Averrhoa carambola L.

Last updated: 17 June 2016

Scientific Name

Averrhoa carambola L.


Averrhoa acutangula Stokes, Sarcotheca philippica (Villar) Hallier f. [1]

Vernacular Name

Malaysia Belimbing manis [2], belimbing, belimbing batu, belimbing besi, belimbing kembola, belimbing saii, belimbing sayur [3]
English Carambola, star fruit [2], caramba, Chinese gooseberry, country gooseberry [3]
China Wu han tzu, wu leng tzu, yang tao [3]
India Amrenga, brihaddala, cakatam, cakattai, carambola, dare huli, dantasatha, darepuli, heinoujom, irumpanpuli, kacerukam, karamanooga, kiranelli, kumrak, meeta-kamarunga, nattuttamarattai, pitaphala, pulachi, putakecam, rohdoi, rujakara, sagadam, seizrak, tamara, tamarattaimaram, tantacatam, taurta, thamaratham, thei her awt, etc [3]
Indonesia Belimbing manis [2][3], blimbing alas, blimbing manis, blimbing legi, blimbing wana (Javabese); balingbing, chalingching amis (Sundanese); balimbieng manih, balimbing manis (Sumatran)
Thailand Ma fueang [2], fu-ang, ma-fu-ang, sa-pu [3]
Laos Füang [2][3]
Philippines Balimbing [2], baimbing, balanga, balinbing, balinbing, birihan, calangan, carambola, daligan, dalihan, dulungan, galangan, galuran, garahan, garnatis, garulan, malimbin, saranate, taranati [3]
Cambodia Spö [2]
Vietnam Khê [2][3]
Japan Go-ren-shi [3]
France Carambolier [2].

Geographical Distributions

Some authors seek the origin of Averrhoa carambola  in tropical America (Brazil), from where it was supposedly taken to the Philippines. However, most authors support the Southeast Asian origin, for instance because there is a Sanskrit name for carambola. This crop is now grown all over the humid tropics and also in the subtropics. [2]

Botanical Description

A. carambola is a member of the Oxalidaceae family. It is a small tree that can grow 6-9 m tall but sometimes can reach up to 15 m. It is a much branched, broad, bushy tree and the branches are usually drooping. [2]

The leaves are 3-6-jugate. [2]

The flowers are usually in axillary panicles and heterodistylous. The petals are coherent, measuring up to 8 mm long and light red with purple heart. The stamens are short rudimentary and lacking anthers. [2]

The fruit is with 5 pronounced ribs, stellate in cross-section, and measuring up to 12.5 cm x 6 cm. [2]

The seeds are with fleshy aril. [2]


A. carambola species prefers a climate with a dry season, thriving where teak (Tectona grandis L.f.) is at home, but also do well in wetter climates. It can be extended to frost-free subtropics; it is grown up to 300°S in Australia and 32°N in Israel. It has a high water requirement, but it needs well-drained soils of pH 5.5-6.5, and grows well on peat. Drought, flooding and salinity are not tolerated. Windbreaks are recommended on exposed sites. [2]

Chemical Constituent

A. carambola  has been reported to contain alanaine, α-keto-glutaric-acid, aluminum, arginine, ascorbic-acid, ash, aspartic-acid, β-apo-8'-carotene, β-carotene, β-cryptoflavin, β-damascenone, beta-ionone, boron, calcium, carbohydrates, carotenoids, citric-acid, copper, cryptochrome, cryptoxanthin, cyanidin, fat, fiber, fumaric-acid, glutamic-acid, glycine, histidine, iron, isoleucine, kilocalories, leucine, lutein, lysine, magnesium, malic-acid, manganese, methionine, mutatoxanthin, niacin, nitrogen, oxalic-acid, p-coumaric-acid, phenylalanine, phosphorus, phytofluene, potassium, proline, protein, riboflavin, serine, sinapic-acid, sodium, succinic-acid, sulfur, tartaric-acid, thiamin, threonine, tryptophan, tyrosine, valine, water, and zinc. [4]

