Inhibitory Effect of Bread Containing Powdered Morus australis Leaves on Postprandial Elevation of Blood Glucose

Abstract

Summary : The present study investigated the inhibitory effect of bread containing powdered Morus australis leaves on postprandial elevation of the blood glucose level. First, we assessed the 1 -deoxynojirimycin （1 -DNJ ） content and α -amylase- and maltase-inhibitory activities of bread containing powdered M. australis leaves. Sec-ond, we investigated the inhibitory effect of this bread on blood glucose elevation in healthy individuals. Al-though the level of 1 -DNJ was reduced during the bread-making process, 1 -DNJ was still present in the bread containing powdered M. australis leaves. The powdered leaves exhibited no α -amylase-inhibitory activity. Al-though the median maltase-inhibitory concentration was higher in the bread containing the powdered leaves than in the powdered leaves alone, this bread retained its maltase-inhibitory activity. Moreover, consumption of the bread containing powdered M. australis leaves suppressed postprandial elevation of the blood glucose and insulin levels to a greater degree than consumption of bread without the powdered leaves. These findings dem-onstrate that bread containing powdered M. australis leaves has an inhibitory effect on postprandial blood glucose elevation.