ABSTRACT

The in vitro antisickling effects of the crude methanolic extract, ethyl acetate, n-hexane, butanol,

and aqueous fractions of methanolic extracts of Dichrostachys cinerea and Sterculia setigera

were determined using different concentrates on sodium metabisulphite-induced sickled red

blood cells. The result showed that antsickling activity was both concentration and time

dependent, with highest activity observed at the longest time interval of 120 min, with the

exception of n-hexane concentrate of 0.1mg/ml and aqueous fraction of 0.2mg/ml of

Dichrostachys cinerea having a percentage unsickling effect of 38.46±1.4% and 33.39±1.4%,

respectively. The ethylacetate butanol, n-hexane, and aqueous concentrates of Dicrostachys

cinerea fractions showed a significant antisickling difference (p<0.05) when compared with

p-hydroxybenzoic acid, (PABA) as positive control. However, the butanol concentrate of

Sterculia setigera did not show any significant difference when compared with the positive

control. Osmotic fragility test was carried out in saline concentrations of 0.1, 0.2, 0.3, 0.5, 0.6,

0.9ml using extract concentrations of 0.5, 1.0, 2.0, and 2.5mg/ml. A significant difference was

observed in percentage inhibition of lysis in ethylacetate fraction of Sterculia setigera for all

saline concentration when compared with a standard drug, Ibuprofen. For butanolic fraction of

Sterculia setigera, there is no significant difference in percentage inhibition of haemolysis when

compared with Ibuprofen in all tested saline concentrations. N-hexane fraction of Sterculia

setigera showed a significant difference in percentage inhibition of haemolysis, when compared

with Ibuprofen. Also, a significant difference was observed in percentage inhibition of lysis

when compared with Ibuprofen. For ethylacetate fraction of Dicrostachys cinerea, a significant

difference was observed in all tested saline concentrations, when compared with Ibuprofen.

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CHAPTER ONE

1.0 Introduction

1.1 Overview

From time immemorial, humans have always relied on plants that can meet their basic

necessities; such as food, shelter, fuel and health. Of all the numerous uses attached to plants,

their therapeutic abilities played an inevitable part in the lives of primitive societies, as they

relied on plants for healing ailments. The knowledge of the healing powers of plants was initially

passed down orally through generations, and as civilizations grew written records were prepared

for the benefit of the population (Malla and Chhetri, 2009). A wide majority of herbal plants

possess pharmacologically active compounds that could have potential therapeutic activities

against various human, animal and even plant diseases, in addition to their food and nutritional

values (Ogbonnia, et al., 2008). World Health Organization reports that 70% – 80% of the world

population relies on traditional medicine for primary health care. In recent years, research has

been focused to find novel compounds from plant, animal and