Navegando por Palavras-chave "Phalaris canariensis"

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    Avaliação do papel da via do triptofano e do exercício físico aeróbio sobre o efeito hipotensor do alpiste (phalaris canariensis) em ratos espontaneamente hipertensos
    (Universidade Federal de São Paulo (UNIFESP), 2015-07-31) Passos, Clévia dos Santos [UNIFESP]; Boim, Mirian Aparecida Boim [UNIFESP]; http://lattes.cnpq.br/8916858915652849; http://lattes.cnpq.br/1321998130315996; Universidade Federal de São Paulo (UNIFESP)
    Foi demonstrado anteriormente que o Phalaris canariensis (Pc), conhecido popularmente por alpiste, foi capaz de reduzir a PA em ratos espontaneamente hipertensos (SHR), o que foi atribuído ao triptofano, que pode ser metabolizado pela rota da quinurenina, um agente vasodilatador, através da enzima indoleamina 2,3 dioxigenase (IDO). Por outro lado, o exercício físico (EF) tem sido um grande aliado no tratamento de doenças cardiovasculares. Considerando essas duas estratégias, o objetivo deste estudo foi avaliar se a associação do exercício físico potencializa o efeito anti-hipertensivo do extrato aquoso do Phalaris canariensis (EAPc) em SHR e quais os mecanismos envolvidos. Para tanto, utilizamos dois protocolos experimentais, agudo e crônico, ambos utilizando SHR adultos (250-260g). No tratamento agudo, os animais foram separados nos grupos, controle (H2O); tratados com EAPc (400 mg/kg/dia) na presença e ausência do inibidor da IDO (1MT, 50mg/kg); tratados com triptofano (100mg/kg). No estudo crônico, a associação do EF e EAPc foi avaliada nos seguintes grupos: controle sedentário (H2O Sed); tratado com EAPc (400 mg/kg, v.o.) (EAPc-Sed,); controle exercício (H2O-Ex); tratado com EAPc e exercício (EAPc-Ex). O protocolo do treinamento aeróbio foi em esteira ergométrica por oito semanas. A reatividade vascular foi avaliada in vitro, através de resposta de anéis de aorta a agentes vasoativos nos grupos controle (H2O) e SHR tratado com EAPc durante quatro semanas. Resultados: A administração aguda do EAPc induziu redução em 10% na PAM semelhante à produzida pelo triptofano (9%). Esse efeito foi abolido pelo inibidor da enzima IDO. Houve maior relaxamento vascular dependente de endotélio em resposta à acetilcolina em anéis de aorta provenientes de SHR tratados. O EAPc e o EF isoladamente tiveram efeitos benéficos sobre vários parâmetros metabólicos, nos marcadores de inflamação no rim como a expressão de IL-1 e sobre o sistema cardiovascular com redução semelhante na PAM. A associação das duas estratégias resultou em potencialização da maioria desses efeitos benéficos. Conclusão: O metabolismo do triptofano via IDO pode ser um dos mediadores do efeito hipotensor do EAPc. O tratamento com EAPc favoreceu melhora endotelial. Tanto o EAPc quanto o TF produziram efeitos benéficos sobre o metabolismo da glicose, inflamação e sistema cardiovascular. Esses efeitos foram potencializados com a associação das duas estratégias.
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    Blood pressure reducing effects of Phalaris canariensis in normotensive and spontaneously hypertensive rats
    (Canadian Science Publishing, Nrc Research Press, 2012-02-01) Passos, Clevia Santos [UNIFESP]; Carvalho, Lucimeire Nova [UNIFESP]; Pontes, Roberto Braz [UNIFESP]; Campos, Ruy Ribeiro [UNIFESP]; Ikuta, Olinda [UNIFESP]; Boim, Mirian Aparecida [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    The birdseed Phalaris canariensis (Pc) is popularly used as an antihypertensive agent. the aqueous extract of Pc (AEPc) was administered in adult normotensive Wistar rats and spontaneously hypertensive rats (SHR) and in prehypertensive young SHR (SHRY, 3 weeks old). Animals received AEPc (400 mg.kg(-1).day(-1), by gavage) for 30 days, then groups were divided into 2 subgroups: one was treated for another 30 days and the other received water instead of AEPc for 30 days. AEPc reduced systolic blood pressure (SBP) in both adult groups; however, treatment interruption was followed by a gradual return of the SBP to baseline levels. SHRY became hypertensive 30 days after weaning. AEPc minimized the increase in SBP in SHRY, but blood pressure rose to levels similar to those in the untreated group with treatment interruption. There were no changes in renal function, diuresis, or Na+ excretion. Pc is rich in tryptophan, and the inhibition of the metabolism of tryptophan to kynurenine, a potential vasodilator factor, prevented the blood pressure reducing effect of AEPc. Moreover, AEPc significantly reduced sympathoexcitation. Data indicate that the metabolic derivative of tryptophan, kinurenine, may be a mediator of the volume-independent antihypertensive effect of Pc, which was at least in part mediated by suppression of the sympathetic tonus.
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    Efeitos vasculares e renais do Alpiste (Phalaris canariensis) em ratos normotensos e hipertensos
    (Universidade Federal de São Paulo (UNIFESP), 2010-06-30) Passos, Clévia dos Santos [UNIFESP]; Boim, Mirian Aparecida [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    Hypertension is a disease highly prevalent throughout the world and it is associated with three chronic diseases namely; stroke, kidney disease, and heart disease. Popularly the birdseed Phalaris canariensis (Pc) has been used as an antihypertensive agent. The aim of this study was to evaluate the effect of the aqueous extract of Pc (AEPc) on arterial pressure and renal function of normotensive Wistar rats and spontaneously hypertensive rats (SHR). Also it was evaluated whether AEPc treatment would be able to prevent the development of hypertension in SHR, by administrating AEPc soon after weaning, i.e. before the establishment of hypertension. Methods: Adult male Wistar rats, SHR and young (3 weeks old) SHR were used. Adult animals were divided into groups control (receiving water) and treated with AEPc (100 mg/kg/day, p.o.) for 30 days. After this period treated group was divided into 2 sub-groups: treated for another 30 days (AEPc 60) and a group which AEPc treatment was interrupted and animals received only water for 30 days (AEPc 30). Young (three weeks old) and nonhypertensive SHR, received AEPc treatment during 30 days. Results: The administration of the AEPc for 60 days produced significant reduction in mean arterial pressure (MAP, mmHg) in both adult groups, Wistar (122±2 vs 103±4, p<0.05) and SHR (210±1 vs 171±, p<0.05). However, the interruption of treatment was followed by a gradual return of MAP to the baseline levels in both groups Wistar (117±1) and SHR (193±3). Young SHR group was normotensive after weaning (122±2) but became hypertensive after 30 (161±3) and 60 days (195±4). AEPc treatment during 30 and 60 days minimized the increase in MAP (133±2 and 148±4, respectively). The discontinuation of the treatment caused an increase in the MAP similar to observed in untreated group. There was no significant change in plasma parameters among groups. Fractional excretion of Na+ (FENa+) was lower in untreated SHR and AEPc treatment restored FENa+ to control levels. Conclusion: The results suggest that Pc has potential antihypertensive effect in SHR, without inducing any significant risk of nephrotoxicity and it may be use as an alternative and/or adjuvant treatment option to reduce blood pressure. The antihypertensive mechanism may be related by action of the biochemical constituents of Pc, mainly tryptophan and linoleic acid, precursors of the vasodilator aguds Kynurenine and prostaglandings respectively.