Thesis Abstract

Abstract
Combretum micranthum is a plant species known for its traditional medicinal uses in various parts of Africa. In this study, the aqueous extract of Combretum micranthum leaves was investigated for its angiotensin converting enzyme (ACE) inhibitory activity and antioxidant properties. The ACE inhibitory activity was evaluated using an in vitro assay, while antioxidant activities were determined using various assays including DPPH scavenging activity, total phenolic content, and total flavonoid content. The results indicated that the aqueous extract of Combretum micranthum leaves exhibited significant ACE inhibitory activity with an IC50 value of 42.6 ?g/mL. This suggests the potential of the plant extract as a natural ACE inhibitor, which could be beneficial for the management of hypertension and other cardiovascular conditions. Additionally, the extract demonstrated strong antioxidant properties as evidenced by its high DPPH scavenging activity and high total phenolic and flavonoid contents. The findings of this study highlight the pharmacological potential of Combretum micranthum leaves as a source of natural ACE inhibitors and antioxidants. Further research is warranted to isolate and identify the bioactive compounds responsible for these activities and to elucidate the underlying mechanisms of action. This research contributes to the growing body of knowledge on the therapeutic properties of medicinal plants and underscores the importance of exploring natural sources for the development of novel therapeutics for various health conditions.

Thesis Overview

1.0 INTRODUCTION

1.1 Background of the Study

The word hypertension is defined as a persistence increase in systemic arterial blood pressure (Sembulingam and Sembuligam, 2006). Clinically, when the systolic pressure remains elevated above 140mmHg and diastolic pressure remains elevated above 90mmHg, it is considered as hypertension. The prevalence varies with age, race, education, occupation and many other variables (Benowitz, 2009). In Nigeria for example, the true incidence of hypertension remains unknown but its prevalence among male and female is estimated to be 11.2% with age adjusted figure of 9.3% (Nurudeenet al., 2013). This translates into approximately 13.4 million Nigerians becoming hypertensive at the age of 15years and above, using the projected national population census figure of 120million (Akinkungbe, 1998). In fact, hypertension is reported to be next to malaria as most serious health problems in developing tropical countries (Agunwa, 1988).

The global dimension of hypertension is immense, as it ranks the most common cardiovascular ailment afflicting about one billion people in the world and causing roughly 7.1 million deaths annually (Brundtland, 2002). Hypertension is said to be the most common cardiovascular disease among Africans and congestive cardiac failure its commonest complication (Akinkungbe 1972, 1985). Earlier studies suggested that hypertension was rare in African population (Sharper et al., 1969, Pobeeet al., 1977), however, epidemiological transition, urbanization, adoption of urban and foreign lifestyles and improved case findings, among others, have made hypertension more prevalent as shown in some studies (Cooper et al., 1998). The last Nigerian National Non-communicable Disease Survey (NNCDS) conducted in 1997 reported 11.4% prevalence of adult hypertension, varying from 14.8% in urban to 9.8% in rural residences respectively. However, a report on Nigeria from the World