Antihyperlipidemic and antioxidant effects of phaseolus vulgaris

Project Abstract

<p> In this study, the antihyperlipidemic and antioxidants activities of the extract and fractions of<br>Phaseolus vulgaris L. were evaluated. The crude extract (PVE) of dried pulverized plant material<br>was obtained by maceration in methylene chloride/methanol (11) while the solvent fractions<br>were obtained by successive solvent-solvent partition in separating funnel between the crude<br>extract suspended in aqueous medium and solvents of increasing polarity to obtain the n-hexane<br>fraction (PVHF), ethylacetate fraction (PVEF), and butanol fraction (PVBF) in that<br>order.Antihyperlipidemic effects of the extracts and fractions were investigated using acute, subacute<br>and chronic models. In all threemodels, treatment with (PVE) caused significantreduction<br>(P&lt;0.05) in the lipid profile parameters with the most significance seen in the sub acute study<br>where total cholesterol was decreased by 38.44%. Triglycerides level was significantly decreased<br>(P&lt;0.05) by 18.18% in the acute study model.Similarly, very low density lipoprotein (VLDLC)<br>and low density lipoprotein (LDL-C) wasrespectively decreased by 18.18% and 48.73% in the<br>acute antihyperlipidemia model. In contrast, high density lipoprotein (HDL-C) level was<br>significantly (P&lt;0.05) increased in the acute phase by 20.85%.In all study protocols involving<br>the various fraction there were significant increase(P&lt;0.05) in lipid profile. PVEF (400 mg/kg)<br>produced- the most significant reduction in total cholesterol level in the acute study with<br>percentage decrease of 22.10% compared to the control treatment. Triglycerides level was<br>similarly reduced by 21.59% and 15.91% at PVHF (200 mg/kg) and PVEF (200 mg/kg) with the<br>acute study.The sub-acute protocol showed significant decrease at PVBF 200 mg/kg percentage<br>decrease of 17.28%. VLDL-C level for the fraction study showed significant decrease (P&lt;0.05)<br>at PVHF 200 mg/kg and PVEF 200 mg/kg with percentage decrease of 21.59% and 15.91%<br>during the acute protocol, the sub-acute protocol showed significant decrease at PVBF 200<br>mg/kg percentage decrease of 17.28. LDL-C level for fraction extract study showed dose<br>dependent significance decrease (P&lt;0.05) seen at PVHF 100 mg/kg, PVEF100 mg/kg, and 200<br>mg/kg with percentage decrease of 47.19%, 41.62% and 53.39% respectively during the acute<br>protocol, Finally in the chronic protocol a significant decrease was seen with PVHF 200mg/kg,<br>PVEF 100 mg/kg, and PVBF 200 mg/kg with percentage decrease of 26.03%, 24.82% and<br>20.05% respectively. HDL-C level for extract study showed dose dependent significant increase<br>(P&lt;0.05) seen at PVHF 100 mg/kg, PVEF 100 mg/kg and 200 mg/kg with percentage increase<br>of 30.44%, 28.88% and 30.86%. DPPH reduction and nitric oxide scavenging assays were used<br>in the investigation of the extract and fractions for the in vitro antioxidant activities study, the<br>antioxidant activities of the extract and fractions were further determined in vivo in rats.<br>Antioxidant enzymes and factors such as catalase, glutathione peroxidase, and lipid peroxidation<br>activities were measured in carbon tetrachloride-treated rats treated with or without the extract<br>and fractions studies. The highest percentage reduction of DPPH was 80.61% seen with PVEF<br>and PVBF fraction at 400 mg/kg. The highest percentage reduction of nitric oxide was 75.86%<br>seen with PVHF at 200 mg/kg. The in vitro study showed significant increased (P&lt;0.05)<br>scavenging activity with the PVHF and PVEF having scavenging activity comparable with<br>ascorbic acid. In in-vivo antioxidant assay showed that the Lipid peroxidation levels estimated by<br>thiobarbituric acid reaction showed no significant (P&gt;0.05) increase or decrease in the serum<br>MDA of both the treated and untreated group, while in catalase activity estimation showed<br>significant (P&lt;0.05) increase was seen with PVE 100 mg/kg of 71.05%, Glutathione peroxidise<br>activity showed the most significant percentage (P&lt;0.05) increase of 76.19% for PVBF 100<br>mg/kg.The results of the study showed that the extracts and fractions of Phaseolus vulgaris<br>xiv<br>xiv<br>posses anti-hyperlipidemic and antioxidant with the PVEF showing better and more consistent<br>effects with all protocols used in the investigation. <br></p>

