Study On The Effect Of Total Flavones From Bidens Pilosa L On Insulin Resistance

Objective:To investigate the antioxidant activity of the total flavonoids of Bidens bipinnata L.in vitro and its mechanism for improving insulin resistance in HepG2 cells.Methods:10 times the volume of total flavonoids of Bidens bipinnata L.was refluxed with 80%ethanol,and eluted by macroporous resin HPD-100 to obtain samples of total flavonoids of Bidens bipinnata L..Total flavonoids of Bidens bipinnata L.were dissolved in the corresponding solvent,and the total antioxidant capacity,DPPH·free radical scavenging ability,O₂^-·free radical scavenging ability,and·OH free radical scavenging ability were determined.Palmitic acid was used to induce HepG2 cells in vitro to construct an insulin resistance（IR）cell model.The glucose oxidase method was used to detect the glucose consumption of the model cells to determine the concentration of palmitic acid;the cell proliferation activity test（MTT）was used to determine the cell proliferation activity;HepG2 cells were used The in vitro IR model was established after being induced by palmitic acid（PA）at a concentration of 75μmol/L for 24h,and divided into normal control group,model group,low,medium and high flavonoids from Bidens pilosa L group（TFB）and metformin positive control group.Enzyme method was used to detect the effect of total concentration of Bidens pilosa L on glucose consumption;Western blot was used to detect the insulin receptor substrate-1（IRS-1）,protein kinase C（PKC）and c-Jun Amino terminal kinase（JNK）expression level.Results:As the concentration of total flavonoids in the sample solution increased,the total antioxidant capacity of the total flavonoids of Bidens pilosa L vulgaris gradually increased,but the ability to compare with ascorbic acid was weaker;its scavenging effect on DPPH·free radicals was extremely significant at the total flavonoid concentration of 0.080 mg/m L,the maximum clearance rate is 87.32%;at a mass concentration of 0.040 mg/m L,the maximum clearance rates for O₂^-·and·OH radicals are 68.75%and 82.70%,respectively,and the semi-inhibitory concentration(IC₅₀)is 0.0166、0.0162 and 0.0072 mg/m L.The expression of IRS-1 protein in the cells of the model group was significantly lower than that of the blank group,with a very significant difference（P<0.01）.Compared with the model group,the expression of IRS-1 protein in cells of the total,total,and high-dose flavonoids of Bidens pilosa L and the metformin-positive control group increased significantly,with significant differences（P<0.05,P<0.01）;The expression of PKC protein in the cells of the model group was increased compared with the blank group,with a very significant difference（P<0.01）.Compared with the model group,the total,total,and high-dose flavonoids of Bidens pilosa and the metformin positive control The expression levels of PKC protein in the cells were significantly reduced,with a significant difference（P<0.05,P<0.01）;the expression level of JNK protein in the model group cells was significantly reduced compared with the blank group,with a very significant difference（P<0.01）.Compared with the model group,the expression levels of JNK protein in the cells of the total and high-dose flavonoids of of Bidens bipinnata L and the metformin positive control group were significantly increased,with significant differences（P<0.05,P<0.01）.Conclusion:The total flavonoid extract of of Bidens bipinnata L showed good antioxidant activity in vitro;it has a significant improvement effect on the IR model of HepG2 cells,and its mechanism may regulate the expression of IRS-JNK-PKC to improve IR.