Study on active components of mulberry leaf for the prevention and treatment of cardiovascular complications of diabetes

Mulberry leaves are used in Chinese traditional medicine to prevent diabetes and the preventive and therapeutic effects of MLE have been seen in preclinical models. Herein, mulberry leaf extract (MLE) was analyzed to identify its active components. Ultra-performance liquid chromatography–mass spectrometry revealed that MLE contained 1-deoxynojirimycin (1-DNJ, 5.47%), chlorogenic acid (CA, 1.21%), resveratrol (RESV, 0.39%), scopoletin (Sco, 0.09%), and astragaloside (AS, 0.04%). Mice with induced diabetic cardiomyopathy were treated with MLE or each of its main components for 12 weeks. MLE and 1-DNJ significantly improved cardiac function, body weight, and glucose and lipid metabolism, while reducing myocardial fibrosis. Moreover, 1-DNJ reduced the levels of reactive oxygen species and oxidative stress, inhibited the TGF-β pathway, prevented the expression of α-SMA and Smad2/3, as well as collagen 1 and 3. Collectively, these findings suggest that1-DNJ is the main active component of MLE that protects the diabetic myocardium and regulates the TGF β–Smad2/3 pathway.