Extraction, Characterization and Biological Activities of Selected Lichens Growing in Serbia

This study presents a comparative analysis of secondary metabolites and antioxidant, antimicrobial, and anticancer activities of acetone extracts obtained from the lichens <i>Lepraria incana</i> and <i>Pertusaria amara</i>. HPLC-UV analysis identified divaric acid, divaricatinic acid, norstictic acid, divaricatic acid and usnic acid in <i>L. incana</i>, and conprotocetraric acid, protocetraric acid, picrolichenic acid and atranorin in <i>P. amara</i>. Free radical scavenging capacity and reducing power assays were employed to assess the antioxidant activity of the extracts. The IC₅₀ values in the free radical scavenging assay were 664.23 μg/mL for <i>L. incana</i> and 750.50 μg/mL for <i>P. amara</i>, while reducing power absorbances varied between 0.0875-0.2562 and 0.0336-0.2011, respectively. Total phenolic contents in <i>L. incana</i> and <i>P. amara</i> extracts were 40.81 and 33.67 μg PE/mg of extract, while total flavonoid contents were 24.74 and 23.61 μg RE/mg of extract, respectively. Antimicrobial activity, determined by the microdilution method, ranged from 156 to 20 × 10³ μg/mL for <i>L. incana</i> and from 312 to 20 × 10³ μg/mL for <i>P. amara</i>. Cytotoxicity was tested using the MTT method. Among the tested samples, the <i>L. incana</i> extract showed the strongest cytotoxic activity toward A549 cells, with an IC₅₀ value of 47.53 μg/mL. Based on the results, the lichens examined demonstrate promise for future studies and potential development in biopharmaceutical applications.