Phytochemical screening, total polyphenolic content, in vitro antioxidant and antibacterial activities of Albizia coriaria Welw ex. Oliver flowers

Abstract

Albizia coriaria is widely utilized across Africa for treating oxidative stress-mediated complications and bacterial diseases. This research performed phytochemical screening, quantification of total phenolics and flavonoids, and assessment of antioxidant and antibacterial potential of A. coriaria flowers. The powdered sample was extracted successively with ethyl acetate, ethanol and distilled water. Phytochemical screening detected alkaloids, phenols, saponins, flavonoids, tannins and terpenes as main the secondary metabolites in the extracts. Total phenolic and flavonoid contents (72.09 ± 0.09 mg GAE / g DW and 10.37 ± 0.02 mg QE / g DW) and antioxidant activity (IC50 = 24.23 ± 0.04 mg/mL) were highest for ethyl acetate extract, followed by ethanolic and aqueous extracts. Ethyl acetate extract had the highest antibacterial potential with inhibition zones of 22.00 ± 1.73 mm, 11.00 ± 2.65 mm, 19.00 ± 2.10 mm and 7.00 ± 0.00 mm against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Salmonella typhi, respectively. Ethanolic extracts elicited lower antibacterial activities while aqueous extracts did not inhibit bacterial growth. This study for the first time indicated that A. coriaria flowers has phytochemicals with antioxidant and antibacterial activities, lending credence to its use in traditional management of oxidative stress-mediated conditions and bacterial diseases.