ABSTRACT
Abstract Background: Labdane-type diterpenes induce lower blood pressure via relaxation of vascular smooth muscle; however, there are no studies describing the effects of labdanes in hypertensive rats. Objective: The present study was designed to investigate the cardiovascular actions of the labdane-type diterpene ent-3-acetoxy-labda-8(17), 13-dien-15-oic acid (labda-15-oic acid) in two-kidney 1 clip (2K-1C) renal hypertension. Methods: Vascular reactivity experiments were performed in aortic rings isolated from 2K-1C and normotensive (2K) male Wistar rats. Nitrate/nitrite (NOx) measurement was performed in aortas by colorimetric assay. Blood pressure measurements were performed in conscious rats. Results: Labda-15-oic acid (0.1-300 µmol/l) and forskolin (0.1 nmol/l - 1 µmol/l) relaxed endothelium-intact and endothelium-denuded aortas from both 2K-1C and 2K rats. Labda-15-oic acid was more effective at inducing relaxation in endothelium-intact aortas from 2K pre-contracted with phenylephrine when compared to the endothelium-denuded ones. Forskolin was more potent than labda-15-oic acid at inducing vascular relaxation in arteries from both 2K and 2K-1C rats. Labda-15-oic acid-induced increase in NOx levels was lower in arteries from 2K-1C rats when compared to 2K rats. Intravenous administration of labda-15-oic acid (0.3-3 mg/kg) or forskolin (0.1-1 mg/kg) induced hypotension in conscious 2K-1C and 2K rats. Conclusion: The present findings show that labda-15-oic acid induces vascular relaxation and hypotension in hypertensive rats.
Resumo Fundamento: Diterpenos do tipo labdano induzem uma queda da pressão arterial por meio do relaxamento do músculo liso vascular; todavia, não há estudos que descrevam os efeitos de labdanos em ratos hipertensos. Objetivo: O presente estudo foi desenvolvido para investigar as ações cardiovasculares do labdano ácido ent-3-acetóxi-labda-8(17),13-dieno-15-óico (labda-15-óico) na hipertensão renal dois rins-1 clipe (2R-1C). Métodos: Foram feitos experimentos de reatividade vascular em anéis aórticos isolados de ratos machos 2R-1C e normotensos (2R). A medição de Nitrato/Nitrito (NOx) foi feita nas aortas por meio de ensaio colorimétrico. As medidas de pressão arterial foram feitas em ratos conscientes. Resultados: O ácido labda-15-óico (0,1 - 300 µmol/l) e a forscolina (0,1 nmol/l - 1 µmol/l) relaxaram as aortas com endotélio intacto e as aortas sem endotélio dos ratos 2R-1C e 2R. O labda-15-óico mostrou-se mais eficaz na indução do relaxamento em aortas com endotélio intacto de 2R pré-contraídas com fenilefrina em comparação àquelas sem endotélio. A forscolina mostrou-se mais potente do que o ácido labda-15-óico na indução do relaxamento vascular nas artérias tanto de ratos 2R-1C quanto de ratos 2R. O aumento dos níveis de NOx induzido pelo ácido labda-15-óico foi menor nas artérias de ratos 2R-1C em comparação a ratos 2R. A administração intravenosa de ácido labda-15-óico (0,3-3 mg/kg) ou forscolina (0,1-1 mg/kg) induziu hipertensão em ratos 2R-1C e 2R conscientes. Conclusão: Os presentes resultados mostram que o labda-15-óico induz relaxamento vascular e hipotensão em ratos hipertensos.
Subject(s)
Animals , Male , Rats , Vasodilator Agents/pharmacology , Blood Pressure/drug effects , Colforsin/pharmacology , Diterpenes/pharmacology , Hypertension, Renovascular/drug therapy , Aorta, Thoracic/drug effects , Phenylephrine/antagonists & inhibitors , Vasoconstrictor Agents/antagonists & inhibitors , Vasodilation/drug effects , Vasodilator Agents/chemistry , Colforsin/chemistry , Rats, Wistar , Disease Models, Animal , Diterpenes/chemistry , Drug Evaluation, Preclinical , Hypertension, Renovascular/physiopathology , Muscle, Smooth, Vascular/drug effects , Nitric Oxide/analysisABSTRACT
Two compounds from the hexane extract of seeds of Byrsonima crassifolia were isolated and their structures elucidated using extensive spectroscopic analyses. These compounds are derived from the new labdane diterpene Labda-17-(1) and the known antimicrobial Labda-8 (17)-(2). The present study was aimed to study the effect antimicrobial of novel diterpene 1 against bacterial pathogens showed a moderate activity with MIC values 18.79-70.12 ug/ml and a MBC ranging between 250-1000 ug/ml against all assayed microorganisms.
Se aislaron dos compuestos del extracto de hexano de semillas de Byrsonima crassifolia y sus estructuras se dilucidaron por medio de extensos análisis espectroscópicos. Estos compuestos derivados del labdano corresponden al nuevo diterpeno Labda-17- (1) y el conocido antimicrobiano Labda-8(17)-(2). En el presente estudio se estudió el efecto antimicrobiano del nuevo diterpeno 1 sobre algunas bacterias patógenas mostrando sobre de estas una actividad moderada, con valores de MIC de 18.79-70.12 ug/ml y un rango de MBC que oscila entre 250-1000 ug/ml frente a todos los microorganismos ensayados.