by piperine and metformin,compared with model group,piperine and metformin significantly increased glucose consumption.The intervention effect of piperine on glucose consumption was the most obvious in 10?M and 24 h.3.Piperine up-regulated the expression of AMP-activated protein kinase ? and p-AMP-activated protein kinase ? to activate AMP-activated protein kinase signal pathway.Piperine also increased the mRNA and protein expression of Adiponectin receptor 1,Liver kinase B1 and Adaptor protein APPL1 in AMP-activated protein kinase signal pathway upstream.Conclusion:Piperine improved the glucose metabolism disorder in the insulin resistance model of C2C12 myotubes.The mechanism was activated AMP-activated protein kinase signal pathway by significantly increasing the expression of AMP-activated protein kinase ? and p-AMP-activated protein kinase ?,meanwhile up-regulating mRNA and protein expression of the signal pathway upstream targets Adiponectin receptor 1,Liver kinase B1,Adaptor protein APPL1.