Dietary supplementation with Artemisia argyi extract on inflammatory mediators and antioxidant capacity in broilers challenged with lipopolysaccharide

This study investigated the effects of Artemisia argyi extract (AAE) on broilers challenged with lipopolysaccharide (LPS). A total of 96 Arbour Acres broilers (1-d-old) were assigned to a 2 × 2 factorial arrangement with two dietary treatments (AAE at 0 or 1000 mg/kg) and two immunological challenge treatments (saline or LPS). On d 14, 16, 18 and 20, the broilers were injected intra-abdominally with LPS solution at 500 μg/kg of body weight or an equivalent amount of sterile saline. Blood, liver, spleen and small intestine were collected on day 21. The increased relative weights of the thymus and spleen induced by LPS were significantly decreased by AAE supplementation. The level of serum nitric oxide (NO) and the activity of inducible NO synthase (iNOS) were significantly compromised by AAE inclusion. Dietary AAE significantly inhibited the mRNA expression of toll-like receptor 4 (TLR4), myeloid differentiation factor 88, nuclear factor-kappa B (NF-κB) and iNOS in the different tissues of LPS-challenged broilers. The AAE supplementation tended to increase the levels of serum GSH-Px and CAT, but significantly reduced the level of serum malondialdehyde (MDA). Collectively, feeding AAE to LPS-challenged broilers could decrease serum NO level, maintain the relative weight of internal organs, enhance the antioxidant capacity, and inhibit TLR4/NF-κB signalling pathway at the transcriptional level.Highlights AAE inclusion significantly inhibited the serum NO level, and the activity of iNOS induced by LPS. AAE supplementation tended to increase the levels of serum GSH-Px and CAT, but significantly reduced the level of serum MDA. Feeding AAE to the LPS-challenged broilers reduced the expression of TLR4, MyD88 and NF-κB in the liver, spleen and small intestine