Abstract: B. Ludvik et al., have recently shown the effect of Caiapo®
(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 single administration of Caiapo®. The present study aimed to determine if the combination therapy of
Caiapo® with a mulberry leaf powder, which inhibits α-glucosidase, or
with a loquat leaf extract, which shows an insulin-like effect, could make it
possible to enhance the antidiabetic activities of Caiapo®, and to shorten
the time necessary for the inhibition of increasing blood glucose levels. A mixture of the pulverized tuber of Caiapo® (357 mg/kg) and the
mulberry leaf powder (143 mg/kg), or a mixture of the pulverized skin of
Caiapo® (194 mg/kg) and the powdered loquat leaf extract (6 mg/kg) was
orally administered to 6 weeks-old male KK-Ay 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 both mixture groups against the control group (p < 0.05) in
the case of Caiapo® only, similar delayed effects were seen in 2–3
weeks after feeding.
