Protective effect and mechanism of curcumin on aorta in rats with metabolic syndrome

Abstract

To investigate the protective effect and mechanism of curcumin on aorta in rats with metabolic syndrome,72 SD rats were randomly divided into blank control group,model control group,positive control group,curcumin low,middle and high dose groups.The rat model of metabolic syndrome was established in all groups except the blank control group. After the intervention by curcumin,the blood pressure,blood lipid,blood glucose,serum insulin and insulin sensitivity index were measured. The contents of serum leptin(LP),adiponectin(ADP) and tumor necrosis factor-α(TNF-α) in rat aorta were detected by enzyme-linked immunosorbent assay(ELISA),and the pathological changes of rat thoracic aorta were observed by HE staining and electron microscope scanning. Western blot assay was used to detect the expression of inducible nitric oxide synthase(i NOS) and endothelial nitric oxide synthase(e NOS) in rats. The results showed that the blood lipid level,fasting blood glucose,fasting insulin,insulin sensitivity index,systolic blood pressure,LP,TNF-α and intima/media thickness ratio in the model control group were significantly higher than those in the blank control group. As compared with the model control group,the levels of blood lipids,fasting blood glucose,fasting insulin,insulin sensitivity index,systolic blood pressure,LP,TNF-α and intima/media thickness ratio were significantly decreased in positive control group,low,middle and high dose curcumin groups. The difference was statistically significant. The results of HE staining showed that the intima of the thoracic aorta in the model group was significantly thickened; the endothelial cell membrane was wrinkled and the organelle was ruptured. The intima of the thoracic aorta in the positive control group was slightly thickened and the structure of endothelial cells was intact,with no foam cells and no abnormality in the adventitia. There was no significant thickening of the thoracic aorta in the low,middle and high dose curcumin groups,and the endothelial cells were still intact. The results of Western blot assay showed that the expression levels of i NOS and e NOS were decreased significantly in the model group,while the expression levels of i NOS and e NOS were increased significantly in the positive control group and curcumin groups. The results indicated that curcumin had a certain protective effect on the aorta of rats with metabolic syndrome and improves the aortic endothelial dysfunction,and its mechanism may be related to the fact that curcumin could reduce the production of oxygen free radicals and up-regulate the expression of i NOS and e NOS in aorta.