The stability of different free polyphenols during multi-stage simulated digestion and their inhibitory properties on starch digestion enzymes and cellular inflammation

Polyphenols, as a bioactive components with both anti-inflammatory and enzyme-inhibitory activities, have significant potential for application in regulating abnormal glucose metabolism diseases. Resveratrol, gallic acid, caffeic acid, quercetin, and catechin were analysed for their stability during simulated digestion, their inhibitory effects on starch-digesting enzymes, and their anti-inflammatory properties, revealing that the degradation of free phenolics was related to the environment of the gastrointestinal tract. There existed a quantitative relationship between the inhibitory activity of polyphenols on starch-digestive enzymes, with resveratrol being second only to acarbose in its overall effect. Treatment of cells with 25 mmol/L D-glucose for 24 hr induced glycositis injury in HBZY-1 cells. Compared to the high-glucose group, 5–100 μmol/L resveratrol exhibited significant inhibitory effects on the secretion of inflammatory factors. These findings provide useful information on the use of polyphenols, especially resveratrol, as food-grade ingredients for the prevention and management of diabetic nephropathy.