ROLE OF PROSTAGLANDIN/cAMP PATHWAY IN THE DIURETIC AND HYPOTENSIVE EFFECTS OF PURIFIED FRACTION OF Maytenus ilicifolia Mart ex Reissek (CELASTRACEAE) UMUARAMA 2013

Mestrado em Ciência Animal com Ênfase em Produtos Bioativos
Autor: Thiago dos Santos Vilhena Leme
Orientador: Arquimedes Gasparotto Junior
Defendido em: 03/05/2013

Resumo

Relevância etnofarmacológica: Apesar de Maytenus ilicifolia ser utilizada na medicina popular brasileira como uma droga diurética, nenhum estudo foi realizado até a presente data afim de comprovar ou refutar tal propriedade farmacológica. Assim, o objetivo deste estudo foi avaliar possíveis mecanismos envolvidos na atividade diurética aguda do sobrenadante etanólico da infusão (SEI), obtido à partir de fracionamento biomonitorado de Maytenus ilicifolia e avaliar sua relação com a atividade hipotensora utilizando ratos Wistar normotensos.

Palavras-chave

Maytenus ilicifolia; Celastraceae; diurético; hipotensores; prostaglandina

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Title

ROLE OF PROSTAGLANDIN/cAMP PATHWAY IN THE DIURETIC AND HYPOTENSIVE EFFECTS OF PURIFIED FRACTION OF Maytenus ilicifolia Mart ex Reissek (CELASTRACEAE) UMUARAMA 2013

Abstract

Although Maytenus ilicifolia be used in Brazilian folk medicine as a diuretic drug, no study has been conducted to date in order to evaluate this statement ethnopharmacological. So, the aim of this study was to evaluate possible mechanisms involved in acute diuretic activity of the ethanolic supernatant of the infusion (SEI) obtained from Maytenus ilicifolia and by a bioassay-guided fractionation assess its relationship with a hypotensive activity using normotensive Wistar rats. The preparation obtained from the infusion (SEI) and their respective fractions (Fr.H2O and Fr.EtOAc) were orally administered in a single dose to rats. The urine excretion rate, pH, density, conductivity and content of Na+, K+, Cl- and HCO3- were measured in the urine of saline-loaded animals. In collected serum samples the concentration of electrolytes, urea, creatinine, aldosterone, vasopressin and angiotensin converting enzyme (ACE) activity were evaluated. The hipotensive activity and the involvement of nitric oxide, bradykinin and prostaglandin/cAMP pathway in the hipotensive and diuretic effects were also determined. Water and Na+ excretion rate was significantly increased by Fr.EtOAc and the arterial pressure was significantly reduced, while the urinary excretion of potassium and chloride were reduced. Pre-treatment with indomethacin or DDA (2’, 5’- dideoxyadenosine) significantly reduced the hypotensive and diuretic activity observed. All other parameters evaluated have not been affected for any treatment. The result validates the ethnopharmacological use of Maytenus ilicifolia for renal diseases. Additionally, showed that the Fr.EtOAc may present compounds responsible for diuretic and hypotensive activities, and this effect, could involve the prostaglandin/cAMP pathway.

Keywords

Maytenus ilicifolia; Celastraceae; diuretic; hypotensive; prostaglandin