Distribution and deterioration of insulin-like principle in Lagerstroemia speciosa (banaba).

The old leaves and ripe fruits are the parts of banaba that contain the greatest number amount of insulin like principle. Twenty grams of old leaves of fruits, dried from one to two weeks, in the form of 100 cc of 20 percent decoction were found to have the activity equivalent to from 6-7.7 units of insulin in lowering the blood sugar
The mature leaves, young leaves and flowers have an activity that ranged from 4.4 to 5.4 units of insulin per 100 cc of 20 percent decoction or equivalent to around 70 percent of the activity of the leaves or fruits
The wood does not contain the insulin like principle while the bark and roots contain a very small amount. The insulin-like principle deteriorates or disappears in the different parts of banaba kept in the laboratory under ordinary condition. The rate of deterioration for every 20 grams of the dried parts of banaba per week is approximately 0.15 units for fruits, 0.3 units of old leaves; 0.58 units for flowers; 0.6 for young leaves and 0.9 units for mature leaves
The daily administration by mouth of 20 banaba tablets for nearly three months and 30 tablets for more than a month even found harmless and non-toxic. These number of tablets will seldom bereachedin the therapeutic application of Banabin when the assay value is at least 5 plantisul unit per tablet. (Author)