title: In vitro study on the antioxidant activity of a polyphenol-rich extract from Pinus brutia bark and its fractions.
abstract: A crude hydromethanolic extract from Pinus brutia bark and its fractions (diethyl ether, ethyl acetate, n-butanol, and aqueous fractions) were studied with regard to their phenolic content and antioxidant activities. The total phenolics and proanthocyanidins in each extract were quantified by spectrophotometric methods; the polyphenolic profile was analyzed by RP-HPLC-DAD-ESI-MS. All extracts were tested with regard to their ability to scavenge free radicals (ABTS radical cation, superoxide and hydroxyl radicals), reduce ferric ions, and inhibit 15-lipoxygenase. P. brutia bark extracts had high phenolic contents (303.79±7.34-448.90±1.39 mg/g). Except diethyl ether extract, all other extracts contained proanthocyanidins ranging from 225.79±3.94 to 250.40±1.44 mg/g. Several polyphenols were identified by RP-HPLC-DAD-ESI-MS: taxifolin in diethyl ether extract, a taxifolin-O-hexoside, catechin, procyanidin dimers, and trimers in ethyl acetate extract. Except diethyl ether extract, all other extracts were effective scavengers of superoxide and hydroxyl radicals (EC₅₀=33.5±1.1-54.93±2.85 μg/mL and 0.47±0.06-0.6±0.0 mg/mL, respectively). All extracts had noticeable 15-lipoxygenase inhibitory effects (EC₅₀=22.47±0.75-34.43±2.25 μg/mL). We conclude that P. brutia bark is very promising for the dietary supplements industry due to its high free radical scavenging and 15-lipoxygenase inhibitory effects.
authors.affiliation: 1 Department of Pharmacognosy, University of Medicine and Pharmacy "Gr. T. Popa" Iasi , Iasi, Romania .
authors.forename: Elena
authors.initials: E
authors.lastname: Cretu
authors.forename: Maarit
authors.initials: M
authors.lastname: Karonen
authors.forename: Juha-Pekka
authors.initials: JP
authors.lastname: Salminen
authors.forename: Cornelia
authors.initials: C
authors.lastname: Mircea
authors.forename: Adriana
authors.initials: A
authors.lastname: Trifan
authors.forename: Christiana
authors.initials: C
authors.lastname: Charalambous
authors.forename: Andreas I
authors.initials: AI
authors.lastname: Constantinou
authors.forename: Anca
authors.initials: A
authors.lastname: Miron
mesh_terms: D000975:Antioxidants / Q000032:analysis / Q000494:pharmacology*; D001093:Arachidonate 15-Lipoxygenase / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000032:analysis / Q000494:pharmacology*; D005609:Free Radicals / Q000378:metabolism*; D028223:Pinus / Q000737:chemistry*; D024301:Plant Bark / Q000737:chemistry; D010936:Plant Extracts / Q000494:pharmacology*; D059808:Polyphenols / Q000032:analysis / Q000494:pharmacology*
chemical_list: D000975:Antioxidants; D004791:Enzyme Inhibitors; D005609:Free Radicals; D010936:Plant Extracts; D059808:Polyphenols; D001093:Arachidonate 15-Lipoxygenase