Plant Part Used

Fruit, leaf, shoot, flower, seeds. [5]

Traditional Use

The crushed leaves or shoots of A. carambola  are applied externally in the treatment of chickenpox, ringworms, tinea and headache. Tea of boiled leaves is also used to relieve aphthous stomatitis and angina. A mixture of the leaves and the fruits can be used to arrest vomiting and to treat fever. [5]

The A. carambola fruits are used as a laxative, a refrigerant, an appetite stimulant, an antipyretic, a sialogogue, an astringent, an antiscorbutic, an antidysentery and an antiphlogistic. They have been used for the treatment of throat inflammation, mouth ulcers, toothache, cough,asthma, hiccups, tight feeling in chest, nausea, vomiting, indigestion, colic, diarrhoea, jaundice and ascites. It is claimed that they are effective as a remedy for bleeding haemorrhoids, haematemesis and melaena. They may be applied to wounds to arrest haemorrhages. The fruits are also used to treat rashes, pruritus, sunstroke, oliguria and strangury. The Chinese and Annamites apply the fruits in an eye-salve to treat eye-related diseases. They are used as a stimulant for the reproductive organs of both men and women. In women, the fruits can be used to increase lactation. In large doses, they can act as an emmenagogue and to induce abortion. [5]           

It can also be used to treat diabetics, to lower blood pressure, sore throat [6] and as diuretic in kidney and bladder complaints. [7]

The boiled flowers of A. carambola are used as an antihelmintic. [8]

The A. carambola seed is used for asthma and colic. [8]

Preclinical Data


Anti-inflammatory activity

Aqueous extract of A. carambola stem used as ethnomedicine for dysuria administered intraperitoneally showed anti-inflammatory activity by inhibited rat paw inflammation by carrageenin., the A. carambola extract showed comparable anti-inflammatory effects to that of acetylsalicylic acid (ASA) at a dose of 300 mg/kg during the first hour and showing stronger activity over a longer duration of time. [9] 

Antibacterial activity

In the same study above, A. carambola exhibited antibacterial activity by inhibiting Staphylococcus aureus as indicated by a minimal bactericidal concentration (MBC) of 15.62 mg/mL or less. The extract from A. carambola also killed Klebsiella sp. (MBC value of 125 mg/mL). [9]

Hypoglycaemic activity

Several insoluble fiber-rich fractions (insoluble dietary fiber, alcohol-insoluble solid and water-soluble solid) isolated from the pomace of A. carambola possessed potential hypoglycaemic effects as demonstrated by a study on several in vitro methods. The fibers could effectively absorb glucose, retard glucose diffusion, postpone the release of glucose from starch and inhibit a-amylase activity to certain extent. [10]  

Antioxidant activity

The analysis of polyphenolic antioxidants in A. carambola by liquid chromatography and mass spectrometry was performed on the fruit juice and residue extract. The peaks were mainly antioxidants which were mainly attributed to phenolic compounds. They were characterised as L-ascorbic acid, (-)epicatechin, gallic acid gallotannin forms and proanthocyanidins. The residue of the star fruit, which is normally discarded during juice drink processing, was further found to contain much higher antioxidant activity than the extracted juice [11]. It is also showed strong antioxidant activity in delaying oxidative rancidity of soya bean oil at 110oC. This property of A. carambola residue extract powder would be of health benefit and suggests great commercial potential as nutraceutical resource or functional food ingredient [12]

Hypocholesterolaemic and hypolipidaemic activities

Water-insoluble fiber-rich fraction (WIFF) isolated from the pomace of A. carambola showed hypocholesterolaemic and hypolipidaemic activities. Investigations in hamsters showed pronounced cholesterol- and lipid-lowering effects of WIFF which might be attributed to its ability to enhance the excretion of cholesterol and bile acids via the faeces. It decreases the serum concentrations of triacylglycerol, total cholesterol, liver cholesterol and increases the concentration of total lipids, cholesterol and bile acids in faeces. [13]


In preliminary investigations to characterize the hypothetical neurotoxin in the A. carambola, the extract provoked persistent convulsions when injected in rats [14]. Further study was conducted by chromatographic isolation of the convulsant fraction from the aqueous extract of the A. carambola . The effects of the neurotoxic fraction AcTx given to experimental animals (rats and mice) showed behavioural changes acting primarily on g-aminobutyric acid (GABA) receptors [15]. These excitatory neurotoxins, probably GABAergic antagonists, may be responsible for seizures in renal patients and animal models [16].   

