Protective effect of Macleaya cordata isoquinoline alkaloids on lipopolysaccharide-induced liver injury in broilers

Abstract

Objective: This experiment aimed to explore the protective action of dietary supplementation with isoquinoline alkaloids (IA) from <i>Macleaya cordata</i> on lipopolysaccharide (LPS)-induced liver injury in broilers.Methods: Total 216 healthy broilers were selected in a 21-d trial and assigned randomly to the following 3 treatments: control (CON) group, LPS group, and LPS+IA group. The CON and LPS groups were provided with a basal diet, whereas the LPS+IA group received the basal diet supplemented with 0.6 mg/kg <i>Macleaya cordata</i> IA. Broilers in LPS and LPS+IA groups were intraperitoneally injected with LPS (1 mg/kg body weight) at 17, 19, and 21 days of age, while those in CON group were injected with equivalent amount of saline solution.Results: Results showed LPS injection caused systemic and liver inflammation in broilers, inhibited immune function, and ultimately lead to liver injury. By contrast, supplementation of IA ameliorated LPS-induced adverse change in serum parameters, boosted immunity in LPS+IA group. Furthermore, IA suppressed the elevation of hepatic inflammatory cytokines and caspases levels induced by LPS, as well as the expressions of genes related to the tolllike receptor 4 (TLR4)/myeloid differentiation primary response 88 (MyD88)/nuclear factorkappa B (NF-κB) pathway.Conclusion: Dietary inclusion of 0.6 mg/kg <i>Macleaya cordata</i> IA could enhance immune function of body and inhibit liver damage via inactivating TLR4/MyD88/NF-κB signaling pathway in broilers.