葡萄籽原花青素对高精料育肥绵羊肝脏炎症反应、抗氧化功能的影响及代谢组学分析

Effects of Grape Seed Proanthocyanidins on Liver Inflammation and Antioxidant Function of Fattening Sheep Fed a High-Concentrate Diet and Metabolomic Analysis

本试验旨在研究葡萄籽原花青素(GSPs)对高精料育肥绵羊肝脏形态结构、肝脏功能、抗氧化功能及炎症反应的影响,通过非靶向代谢组学分析肝脏代谢变化。试验选取48只日龄、体重[(22.75±1.20)kg]相近的杜寒F1代杂交公羔羊,随机分为4组,每组12只羊。基础饲粮精粗比为70∶30,对照组饲喂基础饲粮,各试验组在饲喂基础饲粮的同时分别再每天补饲10(LGSPs组)、20(MGSPs组)、40 mg/kg BW GSPs(HGSPs组)。试验羊单栏饲养,自由采食、饮水,GSPs于每次晨饲前单独混合于100 g基础饲粮中饲喂。试验期60 d,其中预试期15 d。结果表明:1)对照组绵羊肝细胞肿胀、空泡化严重,各GSPs添加组肝脏组织损伤均有不同程度缓解。2)随着GSPs添加水平的提高,绵羊血清总蛋白和白蛋白含量线性升高(P<0.05),血清天冬氨酸转氨酶和谷丙转氨酶活性线性降低(P<0.05);肝脏组织总抗氧化能力(T-AOC)呈二次曲线变化,谷胱甘肽过氧化物酶(GSH-Px)活性线性升高,丙二醛(MDA)含量线性降低(P<0.05);肝脏组织中髓过氧化物酶(MPO)活性线性降低,炎症因子白细胞介素-1β(IL-1β)、白细胞介素-6(IL-6)和肿瘤坏死因子-α(TNF-α)含量线性降低(P<0.05)。与对照组相比,MGSPs和HGSPs组血清脂多糖(LPS)和脂多糖结合蛋白(LBP)含量显著降低(P<0.05)。3)随着GSPs添加水平的提高,肝脏组织中甘油三酯、总胆固醇和低密度脂蛋白胆固醇含量线性降低(P<0.05)。4)非靶向代谢组学结果表明,MGSPs组与对照组间共有99种差异代谢物,其中67种脂类物质。99种差异代谢产物中71种显著上调,28种显著下调。共有差异代谢物富集在癌症中的胆碱代谢、甘油磷脂代谢、逆行内源性大麻素信号、自噬-其他/动物等潜在靶向通路。综上所述,GSPs可以提高高精料饲粮条件下绵羊肝脏抗氧化功能,降低炎症因子含量,并可能通过调节肝脏脂质代谢、胆碱代谢及肝细胞自噬共同应答肝脏炎性反应和氧化应激,缓解炎性损伤。

The aim of this study was to investigate the effects of grape seed proanthocyanidins(GSPs)on liver morphological structure,liver function,antioxidant capacity and inflammatory response of sheep fed a high-concentrate diet,and analyze liver metabolic changes using non-targeted metabolomics.A total of forty-eight 4-month-old Dorper×thin-tailed Han ram lambs with similar body weight[(22.75±1.20)kg]were fed a 70∶30 concentrate:forage basal diet and randomly assigned to one of four groups of 12 lambs each.The basal diet supplemented with 0(control group),10(10GSPs group),20(20GSPs group),or 40 mg/kg BW GSPs(40GSPs group)per day.The experimental sheep were raised in a single pen and fed freely with diets and water.The experiment lasted for 60 days,including 15 days of pre-test.The results showed as follows:1)the hepatocytes swelling and vacuolation were severe in the control group,while the damage of liver tissue in each GSPs supplementation group was alleviated to different degrees.2)The contents of serum total protein and albumin were linearly increased(P<0.05),while the activities of serum aspartate aminotransferase and glutaminotransferase were linearly decreased(P<0.05).The total antioxidant capacity(T-AOC)of liver showed a quadratic curve,the activity of glutathione peroxidase(GSH-Px)increased linearly,and the content of malondialdehyde(MDA)decreased linearly(P<0.05).The activity of myeloperoxidase(MPO)in liver was linearly decreased,and the contents of inflammatory factors interleukin-1β(IL-1β),interleukin-6(IL-6)and tumor necrosis factor-α(TNF-α)were linearly decreased(P<0.05).Compared with control group,serum lipopolysaccharide(LPS)and lipopolysaccharids-binding protein(LBP)contents in MGSPs and HGSPs groups were significantly decreased(P<0.05).3)With the increase of GSPs supplemental level,the contents of triglyceride,total cholesterol and low density lipoprotein cholesterol in liver were linearly decreased(P<0.05).4)The non-targeted metabolomics results showed that there were a total of 99 different metabolites between the MGSPs group and the control group,including 67 lipid substances.Among the 99 kinds of metabolites,71 were significantly up-regulated and 28 were significantly down-regulated.Differential metabolites were enriched in choline metabolism in cancer,glycerophospholipid metabolism,retrograde endocannabinoid signaling,autophagy-other/animal and other potential target pathways.In conclusion,GSPs can improve the antioxidant capacity of liver of sheep fed a high-concentrate diet,reduce the contents of inflammatory factors.It may alleviate inflammatory damage through regulating liver lipid metabolism,choline metabolism,and liver cell autophagy to jointly respond to liver inflammatory response and oxidative stress.