Antioxidant and Cytotoxic Activities of <i>Usnea barbata</i> (L.) F.H. Wigg. Dry Extracts in Different Solvents
Violeta Popovici,
Laura Bucur,
Antoanela Popescu,
Verginica Schröder,
Teodor Costache,
Dan Rambu,
Iulia Elena Cucolea,
Cerasela Elena Gîrd,
Aureliana Caraiane,
Daniela Gherghel,
Gabriela Vochita,
Victoria Badea
Affiliations
Violeta Popovici
Department of Microbiology and Immunology, Faculty of Dental Medicine, Ovidius University of Constanta, 7 Ilarie Voronca Street, 900684 Constanta, Romania
Laura Bucur
Department of Pharmacognosy, Faculty of Pharmacy, Ovidius University of Constanta, 6 Capitan Al. Serbanescu Street, 900001 Constanta, Romania
Antoanela Popescu
Department of Pharmacognosy, Faculty of Pharmacy, Ovidius University of Constanta, 6 Capitan Al. Serbanescu Street, 900001 Constanta, Romania
Verginica Schröder
Department of Cellular and Molecular Biology, Faculty of Pharmacy, Ovidius University of Constanta, 6 Capitan Al. Serbanescu Street, 900001 Constanta, Romania
Teodor Costache
Research Center for Instrumental Analysis SCIENT, 1E Petre Ispirescu Street, 077167 Ilfov, Romania
Dan Rambu
Research Center for Instrumental Analysis SCIENT, 1E Petre Ispirescu Street, 077167 Ilfov, Romania
Iulia Elena Cucolea
Research Center for Instrumental Analysis SCIENT, 1E Petre Ispirescu Street, 077167 Ilfov, Romania
Cerasela Elena Gîrd
Department of Pharmacognosy, Phytochemistry, and Phytotherapy, Faculty of Pharmacy, Carol Davila University of Medicine and Pharmacy, 6 Traian Vuia Street, 020956 Bucharest, Romania
Aureliana Caraiane
Department of Oral Rehabilitation, Faculty of Dental Medicine, Ovidius University of Constanta, 7 Ilarie Voronca Street, 900684 Constanta, Romania
Daniela Gherghel
Institute of Biological Research Iasi, Branch of NIRDBS, 47 Lascar Catargi Street, 700107 Iasi, Romania
Gabriela Vochita
Institute of Biological Research Iasi, Branch of NIRDBS, 47 Lascar Catargi Street, 700107 Iasi, Romania
Victoria Badea
Department of Microbiology and Immunology, Faculty of Dental Medicine, Ovidius University of Constanta, 7 Ilarie Voronca Street, 900684 Constanta, Romania
Lichens represent a significant source of antioxidants due to numerous metabolites that can reduce free radicals. Usnea barbata (L.) F.H. Wigg. has been recognized and used since ancient times for its therapeutic effects, some of which are based on its antioxidant properties. The present study aims to analyze the phytochemical profile and to evaluate the antioxidant and cytotoxic potential of this lichen species. Five dry extracts of U. barbata (UBDE) in different solvents (acetone, ethyl acetate, ethanol, methanol, water) were prepared by refluxing at Soxhlet to achieve these proposed objectives and to identify which solvent is the most effective for the extraction. The usnic acid content (UAC) was quantified by ultra-high performance liquid chromatography (UHPLC). The total polyphenols content (TPC) and tannins content (TC) were evaluated by spectrophotometry, and the total polysaccharides (PSC) were extracted by a gravimetric method. The 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) free radical method was used to assess the antioxidant activity (AA) and the Brine Shrimp Lethality (BSL) assay was the biotest for cytotoxic activity evaluation. The ethyl acetate extract had the highest usnic acid content, and acetone extract had the highest content of total polyphenols and tannins. The most significant antioxidant effect was reported to methanol extract, and all the extracts proved high cytotoxicity. The water extract has the lowest cytotoxicity because usnic acid is slightly soluble in this solvent, and it was not found at UHPLC analysis. All extracts recorded a moderate correlation between the content of usnic acid, polyphenols, tannins, and AA; furthermore, it has been observed that the cytotoxicity varies inversely with the antioxidant effect.
