title: Hypoglycaemic activity and molecular mechanisms of Caesalpinia ferrea Martius bark extract on streptozotocin-induced diabetes in Wistar rats.
abstract: BACKGROUND
  The tea from the stem bark of Caesalpinia ferrea Martius (Leguminosae) has been popularly used in the treatment of diabetes in Brazil.
  
  
  OBJECTIVE
  To investigate the hypoglycaemic properties and to elucidate the mechanisms by which the aqueous extract of the stem bark of Caesalpinia ferrea reduces blood glucose levels in streptozotocin-induced diabetic rats via the enzymatic pathways of protein kinase B (PKB/Akt), AMP-activated protein kinase (AMPK) and acetyl-CoA carboxylase (ACC).
  
  
  METHODS
  The aqueous extract of the stem bark of Caesalpinia ferrea (300 and 450 mg/kg/day), vehicle and metformin (500 mg/kg/day) were administered orally to STZ-diabetic rats (n = 7/group) for 4 weeks. Changes in body weight, food and water intake, fasting glucose levels and oral glucose tolerance were evaluated. Phosphorylation (P) and the expression of Akt, AMPK and ACC in the liver and skeletal muscle were determined using Western blot.
  
  
  RESULTS
  The aqueous extract of the stem bark of Caesalpinia ferrea reduced blood glucose levels and improved the metabolic state of the animals. P-Akt was increased in the liver and skeletal muscle of the treated animals, P-AMPK was reduced only in the skeletal muscle of these animals and P-ACC was reduced in both when compared with untreated rats.
  
  
  CONCLUSIONS
  The results indicate that the aqueous extract of the stem bark of Caesalpinia ferrea has hypoglycaemic properties and possibly acts to regulate glucose uptake in liver and muscles by way of Akt activation, restoring the intracellular energy balance confirmed by inhibition of AMPK activation.
authors.affiliation: Department of Pharmaceutical Sciences, Federal University of Pernambuco, Recife 50670-901, Brazil.
authors.forename: C F B
authors.initials: CF
authors.lastname: Vasconcelos
authors.forename: H M L
authors.initials: HM
authors.lastname: Maranhão
authors.forename: T M
authors.initials: TM
authors.lastname: Batista
authors.forename: E M
authors.initials: EM
authors.lastname: Carneiro
authors.forename: F
authors.initials: F
authors.lastname: Ferreira
authors.forename: J
authors.initials: J
authors.lastname: Costa
authors.forename: L A L
authors.initials: LA
authors.lastname: Soares
authors.forename: M D C
authors.initials: MD
authors.lastname: Sá
authors.forename: T P
authors.initials: TP
authors.lastname: Souza
authors.forename: A G
authors.initials: AG
authors.lastname: Wanderley
mesh_terms: D055372:AMP-Activated Protein Kinases / Q000378:metabolism; D000103:Acetyl-CoA Carboxylase / Q000378:metabolism; D000284:Administration, Oral; D000818:Animals; D001786:Blood Glucose / Q000187:drug effects* / Q000378:metabolism; D015153:Blotting, Western; D001835:Body Weight / Q000187:drug effects; D029911:Caesalpinia / Q000737:chemistry; D003921:Diabetes Mellitus, Experimental / Q000097:blood / Q000188:drug therapy*; D004326:Drinking / Q000187:drug effects; D004435:Eating / Q000187:drug effects; D004734:Energy Metabolism / Q000187:drug effects; D005951:Glucose Tolerance Test; D007004:Hypoglycemic Agents / Q000008:administration & dosage / Q000302:isolation & purification / Q000494:pharmacology*; D008099:Liver / Q000187:drug effects / Q000201:enzymology; D008297:Male; D008687:Metformin / Q000494:pharmacology; D018482:Muscle, Skeletal / Q000187:drug effects / Q000201:enzymology; D010766:Phosphorylation; D024301:Plant Bark; D010936:Plant Extracts / Q000008:administration & dosage / Q000302:isolation & purification / Q000494:pharmacology*; D010946:Plants, Medicinal; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D015398:Signal Transduction / Q000187:drug effects; D013997:Time Factors
chemical_list: D001786:Blood Glucose; D007004:Hypoglycemic Agents; D010936:Plant Extracts; D008687:Metformin; D051057:Proto-Oncogene Proteins c-akt; D055372:AMP-Activated Protein Kinases; D000103:Acetyl-CoA Carboxylase