Abstract
The inhibitory effects of himeukogi (Acanthopanax sieboldianus) leaf tea on postprandial blood glucose elevation were investigated in normal rats and healthy human volunteers. First, extraction methods for himeukogi leaf tea were examined in vitro using the decrease of α-glucosidase activity as an indicator. The decrease of α-glucosidase activity of himeukogi leaf tea was enhanced by extraction with hot water containing 2% himeukogi leaf (w/v). In sugar tolerance tests in rats, himeukogi leaf tea significantly suppressed the increase in the blood glucose level after oral administration of maltose or starch. In human subjects, the postprandial blood glucose level after ingestion of boiled rice was measured after oral administration of himeukogi leaf tea. Himeukogi leaf tea suppressed the increase of blood glucose at 30 min after the meal, and the effect was especially marked in subjects whose postprandial blood glucose levels were higher than the mean (144 mg/dL) at this time point. These results suggest that intake of himeukogi leaf tea prevents the increase in the postprandial blood glucose level by decreasing the digestion of sugars in the gastrointestinal tract.
