This paper, written by researchers from Key Laboratory of Tibetan Medicine Pharmacology and Safety Evaluation in Qinghai Province and others, discusses Characterization and cardioprotective activity of anthocyanins from Nitraria tangutorum Bobr. by-products. The paper is published in an important journal < Food & Function >. IF：3.289.

In recent years, the research work of microwave chemical instrument used in the synthesis of materials has become a hot direction of scientific research, which has been paid great attention to by many scholars!

Nitraria tangutorum Bobr. fruit is an indigenous berry of the shrub belonging to the Zygophyllaceae family which grows at an altitude of over 3,000 m in the Tibetan Plateau, and is used as a native medicinal food for treating weakness of the spleen and 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 identified to be composed of 16 anthocyanins deriving from six anthocyanidins by HPLC-ESI-MS, and have an appreciable cardioprotective effect in the doxorubicin-induced injured H9c2 cardiomyocytes. The cardioprotective mechanism research showed that NJBAE could directly scavenge ROS, restrict further generation of ROS, promote 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 a great potential to be used for preventing and treating cardiovascular disease in the food, pharmaceutical and other emerging industries.

Anthocyanins (namely NJBAE) from industrial by-products of N. tangutorum juice were composed of 16 anthocyanins deriving from six anthocyanidins, and exerted an excellent protective effect on DOX-injury of H9c2 myoblast cells through directly scavenging ROS, preventing further generation of ROS, promoting activity of key antioxidase, enhancing glutathione redox cycling, affecting the apoptotic signaling changes in positive ways including increasing anti-apoptotic Bcl-2 expression as well as decreasing pro-395 apoptotic Bax-α expression, and finally mediating caspase-dependent cell death pathway. Therefore, NJBAE had a great potential to be used for cardioprotection in the food, pharmaceutical, and other emerging industries.

Anthocyanins were extracted from NJB by using a SMU-AEE method under optimal conditions as described in our previous study.5 113 Briefly, NJB was mixed with 0.1 M pH 4.5 phosphate buffer (solvent to raw material ratio 6:1 v/w) and 0.6% (wt.%) of Celluclast® 1.5 L. The mixture was incubated at 45°C for 20 min in a rotary shaker at 160 rpm. Then, absolute ethanol was added to the mixture until its ethanol concentration reached to 70%. The reaction mixture was simultaneously irradiated by 420 W of microwave power and 800 W of ultrasonic power at a temperature of 66°C for 43 min in a microwave/ultrasonic synergistic extraction apparatus (XH-300B, Beijing Xianghu Science and Technology Development Co., Ltd., Beijing, China). The resulting supernatant was collected by centrifugation and vacuum dried at 30°C to generate NJBE. Subsequently, NJBE was selectively purified on an Amberlite™ XAD-7HP cation-exchange resin column by successively elution with deionized water (0.01% HCl) and 35% ethanol (0.01% HCl). The ethanolic eluate was collected and freeze-dried, finally resulting in an anthocyanin fraction (NJBAE).