Project Overview

<p> <strong>1.0. INTRODUCTION</strong><br>A large volume of scientific research suggests that in situations of oxidative stress, reactive<br>oxygen species (ROS) are generated and a homeostatic environment between anti-oxidant and<br>oxidation is created, which are known to be an important concept for maintaining a healthy<br>biological system (Davies, 2000). Reactive oxygen species (ROS) such as superoxide anions (O2<br>–<br>), nitric oxide (NO) and hydroxyl radical (OH-) aids in the inactivation of enzymes and this result<br>in damage to important cellular components which leads to complication such as coronary heart<br>diseases (Gessin et al., 1990).<br>Disease of coronary origins such as stroke, atherosclerosis, etc., continues to be a leading cause<br>of death in most countries of the world (Davey, 1993).One of the greatest risk factors in the<br>severity and prevalence of coronary heart diseases is disorders of lipid metabolism known as<br>hyperlipidemia (Grundy, 1986). According to reports by the World Health Organization<br>approximately 56% of coronary heart diseases are as a result of hyperlipidemia and this result in<br>about 4.4million deaths each year worldwide (World Health Organization, 2002).<br>Hyperlipidemia is a disorder of lipoprotein metabolism, including lipoprotein overproduction or<br>deficiency and manifested by elevation of the serum total cholesterol, low-density lipoprotein<br>(LDL) cholesterol and triglyceride concentrations with a decrease in the high-density lipoprotein<br>(HDL) cholesterol concentration (Adam, 2005).<br>Man as always looked for a way to fight and control diseased state with inspiration and aid from<br>his immediate natural environment; this guidance’s have been used for centuries as remedies for<br>human diseases because they contain components of therapeutic value (Nostro et al., 2000). The<br>use of medicinal plants in the management of diseases is common around the world (Aliyu et al.,<br>2007). Herbal medicine, the study and use of medicinal properties of plants, is an aspect of<br>2<br>modern medicine (World Health Organization, 2008).The use of traditional medicine is<br>recognized as the most viable method of identifying of new medicinal plants species<br>(Farnsworth, 1966; Ajanahoun et al., 1991).<br>Medicinal plants are used for their beneficial antioxidant and lipid lowering effects thus reducing<br>the risk of cardiovascular diseases in many countries. HMG-CoA reductase inhibitor that is the<br>statins is the most recent lipid lowering drugs. They are very effective in lowering total and<br>LDL- cholesterol and have been shown to reduce coronary events and mortality. They have very<br>few side effects and are now usually the drugs of first choice (Neal, 2002). Also, ascorbic acid<br>and tocopherols are widely used anti-oxidants. In recent times antioxidants derived from natural<br>sources mainly plants have been intensively used to prevent oxidative damage because of its<br>advantage over synthetic ones; as they are easily obtained, economical and have slight or<br>negligible effects (Onay-ucar et al., 2006). Although the adverse effect of statins is relatively<br>low, one rare effect called rhabdomyolysis can be very serious (Miller, 2001). Statins and<br>fibrates both used in elevated cholesterol, especially in combination; cerivastatin (Baycol) was<br>withdrawn in 2001 after numerous incidence of rhabdomyolysis (Armitage, 2007). Hence, there<br>is an urgent need to research natural products that would have minimal or no lipid lowering side<br>effects.<br>Phaseolus vulgaris (family: Fabaceae) is a plant whose leaf, bark, roots and seeds are used for<br>medicinal purposes. It is commonly known as kidney bean, various parts of the plant have been<br>used extensively for the treatment of diabetes mellitus traditionally (Chopra et al., 1958).<br>Previous studies have reported the hypolipidemic activities of the aqueous extract (Roman-<br>Ramos et al., 1995), as well as, the anti-inflammatory, antimutagenic, antioxidant, antimicrobial<br>and antioxidant activities of the extract (Jorgeet al.,2013). The present study aims to establish the<br>anti-hyperlipidemic and antioxidants effects of various fractions of Phaseolus vulgaris L. fruit<br>and determine the most active of the fractions <br></p>