title: Isoflavin-β modifies muscle oxidative stress and prevents a thyrotoxicosis-induced loss of muscle mass in rats.
abstract: BACKGROUND
  We sought to verify whether isoflavin-beta (Iso-β), a mixture of isoflavones with antioxidant properties, could prevent thyrotoxicosis-induced loss of muscle mass and the participation of oxidative stress (OS) in the mechanisms of this prevention.
  
  
  METHODS
  Two experimental periods of thyrotoxicosis induction were used in Wistar rats: 3 and 5 days to assess Iso-β effects before and after thyrotoxicosis-induced muscle wasting. After euthanasia, peritoneal fat and gastrocnemius muscle were collected, weighed, and muscle OS was assessed.
  
  
  RESULTS
  Iso-β prevented the loss of gastrocnemius mass in thyrotoxic rats through the prevention of muscle OS generation during thyrotoxicosis, increasing muscle total antioxidant capacity and decreasing mitochondrial cytochrome c oxidase activity, lipid peroxidation, and protein carbonyl content.
  
  
  CONCLUSIONS
  Iso-β decreased oxidative modification of proteins, which is known to exert a major role during proteolysis induction and is present in thyrotoxic myopathy, highlighting the potential action of Iso-β in this complication of the disease. Muscle Nerve 56: 975-981, 2017.
authors.affiliation: Laboratory of Molecular Pathology, State University of Londrina, Rodovia Celso Garcia Cid, PR445, Km 380 Campus Universitário, Londrina, CEP 86051-990, Paraná, Brazil.
authors.forename: Poliana C
authors.initials: PC
authors.lastname: Marinello
authors.affiliation: Laboratory of Molecular Pathology, State University of Londrina, Rodovia Celso Garcia Cid, PR445, Km 380 Campus Universitário, Londrina, CEP 86051-990, Paraná, Brazil.
authors.forename: Sara S
authors.initials: SS
authors.lastname: Bernardes
authors.affiliation: Laboratory of Pathophysiology and Muscle Adaptation, State University of Londrina, Londrina, Paraná, Brazil.
authors.forename: Flávia A
authors.initials: FA
authors.lastname: Guarnier
authors.affiliation: Laboratory of Pathophysiology and Muscle Adaptation, State University of Londrina, Londrina, Paraná, Brazil.
authors.forename: Thamara N X
authors.initials: TNX
authors.lastname: Da Silva
authors.affiliation: Laboratory of Pathophysiology and Free Radicals, State University of Londrina, Londrina, Paraná, Brazil.
authors.forename: Fernando H
authors.initials: FH
authors.lastname: Borges
authors.affiliation: Laboratory of Molecular Pathology, State University of Londrina, Rodovia Celso Garcia Cid, PR445, Km 380 Campus Universitário, Londrina, CEP 86051-990, Paraná, Brazil.
authors.forename: Natália M D
authors.initials: NMD
authors.lastname: Lopes
authors.affiliation: Department of Pathology, Clinical and Toxicological Analysis, University Hospital of State University of Londrina, Londrina, Paraná, Brazil.
authors.forename: Andréa N C
authors.initials: ANC
authors.lastname: Simão
authors.affiliation: Department of Surgery, University Hospital of State University of Londrina, Londrina, Paraná, Brazil.
authors.forename: André
authors.initials: A
authors.lastname: Armani
authors.affiliation: Laboratory of Pathophysiology and Free Radicals, State University of Londrina, Londrina, Paraná, Brazil.
authors.forename: Rubens
authors.initials: R
authors.lastname: Cecchini
authors.affiliation: Laboratory of Molecular Pathology, State University of Londrina, Rodovia Celso Garcia Cid, PR445, Km 380 Campus Universitário, Londrina, CEP 86051-990, Paraná, Brazil.
authors.forename: Alessandra L
authors.initials: AL
authors.lastname: Cecchini
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology / Q000627:therapeutic use*; D002918:Chymotrypsin / Q000378:metabolism; D003511:Cyclohexanols / Q000097:blood / Q000633:toxicity; D004195:Disease Models, Animal; D004334:Drug Administration Schedule; D003576:Electron Transport Complex IV / Q000378:metabolism; D005990:Glycerol / Q000097:blood; D007529:Isoflavones / Q000494:pharmacology / Q000627:therapeutic use*; D008297:Male; D018482:Muscle, Skeletal / Q000187:drug effects / Q000473:pathology; D009133:Muscular Atrophy; D018384:Oxidative Stress / Q000187:drug effects*; D050050:Protein Carbonylation / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar; D013482:Superoxide Dismutase / Q000378:metabolism; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism; D013971:Thyrotoxicosis / Q000097:blood / Q000139:chemically induced / Q000473:pathology* / Q000517:prevention & control*; D020122:tert-Butylhydroperoxide / Q000378:metabolism
chemical_list: D000975:Antioxidants; D003511:Cyclohexanols; D007529:Isoflavones; D017392:Thiobarbituric Acid Reactive Substances; C037269:3,3,5-trimethylcyclohexanol; D020122:tert-Butylhydroperoxide; D013482:Superoxide Dismutase; D003576:Electron Transport Complex IV; D002918:Chymotrypsin; D005990:Glycerol
keywords: isoflavin-β; isoflavones; muscle proteolysis; myopathy; thyrotoxicosis