In the Amazon Rainforest, Amargo is used much like Quinine Bark, for malaria and fevers. It grows at lower elevations where Quinine Bark does not grow and contains many of the same antimalarial phytochemicals that Quinine contains. In addition, it is used as an insecticide, as a tonic, and for fevers and hepatitis. Brazilian Indians use the leaves in a bath for measles as well as a mouthwash after tooth extractions. Indians in Suriname use the bark for fever and parasites and Mark Plotkin reports that it is a potent aphidcide.

In Brazilian herbal medicine today, Amargo bark is considered tonic, stomachic, and aperitive; recommended for diarrhea, dysentery, dyspepsia, blennorhagia, intestinal gas, stomachaches, anemia, liver disorders, and gastrointestinal disorders. In herbal medicine in the U.S. and Europe, very little distinction is made between the two species of trees and they are used identically. It is reported to be used as bitter tonic for stomach and digestive problems, as a laxative, and as a amebicide and anthelminthic (via enema). The PDR for Herbal Medicine cites that Quassia bark stimulates secretion of gastric juices, increases appetite, aids in digestion and may have a choleretic effect. Herbalist David Hoffman recommends it as an excellent remedy in dyspeptic conditions, to stimulate production of saliva and digestive juices and to increase the appetite, as well as for lice infestations, and threadworms. He also reports "It may safely be used in all cases of lack of appetite such as anorexia nervosa and digestive sluggishness." Dr. James Duke reports that quassia is a folk remedy for carcinoma, debility, dyspepsia, fever, hepatosis, hyperglycemia, malaria, snakebite and spasms and the bark is considered to be aperitif, depurative, insecticidal, laxative, pediculicide, stomachic, tonic, and vermifuge.

Amargo bark contains many active constituents and phytochemicals, including bitter principles reported to be 50 times more bitter than quinine. While Amargo contains many of the same types of quassinoids as Quinine Bark, it also contain another chemical called quassin and Amargo has a bitterness rating of 40,000 due to the large amount of quassin in the bark and wood. Several of the quassinoids found in the bark have been documented with antineoplastic actions. A Japanese company filed a U.S. Patent in 1986 on the extraction of various quassinoids from Amargo as novel anti-ulcer agents. The bark also contains another phytochemical called quassimarin which has demonstrated antineoplastic, antileukemic, and antitumorous properties. Several earlier clinical studies were performed on Amargo which have demonstrated it to be effective as a treatment for head lice infestation (pediculosis). Then, in a 1991 double blind placebo trial on 148 children with headlice, those treated with an Amargo bark extract reported fewer numbers of new cases demonstrating a prophylactic activity against lice. Scientists at Texas Christian University demonstrated in 1996 that a water extract of Amargo had in vitro antiviral properties against MT-2-Lymphoblastoid cells infected with HIV. Researchers in India discovered its larvicidal activity against several types of insect including mosquitos. More recently, in 1997 scientists in Nigeria have documented that Amargo has in vivo antifertility effects; lowering sperm counts as well as testosterone levels in rats. Toxicity studies were performed on rats and mice which determined no signs of toxicity in oral dosages up to 1 gram per kilogram of bodyweight in 1997.

References/Footnotes:

• Rutter, R.A. 1990. Catalogo de Plantas Utiles de la Amazonia Peruana. Instituto Linguistico de Verano. Yarinacocha, Peru.
• Branch, L.C. and da Silva, I.M.F. 1983. "Folk Medicine of Alter do Chao, Para, Brazil." Acta Amazonica 13(5/6):737-797.
• Duke, James & Vasquez, Rudolfo, 1994 Amazonian Ethnobotanical Dictionary, CRC Press Inc.: Boca Raton, FL
• Plotkin, Mark, J., 1993. Tales of Shaman's Apprentice. Penguin Books, Middlesex, England
• Cruz, G.L. 1995. Dicionario Das Plantas Uteis Do Brasil, 5th ed., Bertrand: Rio de Janeiro, Brazil
• Coimbra, Raul, 1994. Manual de Fitoterapia 2nd Ed., Editora Cejup: Belem, Brazil.
• Lung. A. and Foster, S. 1996. Encyclopedia of Common Natural Ingredients, Wiley & Sons: New York, NY.
• Bartram, Thomas. 1995. Encyclopedia of Herbal Medicine. Grace Publishers: Dorset, England.
• Wichtl, M. 1994. Herbal Drugs and Phytopharmaceuticals, CRC Press: Boca Roton, FL
• Physicians' Desk Reference for Herbal Medicines, 2nd Ed., Medical Economics Company, Inc. Montvale, NJ, 2000
• Hoffman, David. 1991. The New Holistic Herbal, Element Books, Inc.: Rockport, MA.
• Duke, JA, CRC Handbook of Medicinal Herbs 1985. Ed. CRC Press Boca Raton, FL
• Tada, et.al., United States Patent 4,731,459 March 15, 1988
• Samuelsson, Gunnar. 1992. Drugs of Natural Origin, Swedish Pharmaceutical Press: Stockholm, Sweden.
• Kupchan SM, 1976 Quassimarin, a new antileukemic quassinoid from Quassia amara. J Org Chem 41(21), 3481-3482 (1976)
• Jensen O, 1979 Treatment of head lice with quassia tincture Ugeskr Laeger 141(4), 225-226 (1979)
• Jensen O, 1978 Pediculosis capitis treated with quassia tincture. Acta Derm Venereol 58(6), 557-559 (1978)
• Ninci ME, 1991 Prophylaxis and treatment of pediculosis with Quassia amarga Rev Fac Cien Med Univ Nac Cordoba 49(2), 27-31 (1991)
• Abdel-Malek, S., et.al., Drug Leads from the Kallawaya Herbalists of Bolivia. 1. Background, Rationale, Protocol and Anti-HIV Activity. J Ethnopharmacol 50 : 157-166 (1996)
• Evans, D. A., et.al., Extracts of Indian Plants as Mosquito Larvicides. Indian J Med Res 88 1: 38-41 (1988)
• Raji, Y. et.al., Antifertility Activity of Quassia amara in Male Rats - in Vivo Study. Life Sci 61 11: 1067-1074 (1997)
• Garcia Gonzalez M, et al. [Pharmacologic activity of the aqueous wood extract from Quassia amara (Simarubaceae) on albino rats and mice]. Rev Biol Trop. 1997 Mar;44-45:47-50.

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