In Vitro Inhibitory Effect on Pancreatic Lipase Activity of Subtractions from Ethanol Extracts of Fermented Oats (Avena satiya L.) and Synergistic Effect of Three Phenolic Acids

摘要

The purpose of the present work is to study the pancreatic lipase inhibitory effects of different subtractions (n-hexane, ethyl acetate (EA), n-butanol, and water) from ethanol extracts of nonfermented and fungi-fermented oats and to delineate the interactions of three primary phenolic acids in the EA subtractions. The EA subtraction showed the highest inhibitory effect on pancreatic lipase activity at 1.5 mg/mL compared to the other subtractions, regardless of whether the oats were fermented. Meanwhile, both of the EA subtractions of two fungi-fermented oats demonstrated more effective inhibitory activity than that of nonfermented oats. A positive correlation between the total phenolics content and inhibitory activity was found. The inhibitory ability of the EA subtraction from nonfermented or fermented oats also displayed a dose-dependent effect. The standards of caffcic, ferulic, and p-coumaric acids, mainly included in EA subtractions of fermented oats, also displayed a dose-dependent inhibitory effect. A synergistic effect of each binary combination of p-coumaric, ferulic, and caffeic acids was observed, especially at 150.0 μg/mL. Those results indicate that fungi-fermented oats have a more effective inhibitory ability on pancreatic lipase and polyphenols may be the most effective component and could be potentially used for dietary therapy of obesity.