Effects Of Glycyrrhizic Acid On Immune,anti-inflammatory And Anti-oxidantion Of Broilers

Objective:Glycyrrhizic acid(GA)is a triterpenoid saponin active substance extracted from natural plant licorice root or rhizome.Liver detoxification,combined drug synergy,increase feed palatability and other functions,can be developed as a non-toxic,green preventive health care functional feed additive.The purpose of this experiment was to study the effects of finished GA on the immune regulation,anti-inflammatory properties and antioxidant properties of yellow feather broilers,in order to provide a reference for the in-depth study of GA and its application in livestock and poultry production.Methods:300 yellow feather broilers weighing close to 1 day of age were selected and randomly divided into 6 groups,with 5 replicates in each group and 10 chickens in each replicate,namely the saline group(blank control),LPS(lipopolysaccharide)group,Astra GA_Lus polysaccharide+LPS group(APS+LPS),high-dose GA+LPS group(GA_H+LPS),middle-dose GA+LPS group(GA_M+LPS)and low-dose GA+LPS group(GA_L+LPS).Models of immune stress and inflammation were established by intraperitoneal injection of LPS.The control group was fed full-price compound feed,while the APS+LPS group,GA_H+LPS group,GA_M+LPS group and GA_L+LPS group were fed with 400 mg/kg APS,120 mg/kg GA,100 mg/kg GA,and 80 mg/kg GA test feed,the test period was 49 days.At 21,28,35,42,and 49 days of age,2 chickens were randomly selected for each replicate to collect blood from wing veins.Enzyme-linked immunosorbent assay(ELISA)was used to determine immune indicators Ig A,Ig G,Ig M,CD4,CD8 and inflammatory cytokines.Interleukin 1β(IL-1β),Interleukin 4(IL-4),Tumor Necrosis Factor(TNF-α),Interferonγ(IFN-γ)and antioxidant indicators T-AOC,SOD,GSH-Px,MDA activity or content,carbon clearance method to detect macrophage phagocytosis index.Results:(1)In the broiler chicken immune stress model established with LPS,GA_Lsignificantly inhibited the decrease of serum CD4 at 35 days of age(P<0.01)and 42 days of age(P<0.05).35,42 days of age extremely significant(P<0.01),49 days of age significantly(P<0.05)to relieve the increase in serum CD8;P<0.05)inhibited the decrease of serum CD4;GA_Hwas extremely significant at 21,28,35,and 42 days of age(P<0.01),and significantly at 49 days of age(P<0.05);At 35,42,and 49 days of age,serum CD8 was significantly relieved(P<0.01);at 21,28,35,42,and 49 days of age,each dose of GA group significantly relieved(P<0.01)the increase in serum Ig A,Ig G,and Ig M..It indicated that GA could effectively relieve the immune stress response of yellow feather broilers to LPS stimulation and enhance the immune regulation ability.(2)In the broiler chicken inflammation model established with LPS,the GA groups at 21,28,35,42,and 49 days of age all significantly(P<0.01)alleviated the macrophage phagocytosis index and serum inflammatory cytokines IL-1β,TNF-α,IFN-γincreased(P<0.01).It indicated that GA could effectively alleviate the inflammatory response induced by LPS stimulation in yellow-feathered broilers,thereby exerting an anti-inflammatory effect.(3)In terms of antioxidant properties,GA_Lhad no significant effect on alleviating the decrease in serum T-AOC(P>0.05),but was extremely significant at 35 days of age(P<0.01)and significantly at 49 days of age(P<0.05).The decrease of GSH-Px was extremely significant at 21,28,42,and 49 days(P<0.01),and the decrease in serum SOD was extremely significant at 21,35 days(P<0.01),and significantly at 28,42,and 49 days.(P<0.05)inhibited the increase of serum MDA;GA_Msignificantly relieved the decrease of serum T-AOC at 42 days of age(P<0.01)and 35 days of age(P<0.05),and at 21,28,35,and 49 days of age At 21,28,35,42,and 49 days,it significantly inhibited the decrease of serum GSH-Px(P<0.01),and at 21,28,35,42,and 49 days of age,it inhibited the decrease of serum SOD significantly(P<0.01).The increase of serum MDA was significantly inhibited at age(P<0.01).GA_Hsignificantly relieved the decrease in serum T-AOC at 42 days of age(P<0.01)and at 28,35,and 49 days of age(P<0.05),and was extremely significant at 21,28,35,42,and 49 days of age(P<0.05).P<0.01)inhibited the decrease of serum GSH-Px,which was extremely significant at 21,35,42,and 49 days(P<0.01)and significantly inhibited the decrease of serum SOD at 21,35,42,and 49 days(P<0.01).)inhibited the elevation of serum MDA.Conclusion:GA can effectively alleviate the inflammatory response and immune stress in yellow feather broiler chickens in the LPS model,and exert immune regulation,anti-inflammatory and antioxidant effects.The protective effect was positively correlated with the dose,and the order from strong to weak was GA_H>GA_M>GA_L.In this thesis,especially the high dose(120 mg/kg)of GA had the best effect.