EVALUATION OF THE ANTIPLASMODIAL ACTIVITY OF METHANOL LEAF EXTRACT AND FRACTIONS OF LANDOLPHIA OWARIENSIS P. BEAUV (APOCYNACEAE) IN MICE

EVALUATION OF THE ANTIPLASMODIAL ACTIVITY OF METHANOL LEAF EXTRACT AND FRACTIONS OF LANDOLPHIA OWARIENSIS P. BEAUV (APOCYNACEAE) IN MICE, A RESEARCH PROJECT TOPIC ON MICROBIOLOGY

ABSTRACT

Landolphia owariensis P. Beauv (Apocynaceae) is a woody liane commonly used in Africa for the treatment of gonorrhea, worm infestation and malaria. The methanol leaf extract (ME) of L. owariensis was obtained by cold maceration and then fractionated into nhexane (nHF), ethylacetate (EF) and methanol (MF) fractions. The methanol extract and fractions were tested against chloroquine-sensitive Plasmodium berghei berghei in early, established and repository models of infection using Peter’s 4-day suppressive model, Rane’s curative model and Peters prophylactic model respectively. The antiplasmodial activity was evaluated by determining the parasitemia, body weight and survival time of each of the eighty-four mice comprising six mice per group. Groups 1-12 were given graded doses of 200, 400 and 800 mg/kg body weight of extract or fractions respectively while group 13 and 14 received 5 mg/kg/day of chloroquine and 3% Tween 80 respectively. All administration was orally.

Acute toxicity was studied using modified Lorke’s method. Phytochemistry of extract and fractions as well as HPLC fingerprinting of ME, EF and MF were also carried out. The methanol extract and all the fractions exhibited significant (P<0 -800=”” .05=”” 200=”” 29.38-58.75=”” 800=”” 96.04=”” activity=”” and=”” antiplasmodial=”” at=”” but=”” chemosuppression=”” chloroquine.=”” comparable=”” elicited=”” extract=”” fractions=”” group=”” highest=”” kg=”” ld=”” least=”” levels=”” metabolites.=”” mf=”” mg=”” model=”” nhf=”” of=”” phytochemical=”” presence=”” prophylactic=”” respectively.=”” revealed=”” screening=”” secondary=”” span=”” the=”” to=”” treated=”” varying=”” while=”” with=””>50 was estimated to be greater than 5000 mg/kg p.o in mice. HPLC analysis of ME, EF and MF showed different peaks representing different components. The results of this study suggest that the leaf extract and fractions pose significant antiplasmodial activity.

CHAPTER ONE

1.0  INTRODUCTION

1.1   Background

Malaria presents a global devastating burden. The latest estimates released December 2013 indicate that about 207 million cases of malaria were reported in 2012 with an uncertainty range of 135 million to 287 million and an estimated 627 000 deaths with an uncertainty range of 473 000 to 789 000 (WHO, 2014). A child dies every minute from malaria in Africa. Malaria though a complex disease is preventable and curable (WHO, 2008a; WHO, 2014). It is a disease caused by infection with single-celled protozoan parasites of the genus Plasmodium.

EVALUATION OF THE ANTIPLASMODIAL ACTIVITY OF METHANOL LEAF EXTRACT AND FRACTIONS OF LANDOLPHIA OWARIENSIS P. BEAUV (APOCYNACEAE) IN MICE, A RESEARCH PROJECT TOPIC ON MICROBIOLOGY