title: In vitro evaluation of the antioxidant activity of liposomal flavonols by the HRP-H2O2-luminol system.
abstract: Considering that antioxidant flavonols have been reported to be beneficial to human health, but that their low water solubility and bioavailability limit their administration through systemic route, the development of suitable flavonol-carriers is of great importance for clinical therapeutics. The aim of this study was to prepare liposomes containing flavonols or not and evaluate their antioxidant activity. Vesicles were obtained by ethanol injection method and characterized in terms of entrapment efficiency, size and zeta potential. Inhibitory activity of liposomal flavonols on reactive oxygen species generation was assessed in vitro using luminol-H(2)O(2)-horseradish peroxidase technique. Antioxidant activity of liposomal flavonols is dependent on concentration and chemical structure of active compound. Quercetin and myricetin are the most active flavonols (IC(50) = 0.6-0.9 µmol/L), followed by kaempferol (IC(50) = 3.0-4.5 µmol/L) and galangin (IC(50) = 4.0-7.0 µmol/L). Our results suggest that antioxidant-loaded liposomes may be promising tools for therapy of diseases where oxidative stress is involved.
authors.affiliation: Departamento de Física e Química, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Monte Alegre, Ribeirão Preto, SP, Brazil. ana.landi@yahoo.com.br
authors.forename: Ana Paula
authors.initials: AP
authors.lastname: Landi-Librandi
authors.forename: Carlos Alberto
authors.initials: CA
authors.lastname: de Oliveira
authors.forename: Ana Elisa Caleiro Seixas
authors.initials: AE
authors.lastname: Azzolini
authors.forename: Luciana Mariko
authors.initials: LM
authors.lastname: Kabeya
authors.forename: José Orestes
authors.initials: JO
authors.lastname: Del Ciampo
authors.forename: Maria Vitória Lopes Badra
authors.initials: MV
authors.lastname: Bentley
authors.forename: Yara Maria
authors.initials: YM
authors.lastname: Lucisano-Valim
mesh_terms: D000975:Antioxidants / Q000737:chemistry*; D004353:Drug Evaluation, Preclinical; D044948:Flavonols / Q000737:chemistry*; D006735:Horseradish Peroxidase / Q000737:chemistry; D006801:Humans; D006861:Hydrogen Peroxide / Q000737:chemistry*; D008081:Liposomes; D008165:Luminol / Q000737:chemistry*
chemical_list: D000975:Antioxidants; D044948:Flavonols; D008081:Liposomes; D008165:Luminol; D006861:Hydrogen Peroxide; D006735:Horseradish Peroxidase