Biomaterial Database

Toxicity studies of Usnea lichens containing (+/-)-usnic acid administered in feed to F344/N Nctr rats and B6C3F1/Nctr mice. 2022

Usnea lichens and purified usnic acids have been used historically in traditional herbal medicine as bactericidal and antimicrobial agents. Usnea lichens contain 1%-3% (+/-)-usnic acid and extracts of these lichens are currently marketed in the United States as herbal antimicrobial agents. (+/-)-Usnic acid exhibits membrane proton uncoupling activity, which not only forms the mechanistic basis of its bactericidal action, but also has provided a rationale for its use as a fat burning, weight-loss agent. Purified (+)-usnic acid has been marketed in the United States for this purpose either alone or in combination with other chemical agents. Use of some of these fat burning products that contain (+)-usnic acid has resulted in serious liver damage. This study investigated the potential toxicity of ground Usnea lichens containing (+/-)-usnic acid in male and female Fischer 344/N Nctr rats and B6C3F1/Nctr mice that were exposed via feed for 3 months. F344/N Nctr rats were administered 0, 30, 60, 120, 360, or 720 ppm in feed, while B6C3F1/Nctr mice were administered 0, 15, 30, 60, 180, or 360 ppm in feed. (Abstract Abridged).

UI	MeSH Term	Description	Entries
D008011	Lichens	Any of a group of plants formed by a symbiotic combination of a fungus with an algae or CYANOBACTERIA, and sometimes both. The fungal component makes up the bulk of the lichen and forms the basis for its name.	Lichen
D008297	Male		Males
D008815	Mice, Inbred Strains	Genetically identical individuals developed from brother and sister matings which have been carried out for twenty or more generations, or by parent x offspring matings carried out with certain restrictions. All animals within an inbred strain trace back to a common ancestor in the twentieth generation.	Inbred Mouse Strains,Inbred Strain of Mice,Inbred Strain of Mouse,Inbred Strains of Mice,Mouse, Inbred Strain,Inbred Mouse Strain,Mouse Inbred Strain,Mouse Inbred Strains,Mouse Strain, Inbred,Mouse Strains, Inbred,Strain, Inbred Mouse,Strains, Inbred Mouse
D011522	Protons	Stable elementary particles having the smallest known positive charge, found in the nuclei of all elements. The proton mass is less than that of a neutron. A proton is the nucleus of the light hydrogen atom, i.e., the hydrogen ion.	Hydrogen Ions,Hydrogen Ion,Ion, Hydrogen,Ions, Hydrogen,Proton
D011916	Rats, Inbred F344	An inbred strain of rat that is used for general BIOMEDICAL RESEARCH purposes.	Fischer Rats,Rats, Inbred CDF,Rats, Inbred Fischer 344,Rats, F344,Rats, Inbred Fisher 344,CDF Rat, Inbred,CDF Rats, Inbred,F344 Rat,F344 Rat, Inbred,F344 Rats,F344 Rats, Inbred,Inbred CDF Rat,Inbred CDF Rats,Inbred F344 Rat,Inbred F344 Rats,Rat, F344,Rat, Inbred CDF,Rat, Inbred F344,Rats, Fischer
D005260	Female		Females
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D001572	Benzofurans	Compounds that contain a BENZENE ring fused to a furan ring.	Coumarones,Diphenylbenzofuran
D051379	Mice	The common name for the genus Mus.	Mice, House,Mus,Mus musculus,Mice, Laboratory,Mouse,Mouse, House,Mouse, Laboratory,Mouse, Swiss,Mus domesticus,Mus musculus domesticus,Swiss Mice,House Mice,House Mouse,Laboratory Mice,Laboratory Mouse,Mice, Swiss,Swiss Mouse,domesticus, Mus musculus
D051381	Rats	The common name for the genus Rattus.	Rattus,Rats, Laboratory,Rats, Norway,Rattus norvegicus,Laboratory Rat,Laboratory Rats,Norway Rat,Norway Rats,Rat,Rat, Laboratory,Rat, Norway,norvegicus, Rattus