Effects Of Virgin Grape Seed Oil On Improving Lipid Metabolism Of High-fat Diet Mice

Long-term high-fat diets can induce lipid metabolism disorders and oxidative stress in the body,leading to a series of chronic diseases associated with disorders of lipid metabolism,such as obesity,cardiovascular disease,and type 2 diabetes.Virgin grape seed oil is rich in polyunsaturated fatty acids,V_E(tocopherols and tocotrienols),phytosterols,squalene,polyphenols and other functional active ingredients,becoming the hottest topics in the study of edible vegetable oils.Studies have shown that virgin grape seed oil has antioxidant,hypolipidemic,anti-aging,anti-cancer and other physiological effects,but the mechanism of action of virgin grape seed oil on the regulation of physiological functions in vivo remain largely unresolved.This article explores the effect of virgin grape seed oil on the regulation of lipid metabolism in high-fat diets mice under the condition of consistent energy intake,which has great significance for further increasing the comprehensive application of grape seed resources.First,under the condition of consistent energy intake,the fat in the high-fat diet was replaced with lard,corn oil and virgin grape seed oil,and the effects of total replacement of virgin grape seed oil on improving lipid metabolism disorders in mice were preliminary investigated.Thirty-six C57BL/6J male mice were randomly divided into three groups:lard group(Lard),corn group(CO)and virgin grape seed oil group(GSO).Glucose tolerance and insulin tolerance were measured during the feeding period.After the mice were sacrificed,the hepatic morphological analysis was performed by microscopy.The concentrations of TC,TG,HDL-C,LDL-C,FFA in the serum and the level of ALT,AST in the liver of mice were measured.The results showed that compared with Lard group,the final body weight and body weight gain of GSO group mice were reduced by 8.3%and 18.3%,respectively;the concentrations of TC,TG,LDL-C,FFA in the serum and the level of ALT,AST in the liver were significantly decreased(p<0.05).Besides,total replacement of virgin grape seed oil can significantly improve glucose tolerance and insulin tolerance in mice.Hepatic morphological results show that total replacement of virgin grape seed oil can significantly reduce liver fat deposition and fat cell size.Then,under the condition of consistent energy intake,the lard composition in the high-fat diet remains the same.To study effects of partial replacement of virgin grape seed oil on improvement of lipid metabolism disorders of high fat diet in mice,we replace plant oil with lard,corn oil and virgin grape seed oil,respectively.Forty-eight C57BL/6J male mice were randomly divided into four groups:normal control group(ND),corn oil group(CO 60%),virgin grape seed oil group(GSO 60%)and lard group(Lard 60%).The body weight of the mice was measured every week.Glucose tolerance,insulin tolerance,fasting blood glucose,and energy metabolism of the mice were measured during the feeding period.After the mice were sacrificed,the hepatic morphological analysis was performed by microscopy.Biochemical indexes in serum,antioxidant factors in the liver were measured.In additions,The inflammatory factors in the liver and the leptin and adiponectin in the adipose tissue were measured by ELISA.RT-qPCR was used to analyze the liver gene expression of PPAR-?,ACC-1,FAS,SREBP-1c,SCD-1 and ACOX-1,adipose tissue gene expression of IL-6,TNF-?and MCP-1.The results showed that compared with Lard60%group,the body weight and weight gain of GSO60%mice were reduced by 6.22%and 12.97%,respectively;respiratory exchange rate(RER),energy expenditure,autonomic activity,glucose tolerance and insulin tolerance in GSO60%mice were significantly increased(p<0.05);the concentrations of TC,TG,LDL-C,FFA,insulin,glucagon and HbA1c in the serum were significantly lower(p<0.05);the level of CAT,SOD,GSH-PX and MDA in the liver were significantly increased and decreased respectively(p<0.05);ELISA results showed the level of inflammatory cytokines IL-6 and TNF-?in the liver decreased significantly(p<0.05),the level of leptin and adiponectin in adipose tissue were significantly decreased and increased respectively(p<0.05).HE staining and oil red O staining results showed that partial replacement of virgin grape seed oil could improve the liver tissue damage by reducing the deposition of hepatic fat and size of fat cells to a certain extent of high fat diet.The results of RT-qPCR showed that partially replaced virgin grape seed oil could increase the expression of PPAR-?gene in the liver and decrease the expression of ACC-1,FAS,SREBP-1c in the liver and inflammatory cytokines IL-6,TNF-?and MCP-1 in the adipose tissue.Finally,The effects of fatty acids,unsaponifiables and polyphenols of virgin grape seed oil on improving lipid metabolism disorders induced by high fat diet in mice were preliminary investigated.Forty-five C57BL/6J male mice were randomly divided into 5 groups:lard group(Lard),refined grape seed oil(GSE)group,refined grape seed oil and unsaponifiable group(GSE+UN),refined grape seed oil and polyphenols(GSE+PO)group,refined grape seed oil,unsaponifiables and polyphenols(GSE+UN+PO)group.The glucose tolerance and fasting blood glucose of mice were measured during the experiment.the levels of TC,TG,ALT,AST and insulin in the serum of the mice were determined after the mice were sacrificed.The results showed that compared with the Lard group,the unsaturated fatty acids,unsaponifiables and polyphenols functional components in virgin grape seed oil can significantly reduce the body weight and the accumulation of liver and fat of mice induced by high-fat diet,the levels of TC,TG and insulin in the serum of the mice(p<0.05).In additions,unsaponifiables and polyphenols components of grape seed oil can also effectively improve the glucose tolerance in mice,and unsaponifiables are more effective than polyphenols in improving lipid metabolism in mice.