PORIMIN: The key to (+)-Usnic acid-induced liver toxicity and oncotic cell death in normal human L02 liver cells.

Ethnopharmacological Relevance: Usnic acid (UA) is one of the well-known lichen metabolites that induces liver injury. It is mainly extracted from Usnea longissima and U. diffracta in China or from other lichens in other countries.

Review: Usnic acid-induced hepatotoxicity and cell death.

Increasing prevalence of herbal and dietary supplement-induced hepatotoxicity has been reported worldwide. Usnic acid (UA) is a well-known hepatotoxin derived from lichens. Since 2000, more than 20 incident reports have been received by the US Food and Drug Administration after intake of UA containing dietary supplement resulting in severe complications.

Identification of photodegraded derivatives of usnic acid with improved toxicity profile and UVA/UVB protection in normal human L02 hepatocytes and epidermal melanocytes.

This study focused on the investigation of photodegradation of usnic acid (UA) which is a natural UV absorbing agent in lichens. Despite years of historical use in food supplement, traditional medicine or cosmetic products in many countries, liver toxicity has been found to be one of the severe and life threatening adverse effects in early 2000's. Such severe side effect has limited UA or its synthesized derivatives for further use clinically or commercially.

Simultaneous determination of usnic, diffractaic, evernic and barbatic acids in rat plasma by ultra-high-performance liquid chromatography-quadrupole exactive Orbitrap mass spectrometry and its application to pharmacokinetic studies.

Usnea longissima Ach. (Usnea) is used in pharmaceuticals, food and cosmetics. Evernic acid (EA), barbatic acid (BA), diffractaic acid (DA) and usnic acid (UA) are the most typical ingredients in U.