RESUMO
The aim of this study was to obtain pharmacokinetic data for the anxiolytic compound galphimine-A (G-A) from Galphimia glauca. G-A is the most abundant anxiolytic compound in this plant, while Galphimine-E (G-E) is the most abundant galphimine, but inactive. G-E was transformed chemically into G-A. The pharmacokinetic study was carried out in ICR mice, which were orally administered a single 200 mg/kg dose of G-A. Samples of blood and brain were taken at different times after administration of G-A. Previously, we established the validation of methods for determining the concentration of G-A. The G-A was detected in plasma 5 min after oral administration, and its concentration reached 2.47 µg/mL. Data from concentration-time curves allowed us to establish the main pharmacokinetic parameters in two models: one- and/or two-compartment. C(max) values were 3.33 and 3.42 µg/mL respectively, likewise AUC(0â1440 min) were 1,951.58 and 1,824.95 µg/mL·min. The G-A in brain tissue was noted to cross the blood-brain barrier, reaching C(max) 2.74 µg/mL, T(max) 81.6 min, and then drop gradually to 0.32 µg/mL detected at 24 h. The presence of G-A in brain tissue, confirmed that this anxiolytic compound can access the target organ and acts directly on the CNS.
Assuntos
Ansiolíticos/química , Ansiolíticos/farmacocinética , Galphimia/química , Triterpenos/química , Triterpenos/farmacocinética , Administração Oral , Animais , Encéfalo/metabolismo , Cromatografia Líquida de Alta Pressão , Estabilidade de Medicamentos , Camundongos , Extratos Vegetais/química , Reprodutibilidade dos TestesRESUMO
ETHNOPHARMACOLOGICAL RELEVANCE: Hibiscus sabdariffa L. (Malvaceae) populary known in Mexico as "Jamaica", "flor de Jamaica", has widely used in Mexican Traditional Medicine as antihypertensive and diuretic, although the latter activity has been reported the present work show evidence about the diuretic, natriuretic and potassium-sparing effects. AIM OF THE STUDY: To evaluate the diuretic activity of Hibiscus sabdariffa aqueous extract on in vivo and in situ models. MATERIALS AND METHODS: The Hibiscus sabdariffa aqueous extract was administrated in increasing doses and evaluated the diuresis produced and disposal of electrolytes. Moreover, in isolated kidney was determined the renal filtration rate with plant extract, furosemide and amiloride. RESULTS: The yield of Hibiscus sabdariffa aqueous extraction was 28.3% and the chemical standardization from 1 g of extract was: 56.5 mg delphinidin-3-O-sambubioside, 20.8 mg/g cyanidin-3-O-sambubioside, 3.2 mg/g quercetin, 2.1 mg/g rutin and 2.7 mg/g chlorogenic acid. The diuretic and natriuretic effect of Hibiscus sabdariffa aqueous extract showed a dose-dependent behavior. The pharmacological constants of natriuretic effect was ED50=86 mg/kg and Emax=0.9 mEq/100 g/5 h. In the model of kidney in situ was observed that renal filtration increased 48% with the aqueous extract of Hibiscus sabdariffa and an additive effect when was perfuse with furosemide. CONCLUSION: The compound presents in Hibiscus sabdariffa as quercetin had effect on the vascular endothelium causing oxide nitric release, increasing renal vasorelaxation by increasing kidney filtration. Therefore, the diuretic effect of Hibiscus sabdariffa may be mediated by nitric oxide release.