The Phytochemical and Antimicrobial Potentials of the Crude Extracts of Bridelia ferruginea and the Extracellular Biosynthesized Silver Nanoparticles

Bridelia ferruginea has been used in African folk medicine for the treatment of several ailments especially throat infections. In this study, the phytochemical analysis, fractioning using different solvents, antimicrobials and silver nanoparticles (SNPs) produced by the ethanolic extract of the bark of B. ferruginea were investigated. The bark extract of the plant was used for the extracellular biosynthesis of SNPs; and characterized using visual observation, UV-Visible Spectrophotometer, Scanning Electron Microscope (SEM) and FTIR analysis. The antimicrobial potential of the characterized SNPs against some pathogenic microorganisms was also determined.

Flavonoids (987 mg/100 g), alkaloids (762 mg/100 g), saponins (437 mg/100 g) and tannins (209 mg/100 g) were the major bioactive compounds present in the plant while phenols and terpenes were absent. All the test organisms were sensitive to the crude extract of B. ferruginea with the highest zone of inhibition observed for Klebsiella pneumoniae (23 mm). In addition, all the test organisms were susceptible to the ethyl acetate fraction of B. ferruginea with Actinobacillus sp. having the highest zone of inhibition (18 mm). The SNPs has a pentagonal shape and the size ranged from 0.0 – 9.4 nm. The antibacterial activities of the crude and synthesized SNPs of B. ferruginea showed that the crude extract exhibited higher activity than the SNPs on the test bacteria with a range of 15-23 mm as against 13-21 mm observed for the SNPs.

In conclusion, the crude ethanolic extract, partitioned fractions, and SNPs of the bark of B. ferruginea had very good potential as antibacterial against some test bacteria.