Angostura

Angostura (Galipea officinalis / Angostura trifoliata): Encyclopedic Reference

1. Identity, Nomenclature, and Botanical Source

The substance known as Angostura or Angostura bark is derived from the inner bark of a tropical tree whose current accepted botanical name is Angostura trifoliata (Willd.) T.S. Elias, belonging to the family Rutaceae (the rue or citrus family). The bark is that of Galipea cusparia St. Hilaire (Galipea officinalis, Hancock; Cusparia febrifuga, Humboldt; Galipea febrifuga, Baillon; Bonplandia trifoliata, Willdenow). The plant belongs to the natural order Rutaceae and is known under the synonyms Cuspariae cortex, Cusparia bark, and Angostura bark.

The taxonomic history of the plant is unusually complex, with the species having accumulated well over a dozen valid synonyms. These include Galipea cusparia St. Hilaire in DC., Galipea febrifuga Baill., Cusparia febrifuga Humb., Cusparia trifoliata Engler, Angostura cusparia Roem. and Sch., Bonplandia trifoliata Willd., and B. Angostura Rich. The older literature most frequently employs Galipea officinalis Hancock as the operative scientific name, and this designation persists in the majority of modern pharmacological studies.

Angostura is a small tree native to Venezuela and other tropical parts of South America. The tree seldom exceeds 20 feet in height, with a stem whose diameter is from 2 to 6 inches, having irregular branches and a smooth bark. The leaves are alternate, trifoliate, and petiolate; the leaflets oval, acute at the base, acuminate at the apex, smooth, glossy, bright-green, having a tobacco-like smell when fresh and bruised, from 6 to 10 inches long and 2 to 4 broad, some of them marked with small, whitish, round spots.

The name "angostura" derives from the Venezuelan town of Angostura (now Ciudad Bolívar), situated on the Orinoco River. The town was named after the native word for "narrow," a reference to the nearby Orinoco River, which was reduced to a trickle in the summer months.

Common Names and Synonyms

• Botanical synonyms: Galipea officinalis Hancock; Galipea cusparia A.St.-Hil.; Cusparia febrifuga Humb.; Bonplandia trifoliata Willd.
• Common trade/common names: Angusture Vraie, Angustura, Carony Bark, Chuspa, Cusparia Bark.
• Spanish: Corteza de Angostura
• German: Angusturarinde
• French: Angusture de Colombie

Dosage Forms and Preparations

The bark of this tree is used in medicine. It usually comes to market in cut pieces six to ten inches long, a line in thickness, and rolled at the sides. The tree has plenteous chunky external bark, which is removed from the tree in elongated, straight shreds, which are either used fresh or dried out and stored for use later. Unlike the curly dry bark of cinnamon, the edges of the bark of Angostura trees remain straight even after they are dried, primarily owing to their partially spongy structure. Preparations documented in the ethnobotanical and historical literature include decoctions, aqueous infusions, alcoholic tinctures (ethanolic extracts), and powdered bark. Traditional preparations typically involve decoctions, tinctures, or powders derived from the inner bark, administered in doses of 1–2 g per day to avoid emetic effects, which occur with larger amounts exceeding 5 g.

In the regulatory context, angostura bark and its extract are recognized as flavoring ingredients. The FDA Food Additive Status List designates angostura (cusparia bark) as an essential oil, solvent-free oleoresin, and spice that is Generally Recognized as Safe (GRAS) under 21 CFR 182.10 and 182.20. 21 CFR 172.510, titled "Natural flavoring substances and natural substances used in conjunction with flavors," contains plant-derived substances approved for use as flavorings, including angostura bark, which is limited to use in beverages.

