Comparison of α-amylase, α-glucosidase and lipase inhibitory activity of different types of vinegar

Abstract

Vinegar is regarded as a fine example of a traditional food that has several medicinal values. It is used as a home-remedy for the management of diabetes and obesity. We investigated how selected vinegar inhibit the digestive enzymes involved in carbohydrate and lipid metabolism. A total of seven types of vinegar were examined as follows: apple cider (ACV), balsamic (BV), brown rice (BRV), distilled white (DWV), malt (MV), nipah palm (NPV), and red wine (RWV) vinegar. In vitro enzyme inhibition tests were performed using α-amylase and lipase from porcine pancreas, and α-glucosidase from Saccharomyces cerevisiae. In the α-amylase assay, NPV (IC50 = 60.97±1.71 mg/mL) exhibited the strongest inhibitory effect, while RWV (IC50 =786.7±0.96 mg/mL) showed the lowest inhibitory effect. RWV (IC50 =92.49±1.51 mg/mL), by contrast, had the highest inhibitory effect against α-glucosidase and was followed by NPV (IC50 = 227.5±1.06 mg/mL) and BRV (IC50 = 565.1±2.65 mg/mL). All of the samples showed potent inhibitory effects against pancreatic lipase, with MV having the strongest and ACV the lowest effects, respectively. IC50 values ranged from 48.45 mg/mL to 399.8 mg/mL. A concentration-dependent inhibitory effect was recorded for each of the vinegar against all three tested enzymes. None of the vinegar, however, exceeded the effects recorded for the standard drugs. Interestingly, a weak correlation was found between total acidity and enzyme inhibition, which asserted the presence of bioactive compounds in the vinegar. As a conclusion, vinegar can be incorporated into the diet to lower the meal’s glycaemic index and benefit those at risk of diabetes as well as diabetics.