Crude Flavonoids Isolated from the Stem Bark of Annona senegalensis have Antimicrobial Activity

This study was aimed at determining the in vitro antimicrobial activity of crude flavonoids isolated from the stem bark of Annona senegalensis. The study was carried out in the laboratory of Biochemistry department, Modibbo Adama University of Technology, Yola, Adamawa State, Nigeria, between July and October, 2013. The antimicrobial activity was carried out using agar well diffusion method. Phytochemical screening of the methanolic stem bark extract of Annona senegalensis revealed the presence of steroids, saponins, anthraquinones, flavonoids, tannins and cardiac glycosides. Crude flavonoid of 1.956g was found to be present in 10g of stem-bark extract of the plant. Streptomycin was used as standard which gave the zones of inhibition of 23mm against Escherichia coli, 26mm against Salmonella typhi and 28mm against Shigella specie while the isolated crude flavonoids from the stem bark of Annona senegalensis gave the zones of inhibition of 18mm against Escherichia coli, 25 mm against Salmonella typhi and 26 mm against Shigella specie. Crude flavonoids exhibited Minimum Inhibitory Concentration (MIC) against Shigella specie and Escherichia coli at 100mg/ml while against Salmonella typhi at 50mg/ml. In conclusion, the crude flavonoids isolated from the stem bark of Annona senegalensis have antimicrobial activity against the test organisms.