Banaba

Scientific Name(s): Lagerstroemia speciosa (L.) Pers.
Common Name(s): Banaba, Crepe myrtle, Pride of India, Queen's crepe myrtle, Queen's flower

Medically reviewed by Drugs.com. Last updated on May 23, 2022.

Clinical Overview

Use

Banaba leaf preparations have been used in Philippine folk medicine for treatment of diabetes. Certain constituents (eg, corosolic acid) possess hypoglycemic activity. Several animal studies of banaba have demonstrated hypoglycemic effects, but more clinical studies are needed.

Dosing

Limited clinical trial data exist to provide dosing recommendations. Doses of 32 mg or 48 mg of the standardized extract from L. speciosa leaves (Glucosol) (standardized to 0.32 and 0.48 mg of corosolic acid, respectively) were given daily for 10 days in one small study of patients with type 2 diabetes.

Contraindications

None well documented.

Pregnancy/Lactation

Avoid use. Information regarding safety and efficacy in pregnancy and lactation is lacking.

Interactions

A case report exists of nephrotoxicity in a diabetic patient, potentially related to an interaction with diclofenac. Anticoagulant/Antiplatelet drugs: Antithrombin activity has been reported for the related species Lagerstroemia indica. Xanthine oxidase: Aqueous extracts from the plant leaves may have an additive effect in the treatment of hyperuricemia.

Adverse Reactions

None well documented.

Toxicology

No toxicity has been reported, even in high doses.

Scientific Family

• Lythraceae

Botany

Banaba is a deciduous, tropical, flowering tree that grows in India, Southeast Asia, and the Philippines. It typically grows 5 to 10 m in height, and sometimes up to 20 m. The smooth, large, spatulate, oblong to elliptic-ovate leaves measure 4 to 8 cm in width and 12 to 25 cm in length. The flowers are pink to purple when in bloom, and give way to oval, nut-like fruits; the leaves turn orange-red in the fall. The bark of the tree is smooth, grey to cream colored, and peels off in flakes.1, 2, 3

History

Banaba has been used as a folk medicine to treat diabetes in various parts of the world, especially in the Philippines and Southeast Asia. Folkloric use of banaba leaf decoctions for diuretic and purgative purposes and of root parts for stomach ailments has also been recorded. The first published research study evaluating the insulin-like activity of an aqueous extract of dried leaves given to rabbits was reported in 1940; since then, studies evaluating banaba for treatment of diabetes have been conducted in animal models, humans, and in vitro laboratory settings.3, 4

Chemistry

Banaba leaves contain ellagic acid derivatives.5 Reports have confirmed the presence of ellagitannins, lagerstroemin, flosin B, and reginin A, all possible glucose transport enhancers.6 Lagertannins, beta-sitosterol, stigmasterol, campesterol, and some olefins also have been found in banaba leaves and extracts.6, 7, 8, 9 Lageracetal (1,1-Dibutoxybutane), 1-pentanol, ellagic acid, and corosolic acid (a triterpene) have been isolated from the leaves.10, 11 One study reports that 16 amino acids, pyrogallol tannins, and lipids are also present in banaba leaf.12 Nonacosane, hentriacontane, tritriacontane, olefins, and ester...