Chinwendum S.A. Alaribe, et al., /Journal of Natural Products, Vol. 5(2012): 60-67 Copyright © 2011, Journal of Natural Products, INDIA, Dr. Sudhanshu Tiwari, All rights reserved 60 ISSN 0974 – 5211 Antiplasmodial and Phytochemical Investigations of Leaf Extract of Anthocleista vogelii (Planch) Chinwendum S.A Alaribe 1 , Herbert A.B. Coker 1 , Francis O. Shode 2 , Gloria Ayoola 1 , Sunday A. Adesegun 3 , Jide Bamiro 4 , Ezenwa .I. Anyim 5 , Chimezie Anyakora 1 1 Dept. of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Lagos, Nigeria. 2 School of Chemistry, University of Kwazulu Natal, Westvile, Durban, South Africa. P/Mail Bag X54001, Durban, 4000, South Africa 3 Dept of Pharmacognosy, Faculty of Pharmacy, University of Lagos, Nigeria. 4 Dept of Obsterics & Gynaecology Research Laboratory,College of Medicine,LUTH,Nigeria 5 Michael Okpara University of Agriculture Umudike, Abia State. Nigeria. * Corresponding Author (Received 21 July 2011; Revised 05 August-08 October 2011; Accepted 16 October 2011) ABSTRACT Anthocleista vogelii Planch (Loganiaceae) is a medicinal plant used widely in Nigeria for management of malaria and other ailments. The aim of this present study was to investigate the anti-plasmodial activities of the leaf extract against residual infection in chloroquine sensitive Plasmodium berghei infected mice. Phytochemical analysis and oral acute toxicity in mice were evaluated. Iron chelating ability of the extract and isolated compound were also determined. The extract was found be safe at up to 2000 mg/kg dose. The extract produced a dose dependent reduction in parasite density compared to the control group when given intraperitoneally. There was no reduction when the extract was administered orally. The phytochemical investigations of extract resulted in isolation of four compounds whose structures were elucidated using IR, GC-MS, LC-MS, 1D and 2D NMR spectroscopy as decussatin (1-hydroxy-3,7,8- trimethoxyxanthone), stigmasterol (stigmasta-5,22-dien-3-beta-ol), swertiaperennin (1,8-dihydroxy-3,7-dimethoxy-xanthone), and hexadecanoic acid. Decussatin demonstrated very weak reduction in parasite density at 10mg/kg. The extract and decussatin demonstrated good iron chelating ability at the tested concentration (1mg/ml) which may be involved in its antiplasmodial activities. Keywords: Anthocleista vogelii; Ferrous chelating ability; Antiplasmodial; Parasite density. INTRODUCTION Malaria is a disease condition most peculiar to Sub-Sahara Africa and still remains a challenge till today as a result of the resistant sensitive protozoa - Plasmodium species to currently existing drugs; therefore the search for newer and effective antimalaria remains a continuous scientific exercise. According to the World Health Organisation's latest global malaria report, though good progress has been made over Journal of Natural Products Volume 5 (2012) www.JournalofNaturalProducts.Com Research Paper