2. Important Clarification: Angostura Bark vs. Angostura Bitters

A widespread source of confusion in the popular literature concerns the relationship between angostura bark as a botanical ingredient and the commercial product known as Angostura Bitters. The bitters were first produced in the namesake town of Angostura (now Ciudad Bolívar, Venezuela) but do not contain angostura bark. Johann Gottlieb Benjamin Siegert (1796–1870) was a German doctor who served in the Napoleonic Wars and later tended troops during the independence wars in Venezuela. In 1820, he landed in Angostura, a port on the vast Orinoco River, and joined up with the revolutionary general Simón Bolívar. Siegert developed a recipe as a tonic, began selling it in 1824, and established a distillery for that purpose in 1830. Angostura Bitters is sometimes used in mixing alcoholic beverages, but no longer contains angostura. It is now made from gentian and other bitters. When the doctor died in 1870, production of the bitters was taken over by his sons, who, in 1875, due to unrest in Venezuela, moved to Trinidad, where they are still made to Doctor Siegert's original secret 1824 formula.

Today, angostura bitters are also produced by various other vendors, some of which add the bark of the angostura tree (Angostura trifoliata). The botanical ingredient covered by this article is angostura bark itself — the raw or processed bark of Galipea officinalis — not the branded bitters product.

3. Traditional and Historical Use

Indigenous and South American Folk Medicine

The inner bark of Angostura trifoliata (synonym Galipea officinalis) has been traditionally employed in South American folk medicine as a febrifuge and antipyretic, with infusions prepared to treat fevers, often regarded as comparable in efficacy to quinine. It is also used for malaria prophylaxis, diarrhea, stomach spasms, and as a general tonic to stimulate digestion and appetite. In traditional practices, the plant serves as a remedy for respiratory issues like bronchitis and as a febrifuge.

The bark is a very popular treatment for fevers in South America, where it is said to rival quinine in its effectiveness. The angostura bark comes from a northern South American tropical tree and is used in traditional medicine to treat dysenteries, paralytic infections, and as a tonic, and to make bitter liquors.

Galipea officinalis Hancock, a shrub growing in tropical America, is used in folk medicine as an antispasmodic, antipyretic, astringent, and tonic. The geographic range of traditional use encompasses primarily Venezuela and Brazil, corresponding to the plant's native distribution. The species is found in South America, specifically Brazil and Venezuela.

Use as a Bitter Tonic and Digestive Aid

The bark used to be the basis of a well-known bitter tonic, Angustura Bitters, though gentian root is now used in its place. Traditional forms leverage the bark's bitter and stimulant properties to promote gastrointestinal motility and alleviate dyspepsia. The bark's properties were broadly compared to those of gentian (Gentiana lutea) in the 19th-century dispensatory literature, as it was considered closely allied in virtues to Gentiana lutea.

Fish Poisoning (Ichthyotoxic Use)

The bark is also bruised and used to intoxicate fish — a practice documented in South American indigenous communities, consistent with a broader tradition of using plant ichthyotoxins as fishing aids.

19th-Century Western Medical Use

Angostura bark entered European and North American medicine in the early 19th century and was included in the Dispensatory of the United States (as Angustura) and the London Pharmacopoeia (as Cusparia cortex). The bark was employed as a tonic and febrifuge, and in the treatment of dysentery and intermittent fevers. It is used in traditional medicine to treat dysenteries, paralytic infections, and as a tonic and to make bitter liquors.

4. Key Constituents and Active Compounds

Quinoline and Tetrahydroquinoline Alkaloids

The bioactive chemistry of angostura bark is dominated by a suite of structurally related quinoline and tetrahydroquinoline (THQ) alkaloids. Galipea officinalis Hancock yields nine quinoline alkaloids, of which galipine, cusparine, cuspareine, demethoxycusparine, and galipinine are the most important.

Galipea officinalis Hancock is a shrubby tree reputed in folk medicine for its many properties which may be related to its alkaloid composition. Five quinoline alkaloids have been structurally elucidated: cuspareine, cusparine, and galipine (previously described), demethoxycusparine (newly isolated in this species), and a new quinoline alkaloid named galipinine, which is the 3′,4′-methylenedioxycuspareine.

