Assessment of antimicrobial activity of crude extracts of stem and root barks from Adansonia digitata (Bombacaceae) (African baobab)

Abstract

This study seeks to validate the antimicrobial activity of crude extracts of stem and root barks from Adansonia digitata (Bombacaceae), investigate the minimum inhibitory concentrations (MICs) of the extracts and bioactive constituents present in the barks. Crude ethanolic and aqueous extracts of stem and root barks were evaluated for antimicrobial activities using agar-well method. Bioactive constituents were investigated using standard procedures for phytochemical analysis. The MICs were investigated using
broth micro dilution method. The results showed that the extracts had significant antibacterial activity. The MICs of the plant extracts ranged from 6 to 1.5 mg/ml. Tannins, phlobatannins, terpenoids, cardiac glycosides and saponins were found to be present in the stem bark. Terpenoids only were found in the root bark. It is concluded that stem and root barks of A. digitata contain bioactive constituents which are responsible for antimicrobial activity of the crude extracts.