title: Oral quercetin supplementation hampers skeletal muscle adaptations in response to exercise training.
abstract: We aimed to test exercise-induced adaptations on skeletal muscle when quercetin is supplemented. Four groups of rats were tested: quercetin sedentary, quercetin exercised, placebo sedentary, and placebo exercised. Treadmill exercise training took place 5 days a week for 6 weeks. Quercetin groups were supplemented with quercetin, via gavage, on alternate days throughout the experimental period. Sirtuin 1 (SIRT1), peroxisome proliferator-activated receptor γ coactivator-1α mRNA levels, mitochondrial DNA (mtDNA) content, and citrate synthase (CS) activity were measured on quadriceps muscle. Redox status was also quantified by measuring muscle antioxidant enzymatic activity and oxidative damage product, such as protein carbonyl content (PCC). Quercetin supplementation increased oxidative damage in both exercised and sedentary rats by inducing higher amounts of PCC (P < 0.001). Quercetin supplementation caused higher catalase (P < 0.001) and superoxide dismutase (P < 0.05) activity in the non-exercised animals, but not when quercetin is supplemented during exercise. Quercetin supplementation increased SIRT1 expression, but when quercetin is supplemented during exercise, this effect is abolished (P < 0.001). The combination of exercise and quercetin supplementation caused lower (P < 0.05) mtDNA content and CS activity when compared with exercise alone. Quercetin supplementation during exercise provides a disadvantage to exercise-induced muscle adaptations.
authors.affiliation: Department of Health Sciences, University of Jaén, Jaén, Spain.
authors.forename: R A
authors.initials: RA
authors.lastname: Casuso
authors.forename: E J
authors.initials: EJ
authors.lastname: Martínez-López
authors.forename: N B
authors.initials: NB
authors.lastname: Nordsborg
authors.forename: F
authors.initials: F
authors.lastname: Hita-Contreras
authors.forename: R
authors.initials: R
authors.lastname: Martínez-Romero
authors.forename: A
authors.initials: A
authors.lastname: Cañuelo
authors.forename: A
authors.initials: A
authors.lastname: Martínez-Amat
mesh_terms: D000222:Adaptation, Physiological / Q000187:drug effects*; D000284:Administration, Oral; D000818:Animals; D000975:Antioxidants / Q000008:administration & dosage / Q000494:pharmacology*; D002374:Catalase / Q000378:metabolism; D002950:Citrate (si)-Synthase / Q000378:metabolism; D004272:DNA, Mitochondrial / Q000378:metabolism; D008297:Male; D000071248:Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; D010805:Physical Conditioning, Animal / Q000502:physiology*; D050050:Protein Carbonylation / Q000187:drug effects; D052097:Quadriceps Muscle / Q000187:drug effects* / Q000378:metabolism*; D011794:Quercetin / Q000008:administration & dosage / Q000494:pharmacology*; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D056564:Sirtuin 1 / Q000378:metabolism; D013482:Superoxide Dismutase / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics
chemical_list: D000975:Antioxidants; D004272:DNA, Mitochondrial; D000071248:Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; C501429:Ppargc1a protein, rat; D012333:RNA, Messenger; D014157:Transcription Factors; D011794:Quercetin; D002374:Catalase; D013482:Superoxide Dismutase; D002950:Citrate (si)-Synthase; D056564:Sirtuin 1
keywords: Flavonoids; PGC-1α; SIRT1; oxidative damage; training