| Intra-uterine growth retardation(IUGR)is always defined as the growth and development of fetus and/or its organ are limited or disordered during the critical stage of pregnancy,failure to reach the potential of genetics.The most notable and direct performance of IUGR neonates is lower birth weight,body circumference and body length than normal neonates.In animal production,IUGR also has a high incidence,with low newborn and newborn animals accounting for about 10%.The causes of IUGR are multifaceted and complex,which may be caused by several reasons.In animal production,the most direct influences of IUGR are low birth weight,high mortality and morbidity,low feed utilization,slow growth and susceptibility to diseases after weaning.Therefore,researches related to the nutritional regulation on IUGR are very needed after birth.Curcumin,a natural plant polyphenol,has been reported to improve growth,increase antioxidant capacity,alleviate the body damage and abnormal metabolism of nutrients.However,reports related to curcumin on IUGR are very limited until now.And the biological mechanism of its function remains to be studied.Therefore,the present research was carried out to determine the effects of IUGR on blood cytokines,hepatic structure,antioxidant capacity and glucose and lipid metabolism of newborn piglets.Then,we investigated the effect of curcumin supplementation on the growth and development,antioxidant capacity,glucose and lipid metabolism of weaned piglets with IUGR.Furthermore,the specific mechanisms of curcumin on IUGR were further researched in a rat model for the apply of curcumin in human.1 Effects of IUGR on blood cytokines,liver inflammation,antioxidant and glucose and lipid metabolism in newborn pigsIn experiment 1,the present study selected 8 normal birth weight(NBW)and 8 IUGR newborn piglets[Duroc ×(Landrace × Yorkshire)].All newborn piglets were not fed with colostrum,slaughtered within 1 hour after birth,with half males and half females.The levels of cytokines and immunoglobulins in serum,hepatic morphology and internal structure,activities of antioxidant enzymes and glucose and lipid metabolism were detected.The results showed that:compared with NBW group,(1)IUGR could cause damage to liver of newborn piglets and affect the internal structure.(2)Levels of TNF-?(P<0.05)and ALT(P<0.01)in the serum of IUGR group were increased.(3)Levels of AST,ALT,MDA and GSSG:GSH ratios were significantly increased(P<0.05)in the liver of IUGR group,while levels of hepatic TAOC,GSH-Px and GR were significantly decreased(P<0.05).(4)Levels of insulin(P=0.05),lactic acid(P<0.01)and HOMA-IR(P<0.01)in the serum of IUGR group were significantly increased,while level of TC was significantly decreased(P<0.01).(5)Concentrations of TC,TG,NEFA and activities of LDH,HK and LPL in the liver of IUGR group were significantly increased(P<0.05),while concentration of pyruvate in the liver of IUGR was significantly decreased(P<0.05).It showed that IUGR could cause the damage of hepatic morphological structure and influence the levels of serum immunoglobulins and cytokines.These results demonstrated that the liver of IUGR newborn piglets showed decreased antioxidant capacity and abnormal hepatic lipid metabolism,so it is necessary to use nutritional regulation on IUGR piglets after birth.2 Effects of curcumin on the regulation of growth and development,antioxidant function of weaned piglets with IUGRIn experiment 2,twenty NBW and twenty IUGR newborn piglets were selected similarly to experiment 1 and weaned at the age of 26,respectively.NBW piglets were divided into NBW group(basal diet)and NC group(basal diet+400 mg/kg curcumin).Similarly,IUGR piglets were divided into IUGR group(basal diet)and IC group(basal diet+400 mg/kg curcumin).At 50 days of age,8 piglets of each group with average body weight in groups were selected to slaughter after fasting overnight,half male and half female.Growth performance,organ index,serum biochemical indexes,antioxidant capacity,and mRNA expressions of hepatic antioxidant genes were determined.The results showed that:as compared with NBW group,(1)Piglets of IUGR had a lower body weight during suckling period,and the body weight of IUGR piglets significantly decreased at the 1,14 and 26 days of age(P<0.05).The average daily weight gain of IUGR suckling piglets at 7-14 days and 0-26 days were significantly lower than that of NBW group(P<0.05).