Artemisia ordosica polysaccharide ameliorated LPS-induced growth inhibition and intestinal injury in broilers through enhancing immune-regulation and antioxidant capacity

Abstract

The study investigated the effects of dietary Artemisia ordosica polysaccharide (AOP) on growth, intestinal morphology, immune responses and antioxidant capacity of broilers challenged with lipopolysaccharide (LPS). A total of 192 1-d-old broilers were randomly allotted to four treatments with 6 replicates (n = 8): (1) CON group, non-challenged broilers fed basal diet; (2) LPS group, LPS-challenged broilers fed basal diet; (3) AOP group, non-challenged broilers fed basal diet supplemented with 750 mg/kg AOP; (4) LPS+AOP group, LPS-challenged broilers fed basal diet supplemented with 750 mg/kg AOP. The trial included starter phase (d 1 to 14), stress period Ⅰ (d 15 to 21), convalescence Ⅰ (d 22 to 28), stress period Ⅱ (d 29 to 35) and convalescence Ⅱ (d 36 to 42). During stress period Ⅰ and Ⅱ, broilers were injected intra-abdominally either with LPS solution or with equal sterile saline. The results showed that AOP alleviated LPS-induced growth inhibition by prompting protein digestibility, and decreasing serum stress hormones and pro-inflammatory cytokines content of broilers. Moreover, AOP decreased LPS-induced over-production of IL-1β and IL-6 through suppressing TLR4/NF-κB pathway, and alleviated LPS-induced decreasing of T-AOC, CAT and GPx activities by activating Nrf2/Keap1 pathway, which ultimately improved jejunum morphology. In conclusion, AOP alleviated LPS-induced growth inhibition and intestinal damage by enhancing anti-inflammatory and antioxidant capacities of broilers.

Keywords: Antioxidant capacity; Artemisia ordosica polysaccharide; Broiler; Immune stress; Immune-regulation.