title: Dietary flavonoids advance timing of moult but do not affect redox status of juvenile blackbirds (Turdus merula).
abstract: Flavonoids are the most abundant plant polyphenols, widely occurring in fruits and berries, and show a strong antioxidant activity in vitro Studies of avian species feeding on berries suggest that dietary flavonoids have health-promoting effects and may enhance the expression of melanin-based plumage traits. These effects are probably mediated by the antioxidant activity of flavonoids. However, the effect of dietary flavonoids on oxidative status has never been investigated in any bird species. We analysed the effects of dietary flavonoids on blood non-enzymatic antioxidants and protein oxidative damage of juvenile European blackbirds (Turdus merula). In addition, we analysed the effects of flavonoid-enriched diet on body condition and on the timing of moult from juvenile to adult plumage. Dietary flavonoids did not significantly affect redox status but significantly advanced the onset of moult, hastening plumage development. Moulting birds showed higher protein oxidative damage compared with those that had not yet started moulting. The probability of initiating moult after 40 days of dietary treatment was higher for birds with low circulating levels of oxidizing agents and high glutathione concentration. The metabolization of flavonoids could have altered their redox potential, resulting in no net effects on redox status. However, flavonoid consumption before and during moult may contribute to enhance plumage development. Moreover, our findings suggest that moulting feathers may result in redox imbalance. Given their effect on moult and growth of melanin-rich feathers, fruit flavonoids may have contributed to shape plant fruiting time in relation to fruit consumption preferences by birds.
authors.affiliation: ISPRA - Istituto Superiore per la Protezione e la Ricerca Ambientale, Via Cà Fornacetta 9, Ozzano dell'Emilia (BO) I-40064, Italy jacopo.cecere@isprambiente.it diego.rubolini@unimi.it.
authors.forename: Jacopo G
authors.identifier: 0000-0002-4925-2730
authors.initials: JG
authors.lastname: Cecere
authors.affiliation: Dipartimento di Bioscienze, Università degli Studi di Milano, via Celoria 26, Milan I-20133, Italy.
authors.forename: Manuela
authors.initials: M
authors.lastname: Caprioli
authors.affiliation: ISPRA - Istituto Superiore per la Protezione e la Ricerca Ambientale, Via Cà Fornacetta 9, Ozzano dell'Emilia (BO) I-40064, Italy.
authors.forename: Chiara
authors.initials: C
authors.lastname: Carnevali
authors.affiliation: Dipartimento di Bioscienze, Università degli Studi di Milano, via Celoria 26, Milan I-20133, Italy.
authors.forename: Graziano
authors.initials: G
authors.lastname: Colombo
authors.affiliation: Dipartimento di Bioscienze, Università degli Studi di Milano, via Celoria 26, Milan I-20133, Italy.
authors.forename: Isabella
authors.initials: I
authors.lastname: Dalle-Donne
authors.affiliation: ISPRA - Istituto Superiore per la Protezione e la Ricerca Ambientale, Via Cà Fornacetta 9, Ozzano dell'Emilia (BO) I-40064, Italy.
authors.forename: Elisa
authors.initials: E
authors.lastname: Mancuso
authors.affiliation: Dipartimento di Bioscienze, Università degli Studi di Milano, via Celoria 26, Milan I-20133, Italy.
authors.forename: Aldo
authors.initials: A
authors.lastname: Milzani
authors.affiliation: Dipartimento di Bioscienze, Università degli Studi di Milano, via Celoria 26, Milan I-20133, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Parolini
authors.affiliation: ISPRA - Istituto Superiore per la Protezione e la Ricerca Ambientale, Via Cà Fornacetta 9, Ozzano dell'Emilia (BO) I-40064, Italy.
authors.forename: Antea
authors.initials: A
authors.lastname: Portanova
authors.affiliation: Dipartimento di Bioscienze, Università degli Studi di Milano, via Celoria 26, Milan I-20133, Italy.
authors.forename: Nicola
authors.initials: N
authors.lastname: Saino
authors.affiliation: ISPRA - Istituto Superiore per la Protezione e la Ricerca Ambientale, Via Cà Fornacetta 9, Ozzano dell'Emilia (BO) I-40064, Italy.
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Serra
authors.affiliation: Dipartimento di Bioscienze, Università degli Studi di Milano, via Celoria 26, Milan I-20133, Italy jacopo.cecere@isprambiente.it diego.rubolini@unimi.it.
authors.forename: Diego
authors.initials: D
authors.lastname: Rubolini
mesh_terms: D000818:Animals; D004032:Diet; D005419:Flavonoids / Q000494:pharmacology*; D005978:Glutathione / Q000378:metabolism; D008954:Models, Biological; D018978:Molting / Q000187:drug effects*; D016877:Oxidants / Q000378:metabolism; D010084:Oxidation-Reduction / Q000187:drug effects; D046109:Passeriformes / Q000254:growth & development*; D013438:Sulfhydryl Compounds / Q000378:metabolism
chemical_list: D005419:Flavonoids; D016877:Oxidants; D013438:Sulfhydryl Compounds; D005978:Glutathione
keywords: Anthocyanins; Antioxidants; Berries; Feather replacement; Melanogenesis; Oxidative stress