(2)The body weight and average daily weight gain of weaned piglets with IUGR group at 50 days of age were significantly decreased(P<0.01).The average daily feed intake of IUGR group was significantly decreased(P<0.05),while curcumin supplementation could significantly increase the average daily feed intake of weaned piglets with IUGR(P<0.05).Moreover,curcumin supplementation could significantly decrease the feed to gain ratio of weaned piglets in NBW group(P<0.05).(3)The weight of liver,kidney and pancreas(P<0.01),the spleen and pancreas indexes in IUGR group were significantly decreased(P<0.05).Curcumin supplementation significantly increased the weight of kidney and the indexes of liver,spleen,kidney and pancreas of IUGR piglets(P<0.05).The liver weight,pancreas weight and liver index of NC group were significantly decreased(P<0.05).(4)Levels of urea nitrogen,creatinine,total protein and albumin in serum of IUGR group were significantly decreased(P<0.05),while total bilirubin level in serum of IUGR group was significantly increased(P<0.05).In the NC group,levels of urea nitrogen,creatinine and total protein in serum were significantly decreased(P<0.05),while total bilirubin level in serum was significantly increased(P<0.05).Level of urea nitrogen in serum was significantly increased in the IC group(P<0.05).(5)Levels of CAT,TAOC and GSH-Px in serum of IUGR group were significantly decreased(P<0.05),and levels of MDA,H2O2 and CAT in liver of IUGR group were significantly increased(P<0.05)and activity of GSH-Px was significantly decreased(P<0.05).Dietary curcumin supplementation significantly decreased contents of MDA in serum and liver,as well as hepatic H2O2 and CAT levels(P<0.05).Levels of CAT,TAOC and GR in serum and levels of TAOC and GSH-Px in liver were significantly increased(P<0.05).(6)The mRNA expressions of Nfe2l2,Hmoxl and Cat in the liver of IUGR group were significantly decreased(P<0.05),and they were significantly up-regulated in the IC group(P<0.05).(7)The protein expressions of Nrf2 and Homxl in IUGR group were significantly decreased(P<0.05).Dietary curcumin supplementation significantly increased the protein expressions of Nrf2 and Homxl in the liver of weaned piglets with IUGR(P<0.05).It could be concluded that curcumin played a positive role in improving the growth and development of weaned piglets with IUGR,and increasing the antioxidant capacity of liver through the regulation of Nrf2/ARE pathway.3 Effects of curcumin on hepatic injury and glucose and lipid metabolism in weaned piglets with IUGRIn experiment 3,the experimental design was as same with experiment 2.Serum cytokines,hepatic structure and function,serum hormones,serum and hepatic glucose and lipid metabolism parameters and mRNA expression of related genes were determined.The results showed that:compared with the NBW group,(1)Levels of TNF-?,IL-? and IL-6 in the serum of IUGR group were significantly increased(P<0.05).Dietary curcumin supplementation significantly decreased the levels of TNF-? and IL-1? in the serum(P<0.05).(2)Among the NBW,NC and IC groups,no abnormal internal structure of the liver were found.In the liver of IUGR piglets,some hepatic mitochondria were showed oval or U-shaped,and some mitochondria had vacuoles,and the distribution density of endoplasmic reticulum was low and there was slightly swelling.(3)Activity of ALT in serum and liver of IUGR group were significantly increased(P<0.05)and hepatic AST activity of IUGR group was significantly decreased(P<0.05);activities of AST and ALT in the serum were significantly increased in the NC group(P<0.05).Compared with the IUGR group,activity of ALT in serum and activities of AST and ALT in liver of IC group showed a downward trend(P>0.05),while activity of AST in serum of IC group was significantly increased(P<0.05).