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A comparative study of the
antimicrobial properties of the ethanolic extracts of
Landolphia owariensis leaf and root
L. A. Nwaogu*, C. S.,
Alisi, C. U. Igwe and C. O. Ujowundu
Department
of Biochemistry, School of Science, Federal University of
Technology, Owerri, Nigeria.
*Corresponding author. E-mail:
nwogulinus@yahoo.com.
Accepted
14 January, 2008 |
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The leaf ethanolic extract (LEEX) and root ethanolic extract
(REEX) of Landolphia owariensis were comparatively
subjected to phytochemical and antimicrobial screening.
Susceptibility of some clinical isolates (Staphylococcus
spp., Proteus spp. and Escherichia coli)
to the extracts was determined using dehydrogenase assay
method. The phytochemical screening indicated the presence
of alkaloids, flavonoids, saponins and tannins in both the
leaf and root extracts with cyanogenic glycosides present in
the root extract only. The response of the bacterial strains
to the leaf and root extracts was concentration dependent.
Dehydrogenase activity was progressively inhibited by the
root extract at a higher concentration range (150 – 2500
µg/ml) than the leaf extract (20 – 2000 µg/ml). LEEX gave an
IC50 of 20, 200, and 550 mg/ml against
Staphylococcus spp., Proteus spp. and
E. coli, respectively, while REEX gave an
IC50 of 340, 320, and 1560 mg/ml against the
organisms, respectively. The LEEX exhibited higher
antibacterial activity than the REEX. Susceptibility of the
organisms to the extracts showed: Staphylococcus spp.
> Proteus spp. > E. coli. The
observed antimicrobial properties could be due to the
presence of alkaloid, flavonoids and tannins, which were
identified in both extracts. The findings may be of clinical
relevance and further substantiates the traditional use of
L. owariensis leaves and roots as antimicrobial
agents.
Key
words:
Ethanolic extract, Landolphia owariensis,
dehydrogenase activity. |
