In order to suppress postprandial elevation of blood glucose, inhibitory substances toward α-glucosidase are attracting attention. Among them, 1-deoxynojirimycin (1-DNJ), one of iminosugars that exists in mulberry leaf, has a potent inhibitory activity. In this review, we outline the inhibition of α-glucosidase by iminosugars and the effect of intake of mulberry leaf powder on postprandial elevation of blood glucose.
