The Mechanism Of Dangua Prescription On Tricarboxylic Acid Cycle By Regulating The Nampt-NAD~+

Objective:To evaluate the effects and mechanism of Dangua prescription on glycolipid metabolism and the tricarboxylic acid cycle by the expressions of Nampt-NAD~+pathway in rats fed on high-sugar and high-fat diet.To provide the experimental basis for the prevention and treatment of glycolipid metabolism disease of traditional Chinese medicine.Method:SPF 30 male SD rats were selected.After 2-weeks of adaptive feeding,6 rats were eliminated for the glucose tolerance test with fasting blood glucose(FBG)<6.1 mmol/L and2h postprandial blood glucose(2hBG)<7.8 mmol/L as normal standards.24 rats were randomly divided into normal group(n=8,fed with normal diet)and model established group(n=16,fed with high-sugar and high-fat diet).The model established group were randomly divided into model group(n=8)and Dangua prescription group(n=8)after 4-weeks.After12-weeks intervention,the basic indicators of glycolipid metabolism were detected,biochemical methods were used to detect ICA,α-KG,and OAA levels of tricarboxylic acid dehydrogenation in liver tissue;the serum INS,liver tissue NAD~+and NADH were measured by ELISA.The ATP were measured by colorimetric method in liver tissue.The expression levers of Nampt and NADH mRNA were measured by using Real-time PCR in liver tissue.Results:1.General situation:After the intervention,the rats in the normal group and the Dangua prescription group responded sensitively,the rats in the model group responded slightly dullly,the rats in the model group and the Danguafang group had slightly darker hair,and the rats in each group had good appetite.Compared with the normal group,the weight of the rats in the model group significantly increased(P<0.01);compared with the model group,the weight of the rats in the Dangua prescription group decreased(P<0.05);The weight of the rats in the three groups significantly increased compared with before intervention(P<0.01).2.Comparison of AUCG,AUCI,HbA1c:Before intervention,compared with the normal group,the AUCG in the model group and the Dangua prescription was significantly increased(P<0.01),and there was no difference in AUCG between the two groups.After the intervention,compared with the normal group,AUCG,AUCI,HbA1c in the model group were significantly increased(P<0.01).Compared with the model group,AUCG and AUCI in the Dangua prescription were reduced(P<0.05),HbA1c was significantly reduced(P<0.01).3.Comparison of TC,TG,LDL-C:After intervention,compared with the normal group,TC and TG in the model group were increased(P<0.05),LDL-C was significantly increased(P<0.01);compared with the model group,TC in the Dangua prescription group was reduced(P<0.05),LDL-C was significantly reduced(P<0.01),but TG showed not difference between the two groups(P>0.05).4.Comparison of intermediates in the tricarboxylic acid cycle:After intervention,compared with the normal group,α-KG in the model group was reduced(P<0.05),ICA,ATP were significantly reduced(P<0.01);compared with the model group,α-KG,ICA were increased in the Dangua prescription group(P<0.05),ATP was significantly increased(P<0.01);there was not difference in OAA among the three groups(P>0.05).5.Comparison of NAD~+,NADH,NAD~+/NADH:After intervention,compared with the normal group,NAD~+in the model group was significantly decreased(P<0.01),there was not difference in NADH between the two groups(P>0.05),NAD~+/NADH value was significantly reduced(P<0.01);compared with the model group,NAD~+in the Dangua prescription group was significantly increased(P<0.01),there was not difference in NADH between the two groups(P>0.05),the NAD~+/NADH value was significantly increased(P<0.01).6.Comparison of Nampt and NADH mRNA:After intervention,compared with the normal group,the expression of Nampt mRNA in the model group was significantly increased(P<0.01);compared with the model group,the expression of Nampt mRNA in the Dangua prescription group was significantly reduced(P<0.01);There was not difference in NADH mRNA expression among the three groups(P>0.05).Conclusion:1.Dangua prescription showed positive effect on glycolipid metabolism in rats fed on high-sugar and high-fat diet.2.Dangua prescription can promote tricarboxylic acid circulation in liver tissue.3.Dangua prescription affect the tricarboxylic acid cycle may be associated with the activation of Nampt-NAD~+pathway.