State Engineering Technology Institute for Karst Desertfication Control, School of Karst Science, Guizhou Normal University, Guiyang 550001, China.
College of Animal Science and Technology, Hunan Biological and Electromechanical Polytechnic, Changsha 410127, China.
J Anim Sci. 2023 Jan 3;101. doi: 10.1093/jas/skad323.
The present experiment was conducted to study the effects of dietary epidermal growth factor (EGF) supplementation on the liver antioxidant capacity of piglets with intrauterine growth retardation (IUGR). The present study consists of two experiments. In experiment 1, six normal-birth-weight (NBW) and six IUGR newborn piglets were slaughtered within 2 to 4 h after birth to compare the effects of IUGR on the liver antioxidant capacity of newborn piglets. The results showed that compared with NBW piglets, IUGR piglets had a lower birth weight and liver relative weight; IUGR piglets had a higher serum malondialdehyde (MDA) level, liver MDA level and hydrogen peroxide (H2O2) level, and had a lower liver total antioxidant capacity (T-AOC) level and glutathione peroxidase (GSH-Px) activity; IUGR trended to increase serum alanine aminotransferase activity, aspartate aminotransferase activity, and H2O2 level, and trended to decrease liver total superoxide dismutase activity. In experiment 2, six NBW piglets, and 12 IUGR piglets weaned at 21 d of age were randomly divided into the NC group (NBW piglets fed with basal diet); IC group (IUGR piglets fed with basal diet), and IE group (IUGR piglets fed with basal diet plus 2 mg/kg EGF), and feeding for 14 d. Organ index, serum parameters, liver antioxidant capacity, and liver antioxidant-related genes expression were measured. The results showed that compared to the IC group, dietary EGF supplementation (IE group) significantly reduced serum malondialdehyde level and H2O2 level, and liver protein carbonyl (PC) level and 8-hydroxydeoxyguanosine level of piglets with IUGR; dietary EGF supplementation (IE group) significantly increased serum T-AOC level, liver T-AOC level and GSH-Px activity; dietary supplemented with EGF (IE group) enhanced liver Nrf2, NQO1, HO1, and GPX1 mRNA expression compared to IC group. Pearson's correlation analysis further showed that EGF can alleviate liver oxidative injury caused by IUGR and improve the performance of IUGR piglets. In conclusion, EGF exhibited potent protective effects on IUGR-induced liver oxidative injury, by activating the Nrf2 signaling pathway to mediate the expression of downstream antioxidant enzymes and phase II detoxification enzymes (NQO1 and HO1), thereby alleviating liver oxidative damage and promoting the growth performance of IUGR piglets.
本实验旨在研究日粮表皮生长因子（EGF）添加对宫内生长迟缓（IUGR）仔猪肝脏抗氧化能力的影响。本研究包括两个实验。实验 1 中，正常出生体重（NBW）和 IUGR 新生仔猪各 6 头，于出生后 2-4 h 内屠宰，比较 IUGR 对新生仔猪肝脏抗氧化能力的影响。结果表明，与 NBW 仔猪相比，IUGR 仔猪出生体重和肝脏相对重量较低；血清丙二醛（MDA）、肝脏 MDA 和过氧化氢（H2O2）水平较高，肝脏总抗氧化能力（T-AOC）和谷胱甘肽过氧化物酶（GSH-Px）活性较低；血清丙氨酸氨基转移酶（ALT）、天冬氨酸氨基转移酶（AST）活性和 H2O2 水平有升高趋势，肝脏总超氧化物歧化酶（T-SOD）活性有降低趋势。实验 2 中，21 日龄断奶的 6 头 NBW 仔猪和 12 头 IUGR 仔猪随机分为 NC 组（NBW 仔猪基础日粮）、IC 组（IUGR 仔猪基础日粮）和 IE 组（IUGR 仔猪基础日粮+2 mg/kg EGF），饲养 14 d。测定器官指数、血清指标、肝脏抗氧化能力及肝脏抗氧化相关基因表达。结果表明，与 IC 组相比，日粮 EGF 补充（IE 组）显著降低了 IUGR 仔猪血清 MDA 水平和 H2O2 水平及肝脏蛋白羰基（PC）水平和 8-羟基脱氧鸟苷（8-OHdG）水平；显著提高了血清 T-AOC 水平、肝脏 T-AOC 水平和 GSH-Px 活性；IE 组仔猪肝脏 Nrf2、NQO1、HO1 和 GPX1 mRNA 表达量均高于 IC 组。Pearson 相关性分析进一步表明，EGF 可缓解 IUGR 引起的肝脏氧化损伤，改善 IUGR 仔猪的生产性能。综上所述，EGF 通过激活 Nrf2 信号通路，调节下游抗氧化酶和Ⅱ相解毒酶（NQO1 和 HO1）的表达，对 IUGR 诱导的肝脏氧化损伤具有较强的保护作用，从而缓解肝脏氧化损伤，促进 IUGR 仔猪的生长性能。
