Banaba "Queen's Flower"

Banaba (Lagerstroemia speciosa Linn.) also known as “Queen’s Flower”, has significant health benefits. Studies have shown that banaba contains corosolic acid (a triterpenoid glycoside), an “insulin-like principle” that helps in reducing blood sugar levels. Therefore, banaba is beneficial for those suffering from diabetes. Studies have also revealed that banaba is helpful in decreasing triglyceride and cholesterol levels. Banaba has also been shown to be good for the kidneys, promote weight loss, help regulate blood pressure, prevent hyperuricemia and aid the digestive system.

Botany

· A decidious tropical flowering tree, 5 to 10 m high, sometimes growing to a height of 20 meters. Leaves, large, spatulate, oblong to elliptic-ovate, 2-4 inches in width, 5-8 inches in length; shedding its leaves the first months of the year. Before shedding, the leaves are bright orange or red during which time it is thought to contain higher levels of corosolic acid). Flowers are racemes, pink to lavender; flowering from March to June. After flowering, the tree bears large clumps of oval nutlike fruits.

Distribution

· Grows wild; widely distributed in the Philippines, in the secondary forests at low and medium altitudes. Cultivated for its beautiful flowers. Propagation by seeds.

Chemical constituents

· Rich in tannin: fruit, 14 to 17 %; leaves 13 %; bark, 10%.

· Studies have isolated: (1) corosolic acid (2) ellagitannin Lagerstroemin (3) gallotannins

· Penta-O-galloyl-glucopyranose (PPG) – identified as the most potent of the gallotannins, with a higher glucose transport stimulatory activity than Lagerstroemin. In addition to stimulating glucose uptake in fat cells, it also has anti-adipogenic properties.

Parts utilized

· Leaves, fruits, flowers and bark.

Folkloric Uses

· Roots have been used for a variety of stomach ailments. Leaf decoction for diabetes; also use as a diuretic and purgative.

· Decoction of old leaves and dried fruit (dried from one to two weeks), 50 gms to a pint of boiling water, 4 to 6 cups daily has been used for diabetes. Old leaves and ripe fruit are preferred, believed to have greater glucose lowering effect. Young leaves and flowers have a similar effect, though only 70% that of matures leaves and fruits. The wood has no known glucose lowering effect; the bark, a very small amount. A decoction of 20 gms of old leaves or dried fruit in 100 cc of water was found to have the equivalent effect to that of 6 to 7.7 units of insulin.

· The bark decoction has been used for the treatment of diarrhea.

· The bark, flowers and leaves used to facilitiate bowel movements.

· Decoction of fruits or roots gargled for aphthous stomatitis.

· Decoction of leaves and flowers used for fevers and as diuretic.

· Leaf decoction or infusion used for bladder and kidney inflammation, dysuria, and other urinary dysfunctions.

Studies

· Corosolic Acid / Lagerstroemin / Gallotannins: Studies have identified several compounds as responsible for its anti-diabetic activity. (1) corosolic acid (2) Lagerstroemin, an ellagitannin (3) gallotannins, of which PPG – penta-O-galloyl-glucopyranose–was identified as the most potent, with a higher glucose transport stimulatory activity than Lagerstroemin. In addition to stimulating glucose uptake in fat cells, it also has anti-adipogenic properties.

· Inhibition of TNF-induced Activation: Diabetes leads to cardiomyocyte hypertrophy in association with upregulation of vasoactive factors and activation of nuclear factor (NF)-kappaB and activating protein-1. Study results indicate L speciosa can inhibit DNA-binding of NF-kappaB which may explain its possible inhibition of diabetes-induced cardiomyocyte hypertrophy.

· Ellagitannins / Insulin-like Glucose Uptake Stimulatory/Inhibitory Activities / Adipocyte Differentiation-Inhibitory Activity: Study yielded seven ellagitannins, including lagerstroemin from the leaves of L speciosa. The ellagitannins exhibited strong activities in both stimulating insulin-like glucose uptake and inhibiting adipocyte differentiation . Also, ellagic acid derivatives showed inhibitory effect on glucose trasport.

· Diabetes: (1) Banaba has been extensively studied for its application in the treatment of diabetes. Early on, Its ability to lower blood sugar was attributed to corosolic acid, a triterpenoid glycoside, belived to facilitate glucose-transport into cells. (2) Studied with abutra, akapulko, makabuhay for antidiabetic activity through activation of gucose transporter activity. One of the active principles from Banaba was the tripertene, corosolic aicd.

· Weight loss: Studies in mice suggest an antiobesity effect. It is becoming a common ingredient in weight-loss supplements / products as a metabolic enhancer.

· Hypertension: It is also being studied for its use in the treatment of blood pressure, renal and immune system benefits.

· Lipid-lowering: Studies in mice suggest a lipid lowering effect - decreasing triglyceride and total cholesterol levels. To date, no toxicity has been identified.

· Hypoglycemic Activity of Irradiated Banaba Leaves: Study showed the effects of nBLE and iBLE were comparable to the hypoglycemic effects of insulin.

· Xanthine oxidase inhibitors from the leaves of Lagerstroemia speciosa (L.) Pers: Xanthine oxidase is a key enzyme involved with hyperuricemia, catalyzing the oxidation of hypoxanthine to xanthine to uric aicd. The study supports the dietary use of the aqueous extracts from Banaba leaves for the prevention and treatment of hyperuricemia.

· Antidiabetic Activity: Study showed a significant reduction of blood glucose levels with the soft gel formulation showing better bioavailability than a dry-powder formulation.

· Other studies report potential uses: (1) antibacterial effects from seed extracts (2) significant protection of HIV-infected cells by ellagic acid constituents (3) antioxidative activity of a water extract (4) inhibition of xanthine oxidase by aqueous extract, 31 and anti-inflammatory activity in mice.

· Anti-Inflammatory / Free Radical Scavenging: Study showed antioxidant and anti-inflammatory activities from the ethyl acetate and ethanol extracts of Lagerstroemia speciosa.

Source: Banaba