Combined supplementation with isochlorogenic acid and quercetagetin ameliorates dexamethasone-induced intestinal injury via attenuation of oxidative stress and inflammation

Oxidative stress is a critical factor impairing intestinal function and homeostasis in broilers, particularly under dexamethasone (DEX)-induced conditions. Isochlorogenic acid (ICA) and quercetagetin (QG) are natural flavonoids with known antioxidant properties, but their combined effects remain unclear. A total of 270 one-day-old Arbor Acres broilers were randomly assigned to three groups: control, DEX-induced injury, and ICA+QG treatment (100 mg/kg each). After 21 days of feeding, oxidative stress was induced by intraperitoneal injection of DEX (3 mg/kg). Serum antioxidant indices, immune parameters, intestinal morphology, and gut microbiota composition were analyzed. Compared with the DEX group, ICA+QG supplementation significantly increased serum superoxide dismutase (SOD) and glutathione (GSH) activities ( P < 0.05), while enhancing intestinal antioxidant capacity. Immune-related indicators, including interleukin-1β (IL-1β), interleukin-4 (IL-4), immunoglobulin M (IgM), and complement component 3 (C3), were significantly elevated ( P < 0.05). Intestinal morphology was improved, with increased villus height and villus-to-crypt ratio. Moreover, gut microbiota structure was modulated toward a more balanced composition. Combined ICA and QG supplementation alleviates DEX-induced oxidative stress and intestinal damage by enhancing antioxidant defenses, modulating immune responses, and improving intestinal morphology and microbial balance. This strategy may provide a practical nutritional approach to support intestinal function in broilers under stress conditions.