title: Molecular approach to identify antidiabetic potential of Azadirachta indica.
abstract: BACKGROUND
  Azadirachta indica (Neem) is a medicinal plant, used in Ayurveda for treating various diseases, one of which is diabetes mellitus. It is known to possess antiinflammatory, antipyretic, antimicrobial, antidiabetic and diverse pharmacological properties. However, the molecular mechanism underlying the effect of A. indica on insulin signal transduction and glucose homeostasis is obscure.
  
  
  OBJECTIVE
  The aim was to study the effects of A. indica aqueous leaf extract on the expression of insulin signaling molecules and glucose oxidation in target tissue of high-fat and fructose-induced type-2 diabetic male rat.
  
  
  METHODS
  The oral effective dose of A. indica leaf extract (400 mg/kg body weight [b.wt]) was given once daily for 30 days to high-fat diet-induced diabetic rats. At the end of the experimental period, fasting blood glucose, oral glucose tolerance, serum lipid profile, and the levels of insulin signaling molecules, glycogen, glucose oxidation in gastrocnemius muscle were assessed.
  
  
  RESULTS
  Diabetic rats showed impaired glucose tolerance and impairment in insulin signaling molecules (insulin receptor, insulin receptor substrate-1, phospho-IRS-1(Tyr632), phospho-IRS-1(Ser636), phospho-Akt(Ser473), and glucose transporter 4 [GLUT4] proteins), glycogen concentration and glucose oxidation. The treatment with A. indica leaf extract normalized the altered levels of blood glucose, serum insulin, lipid profile and insulin signaling molecules as well as GLUT4 proteins at 400 mg/kg b.wt dose.
  
  
  CONCLUSIONS
  It is concluded from the present study that A. indica may play a significant role in the management of type-2 diabetes mellitus, by improving the insulin signaling molecules and glucose utilization in the skeletal muscle.
authors.affiliation: Department of Medical Biochemistry, Bharath University, Selaiyur, Chennai, India.
authors.forename: K
authors.initials: K
authors.lastname: Satyanarayana
authors.affiliation: Department of Pharmacology, Sakshi Medical College and Research Centre, Myana, Chennai, India.
authors.forename: K
authors.initials: K
authors.lastname: Sravanthi
authors.affiliation: Department of Medical Biochemistry, Bharath University, Selaiyur, Chennai, India.
authors.forename: I Anand
authors.initials: IA
authors.lastname: Shaker
authors.affiliation: Department of Zoology, Ethiraj College for Women, Chennai, India.
authors.forename: R
authors.initials: R
authors.lastname: Ponnulakshmi
keywords: Azadirachta indica; high-fat diet; insulin resistance; type-2 diabetes