Investigations on Dieffenbachia amoena Gentil. I: Endocrine effects and contraceptive activity

Contraceptive activity and the correlated endocrine alterations of an aqueous extract of the leaves of Dieffenbachia amoena were investigated. In female Wistar rats the extract, given for 4 days during the estrous cycle, induced significant variations of luteinizing hormone (LH), follicle-stimulating hormone (FSH), prolactin (PRL) progesterone and 17 beta-estradiol levels. It also determined a reversible interruption of the estrous cycle with consequent temporary inhibition of ovulation.

A drug used in traditional medicine. Harpagophytum procumbens DC. I. Scanning electron microscope observations

Histological characteristics, as observed by scanning electron microscope, of the secondary roots of Harpagophytum procumbens DC. (Pedaliaceae), a drug widely used in South African traditional medicine, specially by Bushmen, Hottentots and Bantu, are described in detail. It has been possible to reveal some morphological elements that, together with superficial granular material containing harpagoside and harpagide, allow drug identification.

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.