CHAPTER ONE
INTRODUCTION AND LITERATURE REVIEW
1.1 INTRODUCTION
Many cultures throughout the world still rely on indigenous medicinal plants for their primary health care needs (Farnsworth et al., 1985). To date, 25% of modern medicines are derived from plants that have been used by traditional medical practitioners (Cragg and Newman, 2005). It is a fact that traditional systems of medicine have become a topic of global importance. African countries are at a stage where traditional medicine is considered more for its capacity to generate other medicine than for its own sake. In many cases research undertakings and the commercial use stemming from that research have always relied on information provided by the local communities and, in many instances, have hardly benefited from the research results (Rukangira, 2004) . In Africa, traditional healers and remedies made from plants play an important role in the health of millions of people. (Rukangira, 2004).
Typically, studies on the medicinal plants such as Alstonia boonei have focused on the bioactivity of its chemical constituents, ethnobotany, pharmacology, and taxonomy. However, a comprehensive or systematic review on the plant is lacking. Furthermore, in much of the older literature concerning West Africa, the name Alstonia congensis has been erroneously used for Alstonia boonei. Consequently, this paper examined the effect of aqueous bark extracts of Alstonia boonei on the haematological parameters of male wistar abino rats.
1.2 LITERATURE REVIEW
1.2.1 Classification
Alstonia comprises about 40 species and has a pantropical distribution. There are about twelve species of the genus Alstonia. Alstonia boonei De Wild belongs to the family Apocynaceae. The species are scattered all over the world of which two are indigenous to Africa. The plant is known locally in Ghana as Onyame dua, Osen-nuru, or Sinduro in