The Effects of Dietary Flavonoid Supplementation on the Antioxidant Status of Laying Hens

Ninety-six 28-week-old Lohmann White laying hens were utilized to test the antioxidant effects of flavonoids (hesperidin, naringin, and quercetin at 0.5 g/kg diet) during an 8-wk experimental period. At the end of the experiment blood samples were collected to determine total protein, cholesterol, and malondialdehyde (MDA) serum levels as well as activities of glutathione reductase (GR), glutathione peroxidase (GSH-Px), glutathione-S-transferase (GST), and superoxide dismutase (SOD) and level of glutathione (GSH) in erythrocyte lysates. Data were analyzed using one-way ANOVA. Naringin supplementation did not alter serum cholesterol concentration, whereas hesperidin and quercetin supplementations decreased serum cholesterol concentration. Naringin and quercetin supplementations did not affect serum protein concentration. All flavonoids decreased MDA concentration as well as increased GSH-Px, GR, GST, and SOD activities and GSH level, being quercetion superior to hesperidin and naringin. In conclusion, flavonoids, especially quercetin, exert antioxidant activity, which may help improve wellbeing when laying hens are exposed to stressors.