(4)Level of insulin in the serum and HOMA-IR value of IUGR group were significantly increased(P<0.05).Dietary curcumin supplementation significantly decreased levels of insulin and glucose in serum and HOMA-IR values(P<0.05),and significantly increased levels of leptin in serum of IUGR weaned piglets(P<0.05).(5)Level of HDL-C in the serum of IUGR group was significantly increased(P<0.05),while concentration of NEFA in liver of IUGR group was significantly decreased(P<0.05).In the NC group,level of HDL-C in serum was significantly increased(P<0.05)while concentration of NEFA in liver was significantly decreased(P<0.05).Compared with the IUGR group,concentration of NEFA in serum of IC group was significantly increased(P<0.05)while level of HDL-C in serum was significantly decreased(P<0.05).(6)In the liver of IUGR group,concentration of glycogen was significantly decreased(P<0.05),activities of LDH,LPL,HL and TL were significantly decreased(P<0.05),and concentrations of lactic acid,TC,TG and NEFA,activity of PK were significantly increased(P<0.05).Compared with the IUGR group,the concentration of hepatic glycogen and activities of HL and TL in the liver of the IC group were significantly increased(P<0.05),while the concentrations of pyruvate,TC,TG,NEFA and PK in the liver of the IC group were significantly decreased(P<0.05).As compared to NB W group,the concentrations of glycogen and lactic acid,PK,LPL and TL activities in the liver of the NC group were significantly increased(P<0.05),while the concentrations of pyruvate,TG,NEFA,LDH and HL activities in the NC group were significantly decreased(P<0.05).(7)The mRNA expressions of Irs1,Pik3c3,Gsk3a,Fabp1 and Srebp in the liver of IUGR group were significantly up-regulated(P<0.05),while the mRNA expressions of Gys2,Lxr and Ppara in the IUGR group were significantly down-regulated(P<0.05);in the NC group,the mRNA expressions of Akt2,Fasn and Cd36 in the liver were significantly down-regulated(P<0.05),while the mRNA expressions of Gsk3a,Lxr and Ppara in the liver were significantly up-regulated(P<0.05).Compared with the IUGR group,the mRNA expressions of Irs1,Pik3c3,Gsk3a,Fasn,Cd36,Scdl and Srebp in the liver of the IC group were significantly down-regulated(P<0.05),while the mRNA expressions of Gys2,Lxr and Ppara in the liver of the IC group were significantly up-regulated(P<0.05).Therefore,dietary curcumin supplementation could promote the synthesis of hepatic glycogen and the oxidation of fatty acids in the liver of weaned piglets with IUGR through regulating the expression of genes,and improving the activities of lipid catabolism enzymes in the liver to alleviate the abnormal glucose and lipid metabolism.4 Regulation of curcumin on hepatic injury and antioxidant capacity in a rat model of IUGRIn experiment 4,the IUGR rat model was established by the diet restriction during pregnancy.At the age of 6 weeks,NBW mice were divided into NBW group(normal diet)and NC group(normal diet+400 mg/kg curcumin)according to their birth weight,and IUGR mice were also divided into IUGR group(normal diet)and IC group(normal diet+400 mg/kg curcumin).At 12 weeks of age,6 female rats in each group were slaughtered.Levels of cytokines in serum,hepatic lipid peroxidation,protein and DNA damage,activities of antioxidant enzymes in serum and liver,mRNA expressions of hepatic cytokines and antioxidant related genes,and phosphorylation levels of hepatic I?B?,NF-?B,JAK2 and STAT3 proteins were determined.The results showed that:compared with NBW group,(1)Birth weight of IUGR mouse was significantly decreased(P<0.01).At the age of 3,4,5 and 6 weeks,the body weight of IUGR mice were lower than that of NBW group(P>0.05,P>0.05,P>0.05,P<0.01;respectively).Compared with NBW group and IUGR group,curcumin supplementation could increase the body weights of NC group and IC group at week 10(P>0.05,P>0.05;respectively)and week 11(P>0.05,P>0.05;respectively).