Piceatannol alleviates inflammation and oxidative stress via modulation of the Nrf2/HO-1 and NF-κB pathways in diabetic cardiomyopathy

Metabolic disturbances and oxidative stress have been highlighted as potential causative factors for the development of diabetic cardiomyopathy. The β-blocker metoprolol is known to improve function in the diabetic rat heart and ameliorates the sequelae associated with oxidative stress, without lowering oxidative stress. The antioxidant ascorbic acid is known to improve function in the diabetic rat heart. We tested whether a combination of ascorbic acid and metoprolol treatment would improve function further than each drug individually. Control and streptozotocin-induced diabetic Wistar rats were treated with metoprolol (15 mg·(kg body mass)−1·day−1, via an osmotic pump) and (or) ascorbic acid (1000 mg·(kg body mass)−1·day−1, via their drinking water). To study the effect of treatment on the development of dysfunction, we examined time points before (5 weeks diabetic) and after (7 weeks diabetic) development of overt systolic dysfunction. Echocardiography and working-heart-perfusion were used to assess cardiac function. Blood and tissue samples were collected to assess the severity of disease and oxidative stress. While both drugs improved function, only ascorbic acid had effects on oxidative damage. Combination treatment had a more pronounced improvement in function. Our β-blocker + antioxidant treatment strategy focused on oxidative stress, not diabetes specifically; therefore, it may prove useful in other diseases where oxidative stress contributes to the pathology.

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Activation of TGR5 Partially Alleviates High Glucose-Induced Cardiomyocyte Injury by Inhibition of Inflammatory Responses and Oxidative Stress

Oxidative Medicine and Cellular Longevity ◽

10.1155/2019/6372786 ◽

2019 ◽

Vol 2019 ◽

pp. 1-11 ◽

Cited By ~ 2

Author(s):

Li Deng ◽

Xuxin Chen ◽

Yi Zhong ◽

Xing Wen ◽

Ying Cai ◽

...

Keyword(s):

Oxidative Stress ◽

Diabetic Cardiomyopathy ◽

High Glucose ◽

Inflammatory Responses ◽

Inhibitory Effects ◽

Rt Pcr ◽

Hoechst 33342 ◽

Selective Agonist ◽

Cardioprotective Effects ◽

And Oxidative Stress

High glucose- (HG-) induced cardiomyocyte injury is the leading cause of diabetic cardiomyopathy, which is associated with the induction of inflammatory responses and oxidative stress. TGR5 plays an important role in the regulation of glucose metabolism. However, whether TGR5 has cardioprotective effects against HG-induced cardiomyocyte injury is unknown. Neonatal mouse cardiomyocytes were isolated and incubated in a HG medium. Protein and mRNA expression was detected by western blotting and RT-PCR, respectively. Cell apoptosis was determined by Hoechst 33342 staining and flow cytometry. After treatment of cells with HG, TGR5-selective agonist INT-777 reduced the increase in expression of proinflammatory cytokines and NF-κB, whereas pretreatment of cells with TGR5 shRNA significantly reduced the inhibitory effects of INT-777. We also found that INT-777 increased the protein expression of Nrf2 and HO-1. In the presence of TGR5 shRNA, the expression of Nrf2 and HO-1 was reduced, indicating that TGR5 may exert an antioxidant effect partially through the Nrf2/HO-1 pathway. Furthermore, INT-777 treatment inhibited HG-induced ROS production and apoptosis that were attenuated in the presence of TGR5 shRNA or ZnPP (HO-1 inhibitor). Activation of TGR5 has cardioprotective effects against HG-induced cardiomyocyte injury and could be a pharmacological target for the treatment of diabetic cardiomyopathy.

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