Antibacterial, Radical Scavenging Activity Evaluation, and Phytochemical Analysis of Root Extracts of Cordia africana from Adama, Oromia Regional State of Ethiopia

Abstract

Microbial drug resistance is a worldwide health threat, and new bioactive molecules must be discovered to deal with resistant pathogens. Plants have been a great source of antimicrobial molecules and are full of promise for discovering new drugs. Although traditional healers in Ethiopia have been using the root of Cordia africana, no study has been done; as a result, the study aims to assess the biological activity and chemical composition of root extracts of C. africana. Root samples of the plant were extracted successively with Dichloromethane: Ethanol (1:1), Ethanol, and Methanol using successive (maceration) techniques. Antibacterial activity was assessed using the standard disc diffusion method, and a DPPH assay was used to analyze the antioxidant activity. Phytochemical screening of the extracts was conducted following the standard procedures. Hydro-distillation was employed to extract essential oils, and their composition was analyzed using GC-MS. The Dichloromethane: Ethanol (1:1) extract was subjected to column chromatography to isolate compounds, and structural elucidations of the isolated compounds were done using FTIR and NMR. The phytochemical analysis reveals the presence of alkaloids, flavonoids, Phenol, steroids, and tannins across all three extracts. The GC-MS analysis of essential oils of the plant roots reveals the presence of 29 compounds, and dodecyl alcohol, 2,4-DTBP, and cyclohexadecane were the major constituents. The fractionation process generated a total of 122 fractions, which were further repacked to yield 154 fractions, of which two compounds were isolated. The antimicrobial activity revealed that MeOH extract, and essential oil showed the highest inhibition against S. pyogenes with inhibition values of 18.50 ± 1.50 and 16.33 ± 1.53 mm, respectively. The essential oil showed the highest radical scavenging activity with an IC50 value of 1.61 μg/mL, followed by MeOH extract (5.52 μg/mL). Thus, the findings of this study showed that the roots of C. africana have a medicinal potential. Further investigations are needed to discover their full potential and implement them in the fight against multi-drug-resistant pathogens.