title: Parkinsonia aculeata (Caesalpineaceae) improves high-fat diet-induced insulin resistance in mice through the enhancement of insulin signaling and mitochondrial biogenesis.
abstract: BACKGROUND
  The search for natural agents that minimize obesity-associated disorders is receiving special attention. Parkinsonia aculeata L. (Caesalpineaceae) has long been used in Brazil as a hypoglycaemic herbal medicine, without any scientific basis.
  
  
  OBJECTIVE
  In this context, we aimed to use molecular and physiological methods to study the effect of a hydroethanolic extract partitioned with ethyl acetate from the aerial parts of Parkinsonia aculeata (HEPa/EtOAc) on insulin resistance in a mouse model of diet-induced obesity (DIO).
  
  
  METHODS
  Firstly, C57BL/6J mice were fed either with standard rodent chow diet or a high-fat diet (HFD) for 12 consecutive weeks. Then, the animals were treated with HEPa/EtOAc at two doses (125 and 250mg/kg/day) or metformin (200mg/kg/day) for 16 days. At the end of the experiment, body weight, fat pad weight, fasting serum glucose (FSG), insulin (FSI) and leptin were measured. Homeostasis Model Assessment for Insulin Resistance (HOMA-IR) was also calculated. Glucose, insulin and pyruvate tolerance tests were performed. The expression and phosphorylation of IRβ(tyr), Akt(ser473), AMPKα and PGC1α in liver, muscle and adipose tissue were determined by Western blot analyses.
  
  
  RESULTS
  Herein we demonstrate for the first time an improvement in insulin resistance following HEPa/EtOAc administration in obese mice, as shown by increased glucose, insulin and pyruvate tolerance, as well as an improvement in FSG, FSI, HOMA-IR and circulating leptin levels, which together are in part due to enhancement of the insulin signaling pathway in its main target tissues. Surprisingly, the increase in activation of the AMPKα-PGC1-α axis by HEPa/EtOAc was similar to that produced by metformin treatment in the liver and muscle tissues.
  
  
  CONCLUSIONS
  In conclusion, P. aculeata appears to be a source of therapeutic agent against obesity-related complications.
authors.affiliation: Department of Physiology and Pharmacology, Federal University of Pernambuco, 50670-901 Recife, PE, Brazil; Department of Internal Medicine, State University of Campinas, 13081-970 Campinas, SP, Brazil. Electronic address: tigaraujo@hotmail.com.
authors.forename: Tiago Gomes
authors.initials: TG
authors.lastname: Araújo
authors.affiliation: Department of Internal Medicine, State University of Campinas, 13081-970 Campinas, SP, Brazil; Department of Physical Education, São Paulo State University (UNESP), 13506-900 Rio Claro, SP, Brazil.
authors.forename: Alexandre Gabarra
authors.initials: AG
authors.lastname: de Oliveira
authors.affiliation: Department of Internal Medicine, State University of Campinas, 13081-970 Campinas, SP, Brazil.
authors.forename: Juliana Falcato
authors.initials: JF
authors.lastname: Vecina
authors.affiliation: Department of Internal Medicine, State University of Campinas, 13081-970 Campinas, SP, Brazil.
authors.forename: Rodrigo Miguel
authors.initials: RM
authors.lastname: Marin
authors.affiliation: Department of Physiology and Pharmacology, Federal University of Pernambuco, 50670-901 Recife, PE, Brazil.
authors.forename: Eryvelton Souza
authors.initials: ES
authors.lastname: Franco
authors.affiliation: Department of Internal Medicine, State University of Campinas, 13081-970 Campinas, SP, Brazil.
authors.forename: Mario J
authors.initials: MJ
authors.lastname: Abdalla Saad
authors.affiliation: Department of Physiology and Pharmacology, Federal University of Pernambuco, 50670-901 Recife, PE, Brazil. Electronic address: mbsm@ufpe.br.
authors.forename: Maria Bernadete
authors.initials: MB
authors.lastname: de Sousa Maia
mesh_terms: D000273:Adipose Tissue / Q000187:drug effects / Q000378:metabolism; D000818:Animals; D001786:Blood Glucose / Q000187:drug effects; D001835:Body Weight / Q000187:drug effects; D001938:Brazil; D059305:Diet, High-Fat / Q000009:adverse effects; D004041:Dietary Fats / Q000009:adverse effects; D007887:Fabaceae / Q000737:chemistry*; D005215:Fasting; D005951:Glucose Tolerance Test / Q000379:methods; D007328:Insulin / Q000378:metabolism*; D007333:Insulin Resistance / Q000502:physiology*; D020738:Leptin / Q000378:metabolism; D008099:Liver / Q000187:drug effects / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008928:Mitochondria / Q000187:drug effects* / Q000378:metabolism; D009765:Obesity / Q000378:metabolism; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D015398:Signal Transduction / Q000187:drug effects*
chemical_list: D001786:Blood Glucose; D004041:Dietary Fats; D007328:Insulin; D020738:Leptin; D010936:Plant Extracts
keywords: AMPKα; Herbal medicine; Insulin resistance; Mitochondrial biogenesis; Obesity; Parkinsonia aculeata