ISSN: 2277- 7695 CODEN Code: PIHNBQ ZDB-Number: 2663038-2 IC Journal No: 7725 Vol. 2 No. 9 2013  Online Available at www.thepharmajournal.com  THE PHARMA INNOVATION - JOURNAL  Vol. 2 No. 9 2013       www.thepharmajournal.com Page | 66   Effects of leaf decoction from Lophira lanceolata Tiegh. Ex Keay (Ochnaceae) on arterial blood pressure and electrocardiogram in anesthetized rabbits Kouakou Kouakou Léandre 1 , Bléyéré Nahounou Mathieu 1* , Oussou N’Guessan Jean-Baptiste 1 , Konan Brou André 2 , Amonkan Kouao Augustin 2 , Abo Kouakou Jean Claude 3 , Yapo Angoué Paul 1 , Ehilé Ehouan Etienne 1 1. Laboratory of Physiology, Pharmacology and African Pharmacopoeia of UFR-SN, University of Nangui Abrogoua, Côte d’Ivoire. [Email: bleyere@yahoo.fr] 2. Laboratory of Pharmacology and Nutrition of UFR-Biosciences, University of Felix Houphouet Boigny, Cocody, Côte d’Ivoire. 3. Laboratory of Animal Physiology of UFR-Biosciences, University of Felix Houphouet Boigny, Cocody, Côte d’Ivoire. Lophira lanceolata (Ochnaceae) is a plant used in traditional medicine to treat many illnesses such as headaches, dysentery, diarrhoea, cough, abdominal pains and cardiovascular diseases. Ethnobotanical surveys in the centre of Côte d’Ivoire revealed that this plant is employed in the treatment of hypertension by traditional healers. As no or few scientific works were undertaken on this side, the present study was aimed to assess the effects of a decoction of Lophira lanceolata on arterial blood pressure and electrocardiogram in rabbits. The recording of the arterial blood pressure was achieved by a mercury manometer kymograph of Ludwig while the registration of electrocardiogram was implemented by an electrocardiograph (CARDIOFAX ECG-6851K Nihon Kohden, Japan). The decoction of the fresh leaves of Lophira lanceolata (DALLA) induced a dose dependent hypotension in rabbits for doses ranging from 0.5 to 40 mg/kg body weight with an ED 50 (effective dose) of 8.67 mg/kg body weight. DALLA significantly decreased the transient hypertension caused by adrenaline at 5.10 -3 mg/kg body weight. The hypotension induced by DALLA was significantly attenuated by atropine (a muscarinic cholinoceptor antagonist). On rabbit electrocardiogram, DALLA decreased the amplitudes of P, QRS and T waves, the duration of PQ interval and heart rate. However, the duration of QT interval increased. The phytochemical screening of the extract revealed the presence of sterols and polyterpenes, phenols, flavonoids, catechic tannins, alkaloids and saponins. These results suggested that DALLA contained cholinomimetic substances and also interacted with adrenoceptors. Some of the phytochemical coumpounds such as phenols, flavonoids, catechic tannins and alkaloids which are known for their antihypertensive effects may explain the use of this plant by traditional healers to treat hypertension. Keyword: Lophira lanceolata, hypertension, electrocardiogram, phytochemical screening, cholinomimetic. 1. Introduction Hypertension is the most common cardiovascular disease in sub-Saharan Africa [1, 2, 3] . With a prevalence of 20% in Côte d’Ivoire [4] , hypertension is an important cause of morbidity and mortality. Alongside the range of antihypertensive drugs offered by modern medicine, several medicinal herbal recipes are recommended by traditional medicine for the treatment of this pathology. In this context, during an ethnobotanical survey of plants used in the treatment of hypertension in Bouaké (Centre of Côte d'Ivoire), several traditional healers mentioned that the decoction of Lophira Received: 13-07-2013 Accepted: 23-08-2013