ABSTRACT
The aim of this study is to determine the antimicrobial activity of crude tannins from the stem bark of Annona senegalensis on some diarrhoea causing bacteria strains. 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 disc diffusion method. The phytochemical analysis revealed the presence of tannins, alkaloids, saponins, cardiac glycosides, steroids, tarpenoids and phenols. Quantitatively, crude tannins of 170.16mg were found to be present in 500mg of the extract which makes up a percentage composition of 34.03%. The extracted crude tannins were used to test for antimicrobial effect against Escherichia coli, Salmonella typhi, and Staphylococcus aureus and were only effective on Staphylococcus aureus with 19mm as the inhibition zone using the concentration of 100mg/ml. The Minimum Inhibitory Concentration (MIC) of the extracted crude tannins was observed at 12.5mg/ml on Staphylococcus aureus. This suggests that the isolated crude tannins have an antistaphylococci activity and can be used to treat infections caused by the organism.
ABSTRACT
This study was aimed at evaluating the antimicrobial effect of tannin isolated from the leaf of Annona senegalensis on Shigella dysenteriae, Escherichia coli and Salmonella typhi. 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 disc diffusion method. The phytochemical screening of the leaf of the plant revealed the presence of tannins, alkaloids, saponins, flavonoids, terpenoids, cardiac glycosides and anthraquinones while phenols and steroids were absent. Quantitatively, tannins were found to be 24% in the leaf of the plant. Isolated tannin exhibited antibacterial activities against all the tested bacteria; Shigella dysenteriae gave the zone of inhibition (18.6mm), Escherichia coli (13.9mm) and Salmonella typhi (10.6mm). Minimum Inhibitory concentration of the crude tannins on the test organisms ranged from 6.25mg/ml to 12.5mg/ml. These findings confirmed the basis of traditional use of the leaf of Annona senegalensis in the treatment of diseases such as dysentery and diarrhea.
ABSTRACT
This study was aimed at evaluating the antimicrobial activity of stem bark extract of Faidherbia albida on E. Coli, Salmonella typhi and Shigella sp. The study was conducted in laboratory of Biochemistry department of Modibbo Adama University of Technology, Yola, Adamawa, Nigeria, between July and October, 2012. The antimicrobial activity was carried out using agar disc diffusion method and the crude extract was separated using column chromatography. The phytochemical analysis of the crude methanolic stem bark extract of Faidherbia albida revealed the presence of tannins, saponins and alkaloids. The in vitro antimicrobial activity of the crude methanolic extract of the stem bark showed highest activity on Salmonella typhi with zone of inhibition of 12.0±0.17mm compared to E. coli and Shigella sp. Column chromatography of the crude extract eluted with benzene/methanol, acetic acid/methanol and ethylacetate/methanol gave three fractions designated: I, II and III; of which fraction III showed highest activity against the test organisms. Minimum inhibitory concentration of the most active fraction is 60mg/ml on E. coli and Salmonella typhi and 80mg/ml on Shigella sp.The in vitro antimicrobial activity of the crude methanolic stem bark extract of Faidherbia albida was also compared to some standard antibiotics. The results showed that azithromycin had highest activity ranging from 17.0 ± 0.11mm to 23.0 ± 0.12mm against the test organisms with no significance difference (P<0.05) compared to the activity of fraction III. There was also no significant (p<0.05) difference between the effect of the crude methanolic stem bark extract and that of cirprofloxacin with zone of inhibition ranging between 12.0±0.08mm to 20.0± 0.15.mm These results reveal the antibacterial nature of the stem bark of Faidherbia albida and suggest that it could be exploited in the management of diseases caused by the tested organisms in human.