Characterization and cardioprotective activity of anthocyanins from Nitraria tangutorum Bobr. by-products.

The Nitraria tangutorum Bobr. fruit is an indigenous berry of the shrub belonging to the Zygophyllaceae family which grows at an altitude of over 3000 m in the Tibetan Plateau, and has been used as a native medicinal food for treating weakness of the spleen, stomach syndrome, dyspepsia, neurasthenia, dizziness, etc. for thousands of years. Nowadays, N. tangutorum industrial juice by-products generated from health food production can be a potential low cost source of some unique bioactive ingredients. In a prior study, we established a simultaneous microwave/ultrasonic assisted enzymatic extraction method for extracting antioxidant ingredients from the industrial by-products of N. tangutorum juice. In this study, these ingredients were selectively fractionated by cation-exchange resin chromatography to obtain an anthocyanin fraction namely NJBAE. NJBAE was found to be composed of 16 anthocyanins derived from six anthocyanidins by HPLC-ESI-MS, and has an appreciable cardioprotective effect on doxorubicin-induced injured H9c2 cardiomyocytes. The cardioprotective mechanism research showed that NJBAE could directly scavenge ROS, restrict further generation of ROS, promote the activity of key antioxidase, enhance glutathione redox cycling, then affect the apoptotic signaling changes in a positive way, and finally mediate caspase-dependent cell death pathways. Therefore, NJBAE has great potential to be used for preventing and treating cardiovascular disease in the food, pharmaceutical and other emerging industries.