Banaba – Munchausia speciosa Linn

banaba leaves

Banaba – Munchausia speciosa Linn

Munchausia speciosa Linn Lagerstroemia reginae Roxb./ Lagerstroemia flos-reginae Retz.

Local names: Agaro (Sbl.); bugarom (S.L. Bis.); banaba (Tag., and many other dialects); duguam (S.L. Bis.); kauilan (P. Bis.); makablos (Pang.); mitla (Pamp.); nabulong (Neg.); pmalauagon (S.L. Bis.); pamarauagon (S.L. Bis.); parasabukung (sub.); tabagau (Ibn., Neg.); tauagnau (Ibn.).

Banaba is found n the Batan Islands and northern Luzon to Palawan, Mindanao, and the Sulu Archipelago, in most or all island and provinces, chiefly in secondary forest at low and medium altitudes. It is also reported to occur in India to southern China and southward through Malaya to tropical Australia.

This is a dangerous tree growing from 5 to 20 meters in height. The bark is smooth, gray to cream-colored, and peel off in irregular flakes. The leaves are smooth, oblong to elliptic-ovate, and 12 to 25 centimeters long. The flowers are 6-parted, purplish lilac or mauve-pink, rarely pink 5 to 7.5 centimeters across, and borne in large, terminal panicles up to 40 centimeters in length. The petals are oblong-obovate or obovate, shortly clawed, and 3 to 3.5 centimeters long; the margins are shortly clawed, and 3 to 3.5 centimeters long; the margins are undulate and hardly fimbriate. The fruit is large capsule, obovoid or ellipsoid, and 2 to 3.5 centimeters long. The seed is pale brown, with a wing 12 to 18 millimeters long.

dried fruit

Banaba is also cultivated for its beautiful flowers. It makes an excellent avenue tree and very effective when massed in parks. Banaba is also useful as a timber tree.

Burkill and Haniff report that the bark contains much tannin. Pasupati reports that the fruit (Burmese) contains 14.26 to 17.28 per cent of tannin; the leaves, 12.83 to 13.3 per cent; and the bark 10 per cent. In the Philippines, Garcia carried out chemical and pharmacological studies of the leaves and reports that the principle constituents consist of a large amount of tannin, a moderate amount of glucose, and a small amount, if any, of glucoside. He summarizes his result as follows:

Oral administration of the deduction of banaba with doses equivalent to 1 or 2 gm. of dried leaves per kg. Body weight reduces blood sugar from 16 to 49 mg. Of glucose per 100 cc. of blood in normal rabbits.

The blood sugar reduction caused by the decoction of banaba was relatively greater when the initial blood sugar was high than when the initial amount was low.

The absence of important plant constituents suggest that the hypoglycemic principle is probably a hormone occurring in plants similar to insulin occurring in animals. This hypoallergenic principle, however, is not glucokinin, for the plant extracts prepared by Collip, which he considered to contain glucokinin, produces a delayed hypoglycemic effect twenty-one hours or more after administration of the extract. In case of the decoction of banaba, the hypoglycemic effect was immediate, similar to that produced by subcutaneous injection of insulin.

In Dr. Garcia’s subsequent paper, he calls the hypoglycemic principle an “insulin-like principle.” He summarizes his result as follows:

The old leaves and ripe fruits are the parts of banaba that contain the greatest amount of an insulin-like principle. Twenty grams of old leaves or fruit, dried from one to two weeks, in the from of 100 cc. of 20 per cent decoction were found to have the activity equivalent to form 6 to 7.7 units of insulin in lowering blood sugar.

The mature leaves, young leaves, and flowers have an activity that range from 4.4 to 5.4 units of insulin per 100 cc. of 20 percent decoction, or equivalent to around 70 per cent of the activity of the leaves or fruit.

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 conditions. The rate of deterioration for every 20 gms. of the dried parts of banaba per week is approximately 0.15 unit for fruit; 0/3 unit for old leaves; 0.58 unit for flowers; 0.6 unit for young leaves, and 0.9 unit for mature leaves.

In the Philippines, banaba is popular medicinal plant. A decoction of the leaves of all ages is used for diabetes mellitus. It is prepared and taken like tea. Some Filipino physicians believe that a decoction of the dried fruit is even better.

Kirtikar and Basu quote Dr. Stewart, who considers the bark stimulant and febrifuge. Burkill and Haniff state that a decoction of it is used in Pahang for abdominal pains. Heyne says that an infusion is taken to stop diarrhea. According to Duchesne a decoction of the roots is used against small ulcers of the mouth. He also considers a decoction of the leaves a deobstruent and diuretic. Grin writes that the bark, leaves, and flowers are given as a purgative. The seeds possess narcotic properties and are employed against aphthae.

Source: Bureau of Plant Industry, Department of Agriculture