(2)IUGR group had significantly lower weights heart,liver,spleen,kidney and body weight(P<0.05).Dietary curcumin supplementation with 400 mg/kg significantly decreased the weight and index of liver(P<0.05),and significantly increased the weight and index of spleen(P<0.05).(3)Concentrations of TNF-?,IL-1? and IL-6 in serum were significantly higher in the IUGR group than in the NBW group(P<0.05).Curcumin supplementation decreased concentrations of TNF-?(P>0.05),IL-1?(P<0.01),and IL-6(P<0.01)in serum.(4)Activities of AST and ALT in the serum of IUGR group were significantly increased(P>0.05).Curcumin suppelentation significantly decreased activities of ALT(P<0.01)and AST(P<0.05)in serum of IUGR group.(5)The concentrations of MDA,PC and 8-OHDG in the liver of IUGR group were significantly increased(P<0.05).Compared with the IUGR group,the concentrations of MDA,PC and 8-OHDG in the liver of the IC group were significantly decreased(P<0.05).(6)Activity of GSH-Px and content of GSH in serum of IUGR group were significantly lower(P<0.01),while activities of SOD,GR and GSH-Px in liver were significantly decreased(P<0.05),while concentration of GSSG(P<0.05)and GSSG:GSH value(P<0.01)were significantly increased.Compared with the IUGR group,concentration of GSH and activity of GSH-Px in serum,activity of GR and ceoncentration of GSH in liver of IC group were significantly increased(P<0.05),while concentration of GSSG and GSSG:GSH value in liver were significantly decreased(P<0.01).Compared with NBW group,concentration of GSH and activity of GSH-Px in serum,activities of SOD and GR in liver of NC group were significantly decreased(P<0.05),and hepatic GSSG:GSH value was significantly increased(P<0.05)in NC group.(7)The Il6 mRNA expression in the IUGR group was significantly increased(P<0.05),while the mRNA expressions of Gst(P<0.05),Nfe2l2,Hmox1,Gpx1 and Sod1(P>0.05)were decreased.Compared with the IUGR group,after curcumin treatment,the mRNA expression of Il1b was significantly decreased(P<0.05),while the mRNA expressions of Nfe2l2,Nqo1,Gst and Gpx1 were significantly increased(P<0.05).(8)The phosphorylation levels of hepatic I?B? and nuclear NF-?B in IUGR group were significantly increased(P<0.05),and the phosphorylation levels of cytoplasm NF-?B was significantly decreased(P<0.05).In addition,the phosphorylation levels of JAK2(P>0.05)and STAT3(P=0.01)in the liver of IUGR group were higher than those of NBW group and NC group.Compared with the IUGR group,the phosphorylation level of hepatic I?B? was significantly decreased in the IC group(P<0.05),and the phosphorylation levels of hepatic JAK2 and NF-?B in the nucleus and cytoplasm were decreased(P>0.05)in the IC group.It was obvious that curcumin supplementation might effectively alleviate inflammation and increase the antioxidant capacity of the liver in IUGR rats,and by regulating the I?B/NF-?B,JAK/STAT pathways,and activating the expressions of Nfe212 and downstream genes.5 Regulation of curcumin on the glucose and lipid metabolism in a rat model of IUGRIn experiment 5,the experimental design was same as experiment 4.Levels of hormones in serum,parameters of glucose and lipid metabolism in serum and hepatic,hepatic histological morphology,mRNA expressions of hepatic lipid metabolism,phosphorylation levels of hepatic IRS-1,GSK3?/?,Akt/PKB,PI3K and expressions of SREBP1 and PPAR were determined.The results showed that:compared with NBW group,(1)Levels of insulin(P>0.05),glucose(P<0.05)and HOMA-IR(P<0.05)in the serum of IUGR group were increased.Curcumin supplementation significantly decreased the levels of insulin,glucose and HOMA-IR in serum of IUGR rats(P<0.01).(2)Concentrations of TC and TG in the serum of IUGR group were significantly decreased(P<0.05).Curcumin supplementation could significantly decrease(P<0.05)concentration of HDL-C in serum and significantly increase(P<0.05)concentration of LDL-C in serum.Compared with NBW group,the concentrations of TC,TG and NEFA in the liver of IUGR group were significantly increased(P<0.05),and concentration of NEFA in the liver of NC group was also significantly decreased(P<0.05).Compared with the IUGR group,the concentrations of TC,TG and NEFA in the liver of IC group were significantly decreased(P<0.05).