Protective effects of quercetin on LPS-induced liver injury in quails

Quercetin, a natural flavonoid with antioxidant and anti-inflammatory activities, shows promise as a feed additive that reduces antibiotic use and enhances animal production and organ health. This study investigated the protective effects of dietary quercetin against lipopolysaccharide (LPS)-induced liver injury in quail and screened for its optimal dietary concentration. Quails were fed a basal diet supplemented with different concentrations of quercetin (0.02 %, 0.04 %, and 0.08 %). Liver injury was then induced via an intraperitoneal LPS injection in the late experimental stage. Results showed that quercetin supplementation alleviated LPS-induced pathological changes in the hepatocytes in a dose-dependent manner. It significantly down-regulated the expression of key pro-inflammatory genes and up-regulated that of anti-inflammatory genes. Specifically, dietary supplementation with 0.04 % and 0.08 % quercetin increased liver albumin content and enhanced the activities of the antioxidant enzymes catalase and glutathione peroxidase. This study demonstrates that quercetin protects the quail liver from LPS-induced injury by activating the antioxidant system and modulating inflammatory responses. These findings provide a theoretical basis for the application of quercetin as a functional feed additive in quail production.