title: Antioxidant, antimicrobial and antiproliferative activities of five lichen species.
abstract: The antioxidative, antimicrobial and antiproliferative potentials of the methanol extracts of the lichen species Parmelia sulcata, Flavoparmelia caperata, Evernia prunastri, Hypogymnia physodes and Cladonia foliacea were evaluated. The total phenolic content of the tested extracts varied from 78.12 to 141.59 mg of gallic acid equivalent (GA)/g of extract and the total flavonoid content from 20.14 to 44.43 mg of rutin equivalent (Ru)/g of extract. The antioxidant capacities of the lichen extracts were determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals scavenging. Hypogymnia physodes with the highest phenolic content showed the strongest DPPH radical scavenging effect. Further, the antimicrobial potential of the lichen extracts was determined by a microdilution method on 29 microorganisms, including 15 strains of bacteria, 10 species of filamentous fungi and 4 yeast species. A high antimicrobial activity of all the tested extracts was observed with more potent inhibitory effects on the growth of Gram (+) bacteria. The highest antimicrobial activity among lichens was demonstrated by Hypogymnia physodes and Cladonia foliacea. Finally, the antiproliferative activity of the lichen extracts was explored on the colon cancer adenocarcinoma cell line HCT-116 by MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) viability assay and acridine orange/ethidium bromide staining. The methanol extracts of Hypogymnia physodes and Cladonia foliacea showed a better cytotoxic activity than the other extracts. All lichen species showed the ability to induce apoptosis of HCT-116 cells.
authors.affiliation: Department of Biology and Ecology, Faculty of Science and Mathematics, University of Niš, 33, Višegradska, 18000 Niš, Serbia; E-Mails:  sslavisa@pmf.ni.ac.rs  (S.S.);  biovlada@yahoo.com  (V.C);  tosicsvetlana59@yahoo.com  (S.T.).
authors.forename: Tatjana
authors.initials: T
authors.lastname: Mitrović
authors.forename: Slaviša
authors.initials: S
authors.lastname: Stamenković
authors.forename: Vladimir
authors.initials: V
authors.lastname: Cvetković
authors.forename: Svetlana
authors.initials: S
authors.lastname: Tošić
authors.forename: Milan
authors.initials: M
authors.lastname: Stanković
authors.forename: Ivana
authors.initials: I
authors.lastname: Radojević
authors.forename: Olgica
authors.initials: O
authors.lastname: Stefanović
authors.forename: Ljiljana
authors.initials: L
authors.lastname: Comić
authors.forename: Dragana
authors.initials: D
authors.lastname: Dačić
authors.forename: Milena
authors.initials: M
authors.lastname: Curčić
authors.forename: Snežana
authors.initials: S
authors.lastname: Marković
mesh_terms: D000890:Anti-Infective Agents / Q000737:chemistry / Q000494:pharmacology*; D000975:Antioxidants / Q000737:chemistry / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D005419:Flavonoids / Q000737:chemistry / Q000494:pharmacology; D045325:HCT116 Cells; D006801:Humans; D020128:Inhibitory Concentration 50; D008011:Lichens / Q000737:chemistry*; D008826:Microbial Sensitivity Tests; D010636:Phenols / Q000737:chemistry / Q000494:pharmacology; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D000890:Anti-Infective Agents; D000975:Antioxidants; D005419:Flavonoids; D010636:Phenols; D010936:Plant Extracts