Leaf Extracts of Vernonia amygdalina Del. from Northern Ghana Contain Bioactive Agents that Inhibit the Growth of Some Beta-lactamase Producing Bacteria in vitro.
Date
2014-01
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Abstract
Aims: The current study was aimed at evaluating the phytochemical profile and in vitro
bacteria growth inhibitory potential of different solvent leaf extracts of V. amygdalina from
northern Ghana.
Study Design: Different solvent extracts of the plant were quantitatively and qualitatively
evaluated for phytochemicals. In vitro bacteria sensitivity assay of the extracts was
evaluated using some beta-lactamase producing bacteria as test microbes.
Methodology: Ethanolic, methanolic, petroleum ether and aqueous leaf extracts of
Vernonia amygdalina were studied in vitro for growth inhibition against beta-lactamase
producing bacteria such as Escherichia coli, Staphylococcus aureus, Klebsiella
pneumoniae and Pseudomonas aeruginosa using agar well diffusion method. Saponins,
flavonoids, glycosides, alkaloids, tannins, phenolics, reducing sugars, anthracenosides,
terpenes and phytosteroids were determined qualitatively and quantified. Results: All the phytochemicals tested were found to be present in both the methanolic
and ethanolic leaf extracts. The aqueous extract showed the presence of saponins,
reducing sugars and anthracenosides. Glycosides, flavonoids, saponins and alkaloids
were the only groups of phytochemicals found in the petroleum ether extract. The
methanolic extract showed the greatest amount of saponins (14.23%), flavonoids (2.15%),
alkaloids (7.49%), tannins (5.4%), terpenes (10.20%) and phenolics (8.24%). The
methanolic extract at concentration of 4 mg/ml showed growth inhibitory activities against
all the test organisms with zone of inhibitions ranging from 16.00±0.50 (against E. coli) to
20.50±0.03 mm (against S. aureus). The ethanolic extract showed activity against only
two of the test organisms viz. 23.00±0.33 mm against P. aeruginosa and 12.00±0.00 mm
against S. aureus at similar concentration. All test organisms were resistant to both
aqueous and pet ether extracts.
Conclusion: The antibacterial activities of the methanolic and ethanolic extracts were
significant (P < 0.05) and may be mediated by the presence of saponins, flavonoids,
tannins, terpenes and alkaloids. Results from present study corroborate previous findings
and also presents methanolic leaf extract of the plant as a credible candidate for the
discovery of new phytotherapeutic agents against the beta-lactamase producing bacteria
tested.
Description
Keywords
Phytochemical evaluation, leaf vegetable, Vernonia amygdalina, bacteria growth inhibition, agar well diffusion, beta-lactamase
Citation
Adebayo Oseni Lateef, James Abugri, Kasim Sumabe Balagra, Jagri Onilimor Peter. Leaf Extracts of Vernonia amygdalina Del. from Northern Ghana Contain Bioactive Agents that Inhibit the Growth of Some Beta-lactamase Producing Bacteria in vitro. British Journal of Pharmaceutical Research. 2014 Jan; 4(2): 192-202.