The tetrahydroquinoline subclass is of particular pharmacological interest. Two tetrahydroquinoline alkaloids have been isolated from the bark of Galipea officinalis Hancock, named angustureine (1,2,3,4-tetrahydro-2(n-pentyl)-1-methylquinoline) and galipeine (2-[(3′-hydroxy-4′-methoxy-phenylethyl)]-2,3,4-tetrahydro-1-methylquinoline).

Alkyl- and arylalkylderivatives of tetrahydroquinoline such as (−)-angustureine, (−)-cuspareine, (−)-galipeine, and (−)-galipinine, extracted from the angostura (Galipea officinalis, Angostura trifoliata) tree, have a variety of medicinal properties.

Additionally, the isolation of N-methyl-4-hydroxy-3-(2′,3′-epoxyisobutyl)-2-quinolone, a new natural compound, and candicine from Galipea officinalis trunk bark has been reported. This is the first report of candicine in the genus Galipea.

Other Phytoconstituents

The bark contains several active compounds including an essential oil and the alkaloids cusparine and galipine. Angostura trifoliata also contains flavonoids, alkaloids, and phenolic compounds. Poncirin, a flavanone glycoside found in Angostura trifoliata, exhibits significant biological activities. It has been studied for its anti-inflammatory properties, particularly in inhibiting PGE2 and IL-6 production, and also shows potential against bacterial and viral infections, gastric diseases, and human gastric cancer.

Established Mechanisms of Action

The bark contains the alkaloids cusparine and galipine, and these alkaloids have been shown to have antispasmodic activity. The antispasmodic effects are attributed principally to the relaxant properties of the quinoline alkaloid fraction on smooth muscle.

The antimalarial activity of the tetrahydroquinoline alkaloids has been studied in vitro. In a 2002 study published in Planta Medica, the antimalarial and toxicological properties of four tetrahydroquinoline alkaloids from Galipea officinalis trunk bark were studied. Crude extracts and pure alkaloids were tested for in vitro antimalarial activity on Plasmodium falciparum. The IC₅₀ values ranged from 1.8 to 40 µg/ml for the chloroquine-sensitive strain (CQS) and from 0.09 to 38 µg/ml for the chloroquine-resistant strains (CQR). Galipinine yielded the best antimalarial effect (IC₅₀: 0.09–0.9 µg/ml on the CQR strain) and this compound interacted particularly between the 32nd and the 40th hour of the P. falciparum erythrocytic cycle.

The antimycobacterial activity of the bark has also been studied at the mechanistic level. The activity of an ethanolic extract of Galipea officinalis bark against Mycobacterium tuberculosis was shown to reside mainly in the basic alkaloidal fraction, although the major part of the alkaloids present were in the neutral fraction. Isolation and testing of fractions and individual alkaloids against ten strains of M. tuberculosis showed that all the alkaloids possessed some activity but that the unidentified most polar basic fraction exhibited the greatest effect.

5. Scientific Evidence by Area of Use

5.1 Antimalarial / Antiplasmodial Activity

Summary of evidence: Preliminary; entirely in vitro; no human clinical trials.

The most systematically investigated pharmacological property of angostura bark alkaloids is antiplasmodial activity. The antimalarial and toxicological properties of four tetrahydroquinoline alkaloids from Galipea officinalis trunk bark were studied; crude extracts and pure alkaloids were tested for in vitro antimalarial activity on Plasmodium falciparum. The 2002 study by Jacquemond-Collet et al. (published in Planta Medica, PMID 11842332) tested galipinine, cuspareine, angustureine, and galipeine. The IC₅₀ values were evaluated after 24 and 72 hours of contact between compounds and the parasite culture, and ranged from 1.8 to 40 µg/ml for the chloroquine-sensitive strain (CQS) and from 0.09 to 38 µg/ml for the chloroquine-resistant strains (CQR). Galipinine yielded the best antimalarial effect (IC₅₀: 0.09–0.9 µg/ml on the CQR strain).

