Anti-diabetic activity of extract from Persea americana Mill. leaf via the activation of protein kinase B (PKB/Akt) in streptozotocin-induced diabetic rats

J Ethnopharmacol. 2012 May 7;141(1):517-25. doi: 10.1016/j.jep.2012.03.026. Epub 2012 Mar 26.


Ethnopharmacological relevance: The leaves of Persea americana Mill. (Lauraceae) have been popularly used in the treatment of diabetes in countries in Latin America and Africa.

Aim of the study: To investigate the hypoglycaemic properties and to determine the molecular mechanism by which the hydroalcoholic extract of the leaves of Persea americana reduce blood glucose levels in streptozotocin (STZ)-induced diabetes in rats via the enzymatic pathway of protein kinase B (PKB/Akt).

Methods: The hydroalcoholic extract of the leaves of Persea americana (0.15 and 0.3g/kg/day), vehicle and metformin (0.5g/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 and the expression of PKB in the liver and soleus muscle were determined by Western blot.

Results: The hydroalcoholic extract of the leaves of Persea americana reduced blood glucose levels and improved the metabolic state of the animals. Additionally, PKB activation was observed in the liver and skeletal muscle of treated rats when compared with untreated rats.

Conclusion: The results indicate that the hydroalcoholic extract of the leaves of Persea americana has anti-diabetic properties and possibly acts to regulate glucose uptake in liver and muscles by way of PKB/Akt activation, restoring the intracellular energy balance.

MeSH terms

  • Administration, Oral
  • Animals
  • Blood Glucose / drug effects
  • Diabetes Mellitus, Experimental / blood
  • Diabetes Mellitus, Experimental / drug therapy*
  • Diabetes Mellitus, Experimental / enzymology
  • Drinking / drug effects
  • Eating / drug effects
  • Energy Metabolism / drug effects
  • Enzyme Activation
  • Enzyme Activators / administration & dosage
  • Enzyme Activators / isolation & purification
  • Enzyme Activators / pharmacology*
  • Ethanol / chemistry
  • Glucose Tolerance Test
  • Hypoglycemic Agents / administration & dosage
  • Hypoglycemic Agents / isolation & purification
  • Hypoglycemic Agents / pharmacology*
  • Insulin / blood
  • Liver / drug effects*
  • Liver / enzymology
  • Male
  • Muscle, Skeletal / drug effects*
  • Muscle, Skeletal / enzymology
  • Persea* / chemistry
  • Phosphorylation
  • Phytotherapy
  • Plant Extracts / administration & dosage
  • Plant Extracts / isolation & purification
  • Plant Extracts / pharmacology*
  • Plant Leaves
  • Plants, Medicinal
  • Proto-Oncogene Proteins c-akt / metabolism*
  • Rats
  • Rats, Wistar
  • Signal Transduction / drug effects
  • Solvents / chemistry
  • Time Factors
  • Weight Gain / drug effects


  • Blood Glucose
  • Enzyme Activators
  • Hypoglycemic Agents
  • Insulin
  • Plant Extracts
  • Solvents
  • Ethanol
  • Proto-Oncogene Proteins c-akt