Determination of antibacterial activity, total phenolic, flavonoid and saponin contents in leaves of Anogeissus leiocarpus (DC.) Guill and Perr

Abstract

Objective: To ascertain the antibacterial property and quantify the contents of the total phenolics, flavonoids and saponins in leaves of Anogeissus leiocarpus (DC.) Guill and Perr. Methods: Preliminary phytochemical screening was performed by the method described by Harborne in 1999. Kirby-Bauer disc diffusion method was used for assaying the antibacterial activity. Folin-Ciocalteau reagent and aluminium chloride colorimetric methods were employed for the estimation of the total phenolic and flavonoid contents, respectively. Vanillinacetic acid and perchloric acid mixture was employed in the determination of the total saponin content. Results: The preliminary phytochemical screening revealed the presence of glycosides, tannins, flavonoids, saponins, terpenoids and steroids in the methanolic extract while alkaloids were absent. Only steroids were identified in the n-hexane extract. The methanolic leaf extract was active against Pseudomonas aeruginosa, Staphylococcus aureus, Klebsiella pneumoniae, Proteus vulgaris while the n-hexane was inactive. The total phenolic content obtained was (47.75 ± 0.12) mg gallic acid equivalent/mg extract, the total flavonoid content was (121.50 ± 0.11) mg quercetin equivalent/mg extract, while the total saponin content was (63.42 ± 0.15) mg ginsenoside Rb 1 equivalent/mg extract. Conclusions: The leaves of Anogeissus leiocarpus have high contents of saponins and