Phytochemical Investigation and Evaluation of the Antioxidant and Antibacterial Potentials of the Organs of Adenanthera pavonina (Fabaceae)

Abstract

This research was conducted on Adenanthera pavonina (Fabaceae), an exotic plant introduced to Côte d'Ivoire mainly for its ornamental value. However, beyond this use, it is of particular interest in certain regions of the world due to its nutritional and therapeutic qualities. Aims: This study aims to promote Adenanthera pavonina from Côte d'Ivoire through chemical characterisation and biological exploration. Methodology: For this purpose, hydroethanolic extracts from the leaves, seeds, and trunk bark of Adenanthera pavonina were prepared. These extracts were then subjected to phytochemical screening using detection tests (color reactions and precipitation), as well as spectrophotometric quantification of total phenols, flavonoids, and condensed tannins. Additionally, the antioxidant activity of these extracts was evaluated using the DPPH (free radical scavenging) and FRAP (ferric reducing antioxidant power) assays. Finally, their antibacterial activity was assessed against five resistant bacterial strains. Results: Phytochemical analysis, carried out through qualitative and quantitative tests, revealed the presence of various bioactive compounds such as polyphenols, flavonoids, coumarins, tannins, and saponins. The FRAP and DPPH tests demonstrated an exceptional antioxidant activity in the bark (IC50 = 0.00268 mg/mL), surpassing that of vitamin C (0.0045 mg/mL), a natural antioxidant. The bark also exhibited bactericidal activity at 100 mg/mL against Escherichia coli and Pseudomonas aeruginosa, unlike the other plant parts. Conclusion: these results highlight the potential of A. pavonina from Côte d’Ivoire as a source of natural antioxidants and antibacterial agents, justifying further research for the isolation of its active compounds.