(3)Concentrations of glycogen in the liver of IUGR group and NC group were significantly decreased(P<0.05),and concentration of pyruvate in the liver of IUGR group and activity of PK in the liver of NC group was significantly increased(P<0.05),respectively.Compared with the IUGR group,the concentration of glycogen in the liver of IC group was significantly increased(P<0.05);after curcumin treatment,the concentration of pyruvate and activity of PK in IUGR rats were significantly decreased(P<0.05).(4)Activities of LPL(P<0.01),HL(P<0.05)and TL(P<0.05)in the liver of IUGR group were significantly decreased.Dietary curcumin supplementation significantly increased activities of LPL(P<0.01),HL(P<0.05),and TL(P<0.01)in the liver.(5)Normal histologic structures were observed in the liver of NBW and NC rats.In the liver sections of IUGR rats,vacuolisation and cell oedema were prevalent in the hepatocytes,and fat cells showed signs of mild denaturation.In the IC group,vacuolisation was significantly reduced and no fat cells were observed.(6)The mRNA expressions of Cd36,Srebf1 and Fasn in the liver of IUGR group were significantly up-regulated(P<0.05),while mRNA expressions of Ppara and HSL in the liver of IUGR group were significantly down-regulated(P<0.05).After curcumin treatment,the mRNA expressions of Ppara and HSL in the liver of IUGR rats were significantly up-regulated(P<0.05),while the mRNA expressions of Cd36,Srebf1 and Fasn in the liver were significantly down-regulated(P<0.05).(7)The phosphorylation levels of IRS-1(P>0.05),AKT(P<0.05)and GSK3?(P<0.05)in the liver of IUGR group were increased,and phosphorylation levels of GSK3? and PI3K were decreased in the liver(P>0.05).Compared with the IUGR group,the phosphorylation levels of IRS-1,AKT and GSK3? in the liver of the IC group were significantly decreased(P<0.05),while the phosphorylation levels of GSK3? and PI3K in the liver of IC group were increased(P>0.05).The protein expression of SREBP1 in IUGR rat was significantly increased(P<0.05),while the expression of PPAR was significantly lower than that of NBW group(P<0.05).After curcumin treatment,the expression of SREBP1 in the IUGR rat was significantly decreased(P<0.05),while the expression of PPARa in the liver of IC group was significantly increased(P<0.05).In conclusion,curcumin could effectively alleviate the insulin resistance of IUGR rats,which might be achieved by regulating the expression of insulin signaling pathway in the liver.Curcumin could also alleviate lipid accumulation in liver of IUGR rats by regulating target genes of SREBPs and lipid metabolism related genes,inhibiting lipid generation and promoting lipid decomposition.In conclusion,through the above five experiments,the present study showed that IUGR could cause a lot of adverse effects on newborn piglets,such as inflammatary damage,decreased hepatic ntioxidant capacity and disregulation of glucose and lipid metabolism in the liver.Therefore,we firstly investigated the effect of curcumin supplementation on the weaned piglets with IUGR.These results showed that curcumin could improve the growth performance,alleviate hepatic damage and increase antioxidant capacity of weaned piglets with IUGR,and the effect of curcumin on antioxidant capacity might be related to its regulation on Nrf2/Hmoxl pathway.Curcumin supplementation could also regulate the disorder metabolism of glucose and lipid in weaned piglets with IUGR,which might be related to the regulation on mRNA expression of related genes.Therefore,we further use a model of IUGR rats to investigate the related mechanism,and the results showed that the attenuation of curcumin on the hepatic inflammatory injury could be regulated by I?B?/NF-?B?JAK/STAT pathway.Moreover,curcumin supplementation could regulate the metabolism of glucose and lipid in the liver of IUGR rats by regulating insulin signaling pathway,SREBP and its target genes. |
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