CHAPTER ONE

1.0 INTRODUCTION

1.1 BACKGROUND OF THE STUDY

Medicinal Plants have recently become of great interest owing to their versatile applications. These plants are considered as rich resources of ingredients which can be used in drug development and synthesis. In many part of the world medicinal plant have been used for antibacterial, antifungal and antiviral activities for hundreds of years (Ali et al., 1998; Barhour et al., 2004; Yasunaka et al., 2005). More than 30% of the pharmaceutical preparations are based on plants (Shinwari and Khan, 1998). An increasing reliance on the use of these medicinal plants in the industrialized societies has been traced to the extraction and development of several drugs and chemotherapeutics from medicinal plants.

Recent research has begun to reveal impressive fact about the scale of the developed world dependence upon medicinal plant and the monetary and social value that these usages represent (Farnsworth et al., 1991). Researchers are increasingly turning attention to medicinal plant and looking for new leads to develop better drugs against diseases (Ibrahim 1997; Tower et al., 2001; Koshy et al., 2009). They have identified number of compounds used in mainstream medicine which were derived from ethnomedical plant source (Fabricant and Farnsworth 2001).

According to World Health Organization (WHO), medicinal plants would be the best source to obtain variety of drugs. An estimate of 80% individuals from developed countries uses traditional medicines, which has compounds derived from medicinal plant. Most populations still rely on traditional medicines for their psychological and physical health requirements (Rabe and VanStoden, 2000), since they cannot afford the products of Western pharmaceutical industries (Salie et al., 1996). These medicinal plant possess therapeutically properties which are useful in healing various diseases and the advantage of these medicinal plant are natural (Kalemba et al., 2003). These plants contain chemicals which are classified into primary and secondary metabolites. The primary metabolites are widely distributed in nature and are obtained from higher plants.

Plants generally produce many secondary metabolites which provide definite physiological action on the human body and these bioactive substances include alkaloids, steroids, tannins, glycosides, volatile oils, fixed oils, resins, phenols and flavonoids which are deposited in their specific parts such as leaves, flowers, bark, seeds, fruits, root and are biosynthetically derived from primary metabolite and constitute an important source of microbicide, pesticide and many pharmaceutical drugs. These secondary metabolites have been directly or indirectly playing an important role in the human society to combat disease (Wink et al., 2005). Secondary metabolites are frequently accumulated by plant in small quantities than the primary metabolites (Karuppusamy, 2009). The most important of these bioactive compounds of plants are alkaloids, flavonoids, tannins and phenolic compounds (Edoga et al., 2005). Screening of these medicinal plants for antimicrobial and elementological activities are important for finding potential new compounds for therapeutic use.

1.2 AIM OF STUDY

Establish the ethno medicinal claims on the aerial parts of ALCHORNEA CORDIFOLIA

Characterize some compound(s) that may be responsible for the claimed ethno medicinal values.

1.3 OBJECTIVE OF THE STUDY

The purpose of this study is to;

i. Determine the phytochemical ingredient contained in the plant

ii. Investigate the antimicrobial activity of the plant extracts.

1.4 SCOPE OF STUDY

This research is designed to screen alchornea cordifolia medicinal plant obtained from Awo-omamma community, Imo state, Nigeria, verifying the extent to which the medicinal plant can contribute to the treatment of various diseases.

In this study, there will be an investigation on the usage of this medicinal plant, through phytochemical screening, antimicrobial studies. It will also be evaluating the systematical screening of plant species with the purpose of discovering new bioactive compounds which will be of great important to chemistry and to pharmaceutical industry.

This study justifies the fact that medicinal plants have a promising future because there are about half a million plants around the world that are yet to be investigated. The choice of Alchornea cordifolia is based on its vast medicinal importance in Awo-omamma community of Imo State and other parts of the South-East region of Nigeria..

Therefore, we have decided to screen the plant to know its microbial potency, phytochemical and bioactive constituents. This study will further help to clarify their role in the treatment of present diseases and however aid as a light to the synthesis of new drugs.