Study On The Effect Of Combined Intake Of High Fructose Corn Syrup And High-fat Diet On Lipid Metabolism And Its Mechanism In Mice

Objective: Child obesity is the result of a combination of genetic,environmental,and socioeconomic factors.Unhealthy living habits and unreasonable diet patterns are common risk factors that lead to obesity.For example,a long-term high-sugar and high-fat diet can cause lipid metabolism disorders and seriously threaten people’s health.In recent years,children’s dietary patterns have gradually changed,and the intake of high fructose corn syrup and high-fat diet has gradually increased.Studies have found that excessive intake of both is related to the prevalence of obesity.Both white adipose tissue and liver are the main sites of lipid metabolism in the body,and they are involved in the regulation of lipid synthesis and lipolysis.However,there are relatively few research reports on adipose tissue.Current research mainly focuses on the effect of high fructose corn syrup and high-fat diet alone on liver lipid metabolism,but the effect and mechanism of the combined feeding of the two on adipose tissue and liver tissue lipid metabolism in mice are still unclear.Therefore,a model of infant mice ingesting high fructose corn syrup and high-fat diet was used to simulate children’s consumption of sugar-sweetened beverages and high-fat diet,and to explore the effects of fructose syrup and high-fat diet intake on lipid synthesis,lipolysis and the progress of childhood obesity,and to provide basic data for the occurrence of childhood obesity and its health hazards.Methods: Seventy-two early weaning C57BL/6 male mice were assigned randomly into control group,high fructose corn syrup group,high-fat group and combination group,and the body weight,food intake and water intake were documented every week.After 12 weeks,an ELISA kit was used for discovering blood lipid levels and tissue triglyceride(TG)levels.We use HE staining method to observe the histopathological morphology of adipose and liver.The SREBP-1c,FAS and HSL protein expression levels in adipose and liver tissue were measured by Western blot.RT-PCR method was used to discover the expression levels of epididymal adipose tissue and liver related to fat synthesis and lipolysis.Results: 1.After 12 weeks of diet intervention,energy intake,body weight and organ coefficient of the mice showed that compared with the control group,the energy intake and body weight of the high fructose corn syrup group were not significantly different(P>0.05separately),but the energy intake and body weight raised considerably in the high-fat group and the combination group(P<0.05 separately).The increasing amount of the energy intake and body weight of mice in the combination group were greater than that the high fructose corn syrup group(P<0.05 separately).The body weight of the combination group was greater than that high-fat group in the mice(P<0.05).Compared with the control group,the fat weight and coefficient of the high fructose corn syrup group,the high-fat group and the combination group were notably elevated(P<0.01 separately).The fat weight and fat coefficient of the combination group were greater than each group in the mice(P<0.01separately),suggesting that the mice in the combination group had more significant fat accumulation.2.Detection of blood lipid levels and TG content in tissues found,compared with the control group,the serum levels of TG,total cholesterol and low-density lipoprotein cholesterol in the high fructose corn syrup group,high-fat group and combination group were noticeably increased(P<0.05 separately),and the high-density lipoprotein cholesterol level was significantly reduced(P<0.05).Compared with the high fructose corn syrup group,the TG level in the serum of mice in the combination group was notably elevated(P<0.01).Compared with the high-fat group,the serum TG and LDL-C levels of the mice in the combination group were significantly increased(P<0.01separately),and the HDL-C levels were significantly decreased(P<0.01).Compared with the control group,the TG content in the adipose tissue and liver tissue of the mice in the high fructose corn syrup group,the high-fat group and the combination group was hugely increased(P<0.05 separately),and the content of TG in the combined group was markedly higher than that in single group(P<0.01).3.The results of detection of lipid metabolismrelated indicators showed that compared with the control group,the fatty acid synthase(FAS)and sterol regulatory element binding protein 1c protein(SREBP-1c)expression levels in the epididymal adipose tissue and liver of the high fructose corn syrup group,the high-fat group and the combination group were significantly increased(P<0.05 separately),and the hormone-sensitive lipase protein(HSL)expression level obvious reduction(P<0.05).The FAS protein expression level in epididymal adipose tissue and liver of the combined group were extraordinary higher than that in the single-intake group in the mice(P<0.05 separately),and the HSL protein expression level in adipose tissue was dramatically lower than that in the single-intake group(P<0.05).The SREBP-1c protein expression level in liver was significantly higher than that in the single intake group(P<0.05).Conclusion: High fructose corn syrup and high-fat diet intake can cause obesity and dyslipidemia,promote fat synthesis,inhibit fat decomposition,and ultimately lead to lipid accumulation in adipose tissue and fatty degeneration in liver tissue,and the combined intake of the two is more significant.