Mechanism Of Aqueous Of Taraxacum Mongolicum Hand.-Mazz In Improving Myocardial Injury In Diabetic Cardiomyopathy Rats

Objective:To investigate the effect of Aqueous of Taraxacum mongolicum Hand.-Mazz（ATM）on myocardial injury of diabetic cardiomyopathy（DCM）in rats,and to explore its possible mechanism of improving myocardial injury.Methods:50 healthy male rats fed adaptively for 7 days and were randomly divided into normal group（Control）,model group（DCM）,metformin group（MET）,low-dose group（ATML）and high-dose group（ATMH）with 10 rats in each group.Except Control group,other groups were fed with high-fat and high-sugar feed combined with low-dose streptozotocin（STZ）35 mg·kg^-1to establish DCM rat models.The model rats were treated by intragastric administration.MET group,200 mg·kg^-1,ATML group,250 mg·kg^-1,ATMH group,500 mg·kg^-1,Control group and DCM group were given the same volume of normal saline once a day for 8weeks.The blood glucose（BG）,oral glucose tolerance test（OGTT）,and the heart-to-body ratio（H/W）was measured.The levels of aspartate aminotransferase（AST）,lactate dehydrogenase（LDH）,superoxide dismutase（SOD）,malondialdehyde（MDA）,interleukin 6（IL-6）,glutathione peroxidase（GSH-Px）,tumor necrosis factora（TNF-a）,cardiac troponin I（c Tn-I）and reactive oxygen species（ROS）in serum of rats were measured by ELISA kit,and the morphological changes of myocardium were observed by HE staining.The protein expressions of Nrf2,HO-1,TXNIP,NLRP3,cleaved-caspase-1 were detected by Western Blotting.Results:Compared with DCM group,the levels of BG,H/W ratio,OGTT blood glucose and AUC in ATMH group decreased significantly（P<0.05）.The results of serum determination by ELISA showed that compared with the DCM group,the expression levels of AST,LDH,IL-6,c Tn-I,TNF-α（11）MDA and ROS in the ATMH treatment group were significantly decreased（P<0.05）,and the expressions of SOD and GSH-Px were significantly increased（P<0.05）.HE staining showed that the myocardial cells in the ATMH treatment group were arranged regularly,the intercellular substance was reduced,and the tissue structure and morphology were clear and complete.The results of Western Blot showed that compared with the DCM group,the protein expression levels of TXNIP,NLRP3 and cleaved-caspase-1 in the ATMH treatment group were significantly decreased（P<0.05）,while the protein expression levels of Nrf2 and HO-1were significantly increased（P<0.05）.Conclusion:Aqueous of Taraxacum mongolicum Hand.-Mazz can effectively improve myocardial injury in DCM rats.The mechanism may be related to inhibiting the activation of ROS/TXNIP/NLRP3 signal pathway,reducing the release of inflammatory cytokines IL-6 and TNF-asignals,activating Nrf2/HO-1 signal pathway,and increasing the expression of antioxidant stress factors.