title: Spectrophotometric analysis of flavonoid-DNA interactions and DNA damaging/protecting and cytotoxic potential of flavonoids in human peripheral blood lymphocytes.
abstract: The ability of luteolin, kaempferol and apigenin to bind to calf thymus (ct)-DNA, mode of action and stability of flavonoids in buffer were investigated. Spectrophotometric analysis revealed a rapid degradation of apigenin in an aqueous medium, while kaempferol and luteolin were stable for 24h upon dissolution in water. Spectrophotometric study of the interactions of kaempferol and luteolin with calf thymus DNA suggests classic intercalation as their dominant binding mode to DNA. Cytotoxicity/genotoxicity and cytoprotective/genoprotective effects of flavonoids in non-stressed and hydrogen peroxide stressed human peripheral lymphocytes were investigated using the fluorescent dye exclusion method and alkaline comet assay. Flavonoids revealed significant genoprotective effects in hydrogen peroxide stressed cells and in cells submitted to longer incubation in the cell culture medium. Luteolin, followed by apigenin and kaempferol, was shown to be the most effective in protecting DNA from oxidative damage induced by hydrogen peroxide. However, the investigated flavonoids also induced DNA damage, indicating their prooxidative capacity. The balance between the protection of DNA from oxidative damage and prooxidative effects was strongly dependent on flavonoid concentration and the incubation period.
authors.affiliation: Faculty of Science, University of Zagreb, Zagreb, Croatia. gordana@botanic.hr
authors.forename: Gordana
authors.initials: G
authors.lastname: Rusak
authors.forename: Ivo
authors.initials: I
authors.lastname: Piantanida
authors.forename: Lozika
authors.initials: L
authors.lastname: Masić
authors.forename: Katarina
authors.initials: K
authors.lastname: Kapuralin
authors.forename: Ksenija
authors.initials: K
authors.lastname: Durgo
authors.forename: Nevenka
authors.initials: N
authors.lastname: Kopjar
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D002417:Cattle; D004247:DNA / Q000187:drug effects*; D004249:DNA Damage; D005419:Flavonoids / Q000494:pharmacology*; D006801:Humans; D008214:Lymphocytes / Q000187:drug effects* / Q000378:metabolism
chemical_list: D005419:Flavonoids; D004247:DNA