title: Chlorella modulates insulin signaling pathway and prevents high-fat diet-induced insulin resistance in mice.
abstract: OBJECTIVE
  The search for natural agents that minimize obesity-associated disorders is receiving special attention. In this regard, the present study aimed to evaluate the prophylactic effect of Chlorella vulgaris (CV) on body weight, lipid profile, blood glucose and insulin signaling in liver, skeletal muscle and adipose tissue of diet-induced obese mice.
  
  
  METHODS
  Balb/C mice were fed either with standard rodent chow diet or high-fat diet (HFD) and received concomitant treatment with CV for 12 consecutive weeks. Triglyceride, free fatty acid, total cholesterol and fractions of cholesterol were measured using commercial assay. Insulin and leptin levels were determined by enzyme-linked immunosorbent assay (ELISA). Insulin and glucose tolerance tests were performed. The expression and phosphorylation of IRβ, IRS-1 and Akt were determined by Western blot analyses.
  
  
  RESULTS
  Herein we demonstrate for the first time in the literature that prevention by CV of high-fat diet-induced insulin resistance in obese mice, as shown by increased glucose and insulin tolerance, is in part due to the improvement in the insulin signaling pathway at its main target tissues, by increasing the phosphorylation levels of proteins such as IR, IRS-1 and Akt. In parallel, the lower phosphorylation levels of IRS-1(ser307) were observed in obese mice. We also found that CV administration prevents high-fat diet-induced dyslipidemia by reducing triglyceride, cholesterol and free fatty acid levels.
  
  
  CONCLUSIONS
  We propose that the modulatory effect of CV treatment preventing the deleterious effects induced by high-fat diet is a good indicator for its use as a prophylactic-therapeutic agent against obesity-related complications.
authors: Department of Pharmacology/Hemocenter, State University of Campinas, Campinas, SP 13083-970, Brazil.
authors: Juliana Falcato
authors: JF
authors: Vecina
authors: Department of Internal Medicine, State University of Campinas, Campinas, SP 13081-970, Brazil.
authors: Alexandre Gabarra
authors: AG
authors: Oliveira
authors: Department of Internal Medicine, State University of Campinas, Campinas, SP 13081-970, Brazil.
authors: Tiago Gomes
authors: TG
authors: Araujo
authors: Food Science and Quality Center (CCQA), Food Technology Institute (ITAL), Campinas, SP 13070-178, Brazil.
authors: Sueli Regina
authors: SR
authors: Baggio
authors: Department of Pharmacology/Hemocenter, State University of Campinas, Campinas, SP 13083-970, Brazil.
authors: Cristiane Okuda
authors: CO
authors: Torello
authors: Department of Internal Medicine, State University of Campinas, Campinas, SP 13081-970, Brazil.
authors: Mario Jose Abdalla
authors: MJ
authors: Saad
authors: Department of Pharmacology/Hemocenter, State University of Campinas, Campinas, SP 13083-970, Brazil. Electronic address: mlsq@uol.com.br.
authors: Mary Luci de Souza
authors: ML
authors: Queiroz
mesh_terms: D000273:Adipose Tissue / Q000187:drug effects / Q000378:metabolism; D000818:Animals; D001786:Blood Glucose / Q000187:drug effects; D001835:Body Weight / Q000187:drug effects; D048408:Chlorella vulgaris / Q000737:chemistry*; D059305:Diet, High-Fat / Q000009:adverse effects; D050171:Dyslipidemias / Q000209:etiology / Q000517:prevention & control; D005951:Glucose Tolerance Test; D007328:Insulin / Q000378:metabolism*; D007333:Insulin Resistance; D020738:Leptin / Q000378:metabolism; D008055:Lipids / Q000097:blood; D008099:Liver / Q000187:drug effects / Q000378:metabolism; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D018482:Muscle, Skeletal / Q000187:drug effects / Q000378:metabolism; D009765:Obesity / Q000150:complications / Q000188:drug therapy*; D010766:Phosphorylation / Q000187:drug effects; D010936:Plant Extracts / Q000494:pharmacology*; D015398:Signal Transduction / Q000187:drug effects
chemical_list: D001786:Blood Glucose; D007328:Insulin; D020738:Leptin; D008055:Lipids; D010936:Plant Extracts
keywords: Chlorella vulgaris; Insulin resistance; Insulin signaling pathway; Obesity