Thesis Abstract

Abstract
Diabetes mellitus is a metabolic disorder characterized by hyperglycemia and altered lipid metabolism, leading to various complications including liver dysfunction. Alloxan is a diabetogenic agent commonly used to induce diabetes in experimental animals. Studies have shown that Alloxan induces oxidative stress and impairs liver function by disrupting the activities of key enzymes involved in glucose and lipid metabolism. In this study, the in-vivo effects of the methanolic extract of A. boonei on liver enzyme function in Alloxan-induced diabetes mellitus were evaluated. A. boonei, also known as Ata-mangrove, is a plant with known traditional medicinal properties, including antidiabetic and antioxidant effects. The aim of this research was to investigate the potential hepatoprotective effects of A. boonei in the context of diabetes-induced liver damage. Male Wistar rats were divided into five groups Group I (control), Group II (diabetic control), Group III (diabetic rats treated with metformin), Group IV (diabetic rats treated with low dose of A. boonei extract), and Group V (diabetic rats treated with high dose of A. boonei extract). Diabetes was induced in groups II-V using Alloxan, and treatment with metformin or A. boonei extract was administered orally for 28 days. Liver enzyme function was assessed by measuring the activities of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), and total bilirubin levels in serum samples. Additionally, histopathological analysis of liver tissues was performed to evaluate the structural changes. The results demonstrated that Alloxan-induced diabetes led to a significant increase in liver enzyme activities, indicating liver dysfunction. Treatment with A. boonei extract, especially at the high dose, significantly attenuated the elevation of ALT, AST, ALP activities, and total bilirubin levels compared to the diabetic control group. Histopathological examination revealed that A. boonei extract ameliorated liver damage by reducing inflammation and restoring the normal liver architecture. In conclusion, the methanolic extract of A. boonei exhibited hepatoprotective effects in Alloxan-induced diabetic rats by improving liver enzyme function and reducing liver damage. These findings support the traditional use of A. boonei as a potential therapeutic agent for managing diabetes-related liver complications.

Thesis Overview

INTRODUCTION

1.1Background of Study

The present decade has witnessed a great and intense resurgence in the interest and use of the plant (Briskin., 2000). The healing power of herbs identified and botanical medicine has been one of the oldest practiced professions by humanity (Oduolaet al ., 2007). In fact, the use of synthetic pharmaceutical products and hepatotoxic agent reported not only to connect or some serious adverse effects but these drugs are costly and not within the reach of all. However, traditional use of herbs to promote healing is not an alien in any continent.

Diabetes mellitus represents a group of metabolic disorders in which there is an impaired glucose utilization hyperglycaemia which is an increase in the blood glucose level beyond normal values (Hazuda, 1991; Adonu et al., 2013). Diabetes is a chronic disease characterized by elevated blood glucose level and disturbances in carbohydrate, fat and protein metabolism (Sky, 2000; Rother, 2007).

A. boonei De Wild belongs to the family Apocynaceae. It is a large evergreen tree and is one of the most widely used medicinal plants in Africa and beyond. It is distributed throughout the tropics and the rain forest of west and Central Africa (Oliver-Bever, 1986; Olajide, et al., 2000). It is known by different names in different cultures and tribal settings. The plant parts are claimed to have medicinal properties in some cultures and climes. In the local markets in West and Central Africa, Alstoniaboonei is often among the most common sold plant as crude drugs. Parts of the plant are employed for the treatment of a variety of ailments in Africa and the stem bark has been listed in the Africa Pharmacopoeia as an antimalarial drug (Bello et al ., 2009). Various pharmacological studies have been carried out on this plant products which showed that the extracts possess anti-malaria, antipyretic, analgesic and anti-inflammatory properties (Ojewole, 1984; Olajideet al., 2000), anthelmintic (Wright et al, 1993), diuretic, spasmolytic and hypotensive properties (Iwu, 1993), antifebrile, astringent, (Iwu and Klayman, 1993), Immuno-stimulant property (Taiwo et al, 1998), antipsychotic and anxiolytic effect (Elisabetsky and Costa-campos, 2006), reversible antifertility effect, (Raji et al, 2005), among others..

1.2.JUSTIFICATION OF STUDY

Alstoniaboonei, a large evergreen tree belonging to the family Apocynaceae is one of the widely used medicinal plants in Africa and beyond. It is distributed throughout the tropics and the rain forest of west and Central Africa (Oliver-Bever, 1986; Olajide 2000). It is known by different names in different cultures and tribal settings. It is not edible as food but possesses roots, stem barks, leaves, fruits, seeds, flowers, and latex which are claimed to have medicinal properties in some cultures and climes.

Various documented and undocumented claims have it that alcoholic or aqueous preparations from some parts of the plant especially the stem bark have medicinal uses for treating febrile illness, jaundice, painful micturition, rheumatic conditions (Ojewole, 1984; Asuzu and Onaga, 1991), as an antivenom against snake bite, as antidote against arrow poisoning etc. The extract of the stem bark is commonly used as a febrifuge in treating malaria and is listed in the African pharmacopoeia as an anti-malarial drug (Olajide et al, 2000).

Currently, there is paucity of information on the hepatic effects of A. boonei on those that it as antidiabetic drug. This study therefore aims at accessing Aspartate aminotransferase (ASP), Alkaline phosphatase (ALP), Alanine aminotransferase (ALT), on alloxan induced diabetic rabbits.

1.3. AIM

This study is aimed at evaluating the in-vivo effects of methanolic extract of A. boonei on liver enzyme function in Alloxan induced diabetes mellitus.

SPECIFIC OBJECTIVES

Determining of aspartate aminotransferease, alkaline phosphatase, alanine aminotransferase on Alloxan induced male diabetic rabbits .Determining of aspartate aminotransferease, alkaline phosphatasea, alanine aminotransferase on Control

Correlate the results generated from the study of the two groups

NULL HYPOTHESIS

Methanolic extract of Alstoniaboonei stem bark, leaves and root, does not have effect on the liver function in alloxan induced diabetic rabbits

ALTERNATE HYPOTHESIS

Methanolic extract of Alstoniabooneileaves, root and stem bark have effect on the liver function of alloxan induced diabetic rabbits