IMBIV   05474
INSTITUTO MULTIDISCIPLINARIO DE BIOLOGIA VEGETAL
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Argentine lichen extracts: determination of usnic acid and anticandidal activity
Autor/es:
GALLERANO LUCIANO; CABRERA JOSE L.; LOMBARDO CARAMELO ANDREA; OVIEDO XIOMARA; PERALTA MARIANA A; CABRAL PEREZ MATÍAS; GONZALEZ ANDREA
Lugar:
Capital Federal
Reunión:
Congreso; 8TH INTERNATIONAL PHYTOCOSMETICS & PHYTOTHERAPY CONGRESS; 2018
Institución organizadora:
International Society for Phytocosmetic Science (ISPS)
Resumen:
Introduction. The lichen genus Usnea (Usneaceae) in Argentina has widespread use in traditional medicine as expectorant and antimicrobial. (+)-Usnic acid (UA), one of the most common metabolites in this genus, has been reported as antimicrobial, antifungal and it is widely used in cosmetic formulations. Despite of the extensive use of UA, the lichen species from Argentina have not been explored in relation to the presence and content of AU nor their antifungal potential against resistant C. albicans strains. The aim of this work was to perform chemical and biological studies about two Argentine lichen species in order to determine the presence of UA in their extracts and evaluate their antifungal properties against azole-resistant (RCa) and azole sensitive (SCa) C. albicans strains.Materials and Methods. The ethanolic extracts of U. columbiana Motyka y Protousnea magellanica (Mont.) Krog were obtained. Their antifungal properties on SCa and RCa, were studied in vitro according to CLSI guidelines. Minimal inhibitory concentration (MIC) was defined as the minimal concentration that exerted a 50% or more of absorbance reduction, measured at 540 nm, with respect to the control. Chromatographic (TLC) and spectrophotometric methods were used in order to determine the presence of UA in the lichen extracts.Results and discussion. Our results showed that P. magellanica extract was the most active against both C. albicans strains, with MICs of 512 µg/ml and 1024 µg/ml for SCa and RCa, respectively. While U. columbiana was less active, achieving inhibitions of growth under the 50% with respect to the control, at the higher concentration tested (1024 µg/ml) in both strains. The chemical studies showed that the lichen U. columbiana, presented a higher percentage of dried extract yield than P. magellanica (19.33% vs 9.39%, respectively). The presence of AU in the ethanolic extracts of both species was determined by means of TLC and UV-V spectrophotometry.Conclusions. Our findings have a double impact, on the one hand it is observed that the extracts of U. columbiana and P. magellanica from Argentina, could be studied as phytoingredients in cosmetics and as sources of UA. On the other hand, the antifungal activity of P. magellanica against C. albicans resistant to therapies of clinical use, provide a pharmacological potential for its use as a phytotherapeutic that deserves more studies.Keywords: Argentine lichen; usnic acid; azole-resistant Candida albicans inhibition