CHAPTER ONE

1.0     INTRODUCTION

       Many of the developing countries including African countries like Nigeria practice traditional medicine as its main source of health care. This traditional medicine is normally gotten from plant origin [Rehan Ahmad et al, 2008, Stephen bent, 2008].Today nearly 88 percent of the global populations switch to plant derived medicines as their first line of defence for maintaining health and combating diseases [Kintzois et al,2006]. Presently there are about 60 types of medicinal plants that have been recognised in primary health care and are classified according to their pharmacological actions such as peptic ulcers, anti flatulence, laxative, anti diarrhoea and anti hepatic[Viomolos et al,2003]. However in future the discovery of novel therapeutic agents will be only dependent on plant origin [Perulmalsamy et al, 1999].

        Senna tora is an example of traditional medicine with pharmacological actions as anticholesterolemic,antispasmodic,carninitative, emolliants, ophthalmic and purgative [Polunin and Stanton,1984,Yeung,1985,Manandhar, 2002]. It can be cardiotonic, antiperiodic, anthelminitic and expectorant  and can also be used in treating  cogh,leprosy ,ring worm ,colic,flatulence,constipation and other disorders[Nature serve,2007]. Senna tora formally regarded as cassia tora is capable of suppressing  the production of prostaglandins and other inflammatory agonists such as cytokines, histamine, kinin and free radical.manila,1998 buttressed his observations confirming its use in the treatment of constipation, edema and liver protection in Korea.

        Liver, the largest internal organ of the human body performs more than five hundred functions, all of which are very vital to life. The liver can regenerate or grow back cells that have been destroyed by short term injury or disease, but if the liver is damaged repeatedly over a long period of time, it may undergo irreversible changes which permanently interferes with its function.

     Carbon tetrachloride is a toxic substance that interrupts the liver and its functions. This is to say that it damages the liver when ingested.CCL₄ is stable in the presence of air and light, it is also inflammable. Despite its toxic effect on the liver, it is useful as grain fumigant ,pesticide etc. Equilibrium of the body fluids and secretions are altered as a result of carbon tetrachloride. For instance lipid metabolism, cholesterol metabolism and  biotransformation  functions of the liver are terminated or altered in the presence of CCL₄.Thus carbon tetrachloride is lethal. The liver produces some enzyme such as aspartate amino transaminases, alkaline phosphatase, lactate dehydrogenase,gamma glutamyl transsferase etc which catalyses the biochemical activities of  the body, and on the attack of CCL₄ to the liver ,these enzymes will not be produced.

      Free radicals are highly reactive compounds with uneven number of electrons in their outermost orbit. This can react with cellular compounds like unsaturated fatty acids and can generate new free radicals which result in irreversible biochemical injury like membrane damage, apotosis and cell necrosis. Antioxidants scavenge  free radicals  and stop the subsequent reactions hence protecting the macromolecules and cellular environment from toxicity and degeneration [Hong B.O. Shao et al, 2008].The oxygen consumption inherent in cell growth leads to the generation of series of reactive oxygen species [ROS].The ROS are molecules such as superoxide anion radicals and hydroxyl radicals[OH]. ROS may be very damaging  attacking  the lipids of cell membrane and DNA mutation which may further propagate the propagation of many diseases[Valontao et al 2002,Gulcin et al 2003]. Reactive oxygen  species are continuously  produced during normal Physiological  events  and are removed by antioxidants defence mechanism [Buyukokuroglu et al,2001]. Many results have shown that some of the cassia species have acquired antimicrobial substances and antioxidant activities.

1.1     AIMS OF THE RESEARCH