DDIT3 and Myocardial fibrosis: Further studies showed that Nar could reduce MAD levels and SOD activity in the myocardium of DM rats (modeling by single intraperitoneal injection of STZ at 60 mg/kg), while decreasing the expression of GRP78, CHOP, and caspase-12 proteins, inhibit ERS and oxidative stress, attenuate myocardial cell apoptosis, and reduce myocardial fibrosis in DCM rats (Zhang et al., 2018).