A. De Pasquale

A drug used in traditional medicine: Harpagophytum procumbens DC. II: Cardiovascular activity

In conscious normotensive rats the dried crude methanolic extract of Harpagophytum procumbens secondary roots caused a significant dose-dependent reduction of arterial blood pressure. The decrease was significant only at higher doses given by gavage (dried extract = 400 mg/kg). At the same time a decrease of heart rate was observed. In the same experimental conditions, harpagoside presented an activity lower than doses of Harpagophytum procumbens extract containing corresponding quantities of harpagoside. In spontaneously beating Langendorff preparations of rabbit heart, the Harpagophytum procumbens methanolic extract caused a mild decrease in the heart rate with a concomitant mild positive inotropic effect at lower doses but a marked negative inotropic effect at higher doses. The coronary flow decreased at higher doses only. The negative chronotropic and positive inotropic effects of harpagoside were comparatively higher with respect to that of the extract, whereas harpagide had only a slight negative chronotropic effect and a considerable negative inotropic one. Both in experiments on intact rats and on isolated rabbit heart, the Harpagophytum procumbens extract also demonstrated a protective action with regard to arrhythmias induced by aconitine, and particularly to those provoked by calcium chloride and epinephrine--chloroform.

Effect of prostaglandins on the increased corticosterone output induced by caffeine in the rat.

The effect of prostaglandins on the increase of corticosterone output induced by caffeine was investigated in rats. PGE2 and some synthetic prostaglandins (11-deoxy-derivatives), which stimulate steroid output in vitro, enhanced the effect of caffeine. Pretreatment with indomethacin inhibited the effect of caffeine.

Morphological Characterization of the Genus Datura: Section Stramonium

AbstractTo achieve a systematic identification and differentiation of the species belonging to the various sections of this genus, the surface characteristics of species of section Stramonium (D. stramonium L., D. inermis Jacq., D. tatula L., D. stramonium L. var. godronii Danert, D. ferox L., D. quercifolia H.B.K.) have been examined by Scanning Electron Microscope (SEM).Cell shape and size, number and disposition of both protective and glandular hairs, stomatal, vein-islet and veinlet termination numbers allow one to characterize the different samples examined.