Cytotoxicity of the extracts and pure alkaloids was assessed on the HeLa cell line and showed IC₅₀ values ranging from 5.8 to above 50 µg/ml. The study was conducted entirely in cell culture; no animal studies or human trials have been conducted to evaluate antiplasmodial efficacy, and the clinical relevance of these in vitro findings remains unknown. There is no good scientific evidence to support use of angostura for preventing the return of malaria.

5.2 Antimycobacterial Activity

Summary of evidence: Preliminary; in vitro only; no human studies.

A 1999 study by Houghton et al. (published in Planta Medica, PMID 10232071) examined the activity of an ethanolic bark extract against M. tuberculosis. The activity of an ethanolic extract of Galipea officinalis bark against Mycobacterium tuberculosis was shown to reside mainly in the basic alkaloidal fraction, although the major part of the alkaloids present were in the neutral fraction. Six alkaloids were isolated from the bark, including two not previously reported from G. officinalis and a new quinoline named allocuspareine, whose structure was determined by spectroscopic methods. Isolation and testing of fractions and individual alkaloids against ten strains of M. tuberculosis showed that all the alkaloids possessed some activity but that the unidentified most polar basic fraction exhibited the greatest effect.

The findings are confined to in vitro microbiological assays. No animal or human studies have followed up on this antitubercular activity, and no dose-response data applicable to clinical use has been established.

5.3 Antispasmodic Activity

Summary of evidence: Mechanistically plausible; supported by in vitro and preclinical data; no human clinical trials.

The bark contains several active compounds including an essential oil and the alkaloids cusparine and galipine. These alkaloids have been shown to have antispasmodic activity. The antispasmodic property has been cited consistently across multiple secondary sources derived from experimental pharmacology literature and forms the basis of angostura's traditional use for gastrointestinal spasms. Angostura has chemicals that help reduce spasms. However, no randomized controlled trials or prospective human studies documenting clinical antispasmodic efficacy have been identified. There is no good scientific evidence to support the use of angostura for spasms.

5.4 Fever and Antipyretic / Antimalarial Use (Febrifuge)

Summary of evidence: Traditional use documented; no controlled clinical studies.

The inner bark has been traditionally employed in South American folk medicine as a febrifuge and antipyretic, with infusions prepared to treat fevers, often regarded as comparable in efficacy to quinine. However, this comparison is based solely on traditional reputation and anecdotal observation. No controlled clinical trials have assessed the antipyretic efficacy of angostura bark in human subjects. There is no good scientific evidence to support the use of angostura for fever.

5.5 Gastrointestinal Uses (Diarrhea, Dysentery, Digestive Tonic)

Summary of evidence: Traditional use well-documented; no controlled human trials.

Angostura bark is used in traditional medicine to treat dysenteries, as a tonic, and to make bitter liquors. Traditional forms leverage the bark's bitter and stimulant properties to promote gastrointestinal motility and alleviate dyspepsia. Its bitter principle is consistent with the established pharmacological mechanism of bitter tonics in general — stimulation of digestive secretions through bitter taste receptor activation — a mechanism documented for structurally related compounds from the Rutaceae family. However, no clinical trials specific to angostura bark's gastrointestinal effects have been identified in the peer-reviewed literature. There is no good scientific evidence to support the use of angostura for diarrhea.

5.6 Anti-tumor / Cytotoxic Research (Preclinical)

Summary of evidence: Highly preliminary; in vitro only; no clinical trials.

Tetrahydroquinoline alkaloids from Galipea officinalis have attracted attention as structural templates in anticancer drug discovery. Tetrahydroquinolines (THQs) are found to be the basic skeleton of numerous natural and synthetic compounds with various biological properties; alkyl- and arylalkyl-derivatives of THQ such as (−)-angustureine, (−)-cuspareine, (−)-galipeine, and (−)-galipinine, extracted from the angostura tree, have a variety of medicinal properties. Research groups have synthesized analogues of Galipea officinalis-type tetrahydroquinoline alkaloids as potential anti-tumor agents, but this work remains at the stage of in vitro cytotoxicity testing and analogue synthesis. No clinical or advanced preclinical anti-tumor studies for crude angostura bark or its direct isolates in humans have been reported.

