Comparison of Anti-Hyperglycemic Activities Between Low- and High-Degree of Polymerization Procyanidin Fractions from Cacao Liquor Extract.

Procyanidins are thought to be effective for prevention of hyperglycemia. To clarify the degree of polymerization (DP) of procyanidins on anti-hyperglycemic effects, we prepared low-DP (DP S 3) and high-DP (DP > 4) procyanidin fractions from cacao liquor, and examined whether these procyanidin fractions prevent hyperglycemia in vitro. We found that both fractions promoted glucose uptake in L6 myotubes in a dose-dependent manner accompanied by translocation of GLUT4 to the plasma membrane. Moreover, both fractions stimulate phosphorylation of AMP-activated protein kinase (AMPK). In these beneficial effects, low-DP fraction was more effective than high-DP one. On the other hand, high-DP fraction showed greater inhibitory effect of intestinal a-glucosidase activity than low-DP fraction in a cell free-incubation system. In conclusion, cacao liquor procyanidins have anti-hyperglycemic activities and low-DP procyanidins mainly contribute to stimulate glucose uptake by glucose transporter 4 translocation through AMPK-dependent pathway in skeletal muscle while high-DP procyanidins mainly contributes to inhibit the a-glucosidase activity in small intestine. [ABSTRACT FROM AUTHOR]