辣椒碱对脂多糖攻毒仔猪肠道抗氧化功能的影响

Effects of capsaicin on intestinal antioxidant function of lipopolysaccharide challenged piglets

旨在研究日粮添加辣椒碱(CAP)对脂多糖(LPS)攻毒仔猪肠道抗氧化功能的影响。选取初始体重相近的28日龄断奶仔猪24头,随机分为3组,对照组(CON)和LPS组饲喂基础日粮,LCA组在基础日粮中添加800 mg/kg的CAP,试验周期35 d;LPS组和LCA组仔猪于采样前4 h按照100μg/kg体重的剂量腹腔注射LPS,CON组仔猪腹腔注射等剂量的生理盐水。结果显示:与CON组相比,LPS攻毒仔猪空肠总抗氧化能力(T-AOC)和还原型谷胱甘肽(GSH)含量显著下降(P<0.05),8-羟基脱氧鸟苷(8-OHdG)含量显著升高(P<0.05),回肠T-AOC和总超氧化物歧化酶(T-SOD)活性以及GSH含量显著下降(P<0.05),丙二醛(MDA)含量显著升高(P<0.05);日粮中添加CAP可显著提高LPS攻毒仔猪空肠过氧化氢酶(CAT)和谷胱甘肽过氧化物酶(GSH-Px)活性,降低8-OHdG含量(P<0.05),显著提高回肠T-SOD和GSH-Px活性(P<0.05);LPS攻毒导致仔猪空肠超氧化物歧化酶1(SOD1)的mRNA表达量显著下降(P<0.05);CAP可显著提高LPS攻毒仔猪空肠磷脂酰肌醇-3-激酶(PI3K)、蛋白激酶B(AKT)、核因子红细胞2相关因子2(Nrf2)和SOD1的mRNA表达量(P<0.05),以及回肠谷胱甘肽过氧化物酶1(GPx1)的mRNA表达量(P<0.05)。结论:日粮中添加CAP具有改善LPS攻毒仔猪肠道抗氧化功能的作用,其中空肠抗氧化功能的提高可能与激活PI3K/AKT/Nrf2信号通路有关。

The aim of this study was to investigate the effects of capsaicin(CAP)supplementation on the antioxidant function of lipopolysaccharide(LPS)challenge piglets in the intestine.Twenty-four 28-day-old weaned piglets with similar initial body weight were chosen and randomly divided into 3 groups.The control(CON)and LPS groups were fed with the basal diet,and the LCA group was fed with the basal diet supplemented with 800 mg/kg CAP.The experiment lasted for 35 days.The piglets in the LPS group and the LCA group were intraperitoneally injected with LPS at 100μg/kg body weight 4 h before sampling,and the piglets in the CON group were intraperitoneally injected with an equal dose of normal saline.The results showed as follows:Compared with the CON group,the total antioxidant capacity(TAOC)and reduced glutathione(GSH)contents of the jejunum of the piglets challenged with LPS were significantly decreased(P<0.05),while the 8-hydroxy-2-deoxyguanosine(8-OHdG)contents were significantly increased(P<0.05);and T-AOC,the activity of total superoxide dismutase(T-SOD),and the contents of GSH in the ileum were significantly decreased(P<0.05),while the contents of malondialdehyde(MDA)were significantly increased(P<0.05).The supplementation of CAP significantly increased the activities of CAT and GSH-Px in the jejunum of the LPS-challenged piglets,and decreased the contents of 8-OHdG(P<0.05)in them,and the activities of TSOD and GSH-Px in their ileum were significantly increased(P<0.05).LPS challenge significantly decreased the mRNA expression levels of SOD1 in the jejunum of the piglets(P<0.05);dietary supplementation of CAP significantly increased the mRNA expression levels of phosphatidylinositol-3-kinase(PI3K),protein kinase B(AKT),nuclear factor erythroid 2-related factor 2(Nrf2)and SOD1 in the jejunum of the piglets challenged with LPS(P<0.05),and the mRNA expression level of GPx1 in their ileum was significantly increased(P<0.05).These results suggested that dietary supplementation of CAP could improve the intestinal antioxidant function of piglets challenged with LPS,and the improvement of jejunum antioxidant function might be related to the activation of the PI3K/AKT/Nrf2 signaling pathway.