6. Body Systems and Health Areas Associated with Angostura

• Gastrointestinal system: Bitter tonic (traditionally used to stimulate appetite and digestion), antispasmodic, antidiarrheal, treatment of dysentery.
• Immune/Infectious disease: Traditionally used as a febrifuge; in vitro antimalarial and antimycobacterial activity demonstrated in laboratory studies.
• Musculoskeletal / Smooth muscle: Antispasmodic effects attributed to quinoline alkaloid constituents, demonstrated in experimental pharmacology.
• Respiratory system: In traditional practices, the plant serves as a remedy for respiratory issues like bronchitis. No scientific evidence for this use exists.

7. Dosage Forms and Dosages Reported in Sources

Formal standardized dosing for angostura bark as a medicinal supplement has not been established through clinical trials. The only dose-range data available derives from traditional and historical ethnobotanical sources:

• Oral traditional dose: 1–2 g per day of bark preparations (decoction, tincture, or powder) to avoid emetic effects; emetic effects occur with larger amounts exceeding 5 g.
• In vitro antimalarial testing used crude extract and pure alkaloid concentrations expressed as IC₅₀ values (µg/ml in cell culture) and cannot be directly translated to human oral doses.
• Flavoring use: Under U.S. regulations, angostura bark as a flavoring ingredient is limited to use in beverages. Quantities used in this context are trace-level and far below any medicinal dose range.

8. Safety Considerations and Notable Interactions

Emetic Effect at High Doses

Emetic effects occur with larger amounts exceeding 5 g of bark preparations, a consistent finding across historical and ethnobotanical literature. This limits the practical dose range for oral use and has historically defined the upper boundary of traditional dosing.

Historical Adulteration with Strychnos nux-vomica ("False Angostura Bark")

The most serious documented safety issue associated with angostura bark is not the plant itself but its historical adulteration with the bark of Strychnos nux-vomica. Angostura bark comes from a northern South American tropical tree; at first appearance, this bark resembles the poisonous bark of the nux-vomica tree. It was not previously uncommon (early 19th century) to find portions of the latter mixed with angostura bark. This proved to be a most dangerous adulteration, causing several deaths between 1804 and 1806 in Germany, Switzerland, and Hungary.

Angostura brand bitters is often incorrectly believed to have poisonous qualities because it is associated with angostura bark (which it does not contain), which, although not toxic, during its use as a medicine was often adulterated by unscrupulous sellers, who padded out the sacks of bark with cheaper, poisonous Strychnos nux-vomica or copalchi bark. The toxin strychnine, derived from Strychnos nux-vomica seeds, may be encountered through contaminated herbal products. Strychnine acts as a competitive antagonist at postsynaptic glycine receptors in the spinal cord, producing unopposed motor neuron excitation. The risk of adulteration is of primarily historical significance but remains relevant to the quality control of crude bark material.

Regulatory Status and General Safety

The FDA Food Additive Status List classifies angostura (cusparia bark) as an essential oil/spice that is GRAS (Generally Recognized as Safe) under 21 CFR 182.10 and 182.20. This GRAS designation applies to its use as a flavoring substance at quantities appropriate for that purpose and does not constitute an endorsement of any medicinal dose.

While people use angostura for fever, diarrhea, spasms, and preventing the return of malaria, there is no good scientific evidence to support these uses. The absence of human clinical safety data means that the tolerability, contraindications, and drug-interaction profile of angostura bark at medicinal doses have not been formally characterized in the modern pharmacological literature. No drug-drug interaction studies have been conducted.

Cytotoxicity Signal in Vitro

Cytotoxicity of the tetrahydroquinoline alkaloid extracts and pure alkaloids was assessed on the HeLa cell line and showed IC₅₀ values ranging from 5.8 to above 50 µg/ml. This in vitro cytotoxicity signal was noted in the same study that demonstrated antiplasmodial activity and represents a potential safety concern if constituents were to accumulate; however, the clinical relevance at oral doses used in traditional medicine has not been studied.

