title: Antiradical and cytotoxic activity of different Helichrysum plicatum flower extracts.
abstract: Flowers of Helichrysum plicatum were extracted under different experimental conditions, and their antioxidant activity was determined by DPPH radical scavenging assay. Extracts obtained with higher concentration of ethyl acetate (90% or 100%) were found to contain the greatest amount of total phenolics (> 250 mg gallic acid equivalents/g of dried extract), and high correlation between total phenolic content and antiradical activity was observed (r = -0.79). Based on the total phenolic content and antiradical activity, some extracts were selected for investigation of cytotoxic activity toward PC3, HeLa and K562 human cancer cell lines in vitro. All tested extracts exhibited moderate activity against HeLa cells (41.9-42.1 microg/mL), whereas the extract obtained with 100% ethyl acetate was the most active against K562 and PC3 cell lines (25.9 and 39.2 microg/mL, respectively). Statistical analysis revealed significant correlation between total phenolic content and cytotoxic activity against PC3 and K562 cells. HPLC identification of phenolic compounds from the extracts indicated the presence of apigenin, naringenin and kaempferol as free aglycones, and glycosides of apigenin, naringenin, quercetin and kaempferol. Among aglycones, kaempferol displayed moderate cytostatic activity against all cell lines (24.8-64.7 microM).
authors.affiliation: Institute for Medicinal Plant Research "Dr Josif Pancić", Tadeusa Kosćuska 1, Belgrade, Serbia.
authors.forename: Dubravka
authors.initials: D
authors.lastname: Bigović
authors.forename: Katarina
authors.initials: K
authors.lastname: Savikin
authors.forename: Teodora
authors.initials: T
authors.lastname: Janković
authors.forename: Nebojsa
authors.initials: N
authors.lastname: Menković
authors.forename: Gordana
authors.initials: G
authors.lastname: Zdunić
authors.forename: Tatjana
authors.initials: T
authors.lastname: Stanojković
authors.forename: Zorica
authors.initials: Z
authors.lastname: Djurić
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000737:chemistry / Q000494:pharmacology*; D045744:Cell Line, Tumor; D035264:Flowers / Q000737:chemistry*; D036562:Helichrysum / Q000737:chemistry*; D006801:Humans; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D010936:Plant Extracts