Thunbergia laurifolia

Synonyms

Thunbergia grandiflora

Vernacular Names:

Malaysia

Akar tuau, Akar Ketuau, Daun Patuk Tuau

English

Bengal Trumpet, Babbler’s Vine, Purple Allamanda, Laurel-leaved Thunbergia, Laurel Clock Vine, Blue Trumpet Vine, Babbler’s Bill

Thailand

Maykote (Lahu tribe); Chau-in-ta-nin, Rang juet, Raang Chuet, Kamlang chang phuaek, Rang yen, Aet ae, Knop cha

Laos

Dauk Nam Naa

Indonesia

Lana

German

Malayische thunbergie [1]

General Information

Description

Thunbergia laurflora is a member of the Acanthaceae family. It is a climbing shrub with much branching. The young branches being terete and green and glabrous. The leaves are opposite with long petiole, oblong-lanceolate, acuminate, entire or sometimes a little toothed. There are three nerves which are reticulated with transverse nerves. The petiolea measure 5-7 cm long, slender, remarkable for being incrassated both at the apex and at the base. At the apex the thickened portion is nearly terete while at thje base the incrassation extends for a greater length, and is flattened or plane on the upper side, and even slightly winged. The raceme of flowers, both axillary and terminal, sometimes bearing a few flower, and destitute of leaves; at other times the raceme consists of whorled flowers, with a pari of opposite leaves at the base, which are smaller than those of the stem. The bracteas of vaginant leaves or large scales, resembling a spatha, open and free at the lower edge, adherent by the upper margin, faintly striated; this embrases the lower gibbous portion of the tube of corolla.  The calyx is very small, cup-shaped, dotted. The corolla very large, pale blue, with a yellowish eye. The tube is obliquely funnel-shaped, wide at the mouth. The limb is very large, spreading, five-lobedl; lobes rotundate, deeply emarginatem, almost bifid. The stamens quite included, inserted near the base of the tube of the corolla. Filaments broad, subulate, curved. The anthers oblong, apiculate, fringed in front, and having two subulate spurs at the base. The ovary sublong, but included within the tube of the corolla; stigma bifidl; each lobe channelled within. [8]

Plant Part Used

Leaves and flowers [1] [2]

Chemical Constituents

8-epi-grandifloric acid and 3'-O-beta-glucopyranosyl-stilbericoside, benzyl beta-glucopyranoside, benzyl beta-(2'-O-beta-glucopyranosyl) glucopyranoside, grandifloric acid, (E)-2-hexenyl beta-glucopyranoside, hexanol beta-glucopyranoside, 6-C-glucopyranosylapigenin and 6,8-di-C-glucopyranosylapigenin.

Traditional Used:

Obstetrics and Gynaecology

In Malaysia the decoction of the leaves are used in the treatment of menorrhagia.[1]

Antiinfectives

Poultice of the leaves makes good remedy for boils, cuts and ulcers as practised by traditional healers of the Malay Peninsula. [1]

Detoxificants

Amongst the Thais the leaves of T. laurifolia is often used in treatment of drug addiction with success. It is also advocated in the treatment of alcoholics and as a firs aid in treatment of both vegetable and animal poisoning. [2]

Ophthalmology

Juice extracted from the flowers are used in treatment of eye diseases.[1]

Pre-Clinical Data

Pharmacology

Antidrug addiction activity

T. laurifolia or known as Rang Chuet in Thailand had been used to treat drug addiction successfully by Thai traditional medicine men. Thongsaard et.al studied the mechanism of action of various extracts of the leaves of this plant. In 2002 [3] they published a paper to initially explain part of the mechanism of action of the crude water extract. It was found that this extract were able to increase K(+)-stimulated dopamine release from rat striatal slices comparable to Amphetamine. In a follow up to this study they published another paper in 2005 [4] where they report the effects of methanol extract of the leaves on cerebral activities of rats. They found that the extract increased signal intensity in the following areas of the brain: nucleus accumbens, globus pallidus, amygdala, frontal cortex, caudate putemen and the hippocampus. This indicates that the extract increases significantly neuronal activity in specific brain regions responsible for reward and locomotor behaviour.

Liver detoxification and protective activity

An in vitro and in vivo study of the potential hepatoprotective activity of T. laurifolia was done by Pramyothin et.al. [5] They found in their in vitro studies that the addition of aqueous extracts of the leaves of T. laurifolia caused an increase in MTT back to normal levels and reduce the ALT and AST levels following exposure of rat hepatocytes to ethanol. In the in vivo study the aqueous extract of the leaves of T. laurifolia were able to normalize the effects of ethanol on rat liver evidenced by the normalization of Htg, ALT and AST.

Antidiabetic acitivity

Aritajat et.al [6] found that aqueous extract of the leaves of T. laurifolia was able to reduce the increased of blood sugar level in alloxan-induced diabetic rats. The recovery of some beta-cells of the pancreas was observed eventhough not completely normal. This is indicative of its antidiabetic potentials however, the exact mechanism has still got to be worked out.

Toxicities

Chivapat et.al [7] conducted chronic toxicity studies on the leave extract of T. laurifolia and found that it did not induce and adverse nor toxic effects in the groups of Wistar rats.

Clinical Data

Clinical Trials

No documentation

Adverse Effects in Human:

The sap of T. laurifolia, is irritant to the skin and can cause dermatitis especially on sensitive skin. [1]

Used in Certain Conditions

Pregnancy / Breastfeeding

No documentation

Age Limitations

Neonates / Adolescents

No documentation

Geriatrics

No documentation

Chronic Disease Conditions

No documentation

Interactions

Interactions with drugs

No documentation

Interactions with Other Herbs / Herbal Constituents

No documentation

Contraindications

Contraindications

No documentation

Case Reports

No documentation

References

  1. Hean Chooi Ong  Tanaman hiasan: khasiat makanan & ubatan Utusan Publications & Distributiors Kuala Lumpur. 2006 pg. 60
  2. Thunbergia Laurifolia as a Medication http://www.ehow.com/about_6581402_thunbergia-laurifolia-medication.html (Accessed date: 25 - 06 – 2010)
  3. Thongsaard W, Marsden CA. A herbal medicine used in the treatment of addiction mimics the action of amphetamine on in vitro rat striatal dopamine release. Neurosci Lett. 2002 Aug 30;329(2):129-32.
  4. Thongsaard W, Marsden CA, Morris P, Prior M, Shah YB. Effect of Thunbergia laurifolia, a Thai natural product used to treat drug addiction, on cerebral activity detected by functional magnetic resonance imaging in the rat.
  5. Pramyothin P, Chirdchupunsare H, Rungsipipat A, Chaichantipyuth C. Hepatoprotective activity of Thunbergia laurifolia Linn extract in rats treated with ethanol: in vitro and in vivo studies. J Ethnopharmacol. 2005 Dec 1;102(3):408-11.
  6. Aritajat S, Wutteerapol S, Saenphet K. Anti-diabetic effect of Thunbergia laurifolia Linn. aqueous extract. Southeast Asian J Trop Med Public Health. 2004;35 Suppl 2:53-8.
  7. Chivapat Songpol, Chavalittumrong Pranee, Attawish Aimmanas, Bansiddhi Jaree, Padungpat Songpol. Chronic Toxicity of Thunbergia laurifolia Lindl. Extract. Journal of Thai Traditional & Alternative Medicine. 2009 Jan-Apr; 7(1): 17-24.
  8. Curtis's botanical magazine, Volume 85 tab. 4985, 1857