title: Evaluation of the in vivo antioxidative activity of redox nanoparticles by using a developing chicken egg as an alternative animal model.
abstract: Antioxidants have been demonstrated to exert beneficial effects as pharmacotherapies for cardiovascular diseases. The in vitro systems generally employed to evaluate antioxidants, however, are limited by having no appreciable in vivo redox status of the antioxidants. Therefore, we used our developing chicken egg model to evaluate the in vivo antioxidative activity of a redox nanoparticle possessing 2,2,6,6-tetramethylpiperidine-1-oxyl (RNP(O)). The 2,2'-azobis(2-methylpropionamidine) dihydrochloride (AAPH) elicited strong oxidative stress and its LD50 value for chick embryos was 3.5±0.9mg/egg. The low molecular weight nitroxide compound, 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPOL), which is known to have the highest level of antioxidant activity, showed no significant protective effect against AAPH-induced embryo lethality. On the contrary, RNP(O) had potent protective effects against AAPH-induced embryo lethality. Moreover, RNP(O) could significantly suppress the production of lipid peroxides in chick serum induced by hydrocortisone. Since RNP(O) has a longer retention time in blood than TEMPOL, RNP(O) may protect the embryo against lethal oxidative stress by suppressing lipid peroxidation. The validity of in vivo experiments using developing chicken eggs was supported by our data, where RNP(O) was determined to elicit strong antioxidative activity in vivo, irrespective of the lack of a significant difference in the in vitro activity between low-molecular weight TEMPOL and RNP(O). Our results support the use of the developing chicken egg model to evaluate the potential in vivo antioxidative activity of RNP(O).
authors.affiliation: Department of Life System, Institute of Technology and Science, Graduate School, The University of Tokushima, 2-1 Minamijosanjima-cho, Tokushima 770-8506, Japan.
authors.forename: Chiaki
authors.initials: C
authors.lastname: Abe
authors.affiliation: Department of Life System, Institute of Technology and Science, Graduate School, The University of Tokushima, 2-1 Minamijosanjima-cho, Tokushima 770-8506, Japan. Electronic address: uto@bio.tokushima-u.ac.jp.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Uto
authors.affiliation: Department of Life System, Institute of Technology and Science, Graduate School, The University of Tokushima, 2-1 Minamijosanjima-cho, Tokushima 770-8506, Japan.
authors.forename: Ayaka
authors.initials: A
authors.lastname: Kawasaki
authors.affiliation: Department of Life System, Institute of Technology and Science, Graduate School, The University of Tokushima, 2-1 Minamijosanjima-cho, Tokushima 770-8506, Japan.
authors.forename: Chiho
authors.initials: C
authors.lastname: Noguchi
authors.affiliation: Department of Life System, Institute of Technology and Science, Graduate School, The University of Tokushima, 2-1 Minamijosanjima-cho, Tokushima 770-8506, Japan.
authors.forename: Ryo
authors.initials: R
authors.lastname: Tanaka
authors.affiliation: Department of Materials Science, Graduate School of Pure and Applied Sciences, University of Tsukuba, Tennoudai 1-1-1, Tsukuba, Ibaraki 305-8573, Japan.
authors.forename: Toru
authors.initials: T
authors.lastname: Yoshitomi
authors.affiliation: Department of Materials Science, Graduate School of Pure and Applied Sciences, University of Tsukuba, Tennoudai 1-1-1, Tsukuba, Ibaraki 305-8573, Japan; Master's School of Medical Sciences, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tennoudai 1-1-1, Tsukuba, Ibaraki 305-8573, Japan; Satellite Laboratory, International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science (NIMS), University of Tsukuba, Tennoudai 1-1-1, Tsukuba, Ibaraki 305-8573, Japan.
authors.forename: Yukio
authors.initials: Y
authors.lastname: Nagasaki
authors.affiliation: Central Research Resource Branch, Cancer Research Institute, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan.
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Endo
authors.affiliation: Department of Life System, Institute of Technology and Science, Graduate School, The University of Tokushima, 2-1 Minamijosanjima-cho, Tokushima 770-8506, Japan.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Hori
mesh_terms: D000578:Amidines / Q000633:toxicity; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D001921:Brain / Q000187:drug effects / Q000378:metabolism; D002642:Chick Embryo; D003497:Cyclic N-Oxides / Q000494:pharmacology*; D006854:Hydrocortisone; D015227:Lipid Peroxidation / Q000187:drug effects; D008099:Liver / Q000187:drug effects / Q000378:metabolism; D023421:Models, Animal; D053758:Nanoparticles / Q000008:administration & dosage*; D016877:Oxidants / Q000633:toxicity; D010084:Oxidation-Reduction; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism
chemical_list: D000578:Amidines; D000975:Antioxidants; D003497:Cyclic N-Oxides; D016877:Oxidants; D017392:Thiobarbituric Acid Reactive Substances; C046728:2,2'-azobis(2-amidinopropane); C003959:TEMPO; D006854:Hydrocortisone
keywords: Developing chicken egg; In vivo; Redox nanoparticle; TEMPOL; antioxidative activity