Tetra-acetylajugasterone a new constituent of Vitex cienkowskii with vasorelaxant activity

Dongmo AB, Nkeng-Efouet PA, Devkota KP, et al. Tetra-acetylajugasterone a new constituent of Vitex cienkowskii with vasorelaxant activity. Phytomedicine. 2014;21(6):787-792.Tetra-acetylajugasterone C (TAAC) was found to be one of the naturally occurring compounds of the Cameroonian medicinal plant Vitex cienkowskii which is responsible for a vasorelaxant activity of an extract of this plant. The evaluation of the underlying mechanisms for the relaxing effect of TAAC was determined using aortic rings of rats and mice. TAAC produced a concentration-dependent relaxation in rat artery rings pre-contracted with 1 mu M noradrenaline (IC50: 8.40 mu M) or 60 mM KCl (IC50: 36.30 mu M). The nitric oxide synthase inhibitor L-NAME (100 mu M) and the soluble guanylate cyclase inhibitor ODQ (10 mu M) significantly attenuated the vasodilatory effect of TAAC. TAAC also exerted a relaxing effect in aorta of wild-type mice (cGKI(+/+); IC50=13.04 mu M) but a weaker effect in aorta of mice lacking cGMP-dependent protein kinase I (cGKI(-/-); IC50=36.12 mu M). The involvement of calcium channels was studied in rings pre-incubated in calcium-free buffer and primed with 1 mu M noradrenaline prior to addition of calcium to elicit contraction. TAAC (100 mu M) completely inhibited the resulting calcium-induced vasoconstriction. The same concentration of TAAC showed a stronger effect on the tonic than on the phasic component of noradrenaline-induced contraction. This study shows that TAAC, a newly detected constituent of Vitex cienkowskii contributes to the relaxing effect of an extract of the plant. The effect is partially mediated by the involvement of the NO/cGMP pathway of the smooth muscle but additionally inhibition of calcium influx into the cell may play a role. (C) 2014 Elsevier GmbH. All rights reserved

Prédication en chapitre général et réforme pontificale de la vita religiosa au XIIIe siècle. À propos des sermons aux chapitres généraux des moines noirs d’Eudes de Châteauroux et Jacques de Furnes

International audienceÀ partir de l’analyse de sermons respectivement donnés par Eudes de Châteauroux et Jacques de Furnes aux chapitres généraux des moines noirs des provinces de Sens et de Reims, l’occasion est offerte de confronter le point de vue de deux acteurs (un gradué séculier ayant la faveur de la papauté et un abbé bénédictin au cœur de la mêlée) sur les réformes monastiques du pape Grégoire IX (1235-1237) et de tenter de cerner les stratégies discursives et les méthodes de gouvernement mises en œuvre par la papauté dans son dessein global de contrôle centralisé de tous les membres de l’Ecclesia. Un sermon de chaque prédicateur est édité en annex