title: Biological activities of undescribed North American lichen species.
abstract: BACKGROUND
  Lichens provide a large array of compounds with the potential for pharmaceutical development. In the present study, extracts from three previously undescribed North American lichen species were examined for antioxidant, antibacterial and anticancer activities.
  
  
  RESULTS
  The results from this study demonstrated the following: (i) Acarospora socialis ethanol extract exhibited significant DPPH antioxidant scavenging activities, which were concentration dependent; (ii) acetone and ethyl acetate extracts of Xanthoparmelia mexicana inhibited Gram-positive bacteria but had no effect on Gram-negative bacteria; X. mexicana acetone extract yielded a minimum inhibitory concentration (MIC) of 20.9 µg mL-1against Staphylococcus aureus, and 41.9 µg mL-1against Enterococcus faecalis; (iii) acetone extract of Lobothallia alphoplaca inhibited growth of cultured breast cancer MCF-7 cells with an effective concentration (EC50) of 87 µg mL-1; the MCF-7 cell cycle appears arrested in the G2 phase, whereas the DNA synthesis cell cycle (S) may be inhibited.
  
  
  CONCLUSIONS
  New lichen species that possess strong biological activities have been identified. These lichens comprise secondary metabolites that possess antioxidant, antibacterial and anticancer properties. © 2017 Society of Chemical Industry.
authors.affiliation: South Dakota School of Mines and Technology, Rapid City, SD, USA.
authors.forename: Erik A
authors.initials: EA
authors.lastname: Yeash
authors.affiliation: Department of Biology, Lakehead University, Thunder Bay, ON, Canada.|Biorefining Research Institute, Lakehead University, Thunder Bay, ON, Canada.
authors.forename: Lyndon
authors.initials: L
authors.lastname: Letwin
authors.affiliation: Department of Biology, Lakehead University, Thunder Bay, ON, Canada.|Biorefining Research Institute, Lakehead University, Thunder Bay, ON, Canada.
authors.forename: Lada
authors.initials: L
authors.lastname: Malek
authors.affiliation: Department of Biology, Lakehead University, Thunder Bay, ON, Canada.|Biorefining Research Institute, Lakehead University, Thunder Bay, ON, Canada.|Northern Ontario School of Medicine, Lakehead University, Thunder Bay, ON, Canada.
authors.forename: Zacharias
authors.initials: Z
authors.lastname: Suntres
authors.affiliation: University of Life Sciences, Prague, Czech Republic.
authors.forename: Kerry
authors.initials: K
authors.lastname: Knudsen
authors.affiliation: South Dakota School of Mines and Technology, Rapid City, SD, USA.
authors.forename: Lew P
authors.initials: LP
authors.lastname: Christopher
mesh_terms: D000900:Anti-Bacterial Agents / Q000032:analysis / Q000494:pharmacology*; D000970:Antineoplastic Agents / Q000032:analysis / Q000494:pharmacology*; D000975:Antioxidants / Q000032:analysis / Q000494:pharmacology*; D049109:Cell Proliferation / Q000187:drug effects; D006090:Gram-Negative Bacteria / Q000187:drug effects; D006094:Gram-Positive Bacteria / Q000187:drug effects; D006801:Humans; D008011:Lichens / Q000737:chemistry* / Q000378:metabolism; D061986:MCF-7 Cells; D009656:North America; D010936:Plant Extracts / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D000970:Antineoplastic Agents; D000975:Antioxidants; D010936:Plant Extracts
keywords: Acarospora socialis; Lobothallia alphoplaca; North America; Xanthoparmelia mexicana; biological activities; lichens