In another experiment, an aqueous extract of the A. carambola leaves is shown to induce some electrophysiological changes in a normal guinea pig heart. In 6 hearts, the extract induced many kinds of atrioventricular blocks (1st, 2nd, and 3rd degrees); increased the QT interval; increased the QRS complex duration, and depressed the cardiac rate. [17]

Clinical Data

Clinical findings

No documentation.


No documentation.

Side effects

No documentation.

Pregnancy/Breast Feeding

No documentation.

Age limitation

No documentation.

Adverse reaction

Neurotoxic effect 

A preliminary report on intoxication by A. carambola fruit observed six cases of patients in a dialysis programme who were apparently intoxicated after ingestion of 2-3 fruits or an equivalent of 150-200 mL of the fruit juice. The six patients who had previously been stable, however developed a variety of symptoms ranging from insomnia and hiccups to agitation, mental confusion and one case of death [14]. In a similar situation, neurologic symptoms following star fruit ingestion were exhibited by 32 uraemic patients. All patients who were promptly and properly treated with haemodialysis recovered without sequelae. Patients with severe intoxication who were not treated or treated with peritoneal dialysis did not survive [18]. It appears that star fruit contains an excitatory neurotoxin and as a precaution, patients with renal failure should avoid consuming it [14].

Interaction & Depletion

Interaction with drug

The chemical component(s) in filtered A. carambola fruit juice has shown potent inhibitory effect on midazolam 1’-hydroxylase activity of human CYP3A activity. [19]

Interaction with other Herbs

No documentation.


No documentation.

Case Report


A 25-year-old female had been enrolled in a regular haemodialysis programme for 6 years. She ate one A. carambola and developed hiccups 2 h later. Four hours later she ate four more fruits and showed intractable hiccups half hour later, followed by vomiting. The patient went to the University Hospital and the hiccups disappeared after a total of 14 h of dialysis in 4 days. The patient had no sequelae. There had been no laboratory tests during these 7 days of follow-up. [18]

A 55-year-old female who enrolled in a regular CAPD programme had been on dialysis for 27 months. She ingested a A. carambola and developed hiccups, vomiting, asthenia and mild psychomotor agitation 3 h later. At the emergency room, she was medicated with chlorpromazine and metoclopramide and was discharged. Seven and a half hours after star fruit ingestion, she presented with mental confusion and was admitted to the hospital. She was admitted to an ICU with moderate mental confusion and, 12 h after fruit ingestion, presented with convulsive activity. She was seen by a neurologist who prescribed hydantoin 400 mg i.v., phenobarbital and diazepam. The convulsive activities progressed to status epilepticus. At 22 h after fruit ingestion, she showed haemodynamic instability with low blood pressure, and was given dopamine. She was continued on dialytic treatment (CAPD, now increased to every 4 h) and was given haemodialysis 22 h after fruit ingestion, but died 2 h later during this procedure. [18]


No documentation.

Poisonous Management

No documentation.

