Angiotensin converting enzyme inhibitory activity and antioxidant activities of aqueous extract of combretum micranthum leaves

Thesis Abstract

Abstract
Combretum micranthum, a plant widely distributed in tropical Africa, has been traditionally used for its medicinal properties. 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 evaluated using an in vitro assay, while various antioxidant assays were employed to determine the extract's antioxidant potential. The results indicated 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 extract as a natural ACE inhibitor, which could be beneficial for managing hypertension. Additionally, the extract demonstrated potent antioxidant activities in various assays, including DPPH radical scavenging, ABTS radical scavenging, and reducing power assays. The extract showed dose-dependent antioxidant activity, indicating its ability to neutralize free radicals and protect against oxidative stress. Furthermore, the phytochemical analysis of the extract revealed the presence of various bioactive compounds, such as flavonoids, phenolics, and tannins, which are known for their antioxidant properties. These compounds may contribute to the observed ACE inhibitory and antioxidant activities of the extract. The total phenolic content of the extract was found to be 74.5 mg GAE/g, indicating a rich source of phenolic compounds with potential health benefits. Overall, the aqueous extract of Combretum micranthum leaves exhibited promising ACE inhibitory activity and potent antioxidant properties. These findings support the traditional use of this plant in herbal medicine and suggest its potential for the development of natural remedies for hypertension and oxidative stress-related conditions. Further studies are warranted to elucidate the underlying mechanisms of action, isolate and identify specific bioactive compounds responsible for the observed activities, and evaluate the extract's efficacy in animal models and clinical trials. This research contributes to the growing body of evidence supporting the therapeutic potential of natural products derived from medicinal plants.