ANTIHYPERLIPIDEMIC AND ANTIOXIDANT EFFECTS OF PHASEOLUS VULGARIS

CHAPTER ONE

1.0. INTRODUCTION

A large volume of scientific research suggests that in situations of oxidative stress, reactiveoxygen species (ROS) are generated and a homeostatic environment between anti-oxidant andoxidation is created, which are known to be an important concept for maintaining a healthybiological system (Davies, 2000). Reactive oxygen species (ROS) such as superoxide anions (O2-), nitric oxide (NO) and hydroxyl radical (OH-) aids in the inactivation of enzymes and this resultin damage to important cellular components which leads to complication such as coronary heartdiseases (Gessin et al., 1990).Disease of coronary origins such as stroke, atherosclerosis, etc., continues to be a leading causeof death in most countries of the world (Davey, 1993).One of the greatest risk factors in theseverity and prevalence of coronary heart diseases is disorders of lipid metabolism known ashyperlipidemia (Grundy, 1986). According to reports by the World Health Organizationapproximately 56% of coronary heart diseases are as a result of hyperlipidemia and this result inabout 4.4million deaths each year worldwide (World Health Organization, 2002).Hyperlipidemia is a disorder of lipoprotein metabolism, including lipoprotein overproduction ordeficiency and manifested by elevation of the serum total cholesterol, low-density lipoprotein(LDL) cholesterol and triglyceride concentrations with a decrease in the high-density lipoprotein(HDL) cholesterol concentration (Adam, 2005).Man as always looked for a way to fight and control diseased state with inspiration and aid from his immediate natural environment; this guidance’s have been used for centuries as remedies for human diseases because they contain components of therapeutic value (Nostro et al., 2000). Theuse of medicinal plants in the management of diseases is common around the world (Aliyu et al.,2007). Herbal medicine, the study and use of medicinal properties of plants, is an aspect of modern medicine (World Health Organization, 2008).The use of traditional medicine is recognized as the most viable method of identifying of new medicinal plants species(Farnsworth, 1966; Ajanahoun et al., 1991).Medicinal plants are used for their beneficial antioxidant and lipid lowering effects thus reducingthe risk of cardiovascular diseases in many countries. HMG-CoA reductase inhibitor that is the statins is the most recent lipid lowering drugs. They are very effective in lowering total and LDL- cholesterol and have been shown to reduce coronary events and mortality. They have very few side effects and are now usually the drugs of first choice (Neal, 2002). Also, ascorbic acid and t ocopherols are widely used anti-oxidants. In recent times antioxidants derived from natural sources mainly plants have been intensively used to prevent oxidative damage because of its advantage over synthetic ones; as they are easily obtained, economical and have slight or negligible effects (Onay-ucar et al., 2006). Although the adverse effect of statins is relatively low, one rare effect called rhabdomyolysis can be very serious (Miller, 2001). Statins andfibrates both used in elevated cholesterol, especially in combination; cerivastatin (Baycol) waswithdrawn in 2001 after numerous incidence of rhabdomyolysis (Armitage, 2007). Hence, thereis an urgent need to research natural products that would have minimal or no lipid lowering sideeffects.

Phaseolus vulgaris (family: Fabaceae) is a plant whose leaf, bark, roots and seeds are used formedicinal purposes. It is commonly known as kidney bean, various parts of the plant have beenused extensively for the treatment of diabetes mellitus traditionally (Chopra et al., 1958).Previous studies have reported the hypolipidemic activities of the aqueous extract (Roman-Ramos et al., 1995), as well as, the anti-inflammatory, antimutagenic, antioxidant, antimicrobialand antioxidant activities of the extract (Jorgeet al.,2013). The present study aims to establish theanti-hyperlipidemic and antioxidants effects of various fractions of Phaseolus vulgaris L. fruitand determine the most active of the fractions