Effects of sennoside A on atherosclerotic plaque formation and expression of 5-hydroxytryptamine signal moleculars in mice with diabetes mellitus type 2

Abstract

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.

Keywords

• sennoside a (sa)
• diabetes mellitus type 2 (t2dm)
• atherosclerosis
• 5-hydroxytryptamine (5-ht)
• 5-hydroxytryptamine receptor 2b (htr2b)