Assessment of Antibacterial Activity of Essential Oil Extracted from Leaves of Thaumatococcus danielli (Benn.) Benth. in Light of its Inhibitory Impact on Extracellular Protease of Shigella dysenteriae.
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Date
2015
Authors
Segun, Adeola A
Samuel, Folorunso O
Aminat, Akintobi T
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Abstract
Aims: This study was carried out to assess the antimicrobial effect of the volatile oil of
Thaumatococcus danielli (Benn.) Benth. leaves against selected enteric pathogens and its possible
inhibition against a partially purified and characterized extracellular protease of Shigella
dysenteriae.
Study Design: The volatile oil was used as antibacterial agent against eight enteric pathogens
and as potential inhibitor to a partially purified extracellular protease of Shigella dysenteriae.
Place and Duration of Study: Department of Biochemistry, Faculty of Science, Lagos State
University, Ojo Lagos State, Nigeria; between May – September 2013. Methodology: The volatile oil was extracted by hydrodistillation. The sensitivity, minimum inhibitory
concentration (MIC) and minimum bactericidal concentration (MBC) of the volatile oil against the
pathogens were determined by disc-diffusion and micro-dilution techniques. The extracellular
protease of Shigella dysenteriae was partially purified by (NH4)2SO4 salting-out followed by gel
filtration chromatography. Enzyme assay was carried out with casein (as substrate) and volatile oil
(as inhibitor).
Results: The average inhibition zones ranged from 16 – 30 mm. Klebsiella pneumoniae,
Staphylococcus aureus and Enterococcus faecalis remained insensitive to the oil. Shigella
dysenteriae and Proteus vulgaris showed highest and lowest sensitivities respectively. Highest
purification fold of 2.63 with specific activity of 18.4μmol/min/mg protein were obtained after
Sephadex G-75 gel filtration of the enzyme extract. The oil competitively inhibited the partially
purified extracellular protease of Shigella dysenteriae with Vmax = 8.33 ΔA/min, Km = 0.85mg/ml (no
inhibitor) and apparent Km´ = 1.54mg/ml (inhibitor). Optimal activities of this protease were obtained
at pH 7.5 and 30ºC.
Conclusion: Though, it may not be clarified whether the oil interacted with the substrate/enzyme.
Nevertheless, there was an inhibition of the extracellular protease of Shigella dysenteriae by the
volatile oil of Thaumatococcus danielli (Benn.) Benth. It was therefore envisaged that elaborate
work on the inhibition of this type of enzyme in pathogens by essential oil would be a platform of
arresting infection caused by bacteria.
Description
Keywords
Thaumatococcus danielli (Benn.) Benth, volatile oil, antimicrobial, Shigella dysenteriae, extracellular protease
Citation
Segun Adeola A, Samuel Folorunso O, Aminat Akintobi T. Assessment of Antibacterial Activity of Essential Oil Extracted from Leaves of Thaumatococcus danielli (Benn.) Benth. in Light of its Inhibitory Impact on Extracellular Protease of Shigella dysenteriae. International Journal of Biochemistry Research & Review 2015 5(1): 9-19.