Vasoconstrictor and inotropic effects induced by the root bark extracts of Anthocleista schweinfurthii.
The present study was undertaken to investigate the cardiovascular effect of three extracts from the root bark of Anthocleista schweinfurthii Gilg.: an aqueous extract (AE), a dichloromethane extract (DCMR) and a fraction enriched in cardiac glycoside type compounds (CARDAN). In isolated perfused frog heart, bolus injection of the extracts produced a positive inotropic effect. The responses to AE and DCMR, but not to CARDAN, were depressed by propranolol. In isolated rat aorta, DCMR produced a transient increase in contractile tension while AE and CARDAN induced a sustained constriction. AE vasoconstrictor effect was abolished by phentolamine, while contraction evoked by CARDAN was antagonized by verapamil. In aortic rings contracted in low K+ media, the addition of K+ evoked a relaxation, which was abolished by ouabain, depressed by DCMR but not affected by either A(E) or CARDAN. These observations indicate that Anthocleista schweinfurthii contains substances that promote vasoconstriction and increase cardiac contraction. The effect of DCMR was only partially mediated by inhibition of the Na+ pump while the mechanism of action of A(E) and CARDAN was distinct from the inhibition of the Na+, K+ - ATPase pump, but could involve adrenergic receptors, or either direct or indirect activation of L-type calcium channels.
Ngombe
Nadège Kabamba
NK
Laboratoire de pharmacognosie, Louvain Drug Research Institute, Université catholique de Louvain, Av. E. Mounier 72, 1200 Bruxelles, Belgium.
Kalenda
Dibungi T
DT
Quetin-Leclercq
Joëlle
J
Morel
Nicole
N
D000319:Adrenergic beta-Antagonists / Q000494:pharmacology; D000818:Animals; D001013:Aorta, Thoracic / Q000187:drug effects; D002121:Calcium Channel Blockers / Q000494:pharmacology; D002316:Cardiotonic Agents / Q000037:antagonists & inhibitors / Q000737:chemistry* / Q000494:pharmacology*; D002855:Chromatography, Thin Layer; D015023:Democratic Republic of the Congo; D029965:Gentianaceae / Q000737:chemistry*; D006321:Heart / Q000187:drug effects; D066298:In Vitro Techniques; D008297:Male; D008752:Methylene Chloride; D009200:Myocardial Contraction / Q000187:drug effects; D010042:Ouabain / Q000494:pharmacology; D010936:Plant Extracts / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000494:pharmacology; D018517:Plant Roots / Q000737:chemistry; D011433:Propranolol / Q000494:pharmacology; D011893:Rana esculenta; D051381:Rats; D000254:Sodium-Potassium-Exchanging ATPase / Q000187:drug effects; D012997:Solvents; D013056:Spectrophotometry, Ultraviolet; D014662:Vasoconstrictor Agents / Q000037:antagonists & inhibitors / Q000737:chemistry* / Q000494:pharmacology*; D014700:Verapamil / Q000494:pharmacology; D014867:Water
D000319:Adrenergic beta-Antagonists; D002121:Calcium Channel Blockers; D002316:Cardiotonic Agents; D010936:Plant Extracts; D012997:Solvents; D014662:Vasoconstrictor Agents; D014867:Water; D008752:Methylene Chloride; D010042:Ouabain; D011433:Propranolol; D014700:Verapamil; D000254:Sodium-Potassium-Exchanging ATPase