title: Nigella sativa seed decreases endothelial dysfunction in streptozotocin-induced diabetic rat aorta.
abstract: OBJECTIVE
  Diabetes is an important risk factor for cardiovascular events. The great percent of morbidity in patients with diabetes is due to endothelial dysfunction. The present study investigated the effects of hydroalcholic extract of Nigella sativa (N. sativa) on contractile and dilatation response of isolated aorta in streptozotocin (STZ)-induced diabetic rat.
  
  
  METHODS
  Rats were divided into six experimental groups (control, untreated STZ-diabetic, and N. sativa hydroalcholic extract or metformin-treated diabetic rats). Treated rats received N. sativa extract (100, 200, and 400 mg/kg) or metformin (300 mg/kg) by gavage, daily for 6 weeks. Isolated rat thoracic rings were mounted in an organ bath system then contractile and dilatation responses induced by phenylephrine (PE), acetylcholine (ACh), potassium chloride (KCl), and sodium nitroprusside (SNP) were evaluated in different situations.
  
  
  RESULTS
  The lower concentrations of N. sativa seed extract (DE 100 and DE 200) and metformin significantly reduced the contractile responses to higher concentrations of PE (10(-6) - 10(-5) M) compared to diabetic group (p<0.05 to p<0.01). The relaxation response to Ach 10(-8) M, was increased in DE 200 and metformin groups compared to diabetic group (p<0.05). The relaxation responses to Ach 10(-7) - 10(-5) M were significantly higher in all treated groups compared to diabetic group (p<0.05 to p<0.001).
  
  
  CONCLUSIONS
  Chronic administration of N. sativa seed extract has a significant hypoglycemic effect and improves aortic reactivity to vasoconstrictor and vasodilator agents in STZ-induced diabetic rats.
authors.affiliation: Department of Physiology, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: Abbasali
authors.initials: A
authors.lastname: Abbasnezhad
authors.affiliation: Department of Physiology, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran ; Cardiovascular Research Center, Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: Saeed
authors.initials: S
authors.lastname: Niazmand
authors.affiliation: Department of Physiology, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran ; Neurogenic Inflammation Research Center, Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: Maryam
authors.initials: M
authors.lastname: Mahmoudabady
authors.affiliation: Department of Biochemistry, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Soukhtanloo
authors.affiliation: Department of Immunology , School of Medicine , Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: Seyed Abdolrahim
authors.initials: SA
authors.lastname: Rezaee
authors.affiliation: Department of Physiology, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: Seyed Mojtaba
authors.initials: SM
authors.lastname: Mousavi
keywords: Diabetes mellitus; Endothelial dysfunction; Isolated aorta; Nigella sativa; Rat