Artemisia ordosica Polysaccharide Alleviated Lipopolysaccharide-induced Oxidative Stress of Broilers via Nrf2/Keap1 and TLR4/NF-κB Pathway

Artemisia ordosica is one of the main shrubby perennials belonging to Artemisia species of Asteraceae and could be used in folk Chinese/Mongolian medicine to treat symptoms of various inflammatory ailments. The present study was conducted to investigate the protective effects of dietary Artemisia ordosica polysaccharide (AOP) against lipopolysaccharide (LPS) induced oxidative stress in broilers via Nrf2/Keap1 and TLR4/NF-kappa B pathway. A total of 192 1-day-old Arbor Acres male 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, LPSchallenged broilers fed basal diet supplemented with 750 mg/kg AOP. The trial included starter phase (d 1-14), stress period I (d 15-21), convalescence I (d 22-28), stress period II (d 29-35) and convalescence II (d 36-42). During stress period I (on d 15, 17, 19 and 21) and stress period II (on d 29, 31, 33 and 35), broilers were injected intra-abdominally either with LPS solution or with an equal amount of sterile saline. The results showed that dietary AOP supplementation alleviated LPS-induced reduction in antioxidant enzyme activity and excessive production of ROS, 8-OHdG and PC in serum of broilers challenged with LPS. Moreover, dietary AOP supplementation alleviated the decrease of T-AOC and activities of SOD, CAT and GPx in liver of broilers challenged with LPS by increasing expression of Nrf2, and inhibiting over-expression of Keap1 both at gene and protein level. Additionally, dietary AOP supplementation decreased the over-production of IL-1 beta and IL-6 in liver of broilers challenged by LPS through decreasing mRNA expression of TLR4, MyD88, NF-kappa B P65, IL-1 beta and IL-6, and alleviating the increase of protein expression of TLR4, IKK beta, NF-kappa B P65, IL-1 beta, IL-6, and the decrease of protein expression of IkB alpha. In conclusion, dietary AOP supplementation could alleviate LPS-induced oxidative stress through Nrf2/Keap1 and TLR4/NF-kappa B pathway.

Automated summary

The study demonstrated that dietary Artemisia ordosica polysaccharide (AOP) could alleviate lipopolysaccharide (LPS)-induced oxidative stress in broilers by enhancing antioxidant enzyme activity, reducing ROS production, and regulating Nrf2/Keap1 and TLR4/NF-kappa B pathways. Additionally, AOP supplementation effectively decreased the over-production of inflammatory cytokines in the liver of broilers challenged by LPS through modulation of gene and protein expression levels related to inflammation.