title: Co-administration of walnut (Juglans regia) prevents systemic hypertension induced by long-term use of dexamethasone: a promising strategy for steroid consumers.
abstract: BACKGROUND
  The long-term consumption of glucocorticoids (GCs) may induce serious adverse effects such as hypertension. There is sufficient evidence related to the benefit of walnuts on the cardiovascular system.
  
  
  OBJECTIVE
  This study assesses the effect of methanol extract of walnut [Juglans regia L. (Juglandaceae)] on dexamethasone-induced hypertension and the possible mechanisms in Wistar rats.
  
  
  METHODS
  Animals were randomized into control, kernel extract (100 and 200 mg/kg/d, orally), dexamethasone (0.03 mg/kg/d, subcutaneously), dexamethasone + kernel (100 and 200 mg/kg/d, separately), and dexamethasone + captopril (25 mg/kg/d, orally) groups. Animals were treated with water, kernel extract or captopril by gavage 4 d before and during 11 d of saline or dexamethasone treatment. On the 16th day, blood pressure (BP) was recorded and blood samples were collected to measure nitric oxide (NO). Animal hearts were frozen for measurement of malondialdehyde (MDA) and glutathione peroxidase (GPX).
  
  
  RESULTS
  Dexamethasone increased the diastolic BP and MDA/GPX ratio in comparison with control group (128 ± 7 vs. 105 ± 3 mmHg, p < 0.05 and 0.2 ± 0.046 vs. 0.08 ± 0.02, p < 0.05). Combination of dexamethasone and walnut (200 mg/kg) prevented the dexamethasone-induced diastolic hypertension (109 ± 3 vs. 128 ± 7 mmHg; p < 0.05), increased the GPX level (14.8 ± 1.46 vs. 5.1 ± 0.64 unit/mg, p < 0.05), reduced the MDA/GPX ratio (0.16 ± 0.015 vs. 0.2 ± 0.046) and improved serum NO level.
  
  
  CONCLUSIONS
  Similar to captopril, walnut extract normalized dexamethasone-induced hypertension. A part of this beneficial effect apparently involves maintaining balance of the redox system and NO production.
authors.affiliation: a Cardiovascular Research Center , Institute of Basic and Clinical Physiology Sciences, Kerman University of Medical Sciences , Kerman , Iran.|b Department of Physiology and Pharmacology, School of Medicine , Kerman University of Medical Sciences , Kerman , Iran.|c Physiology Research Center , Kerman University of Medical Sciences , Kerman , Iran.
authors.forename: Siyavash
authors.initials: S
authors.lastname: Joukar
authors.affiliation: c Physiology Research Center , Kerman University of Medical Sciences , Kerman , Iran.
authors.forename: Sahar
authors.initials: S
authors.lastname: Ebrahimi
authors.affiliation: d Neurogenic Inflammation Research Center and Department of Physiology, School of Medicine , Mashhad University of Medical Sciences , Mashhad , Iran.
authors.forename: Majid
authors.initials: M
authors.lastname: Khazaei
authors.affiliation: e Faculty of Veterinary Medicine , Shahid Bahonar University of Kerman , Kerman , Iran.
authors.forename: Alireza
authors.initials: A
authors.lastname: Bashiri
authors.affiliation: f Department of Internal Medicine, School of Medicine , Kerman University of Medical Sciences , Kerman , Iran.
authors.forename: Mohammad Reza
authors.initials: MR
authors.lastname: Shakibi
authors.affiliation: c Physiology Research Center , Kerman University of Medical Sciences , Kerman , Iran.
authors.forename: Vida
authors.initials: V
authors.lastname: Naderi
authors.affiliation: c Physiology Research Center , Kerman University of Medical Sciences , Kerman , Iran.
authors.forename: Beydolah
authors.initials: B
authors.lastname: Shahouzehi
authors.affiliation: g Department of Physiology , Isfahan University of Medical Sciences , Isfahan , Iran.
authors.forename: Masoud
authors.initials: M
authors.lastname: Alasvand
mesh_terms: D000818:Animals; D000959:Antihypertensive Agents / Q000302:isolation & purification / Q000494:pharmacology*; D000975:Antioxidants / Q000302:isolation & purification / Q000494:pharmacology; D001794:Blood Pressure / Q000187:drug effects*; D003907:Dexamethasone; D004195:Disease Models, Animal; D005979:Glutathione Peroxidase / Q000378:metabolism; D006339:Heart Rate / Q000187:drug effects; D006973:Hypertension / Q000097:blood / Q000139:chemically induced / Q000503:physiopathology / Q000517:prevention & control*; D031324:Juglans / Q000737:chemistry*; D008297:Male; D008315:Malondialdehyde / Q000378:metabolism; D009206:Myocardium / Q000378:metabolism; D009569:Nitric Oxide / Q000097:blood; D009754:Nuts; D010084:Oxidation-Reduction; D008517:Phytotherapy; D010936:Plant Extracts / Q000302:isolation & purification / Q000494:pharmacology*; D010946:Plants, Medicinal; D017208:Rats, Wistar; D013997:Time Factors
chemical_list: D000959:Antihypertensive Agents; D000975:Antioxidants; D010936:Plant Extracts; D009569:Nitric Oxide; D008315:Malondialdehyde; D003907:Dexamethasone; D005979:Glutathione Peroxidase
keywords: Kernel; glucocorticoid; redox system