Effects of sennoside A on atherosclerotic plaque formation and expression of 5-hydroxytryptamine signal moleculars in mice with diabetes mellitus type 2
Objective·To investigate the effects of sennoside A(SA)on the formation of atherosclerotic plaque and the expression of 5-hydroxytryptamine(5-HT)and its receptor in mice with diabetes mellitus type 2(T2DM).Methods·Twelve mice with knocked-out apolipoprotein E gene were randomly divided into two groups,namely the model group and the model+SA group,with six mice in each group.Six C57BL/6J mice with the same genetic background were used as the control group.The control group was fed with normal diet,and the model group and the model+SA group were given intraperitoneal injection of streptozotocin(30 mg/kg)daily on the basis of high-fat diet to establish a model of T2DM.The model+SA group was given SA daily by gavage for 8 weeks,and the control group and the model group were given equal volume of distillation-distillation H2O by gavage.The body weight,fasting blood glucose(FBG)and 2-h postprandial blood glucose of mice were compared before and after modeling and treatment.The area of aortic plaque was observed by oil red O staining and hematoxylin-eosin(H-E)staining,and the level of 5-HT in serum and thoracic aorta was measured by ELISA kit.Western blotting was used to detect the expression of 5-hydroxytryptamine receptor 2B(HTR2B)and serotonin transporter(SERT)in thoracic aorta of mice.Results·Compared with the control group,the body weight,FBG and 2-h postprandial blood glucose in the model group increased,and glucose metabolism was disordered.The expression of HTR2B and SERT protein in thoracic aorta increased,while the concentration of 5-HT in thoracic aorta decreased.The serum 5-HT concentration increased(all P<0.05).After treatment with SA,compared with the model group,the body weight of the model+SA group decreased,and FBG and 2-h postprandial blood glucose were significantly improved.The area of aortic plaque and the expression of HTR2B and SERT protein in thoracic aorta significantly decreased,while the concentration of 5-HT increased.The serum 5-HT concentration decreased(all P<0.05).Conclusion·SA can reduce atherosclerotic plaque area in T2DM mice,which may be related to lowering blood glucose and inhibiting the expression of 5-HT and its receptor.
sennoside A(SA)diabetes mellitus type 2(T2DM)atherosclerosis5-hydroxytryptamine(5-HT)5-hydroxytryptamine receptor 2B(HTR2B)