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.