水飞蓟素对免疫应激肉鸡免疫器官抗氧化功能的影响OA

[Objective]This study aimed to evaluate the impact of dietary silymarin(SM)supplementation on the antioxidant capacity of the spleen,thymus,and bursa of Fabricius in broilers subjected to immune stress.[Method]A total of 180 one-day-old broilers were randomly assigned to one of 3 groups:the control group(CON),the lipopolysaccharide group(LPS),and the lipopolysaccharide+silymarin group(LPS+SM),with each group consisting of 6 replicates of 10 broilers.The CON and LPS groups were provided a basal diet,whereas the LPS+SM group received a basal diet supplemented with 0.10%SM.On days 16,18,and 20,the LPS and LPS+SM groups were administered intraperitoneal injections of LPS at a dose of 500 μL/kg body weight,while the CON group received an equivalent volume of normal saline.Four hours post-LPS administration on day 20,samples from the immune organs were collected for the assessment of antioxidant function-related indicators.[Result](1)The intraperitoneal administration of LPS resulted in a significant increase in the organ index of the spleen in broilers(P<0.05),whereas the supplementation of the diet with SM did not exert a significant impact on the immune organ index(P>0.05).(2)LPS administration significantly elevated the malondialdehyde(MDA)content in the thymus and spleen(P<0.05),while it reduced the total antioxidant capacity(T-AOC)and superoxide dismutase(SOD)activities in these organs(P<0.05),and decreased the glutathione peroxidase(GSH-Px)activity in the spleen(P<0.05).Conversely,the diet with SM in the diet significantly enhanced the GSH-Px and SOD activities in the bursa of Fabricius of immune-stressed broilers(P<0.05),reduced the MDA content,and increased the T-AOC and SOD activities in the thymus and spleen(P<0.05),along with an increase in GSH-Px activity in the spleen(P<0.05).(3)LPS administration significantly downregulated the expression of NQO1 mRNA in the thymus and HO-1 mRNA in both the spleen and thymus of broilers under immune stress(P<0.05),while it upregulated the expression of NQO1 mRNA in the bursa of Fabricius(P<0.05).The dietary addition of SM significantly upregulated the expression of NQO1,HO-1,and Nrf2 mRNA in the thymus of immune-stressed broilers(P<0.05),while it led to a downregulation of Nrf2 mRNA expression in the bursa of Fabricius(P<0.05).[Conclusion]These findings suggest that dietary SM supplementation alleviates the damage of immune stress to the antioxidant function of immune organs in broilers.