槲皮素对PEDV感染幼龄仔猪肠道形态、抗氧化功能及空肠脂质代谢基因表达的影响

【目的】 通过研究槲皮素对猪流行性腹泻病毒（PEDV）感染仔猪肠道形态、肠道抗氧化功能及空肠脂质代谢相关基因相对表达量的影响，旨在探讨槲皮素对PEDV感染仔猪肠道的保护作用。【方法】 选取18头健康的7日龄断奶仔猪，随机分为3组：对照组、PEDV组和槲皮素＋PEDV组，每组6个重复，每个重复1头猪。试验期8 d，于试验第0~7天，对槲皮素＋PEDV组仔猪每天口腔灌服10 mg/kg BW的槲皮素，其余组灌服等体积的人工奶。于试验第5天晚上给PEDV组和槲皮素＋PEDV组仔猪口腔灌服10^4.5TCID₅₀的PEDV，对照组仔猪灌服相同体积的PBS溶液。于试验第8天早上屠宰，取仔猪十二指肠、空肠、回肠及结肠组织样品进行检测。【结果】 与对照组相比，PEDV组仔猪空肠和回肠的绒毛高度以及绒毛高度与隐窝深度比值极显著降低（P<0.01），空肠、回肠和结肠中谷胱甘肽过氧化物酶（GSH-Px）和总超氧化物歧化酶（T-SOD）的活力显著降低（P<0.05），十二指肠、空肠、回肠和结肠中过氧化氢酶（CAT）的活力显著降低（P<0.05），回肠和结肠中丙二醛（MDA）的含量显著升高（P<0.05），空肠中载脂蛋白A1（APOA1）、载脂蛋白B （APOB）、载脂蛋白C2（APOC2）、脂肪酸结合蛋白2（FABP2）、酰基辅酶A合成酶长链家族成员3（ACSL-3）和脂肪酸合酶（FASN）基因的相对表达量极显著下调（P<0.01）。与PEDV组相比，槲皮素＋PEDV组仔猪空肠和回肠的绒毛高度以及绒毛高度与隐窝深度比值极显著提高（P<0.01），空肠、回肠和结肠中GSH-Px和T-SOD的活力显著提高（P<0.05），十二指肠、空肠和结肠中CAT的活力显著提高（P<0.05），回肠和结肠中MDA的含量显著降低（P<0.05），空肠中APOB、FABP2和FASN基因的相对表达量极显著上调（P<0.01）。【结论】 添加槲皮素可有效缓解PEDV感染导致的仔猪肠道损伤，提高仔猪肠道抗氧化能力以及空肠脂质代谢的能力。

Effects of Quercetin on Intestinal Morphology,Antioxidant Function and Jejunal Lipid Metabolism Gene Expression in Piglets with Porcine Epidemic Diarrhea Virus

【Objective】 The objective of this trial was to investigate the protective effect of quercetin on the intestinal tract of Porcine epidemic diarrhea virus(PEDV)-infected piglets by studying the effect of quercetin on the intestinal morphology, intestinal antioxidant function and relative expression of genes related to jejunal lipid metabolism in pigs infected with PEDV.【Method】 Eighteen healthy 7-day-old weaned piglets were randomly divided into 3 groups:, control group, PEDV group, and quercetin+PEDV group, with 6 replicates per group and one pig per replicate.The trial lasted for 8 days.On the 0-7th days of the trial, the piglets in the quercetin+PEDV group were orally administered with quercetin at the dosage of 10 mg/kg BW, the rest of the groups were orally administered with equal volume of artificial milk.On the 5th day of the trial, piglets in the PEDV group and PEDV+quercetin group were administered with PEDV (10^4.5TCID₅₀), and piglets in control group were given the same volume of PBS solution.On 8th day of the trail, all piglets were sacrificed, duodenum, jejunum, ileum and colon samples were taken for testing and small intestinal tissue was sliced.【Result】 Compared with the control group, in the PEDV group, the villous height and the ratio of villi height to crypt depth of the jejun and ileum were reduced (P<0.01), the activities of glutathione peroxidase (GSH-Px) and total superoxide dismutase (T-SOD) were decreased in jejunum, ileum, and colon (P<0.05), the viabilities of catalase (CAT) was decreased in duodenum, jejunum, ileum and colon (P<0.05), and the contents of malondialdehyde (MDA) was increased in ileum and colon (P<0.05), the relative expression of apolipoprotein A1(APOA1), apolipoprotein B(APOB), apolipoprotein C2 (APOC2), fatty acid binding protein 2 (FABP2), acyl-coenzyme A synthase long-chain family member 3 (ACSL-3) and fatty acid synthase (FASN) genes were downregulated in jejunum (P<0.01).Compared with the PEDV group, in the PEDV+quercetin group, the villus height and villus height to crypt depth ratio were increased in the jejunum and ileum of piglets (P<0.01), the activities of GSH-Px and T-SOD were increased in the jejunum, ileum and colon (P<0.05), the viabilities of CAT was increased in duodenum, jejunum and colon (P<0.05), the contents of MDA was decreased in the ileum and colon (P<0.05), the relative expression of APOB, FABP2, and FASN genes were upregulated in the jejunum(P<0.01).【Conclusion】 Dietary quercetin supplementation could alleviates the intestinal injury of piglets caused by PEDV infection, the intestinal antioxidant capacity and jejunal lipid metabolism of piglets were improved.