Dietary supplementation of enzymatically treated Artemisia annua could alleviate the intestinal inflammatory response in heat-stressed broilers

The study was undertaken to evaluate the effects of enzymatically treated Artemisia annua (EA) on the intestinal inflammatory response of heat-stressed broilers. A total of 144 male Arbor Acres broilers aged 21 days were randomly divided into 3 groups with 6 replicates per group and 8 broilers in each replicate. The 3 treatment groups were as follows: the control group, in which broiler chickens were raised at 22 ± 1 °C and fed basal diets, the heat stress (HS) and HS-EA groups, in which broiler chickens were raised at 34 ± 1 °C for 8 h (0900-1700 h) and 22 ± 1 °C for 16 h, and fed basal diets supplemented with 0 or 1 g/kg EA, respectively. From 22 to 41 days, the heat treatment lasted for 20 consecutive days. Compared with the control group, HS increased the activity of plasma diamine oxidase (P < 0.05) and the concentration of intestinal interleukin-1β, and up-regulated (P < 0.05) the mRNA expression of intestinal interleukin-1β, interleukin-6, interferon-γ, toll-like receptor 4 and heat shock protein 70, down-regulated (P < 0.05) jejunal zonula occludens-1 and ileal occluding mRNA abundances and intestinal interleukin-10 at both protein and transcriptional levels. However, EA treatment significantly decreased (P < 0.05) plasma diamine oxidase activity, the mRNA expression of heat shock protein 70, toll-like receptor 4, interleukin-6, interleukin-1β and interferon-γ in intestine of heat-stressed broilers, whereas upregulated (P < 0.05) the mRNA expression of ileal occluding, jejunal zonula occludens-1 and occluding. In addition, both protein and transcriptional levels of interleukin-10 in jejunum and ileum were increased (P < 0.05) by EA treatment in the HS group. In conclusion, dietary EA supplementation could alleviate the intestinal inflammatory response, and improve the intestinal barrier function in broilers during the heat stress period.