title: The antioxidant effects of green tea reduces blood pressure and sympathoexcitation in an experimental model of hypertension.
abstract: Oxidative stress is a key mediator in the maintenance of sympathoexcitation and hypertension in human and experimental models. Green tea is widely known to be potent antioxidant.
  
  
  
  We aimed to evaluate the effects of green tea in a model of hypertension.
  
  
  
  Hypertension was induced by the nitric oxide synthase inhibitor [N-nitro-L-arginine-methyl-ester (L-NAME); 20 mg/kg per day, orally, for 2 weeks] in male Wistar rats. After the first week of L-NAME treatment, animals received green tea ad libitum for 1 week. At the end of the treatment period, blood pressure, heart rate, baroreflex sensitivity, renal sympathetic nerve activity, and vascular and systemic oxidative stress were assessed.
  
  
  
  L-NAME-treated animals exhibited an increase in blood pressure (165 ± 2 mmHg) compared with control rats (103 ± 1 mmHg) and green tea treatment reduced hypertension (119 ± 1 mmHg). Hypertensive animals showed a higher renal sympathetic nerve activity (161 ± 12 spikes/s) than the control group (97 ± 2 spikes/s), and green tea also decreased this parameter in the hypertensive treated group (125 ± 5 spikes/s). Arterial baroreceptor function and vascular and systemic oxidative stress were improved in hypertensive rats after green tea treatment.
  
  
  
  Taken together, short-term green tea treatment improved cardiovascular function in a hypertension model characterized by sympathoexcitation, which may be because of its antioxidant properties.
authors.affiliation: aDepartment of Physiology, Escola Paulista de Medicina, Universidade Federal de São PaulobDepartment of Biomaterials and Oral Biology, Faculdade de Odontologia, Universidade de São PaulocDepartment of Medicine, Universidade Federal de São Paulo, São PaulodDepartment of Plant Biology, Universidade Estadual de Campinas, CampinaeLaboratory of Multidisciplinary Research, Universidade São Francisco, São Paulo, Brazil.
authors.forename: Michelle L
authors.initials: ML
authors.lastname: Garcia
authors.forename: Roberto B
authors.initials: RB
authors.lastname: Pontes
authors.forename: Erika E
authors.initials: EE
authors.lastname: Nishi
authors.forename: Flávia K
authors.initials: FK
authors.lastname: Ibuki
authors.forename: Vanessa
authors.initials: V
authors.lastname: Oliveira
authors.forename: Alexandra C H
authors.initials: AC
authors.lastname: Sawaya
authors.forename: Patrícia O
authors.initials: PO
authors.lastname: Carvalho
authors.forename: Fernando N
authors.initials: FN
authors.lastname: Nogueira
authors.forename: Maria do Carmo
authors.initials: MD
authors.lastname: Franco
authors.forename: Ruy R
authors.initials: RR
authors.lastname: Campos
authors.forename: Lila M
authors.initials: LM
authors.lastname: Oyama
authors.forename: Cássia T
authors.initials: CT
authors.lastname: Bergamaschi
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D017704:Baroreflex / Q000187:drug effects; D001794:Blood Pressure / Q000187:drug effects*; D004195:Disease Models, Animal; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006339:Heart Rate / Q000187:drug effects; D006973:Hypertension / Q000139:chemically induced / Q000503:physiopathology*; D007668:Kidney / Q000503:physiopathology; D008297:Male; D019331:NG-Nitroarginine Methyl Ester; D009569:Nitric Oxide; D018384:Oxidative Stress / Q000187:drug effects*; D010936:Plant Extracts / Q000494:pharmacology*; D018515:Plant Leaves; D051381:Rats; D017208:Rats, Wistar; D013564:Sympathetic Nervous System / Q000187:drug effects; D013662:Tea
chemical_list: D000975:Antioxidants; D004791:Enzyme Inhibitors; D010936:Plant Extracts; D013662:Tea; D009569:Nitric Oxide; D019331:NG-Nitroarginine Methyl Ester