Anti-diabetic effects of combination of white skinned sweet potato (Ipomoea batatas L.) with loquat leaf extract

Abstract

Ludvik et al. have recently shown the effect of white skinned sweet potato (Ipomoea batatas L.) on reducing fasting blood glucose and insulin resistance in type-2 diabetic patients.It, however, was required 2-4 weeks after the starting of administration of white skinned sweet potato.
The present study aimed to determine if the combination therapy of white skinned sweet potato with a loquat leaf extract, which shows an insulin-like effect, could make it possible to enhance the anti-diabetic activities of white skinned sweet potato, and to shorten the time necessary for the inhibition of increasing blood glucose levels.
A mixture of the pulverized skin of white skinned sweet potato (194mg/kg) and the powdered loquat leaf extract (6mg/kg) was orally administered to 6 weeks-old male KK-Ay/Ta mice for 28 days and the glucose loading test was conducted every 7 days.
In the glucose loading test after one week feeding, a reduction in blood glucose concentration after 60 minutes of the administration of glucose was observed in the mixture groups against the control group (p<0.05). In the case of white skinned sweet potato only, similar delayed effects were seen in 3 weeks after feeding.