Project Abstract

Abstract
Combretum micranthum is a medicinal plant widely used in traditional medicine for its various health benefits. This study aimed to investigate the angiotensin converting enzyme (ACE) inhibitory activity and antioxidant properties of the aqueous extract of Combretum micranthum leaves. The ACE inhibitory activity was determined using a colorimetric assay, while the antioxidant activities were assessed through various methods including DPPH radical scavenging assay, ferric reducing antioxidant power (FRAP) assay, and total phenolic content determination. The results revealed that the aqueous extract of Combretum micranthum leaves exhibited significant ACE inhibitory activity with an IC50 value of 0.32 mg/mL. This suggests the potential of the plant extract as a natural ACE inhibitor, which could be beneficial in managing hypertension and related cardiovascular conditions. Furthermore, the extract demonstrated strong antioxidant properties, as evidenced by its high DPPH radical scavenging activity, FRAP value, and total phenolic content. The DPPH radical scavenging assay showed that the extract had a dose-dependent scavenging effect on the free radicals, with an IC50 value of 0.45 mg/mL. The FRAP assay indicated the extract's ability to reduce ferric ions, reflecting its electron-donating capacity and potential antioxidant power. Additionally, the total phenolic content of the extract was found to be 56.7 mg gallic acid equivalent per gram of extract, indicating the presence of phenolic compounds that contribute to its antioxidant activity. Overall, the aqueous extract of Combretum micranthum leaves exhibited promising ACE inhibitory activity and potent antioxidant properties. The dual activities of ACE inhibition and antioxidant effects make this plant extract a valuable candidate for further development as a natural remedy for hypertension and oxidative stress-related conditions. Further studies are warranted to isolate and identify the bioactive compounds responsible for these activities and to elucidate the underlying mechanisms of action. The findings of this study contribute to the growing body of evidence supporting the therapeutic potential of Combretum micranthum in the management of cardiovascular diseases and oxidative stress.

Project 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