9. Overall Evidence Assessment

The scientific evidence base for angostura bark (Galipea officinalis) as a medicinal supplement is characterized by a substantial body of phytochemical and in vitro pharmacological research alongside a near-complete absence of human clinical trials. The following summarizes the state of evidence:

• Phytochemistry: Well-characterized. A family of quinoline and tetrahydroquinoline alkaloids has been isolated, structurally elucidated, and shown to possess measurable in vitro biological activity.
• Antiplasmodial activity: Demonstrated in vitro against both chloroquine-sensitive and chloroquine-resistant strains of P. falciparum; no animal or human efficacy data exist.
• Antimycobacterial activity: Demonstrated in vitro against ten strains of M. tuberculosis; no animal or human data exist.
• Antispasmodic activity: Supported by in vitro experimental pharmacology; no human clinical trial data.
• Traditional uses (fever, diarrhea, digestive tonic): Well-documented ethnobotanically but entirely unsupported by controlled clinical evidence.

As summarized by the available clinical reference literature, people use angostura for fever, diarrhea, spasms, preventing the return of malaria, and other conditions, but there is no good scientific evidence to support these uses.

References

• Houghton PJ, Woldemariam TZ, Watanabe Y, Yates M. Activity against Mycobacterium tuberculosis of alkaloid constituents of Angostura bark, Galipea officinalis. Planta Med. 1999;65(3):250–254. PubMed PMID: 10232071
• Jacquemond-Collet I, Benoit-Vical F, Valentin A, Stanislas E, Mallié M, Fourasté I. Antiplasmodial and cytotoxic activity of galipinine and other tetrahydroquinolines from Galipea officinalis. Planta Med. 2002;68(1):68–69. PubMed PMID: 11842332
• Jacquemond-Collet I et al. Alkaloids from Galipea officinalis. Planta Med. 2007;73(2). PubMed PMID: 17253322
• Frederich M et al. Metabolomic analysis of Strychnos nux-vomica, Strychnos icaja and Strychnos ignatii extracts by 1H nuclear magnetic resonance spectrometry and multivariate analysis techniques. Phytochemistry. 2004;65(13):1993–2001. ScienceDirect
• WebMD Natural Medicines. Angostura: Overview, Uses, Side Effects, Precautions, Interactions, Dosing. (Compiled from Therapeutic Research Center; sources cited include peer-reviewed references)
• King's American Dispensatory (Felter & Lloyd, 1898). Angustura — Angustura Bark. Henriette's Herbal Homepage (NLM Digital Collections)
• Fern K. Angostura trifoliata. Useful Tropical Plants Database. tropical.theferns.info. 2024
• Galipea officinalis. In: ScienceDirect Topics — Oxoglaucine (overview of Rutaceae alkaloids)
• U.S. FDA. Food Additive Status List (2022). "Angostura (cusparia bark) — ESO/SP, GRAS — 182.10 and 182.20." regulations.gov
• LegalClarity. FDA Natural Flavors List: What's Approved and Why. (Citing 21 CFR 172.510; angostura bark limited to beverages)
• Wikipedia. Angostura Bitters.
• Wikipedia. House of Angostura.
• Garg A, Deshpande A. Strychnine Toxicity. In: StatPearls. Treasure Island (FL): StatPearls Publishing; 2024. NCBI Bookshelf NBK459306
• ResearchGate: Jacquemond-Collet I et al. Antiplasmodial and Cytotoxic Activity of Galipinine and other Tetrahydroquinolines from Galipea officinalis. Planta Med. 2002
• ResearchGate: Preparation of Galipea officinalis Hancock type tetrahydroquinoline alkaloid analogues as anti-tumour agents
• U.S. National Library of Medicine (NLM Digital Collections). Angostura (Galipea officinalis, Angostura trifoliata) — historical pharmacopoeial texts including the Dispensatory of the United States of America and King's American Dispensatory