Karmaranga
Averrhoa carambola
Karmaranga (Averrhoa carambola) is a plant used in Ayurveda. Proanthocyanidins and epicatechin show moderate bioavailability (20-30%). L-ascorbic acid (vitamin C) is readily absorbed. Caution: oxalic acid may precipitate calcium — not recommended for patients with renal calculi.
| Botanical name | Averrhoa carambola |
|---|---|
| Family | Oxalidaceae · other entries in this family |
| Order | Oxalidales |
| Taxon identifiers | GBIF 2891641 · Wikidata Q159447 · NCBI Taxonomy 28974 |
Names and identification
| Language | Name |
|---|---|
| English | Karmaranga |
Ayurvedic pharmacology (Dravyaguna)
| Property | Value | Description |
|---|---|---|
| Rasa (Taste) | Amla, Madhura | Primary taste |
| Guna (Quality) | Laghu | Physical quality |
| Virya (Potency) | Sheeta | Heating/Cooling effect |
| Vipaka (Post-digestive) | Amla | Post-digestive effect |
Dosage forms and preparation
Dosage Forms: Swarasa (fresh juice), Churna (dried fruit powder), Avaleha (preserve), Capsule, Kashayam (decoction)
Standard Dosage: 20-40 mL fresh fruit juice twice daily; 3-5 g powder with honey; 10-15 g Avaleha
Bioavailability: High oxalic acid content influences mineral absorption. Proanthocyanidins and epicatechin show moderate bioavailability (20-30%). L-ascorbic acid (vitamin C) is readily absorbed. Caution: oxalic acid may precipitate calcium — not recommended for patients with renal calculi. Polyphenol bioavailability improved through fermentation or enzymatic processing.
Optimal Timing: After meals to minimize oxalate-related GI effects; not to be taken on empty stomach
Standardized Extract: Standardized to minimum 3% total polyphenols (as gallic acid equivalents); oxalic acid content must be tested and limited to <0.5% in processed extracts
Shelf Life: 24 hours for fresh juice (refrigerated); 18 months for freeze-dried powder; 24 months for Avaleha; 24 months for capsules
Storage: Fresh juice requires immediate refrigeration (2-8°C). Dried preparations in airtight containers at 15-30°C. Protect from moisture and light.
Marker Compounds: Epicatechin, Proanthocyanidins, L-Ascorbic acid, Oxalic acid (to be minimized), Caramboxin (neurotoxin — must be absent in final product), Saponins, Gallic acid
Extraction Methods
- Cold pressing of ripe fruits
- Freeze-drying of juice
- Hydroalcoholic extraction (40-50% ethanol)
- Spray drying with maltodextrin carrier
Synergistic Combinations
- Amalaki for enhanced antioxidant vitamin C combination
- Draksha for nutritive tonic formulations
- Haritaki in digestive formulations
- Dadima for hematinic formulations
Published research
Literature indexed in PubMed that concerns this subject, grouped by study type. A paper appearing here is a record of what has been published, not evidence that the subject works, and laboratory or animal results do not transfer to people. Study titles link to PubMed so you can read the source rather than take our word.
Systematic reviews and meta-analyses1
- 2017. Toxicity of star fruit (Averrhoa carambola) in renal patients: A systematic review of the literatureSaudi journal of kidney diseases and transplantation : an official publication of the Saudi Center for Organ Transplantation, Saudi Arabia. PMID 28748871
Other clinical studies and reviews7
- 2021. Nutritional and medicinal properties of Star fruit (Averrhoa carambola): A reviewFood science & nutrition. PMID 33747490 · doi:10.1002/fsn3.2135
- 2021. Nephrotoxicity and neurotoxicity following star fruit (Averrhoa carambola) ingestion: a narrative reviewTransactions of the Royal Society of Tropical Medicine and Hygiene. PMID 33693950 · doi:10.1093/trstmh/trab026
- 2021. Traditional Uses, Phytochemical Constituents and Pharmacological Properties of Averrhoa carambola L.: A ReviewFrontiers in pharmacology. PMID 34475822 · doi:10.3389/fphar.2021.699899
- 2020. Mechanisms of star fruit (Averrhoa carambola) toxicity: A mini-reviewToxicon : official journal of the International Society on Toxinology. PMID 32966829 · doi:10.1016/j.toxicon.2020.09.010
- 2017. Association of renal function and symptoms with mortality in star fruit (Averrhoa carambola) intoxicationClinical toxicology (Philadelphia, Pa.). PMID 28443386 · doi:10.1080/15563650.2017.1314490
- 2016. Nutritional, Medicinal and Toxicological Attributes of Star-Fruits (Averrhoa carambola L.): A ReviewBioinformation. PMID 28405126 · doi:10.6026/97320630012420
- 2013. Mechanisms of herb-induced nephrotoxicityCurrent medicinal chemistry. PMID 23597204 · doi:10.2174/0929867311320220006
Laboratory and animal studies4
- 2022. Acute and sub-chronic toxicological evaluation of Averrhoa carambola leaves in Sprague Dawley ratsEnvironmental science and pollution research international. PMID 35864392 · doi:10.1007/s11356-022-22019-7
- 2020. Flavan-3-ols and 2-diglycosyloxybenzoates from the leaves of Averrhoa carambolaFitoterapia. PMID 31790769 · doi:10.1016/j.fitote.2019.104442
- 2020. Dihydrochalcone C-glycosides from Averrhoa carambola leavesPhytochemistry. PMID 32247075 · doi:10.1016/j.phytochem.2020.112364
- 2019. Antihyperlipidemic and Antioxidant Effects of Averrhoa Carambola Extract in High-Fat Diet-Fed RatsBiomedicines. PMID 31527433 · doi:10.3390/biomedicines7030072
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