Buchu, also known as round leaf buchu, is a flowering evergreen shrub native to South Africa. The plant yields an essential oil that tastes similar to blackcurrant, which is used to flavor alcoholic beverages and candy confections. Buchu also is used in traditional medicine to treat disorders of the bladder and urinary tract. Topically, it is used to treat wounds, bruises, rheumatism and gout. Although buchu is approved for use in food in the U.S. and the E.U., buchu leaf is not necessarily safe in pregnancy because it contains a known hepatotoxin, meaning a chemical that damages the liver.
Herb Profile
Agathosma betulina, or buchu, is a member of the Rutaceae family, which includes the citrus genus. The herb has a long history of use by the Khoi people of the Western Cape Province in South Africa. Aside from minor cultivation in South Africa and western Australia, the wild-harvesting of buchu is largely limited to the Cape today. South Africa produces approximately 300 tons of buchu leaf each year, 250 of which are exported.
Chemical Composition
Buchu contains mucilage, resins, various flavonoids and sulfur compounds that lend the characteristic blackcurrant-like flavor. The essential oil of the plant contains limonene, terpinen-4-ol, isomenthone and diosphenol. Another main component of buchu is pulegone, a monoterpene also found in pennyroyal and peppermint that is associated with liver damage. It should be noted that some herbal preparations might contain A. crenulata, a closely related species of buchu that contains higher levels of pulegone.
Pharmacological Effects
Buchu is antiseptic, anti-inflammatory and diuretic, which means it increases urine output. The extract and essential oil are reputed to be antimicrobial and antispasmodic, but in a 2001 study published in the "Journal of Pharmacy and Pharmacology," the essential oils of both Agathosma betulina and A. crenulata reduced spasms in smooth muscle tissue taken from a guinea pig but failed to demonstrate significant antimicrobial activity. In terms of toxicity, ingestion of pulegone in small doses might cause vomiting with blood, abdominal pain, convulsions and liver damage. Large doses of this substance might produce fatal hepatic necrosis or renal failure.
Safety Precautions
Ingesting any herbal product during pregnancy without medical approval and close supervision might increase the risk of miscarriage or birth defects. In the case of buchu, the presence of pulegone makes the internal use of this herb during pregnancy potentially hazardous to mother and child. Even topical use of buchu oil while pregnant might pose a risk of systemic toxicity after absorption through the skin or entering the bloodstream.
References
- University of Pretoria: Agathosma Betulina
- International Centre for Science and High Technology: Agathosma Betulina (P.J. Bergius) Pillans
- Santa Cruz Biotechnology: MSDS: Pulegone
- "Journal of Pharmacy and Pharmacology"; Buchu (Agathosma betulina and A. crenulata, Rutaceae) Essential Oils: Their Pharmacological Action on Guinea-pig Ileum and Antimicrobial Activity on Microorganisms; M. Lis-Balchin; 2001
