title: Protective effects of three extracts from Antarctic plants against ultraviolet radiation in several biological models.
abstract: The photoprotective effect of the methanolic extracts of three Antarctic plant species - Deschampsia antarctica Desv., Colobanthus quitensis (Kunth) Bartl., and Polytrichum juniperinum Hedw. against UV-induced DNA damage was investigated in hamster lung fibroblasts (V79 cells) and in a biomonitor organism Helix aspersas, using comet assay. The protective, mutagenic, and antimutagenic profiles of these extracts were also evaluated using haploid strains of the simple eukaryote Saccharomyces cerevisiae, and antioxidant activity were investigated using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging assay, as well as the hypoxanthine/xanthine oxidase assay. At the concentration range employed, the extracts were not cytotoxic or mutagenic to S. cerevisiae. In addition, the treatment with these extracts enhanced survival, and decreased induced reverse, frameshift, and forward mutations in a dose-response manner in all UVC doses employed. The plants extracts did not generate DNA strand breaks in V79 cells, and the treatment significantly decreased DNA damage induced by UVC. Extracts significantly decreased UVC-induced lipid peroxidation in V79 cells, showing a clear antioxidant property. Moreover, results of comet assay in V79 cells, employing Fpg, Endo III, and Endo V enzymes, demonstrated significant reduction of UVC-induced DNA damage after pre-incubation with these extracts. The treatment with all tested extracts were much less efficient against UVC-induced cytotoxicity in the yeast strain defective in photolyase as compared to the wild type strain, suggesting that this DNA repair pathway is stimulated by substances present in the extracts. All extracts showed a significant inhibitory effect in the hypoxanthine/xanthine oxidase assay, and they had the ability to scavenge DPPH. In H. aspersas, the treatment was able to protect against UVC-induced damage. In conclusion, D. antarctica, C. quitensis, and P. juniperinum extracts present photoprotective properties, which can be attributed to molecules, such as flavonoids and carotenoids, which act as UV-absorbing molecules and as antioxidants, as well as stimulate DNA-repair processes.
authors.affiliation: Centro de Biotecnologia e Departamento de Biofísica, Universidade Federal do Rio Grande do Sul, Rio Grande do Sul, Brazil.
authors.forename: Betina Kappel
authors.initials: BK
authors.lastname: Pereira
authors.forename: Renato Moreira
authors.initials: RM
authors.lastname: Rosa
authors.forename: Juliana
authors.initials: J
authors.lastname: da Silva
authors.forename: Temenouga Nikolova
authors.initials: TN
authors.lastname: Guecheva
authors.forename: Iuri Marques de
authors.initials: IM
authors.lastname: Oliveira
authors.forename: Martus
authors.initials: M
authors.lastname: Ianistcki
authors.forename: Vinícius Cosmos
authors.initials: VC
authors.lastname: Benvegnú
authors.forename: Gabriel Vasata
authors.initials: GV
authors.lastname: Furtado
authors.forename: Alexandre
authors.initials: A
authors.lastname: Ferraz
authors.forename: Marc François
authors.initials: MF
authors.lastname: Richter
authors.forename: Nádia
authors.initials: N
authors.lastname: Schroder
authors.forename: Antônio Batista
authors.initials: AB
authors.lastname: Pereira
authors.forename: João Antonio Pêgas
authors.initials: JA
authors.lastname: Henriques
mesh_terms: D000818:Animals; D000864:Antarctic Regions; D002460:Cell Line; D002478:Cells, Cultured; D006224:Cricetinae; D004249:DNA Damage / Q000187:drug effects* / Q000528:radiation effects; D006372:Helix, Snails; D008954:Models, Biological; D010936:Plant Extracts / Q000494:pharmacology*; D014466:Ultraviolet Rays
chemical_list: D010936:Plant Extracts