Glucose-lowering effect of powder formulation of African black tea extract in KK-A(y)/TaJcl diabetic mouse.

We observed the suppressive effect of a powder formulation of African black tea extract prepared from the leaves of Camellia sinensis on type 2 non-insulin dependent diabetic mice, KK-A(y)/TaJcl. Black tea extract significantly showed suppressive effect of the elevation of blood glucose on oral glucose tolerance test of 8 week-old KK-A(y)/TaJcl mice (P < 0.05). Long-term treatment with black tea extract showed significant suppression of post-prandial blood glucose and obesity (P < 0.05). The weight of the intestine of mice treated with black tea extract was significantly reduced (P < 0.05). From these results, African black tea used in this study showed a suppressive effect on the elevation of blood glucose during food intake and the body weight.