Nutritional And Bioactive Compounds In Bok-choy,and Their Impact On Physiology And Pathology Of Lipid Metabolism In Syrian Golden Hamsters

Bok-choy(Brassica rapa ssp.chinensis)is an important annual or biennial leafy vegetable and packed with impressive health benefits.Bok choy is rich in many nutritive and non-nutritive bioactive compounds.Nutritive compounds include vitamins,minerals,dietary fiber,etc.;Non-nutritive bioactive compounds include flavonoids,anthocyanins,kaempferol,quercetin and so on.These bioactive compounds have protective effects on chronic diseases,such as inflammation,Alzheimer' s,cardiovascular,and other diseases.Broadly,bok-choy is known for its benefit as part of a human diet.However,deeper investigations of the effects of bok-choy on health are still insufficient.To investigate the beneficial effects of two cultivars of bok-choy,‘Suzhouqing'(green cultivar)and‘Ziluolan'(purple cultivar)on growth performance,lipid metabolism and related genes expressions in Syrian golden hamster.Fifty-six male Syrian golden hamsters(6-month-old)were randomly assigned into 6 groups;normal diet(A),high-fat diet(B),high fat diet+5%‘Suzhouqing'(C),High fat diet+7%‘Suzhouqing'(D),High fat diet+5%‘Ziluolan'(E)and High fat diet+7%‘Ziluolan'(F)fed for 56 consecutive days.On day 0,28 and 56,blood and liver samples were collected to examine lipid profile,liver enzymes activity,histomorphology and related gene expressions.The results showed that group B had significantly increased levels of total cholesterol,triglycerides,low-density lipoprotein cholesterol,alanine aminotransferase,aspartate aminotransferase and alkaline phosphatase,and impaired levels(P<0.05)of highdensity lipoprotein cholesterol compared with group A.Group D,E and F had significantly reduced levels of total cholesterol,triglycerides,low-density lipoprotein cholesterol,alanine aminotransferase,aspartate aminotransferase and alkaline phosphatase,while the level of high-density lipoprotein cholesterol was significantly increased compared with group B.Remarkably,the mRNA expressions of CCAAT enhancer binding protein alpha(CEBP-?),diacylglycerol o-acyltransferase 1(DGAT1),lipoprotein lipase(LPL),fatty acid synthase(FASN)and 3-hydroxy-3-methylglutaryl-CoA(HMG-CoA)were significantly upregulated and carnitine palmitoyl tranferase 2(CPT2),cytochrome P450 family 27 subfamilies A member 1(Cyp27Al)and proliferator activated receptor alpha(PPAR-?)were significantly downregulated in group B compared with group A.However,in group D,E and F,the mRNA expression levels of CCAAT enhancer binding protein alpha,DGAT1,LPL,FASN and HMG-CoA were significantly down-regulated and CPT2,Cyp27A1 and PPAR-a were significantly up-regulated compared with group B.We investigated the anti-obesity and anti-hyperlipidemic effects of bok-choy on Syrian golden-hamsters fed with high fat diet.The results showed that HFD increased the body weight of hamsters by 24.50%compare to normal diet,but Supplementation of 7%SZQ and 7%ZLL reduced body weight by 11.01%and 17.20%respectively compare to HFD.The antioxidant activities of glutathione peroxidase(GSH-Px),superoxide dismutase(SOD),and glutathione(GSH)content in 7%SZQ+HFD,and 7%ZLL+HFD groups were(P<0.05)significantly higher and malondialdehyde(MDA)content significantly(P<0.05)lower compared to HFD group.Furthermore,the mRNA expression levels of stearoyl-CoA desaturase(SCD-1),stearoyl-CoA desaturase(SCD-2),peroxisome proliferator-activated receptor-?(PPAR?),fatty acid synthase(FAS),and liver X receptor(LXR-a)were significantly(P<0.05)increased in HFD compared to 7%SZQ and 7%ZLL supplementation group.In conclusion,bok-choy diet has anti-obesity and antihyperlipidemia protective effects on hamsters.7%Ziluolan supplement has better effects on preventing obesity and hyperlipidemia.In conclusion,different amount of bok-choy added to the diets incredibly improved the lipid-profile,enhanced liver enzymes activities,antioxidant activities and related genes expression.Moreover,bok-choy diet has shown healthier effects on preventing obesity and hyperlipidemia.Furthermore,the hamsters supplemented with 7%‘Ziluolan' exhibited the better performances among all the other highfat groups,showed that‘Ziluolan',which was rich in anthocyanin,could be a great alternative for reduction of fat accumulation in the body and conserving health.