Banaba in the Tagalog name, Lagerstroemia speciosa L., has been used as a f
olk medicine for a long time among diabetics in the Philippines. Extracts f
rom banaba leaves have been reported to reduce diabetic symptoms in genetic
ally diabetic mice (Type II, KK-A(y)). In the present study, female mice of
the same strain showing remarkable body weight gain were used to examine t
he antiobesity effect of dietary banaba extract. Five-week-old female KK-A(
y) mice were fed a control diet or test diet containing 5% of a hot-water e
xtract from banaba leaves instead of cellulose for 12 wk. Neither group sho
wed any changes in diet intake during the experimental period. Body weight
gain and parametrial adipose tissue weight were lowered significantly in th
e banaba diet group. Blood glucose levels were not suppressed in the banaba
diet group, but hemoglobin A(1C) was found to be suppressed at the end of
the experiment. No effects on the serum lipids were observed, but the mice
fed banaba extract showed a significant decrease, to 65% of the control lev
el in total hepatic lipid contents. This decrease was due to a reduction in
the accumulation of triglyceride. These results suggest that banaba had a
beneficial effect on obese female KK-A(y) mice.