The Anti-atherogenic Effects Of Lycopene And Proteomics Of Low Density Lipoprotein In Rabbits Plasma

Background:Some studies had found that atherosclerosis was an excessive chronic inflammatory hyperplasia at some region of blood vessel due to the injury of vascular endothelial and smooth muscle cells induced by various risk factors such as virus,machinery damage,immune complex,especially oxidative low density lipoprotein(ox-LDL)and so on.Scientific evidence indicates that oxidation of low density lipoproteins(LDL),which carry cholesterol in the blood stream plays an important role in the development of atherosclerosis.Thus,application adequate antioxidants may restrain or postpone the development of atherosclerosis.Recent investigations showed that all categories of high-risk patients benefit from LDL-lowering therapy with statins.Fluvastatin is a widely accepted drug for treatment in patient with coronary atherosclerosis because of the antioxidation and suppression of LDL levels. But cost and risk for side effects should be taken into consideration while use fluvastatin. Thus,it would be valuable to search for substances or ingredients with antioxidative effects in our daily food.Epidemiologic investigations revealed that lycopene could reduce and prevent the development of cardiovascular disease.Experimental studies showed that it had many important bioactivities,e.g.quenching singlet oxygen, eliminating oxygen free radicals,blocking lipid peroxidation,suppressing cell reproduction,reinforcing immunity and inducing gap junction intercellular communication.The molecular mechanisms underlying the relationship between lipoprotein and the risk of atherosclerosis are not clear.Therefore,detailed information about the protein composition of lipoprotein may contribute to reveal its role in atherogenesis and the mechanisms that lead to coronary disease in human being.Now there have been few laboratorial evidences about the effect of lycopene on diseases prevention,especially there have been no reports about the pharmacological effect of lycopene in vivo.Objectives:The anti-atherogenic effects of lycopene and proteomics of low density lipoprotein in rabbits plasma. Methods:(1)Forty adult male rabbits were divided into five groups,fed with ordinary diet,high lipid diet,high-lipid diet plus 4 mg/kg lycopene,high-lipid diet plus 12 mg/kg lycopene and high-lipid diet plus 10 mg/kg fluvastatin,respectively.Both lycopene and fluvastatin were administered intragastrieally.The level of serum total cholesterol(TC),total triglyceride(TG),high density Iipoprotein-cholesterol(HDL-C), low density lipoprotein-cholesterol(LDL-C),total antioxidant capacity(T-AOC),and malondialdehyde(MDA)were measured before,and after 4 and 8 weeks of experimental treatment.In addition,plasma levels of lycopene,oxidized LDL(ox-LDL) and serum nitric oxide(NO),interleukin 1(IL-1)were measured after the experiment. The area of atherosclerotic plaque and the pathological changes of aorta were evaluated. (2)Application proteomics technique approach influence of lycopene to LDL protein in rabbits plasma(induced atherosclerosis by high-fat diet).Results:1.Compared with the control,the level of TC,TG,LDL-C,MDA,ox-LDL and IL-lwere increased and T-AOC and NO were decreased in the animals with high-fat diet(p＜0.05).The changes in these indicators were decreased in the lycopene group and fluvastain group compared with high-fat group(p＜0.05).In this case,the data showed that lycopene was better than the fluvastatin intervention. Morphological analysis revealed that both lycopene and fluvastatin markedly reduced the formation of the plague and pathological changes of aorta compared with the rabbits in model group which received no drug interventions.2.After the ultracentrifugation extraction of the rabbit plasma LDL,we determined that the LDL protein content of 12mg/(kg bw·d)lycopene group was 0.56μg/μl and fluvastain group was 0.34μg/μl.The LDL proteins were systematically identified by SDS-PAGE combined with ESI MS/MS.One hundred and twenty two protein were found in thirty six gel band altogether.Among them 12mg/(kg bw·d)lycopene group identified fifty-eight proteins which had twenty-five Apo B and the left sixty-four from fluvastain group which had seventeen Apo B.Conclusion:1.Our results in this study show that lycopene can attenuates the formation of atherosclerotic plaques,inhibits the increase of serum TC,TG,MDA,ox-LDL,IL-1, and LDL-C,and inhibits decrease the level of T-AOC and NO in high-fat diet rabbits,but not significant change are found in HDL-C.Morphological changes of artery in 12 mg/(kg bw·d)lycopene group is similar to fluvastatin group in rabbits with high-fat diet.2.Lycopene controls speed of synthetize of cholesterol by inhibition HMGCoA reducase in rabbits on high-fat diet.It is assumed that the anti-atherogenic effect of lycopene is associated with improved lipid homostasis,anti-oxidation,inhibition of ox- LDL modification,protection of vascular endothelium and anti-inflammation, inhibition generation of vascular smooth muscle cell.3.The LDL protein content of 12mg/(kg bw·d)lycopene group is 0.56μg/μl and that of fluvastain group is 0.34μg/μl.The LDL proteins were systematically identified by SDS-PAGE combined with ESI MS/MS.One hundred and twenty two protein were found in thirty six gel band altogether.Among them 12mg/(kg bw·d)lycopene group identified fifty-eight proteins which has twenty-five Apo B and the left sixty-four from fluvastain group which has seventeen Apo B.Lycopene is mainly functioning as the regulator of the low density lipoprotein receptor to control the synthesis of cholesterol in vivo.4.Besides Apo B,LDL associated proteins of lycopene group contains 13 proteins, which include Apo E,Apo D,Apo A-Ⅰ,cell-surface antigen 4F2,ADP/ATP carrier protein(2,T1),solute cartier family 7,unnaned protein,serum albumin,β-lactoglobulin,calcium binding protein A16,myoglobin,lysozyme,and chymotrypsin.LDL associated proteins of fluvastain group contains 21 proteins, which include Apo E,Apo D,Apo A-Ⅰ,Apo C-ⅠApo E,Apo D,Apo A-Ⅰ, Apo C-Ⅰ,cell-surface antigen 4F2,leucocyte antigen,HLA(B5301,B),unnaned protein,ADP/ATP carrier protein(Ⅰ,T1),ATPase,solute carrier familyⅠ, ubiquinol-cytochrome c reductase core proteinⅠ,β-lactoglobulin,α-sl-casein, CA-Ⅱ,serum albumin,myoglobin,lysozyme C,Chain B,transferrin,and AT-2.Systematically analysis of the Apo protein-protein interaction and the protein complex is on schedule and it can be a feasible strategy for searching the effective pathway of the proteins in vivo.