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Evaluation of
antibacterial activity and acute toxicity of the
hydroethanolic extract of Stachytarpheta angustifolia
(Mill) Vahl.
Enwuru, N. V.1*, Ogbonnia, S.
O.2, Nkemehule, F.2,
Enwuru, C. A.3 and Tolani, O.1
1Department
of Pharmaceutical Technology and Pharmaceutical
Microbiology, Faculty of Pharmacy, University of Lagos
College of Medicine Campus, Idi-Araba, Lagos, Nigeria.
2Department
of Pharmacognosy, Faculty of Pharmacy, University of Lagos
College of Medicine Campus, Idi-Araba, Lagos, Nigeria.
3Microbiology
Unit, Nigeria Institute of Medical Research, Yaba, Lagos,
Nigeria.
*Corresponding author. E-mail: nvenwuru111@yahoo.ca.
Accepted 13 May, 2008 |
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The aim of this study was to evaluate antibacterial
activity, acute toxicity in mice and phytochemical profiles
of hydroethanolic extract of Stachytarpheta angustifolia
plant. The plant S. angustifolia has attracted
the attention of the researchers because of its use as an
anti-infection agent. The aqueous ethanol (80%) extract of
the powdered dried whole plant was obtained by maceration.
The bacteria organisms tested include Shigella dysentriae
(ATCC 32412), Salmonella typhi (ATCC 213415), and the
following clinical isolates: coagulase-negative
Staphylococcus, Staphylococcus aureus, Proteus
mirabilis, Klebsiella species and Escherichia
coli. Susceptibility test, acute toxicity test and
phytochemical screening of the plant extract were performed
using standard procedures. The results showed that the
extract had a good antibacterial activity against S.
aureus, S. dysentriae, coagulase-negative
Staphylococcus and Proteus mirabilis. The
minimum inhibitory concentration (MIC) was found to be
between 11.6 and 14.0 mg/ml for the susceptible organisms.
The extract exhibited minimum bactericidal concentration
(MBC) of 150 mg/ml against S. dysentriae only while
other susceptible tested bacteria strains required higher
concentrations. The median acute toxicity value (LD50)
of the extract was determined to be 8.721 g/kg body weight
indicating the extract as being slightly toxic. The extract
contained triterpenoid saponins as the major bioactive
constituent.
Key words:
Stachytarpheta angustifolia, acute, toxicity,
antibacterial and phytochemical. |
