Dietary rutin improves growth performance, intestinal barrier, mitochondrial homeostasis and redox balance in broilers under heat stress

The benefits of rutin administration were evaluated, focusing on effects on broiler growth performance, intestinal barrier, mitochondrial homeostasis, and redox balance under heat stress. The results demonstrated that compared to the HS group, dietary rutin improved growth performance (increasing final body weight, average daily feed intake, and average daily gain), jejunal morphology (expanding villus width and surface area), jejunal barrier (elevating concentrations of Occludin, Claudin-1, and Mucin-2; upregulating mRNA expression of Occludin and Mucin-2), redox balance in both serum and jejunum (boosting total antioxidant capacity, superoxide dismutase activity, glutathione levels, and the glutathione-to-oxidised glutathione ratio; increasing mRNA expression of glutathione S-transferase and nuclear factor erythroid 2–related factor 2), and jejunal mitochondrial homeostasis (amplifying mitochondrial DNA copy number and ATP synthase α-subunit mRNA levels) (p < 0.05). Moreover, dietary rutin reduced the ratio of feed to gain, lowered liver alkaline phosphatase activity, decreased concentrations of serum diamine oxidase and malondialdehyde, reduced jejunal oxidised glutathione levels, and downregulated jejunal mucosa mRNA expression of B-cell lymphoma 2 associated X, kelch-like ECH-associated protein 1, and heat shock protein 90 (p < 0.05). Overall, rutin supplementation (optimal dose of 500 mg/kg) effectively attenuates HS-induced decline in broilers’ growth performance, impairment of intestinal morphology and barrier integrity, disruption of mitochondrial homeostasis, and redox imbalance, potentially through Nrf2-mediated mechanisms.