From waste to bioactive compounds: A response surface methodology approach to extract antioxidants from Pistacia vera shells for postprandial hyperglycaemia management
Anna Elisabetta Maccarronello, Nunzio Cardullo, Ana Margarida Silva, Antonella Di Francesco, Paulo Costa, Francisca Rodrigues, Vera Muccilli
Abstract
Pistacia vera shells, an abundant agricultural by-product, are a rich source of undiscovered bioactive compounds. This study employed a response surface methodology (RSM) approach to optimize the microwave-assisted extraction of antioxidants. The highest total phenolic content, and antioxidant activity were achieved under the optimized extraction conditions (20% ethanol, 1000 W, 135 s, and solvent-to-solid ratio of 27 mL/g). The resulting extract (OPVS-E) included gallic acid derivatives, hydrolysable tannins, flavonoids, fatty acids, and anacardic acids. Remarkably, OPVS-E displayed potent inhibitory activity against α-amylase (IC50 = 2.05 μg/mL) and α-glucosidase (IC50 = 41.07 μg/mL), by far more powerful than the anti-diabetic drug acarbose., OPVS-E exhibited a strong antiradical capacity against reactive oxygen species (ROS) without causing toxicity in intestinal cells (HT29-MTX and Caco-2). These findings introduce OPVS-E as a potential novel dual-action nutraceutical ingredient, able to mitigate postprandial hyperglycemia and counteract the ROS overproduction occurring in type 2 diabetes mellitus.