In-vitro antifungal and antibacterial activity of the ethanolic extract of Usnea laevis against Candida albicans, Staphylococcus aureus and Pseudomonas aeruginosa

Abstract

Lichens are symbiotic associations between fungi and seaweed or cyanobacteria. Objective: to evaluate the in-vitro antifungal and antibacterial activity of the ethanolic extract of Usnea laevis against Candida albicans, Staphylococcus aureus and Pseudomonas aeruginosa. Methods: lichened substances present in Usnea laevis were extracted using the Soxhlet methods and were analyzed by chromatography coupled to mass spectrometry. The Kirby-Bauer method was used to evaluate both the antibacterial and antifungal activity. Results: Usnic acid, eugenol, and ergosterol were the compounds found. S. aureus was sensitive at a concentration of 27 mg/ml of the enolic extract, the 11 mg/ml concentration was not effective. Conclusions: The ethanolic extract of Usnea laevis has antibacterial and antifungal properties against the pathogens tested.