Line drawing


Figure 1: The line drawing of A. carambola [2]


  1. The Plant List. Ver1.1. Averrhoa carambola L. [homepage on the Internet]. c2013 [updated 2012 Apr 18; cited 2016 Jun 17]. Available from: http://www.theplantlist.org/tpl1.1/record/kew-2666746
  2. Samson, J.A., 1991. Averrhoa L.In: Verheij, E.W.M. and Coronel, R.E. (Editors). Plant Resources of South-East Asia No. 2: Edible fruits and nuts. Pudoc, Wageningen, The Netherlands, pp. 96-98
  3. Quattrocchi U. CRC world dictionary of medicinal and poisonous plants: Common names, scientific names, eponyms, synonyms, and etymology. Volume I A-B. Boca Raton, Florida: CRC Press, 2012; p. 494.
  4. US Department of Agriculture, Agricultural Research Service. Dr Duke’s Phytochemical and Ethnobotanical Databases. [homepage on the Internet] c1992-2016 [updated 2016 Jun 02; cited 2016 Jun 27]. Available from: https://phytochem.nal.usda.gov/phytochem/plants/show/217?et=
  5. Herbal Medicine Research Centre, Institute for Medical Research. Compendium of medicinal plants used in Malaysia. Volume 1. Kuala Lumpur: HMRC IMR, 2002; p. 92.
  6. Mat-salleh K, Latiff A. Tumbuhan ubatan Malaysia. Selangor, Malaysia: Universiti Kebangsaan Malaysia, 2002; p.
  7. National Tropical Botanical Garden Plant Database. Averrhoa carambola. [homepage on the Internet]. c2016 [cited 2016 Jun 27]. Available from: http://ntbg.org/plants/plant_details.php?plantid=1377
  8. Philippine Medicinal Plants. Balimbing. Averrhoa carambola Linn. [homepage on the Internet]. No date [updated 2013 Aug; cited 2016 Jun 27] Available from: http://www.stuartxchange.org/Balimbing.html
  9. Sripanidkulchai B, Tattawasart U, Laupattarakasem P, Wongpanich V. Anti-inflammatory and bactericidal properties of selected indigenous medicinal plants used for dysuria. Thai J Pharm Sci. 2002;26(1-2):34-38.
  10. Chau CF, Chen CH, Lin CY. Insoluble fiber-rich fractions derived from Averrhoa carambola: hypoglycaemic effects determined by in vitro methods. LWT-Foos Sci Technol. 2004;37(3):331-335.
  11. Shui G, Leong LP. Analysis of polyphenolic antioxidants in star fruit using liquid chromatography and mass spectrometryJ Chromatogr A. 2004 Jan 2;1022(1-2):67-75.
  12. Shui G, Leong LP. Residue from star fruit as valuable source for functional food ingredients and antioxidant nutraceuticals. Food Chem. 2006;97(2):277-284.
  13. Chau CF, Chen CH, Wang TW. Effects of a novel pomace fibre on lipid and cholesterol metabolism in the hamster. Nutr Res. 2004;24(5):337-345.
  14. Neto MM, Robl F, Netto JC. Intoxication by star fruit (Averrhoa carambola) in six dialysis patients ? (Preliminary report). Nephrol Dial Transplant. 1998;13(3):570-572.
  15. Carolino RO, Beleboni RO, Pizzo AB, et al. Convulsant activity and neurochemical alterations induced by a fraction obtained from fruit Averrhoa carambola (Oxalidaceae: Geraniales). Neurochem Int. 2005 Jun;46(7):523-531.
  16. Rodrigues MCA, Rossetti F, Foresti ML. Correlation between shaking behaviors and seizure severity in five animal models of convulsive seizures. Epilepsy Behav. 2005 May;6(3):328-336
  17. Vasconcelos CM, Araújo MS, Conde-Garcia EA. Electrophysiological effects of the aqueous extract of Averrhoa carambola L. leaves on the guinea pig heart. Phytomedicine. 2006;13(7):501-508
  18. Neto MM, da Costa JAC, Garcia-Cairasco N, Netto JC, Nakagawa B, Dantas M. Intoxication by star fruit (Averrhoa carambola) in 32 uraemic patients: treatment and outcome. Nephrol Dial Transplant. 2003;18(1):120-125.
  19. Hidaka M, Fujita K, Ogikubo T, et al. Potent inhibition by star fruit of human cytochrome P450 3A (CYP3A) activity. Drug Metab Dispos. 2004;32(6):581-583.