Review of usnic acid and Usnea barbata toxicity.

Abstract

Usnic acid is a prominent secondary lichen metabolite that has been used for various purposes worldwide. Crude extracts of usnic acid or pure usnic acid have been marketed in the United States as dietary supplements to aid in weight loss. The US Food and Drug Administration (FDA) received 21 reports of liver toxicity related to the ingestion of dietary supplements that contain usnic acid. This prompted the FDA to issue a warning about one such supplement, LipoKinetix, in 2001 (http://www.cfsan.fda.gov/~dms/ds-lipo.html). Subsequently, usnic acid and Usnea barbata lichen were nominated by the National Toxicology Program (NTP) for toxicity evaluations. At present, a toxicological evaluation of usnic acid is being conducted by the NTP. This review focuses on the recent findings of usnic acid-induced toxicities and their underlying mechanisms of action.

• Authors: Lei Guo, Qiang Shi, Jia-Long Fang, Nan Mei, A Afshan Ali, Sherry M Lewis, Julian E A Leakey, Vasilios H Frankos
• Journal: Journal of environmental science and health. Part C, Environmental carcinogenesis & ecotoxicology reviews (J Environ Sci Health C Environ Carcinog Ecotoxicol Rev) 2008 Oct-Dec Vol. 26 Issue 4 Pg. 317-38 ISSN: 1532-4095 [Electronic] United States
• PMID: 19034791 (Publication Type: Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Review)

Chemical References

• Benzofurans
• Plant Extracts
• usnic acid

Topics

• Animals
• Benzofurans (chemistry, pharmacokinetics, pharmacology, toxicity)
• Humans
• Liver (drug effects)
• Mutagenicity Tests
• Plant Extracts (pharmacokinetics, pharmacology, toxicity)
• Usnea (chemistry)
• Weight Loss