title: Eicosapentaenoic acid-enriched phospholipid ameliorates insulin resistance and lipid metabolism in diet-induced-obese mice.
abstract: BACKGROUND
  Over the past two decades, a striking increase in the number of people with metabolic syndrome (MS) has taken place worldwide. With the elevated risk of not only diabetes but also cardiovascular morbidity and mortality, there is urgent need for strategies to prevent this emerging global epidemic. The present study was undertaken to investigate the effects of dietary eicosapentaenoic acid-enriched phospholipid (EPA-PL) on metabolic disorders.
  
  
  METHODS
  Male C57BL/6J mice (n = 7) were fed one of the following 4 diets for a period of 4 weeks: 1) a modified AIN-96G diet with 5% corn oil (control diet); 2) a high fat (20%, wt/wt) and high fructose (20%, wt/wt) diet (HF diet); 3) the HF diet containing 1% SOY-PL (SOY-PL diet); 4) the HF diet containing 1% EPA-PL (EPA-PL diet). The oral glucose tolerance test was performed. Plasma TG, TC, glucose, NEFA, insulin, leptin, adiponectin, TNF-α and IL-6 levels were assessed. In addition, hepatic lipid levels, lipogenic, and lipidolytic enzyme activities and gene expressions were evaluated.
  
  
  RESULTS
  Both EPA-PL and SOY-PL significantly inhibited body weight gain and white adipose tissue accumulation, alleviated glucose intolerance, and lowered both serum fasting glucose and NEFA levels substantially. Only EPA-PL significantly reduced serum TNF-α and IL-6 levels, and increased serum adiponectin level. EPA-PL was more effective in reducing hepatic and serum TG and TC levels than SOY-PL. Both EPA-PL and SOY-PL reduced the activities of hepatic lipogenic enzymes, such as FAS and G6PDH, but only EPA-PL significantly increased CPT, peroxisomal β-oxidation enzymes activities and CPT-1a mRNA level. Alterations of hepatic lipogenic gene expressions, such as FAS, G6PDH, ACC, SCD-1 and SREBP-1c were consistent with changes in related enzyme activities.
  
  
  CONCLUSIONS
  According to our study, EPA-PL supplementation was efficacious in suppressing body fat accumulation, and alleviating insulin resistance and hepatic steatosis by modulating the secretion of adipocytokines and inflammatory cytokines, suppression of SREBP-1c mediated lipogenesis and enhancement of fatty acid β-oxidation. These results demonstrate that EPA-PL is a novel beneficial food component for the prevention and improvement of metabolic disorders.
authors.affiliation: College of Food Science and Engineering, Ocean University of China, No,5 Yushan Road, Qingdao, Shandong Province 266003, PR China.
authors.forename: Xiaofang
authors.initials: X
authors.lastname: Liu
authors.forename: Yong
authors.initials: Y
authors.lastname: Xue
authors.forename: Chunhua
authors.initials: C
authors.lastname: Liu
authors.forename: Qiaoming
authors.initials: Q
authors.lastname: Lou
authors.forename: Jingfeng
authors.initials: J
authors.lastname: Wang
authors.forename: Teruyoshi
authors.initials: T
authors.lastname: Yanagita
authors.forename: Changhu
authors.initials: C
authors.lastname: Xue
authors.forename: Yuming
authors.initials: Y
authors.lastname: Wang
mesh_terms: D052242:Adiponectin / Q000378:metabolism; D000273:Adipose Tissue; D000818:Animals; D059305:Diet, High-Fat; D015118:Eicosapentaenoic Acid / Q000008:administration & dosage*; D005234:Fatty Liver / Q000188:drug therapy / Q000473:pathology; D005951:Glucose Tolerance Test; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D015850:Interleukin-6 / Q000097:blood; D050356:Lipid Metabolism; D050155:Lipogenesis / Q000187:drug effects* / Q000235:genetics; D008297:Male; D024821:Metabolic Syndrome / Q000378:metabolism; D051379:Mice; D008820:Mice, Obese; D010743:Phospholipids / Q000008:administration & dosage; D051780:Sterol Regulatory Element Binding Protein 1 / Q000097:blood; D014280:Triglycerides / Q000097:blood; D014409:Tumor Necrosis Factor-alpha / Q000097:blood
chemical_list: D052242:Adiponectin; D007328:Insulin; D015850:Interleukin-6; D010743:Phospholipids; D051780:Sterol Regulatory Element Binding Protein 1; D014280:Triglycerides; D014409:Tumor Necrosis Factor-alpha; D015118:Eicosapentaenoic Acid