Essais cliniques des médicaments à base de plantes : revue bibliographique

Contexte : Plus de 80 % de la population a recours à la médecine traditionnelle. Ainsi, trouver une méthodologie simplifiée d'évaluation de l'efficacité et de la sécurité d'emploi des plantes médicinales est envisagé. Méthodes : Nous avons identifié sur Internet les études publiées entre 1980 et 2000, sans distinction de leur origine. Résultats : La plupart des 48 essais cliniques recensés ont été réalisés dans les pays développés après avoir satisfait aux essais précliniques. Les principes méthodologiques appliqués ont été ceux des essais classiques : randomisation (85,4 %), comparaison (87,5 %) versus placebo (95,2 %), double ou simple insu (81,3 %). La durée des études était le plus souvent courte, avec des effectifs de 30 à 99 sujets inclus. Conclusion : Les essais de bonne qualité scientifique sur les plantes sont possibles mais rarement réalisés. Le respect des recommandations de l'OMS (Organisation Mondiale de la Santé) dans un cadre réglementaire et législatif stimulerait la réalisation de telles études, permettant revalorisation et reconnaissance internationale de la pharmacopée traditionnelle

Sodium and Blood Pressure in Africa

In the pathophysiology of hypertension, the profile hemodynamic is modified by the relation between the increased sodium intake and blood pressure (BP) level. An increased sodium diet is related not only on the amount of fluid volume within the organism but also to the elasticity of the cardiovascular system. In humans, age and salt excess reduced elasticity is linked to BP level and to stiffness material within the vascular wall of larges arteries. Actions of vasoactives hormones such as angiotensin II, antidiuretic hormone, and aldosterone are also linked. The purpose of this article is : (i) to report existing work in Africa relating to “salt and hypertension”, (ii) to determine the characteristic of hypertension among black populations, and for epidemiologic study in Ivory Coast, (iii) to determine the various characteristics of hypertension, prevention of cardiovascular risk, and to show usual antihypertensive drugs for reduce rigidity and vascular fibrosis

Ethanol Extract of Leaves of Cassia siamea Lam Protects against Diabetes-Induced Insulin Resistance, Hepatic, and Endothelial Dysfunctions in ob/ob Mice

International audienceDespite long traditional utilization and some reports on the antihyperglycemic and antihyperlipidemic action of Cassia siamea, the mechanisms involved have not been investigated yet. Thus, the objective of the present study was to investigate whether and how oral administration of the ethanolic extract of Cassia siamea Lam leaves (LECS) improves glucose and insulin homoeostasis, liver damage, and endothelial dysfunction in an experimental model of type 2 diabetes, the leptin-deficient ob/ob mice. Oxidative stress and protein expression of insulin-dependent and insulin -independent signaling pathways were studied. Obese ( ob/ob) vs. control (ob/+) mice were treated daily with intragastric administration of either vehicle or LECS (200 mg/kg, per day) for 4 weeks. Fasting blood glucose, body weight, food intake, glucose and insulin tolerance, oxidative stress, and liver damage as well as vascular complications with respect to endothelial dysfunction were examined. Administration of LECS in obese mice significantly reduced blood glucose and insulin levels, improved glucose tolerance and insulin sensitivity, and restored the increase of circulating AST and ALT without modification of body weight and food intake. These effects were associated with increased activity of both insulin and AMPK pathways in the liver and skeletal muscles. Of particular interest, administration of LECS in obese mice completely prevented the endothelial dysfunction resulting from an increased NO· and decreased reactive oxygen species (ROS) production in the aorta. Altogether, oral administration of LECS remarkably attenuates features of type 2 diabetes on glucose, hepatic inflammation, insulin resistance, endothelial function, and vascular oxidative stress, being as most of these effects are related to insulin-dependent and insulin-independent mechanisms. Therefore, this study points for the therapeutic potential of Cassia siamea in correcting both metabolic and vascular alterations linked to type 2 diabetes

The acute diuretic effect of an ethanolic fraction of Phyllanthus amarus (Euphorbiaceae) in rats involves prostaglandins

Abstract Background Phyllanthus amarus (Schum & Thonn), a plant belonging to the family of Euphorbiaceae is used in Ivorian traditional medicine to treat cardiovascular disorders such as hypertension. However, although this plant has been described as a diuretic agent, the underlying mechanism remains unclear. Therefore, the aim of the present study was to investigate the mechanism action of diuretic effects of an ethanolic fraction of Phyllanthus amarus (EFPA) in rats. Methods Effects of EFPA on urinary excretion were carried out for doses ranging from 5 to 80 mg/kg given by intraperitoneal injection (i.p.) and compared with that induced by furosemide (5 mg/kg) after 8 h. Thereafter, the diuretic activity of EFPA was also evaluated in the presence of indomethacin (5 mg/kg, i.p.) in order to determine the involvement of prostaglandins, after 24 h. Results Between 5 and 80 mg/kg, EFPA induced a significant urinary excretion. The profile of urinary excretion showed that after 2 h, the highest dose of 80 mg/kg induced a urinary volumetric excretion (UVE), which was similar to that induced by furosemide. After 24 h, EFPA at 10 mg/kg increased significantly UVE, Na+ (43 mEq) and Cl¯ (97 mEq) urinary excretions without promoting kaliuresis. In rats pretreated with indomethacin, the urinary excretion and the natriuretic response of EFPA were significantly reduced. Conclusion Altogether, this study has shown that EFPA promotes a significant urinary excretion of water and Na+, confirming its diuretic activity. Moreover, the increased diuresis could be attributed, at least in part, to the involvement of prostaglandins

Additional file 3: of The acute diuretic effect of an ethanolic fraction of Phyllanthus amarus (Euphorbiaceae) in rats involves prostaglandins

Figure S3. Inhibitory effect of indomethacin on plasma electrolyte level induced by EFPA in rats. Rats were treated over a 24 h period with a single dose of either vehicle (control group), EFPA (10 mg/kg) or EFPA (10 mg/kg) + indomethacin (5 mg/kg, 1 h pretreatment) administered i.p. Data are given as means ± SEM of 6 different experiments. Statistical analyses were assessed using two-way analysis of variance (ANOVA) followed by Bonferroni’s post- test. *p < 0.05 versus control, and #p < 0.05 versus EFPA. (TIFF 174 kb