日粮添加姜黄素对IUGR猪肝脏抗氧化功能和脂代谢的影响

Effects of dietary curcumin on liver antioxidant function and lipid metabolism in IUGR pig

[目的]本试验旨在探讨日粮添加姜黄素对宫内发育迟缓(IUGR)猪肝脏抗氧化功能及脂代谢的影响。[方法]择取分娩时间与遗传背景相似的妊娠母猪12头,分娩当日,从每窝新生仔猪(杜长大)分别选择1头正常出生重(NBW,约1.51 kg)和2头IUGR(约0.75 kg)仔猪,26日龄断奶后将所有仔猪分为NBW、IUGR和IUGR+姜黄素(curcumin,Cur)3组,每组6个重复,每重复2头猪。NBW和IUGR组饲喂基础日粮,IUGR+Cur组饲喂基础日粮+200 mg·kg^(-1)姜黄素,饲养至195日龄后每组随机选择6头猪屠宰并取样分析。[结果]在NBW、IUGR及IUGR+Cur组之间,猪肝脏相对质量无显著差异(P>0.05)。与NBW组相比,IUGR猪血清和肝脏中过氧化氢酶(CAT)活性和还原型谷胱甘肽(GSH)含量显著降低(P<0.05),甘油三酯(TG)水平显著升高(P<0.01);与IUGR组相比,日粮添加200 mg·kg^(-1)姜黄素可显著降低IUGR猪血清和肝脏中丙二醛(MDA)和TG水平(P<0.05),并显著提高总超氧化物歧化酶(T-SOD)和CAT活性(P<0.05);低密度脂蛋白胆固醇(LDL-C)水平在3组之间无显著性差异(P>0.05),但IUGR+Cur组猪肝脏中谷胱甘肽过氧化物酶(GSH-Px)活性和GSH、高密度脂蛋白胆固醇(HDL-C)含量均显著高于IUGR组(P<0.05)。与NBW组相比,IUGR组猪肝脏中CAT mRNA相对表达量显著降低(P<0.05),脂滴包被蛋白(PLIN)mRNA表达量增加(P<0.05),而日粮添加200 mg·kg^(-1)姜黄素使GST、CAT、GSH-Px、核相关E2相关因子2(Nrf2)以及血红素酶-1(HO-1)mRNA表达量显著增加(P<0.05)。此外,IUGR+Cur组猪肝脏激素敏感性脂肪酶(HSL)和脂肪甘油三酯脂酶(ATGL)mRNA的相对表达量显著高于IUGR组(P<0.05),PLIN mRNA表达量显著降低(P<0.05)。与NBW组相比,IUGR猪肝脏油红O染色面积显著增加(P<0.05),而日粮添加200 mg·kg^(-1)姜黄素显著降低IUGR猪肝脏油红O染色面积(P<0.05),但NBW组与IUGR+Cur组之间油红O染色面积无明显变化(P>0.05)。[结论]日粮添加200 mg·kg^(-1)姜黄素可能通过Nrf2信号通路增强IUGR猪肝脏抗氧化功能,缓解氧化应激;并通过抑制PLIN基因表达,上调ATGL表达而有效促进脂质分解代谢,缓解IUGR猪脂质沉积。

[Objectives]This experiment was conducted to study the effects of dietary supplemented curcumin on liver antioxidant function and lipid metabolism in pigs with intrauterine growth retardation(IUGR).[Methods]Twelve gestational sows with similar parturition time and genetic background were selected,and on the day of parturition,one piglet with normal birth weight(NBW,approximate 1.51 kg)and two piglets(Duroc Landrace Yorkshire)with IUGR(approximate 0.75 kg)were selected from each litter,respectively.At 26 day-old,weaning pigs were divided into three groups with six replicates per group and two pigs per replicate,including NBW,IUGR and IUGR+Curcumin(Cur).The NBW and IUGR groups were fed a basal diet,and the IUGR+Cur group was fed with the basal diet plus 200 mg·kg^(-1) curcumin.After the feeding trial(at 195 day-old),6 pigs from each group were randomly selected for slaughter and sample analysis.[Results]There was no significant difference in the relative liver weight among NBW,IUGR,and IUGR+Cur groups(P>0.05).Compared with NBW group,the catalase(CAT)activity and reduced glutathione(GSH)content significantly decreased(P<0.05),and the triglyceride(TG)level significantly increased in serum and liver of IUGR pigs(P<0.01);dietary supplemented with 200 mg·kg^(-1) curcumin significantly decreased the contents of malondialdehyde(MDA)and TG(P<0.05),and significantly increased activities of total superoxide dismutase(T-SOD)and CAT in serum and liver of IUGR pigs(P<0.05).There was no significant difference in the level of low-density lipoprotein cholesterol(LDL-C)among these three groups(P>0.05),but the glutathione peroxidase(GSH-Px)activity and contents of GSH and high-density lipoprotein cholesterol(HDL-C)in the liver of the IUGR+Cur group were significantly higher than those in the IUGR group(P<0.05).Compared with NBW group,the relative mRNA expression level of CAT in the liver of the IUGR group was significantly reduced(P<0.05),and the mRNA expression level of perilipin(PLIN)was higher(P<0.05),while dietary supplemented 200 mg·kg^(-1) curcumin significantly increased the mRNA expression levels of GST,CAT,GSH-Px,nuclear-related E2-related factor 2(Nrf2)and heme oxygenase-1(HO-1)in liver of IUGR pigs(P<0.05).In addition,the relative mRNA expression levels of liver hormone-sensitive lipase(HSL)and fatty triglyceride lipase(ATGL)in the IUGR+Cur group were significantly higher than those in the IUGR groups(P<0.05),and the mRNA expression level of PLIN was significantly reduced(P<0.05).Compared with NBW group,the oil red O staining area of liver in IUGR pigs significantly increased(P<0.05),while compared with IUGR group,supplemented 200 mg·kg^(-1) curcumin significantly decreased the oil red O staining area(P<0.05).But there was no significant difference in the oil red O staining area between NBW and IUGR+Cur groups(P>0.05).[Conclusions]Dietary supplementation of 200 mg·kg^(-1) curcumin could enhance the antioxidant function through the Nrf2 signaling pathway and relieve oxidative stress;and effectively promote lipid catabolism and relieve lipid deposition in the liver of IUGR pigs via inhibiting the expression of PLIN gene,and up-regulating the ATGL expression.