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In vitro
antibacterial activity of
crude leaf extracts of Mangifera indica Linn
Doughari, J. H.* and Manzara, S.
Department of Microbiology, School of Pure and Applied
Sciences, Federal
University of
Technology,
P. M. B 2076; Yola, 640002. Adamawa State, Nigeria.
*Corresponding author: E-mail:
jameshamuel@yahoo.com.
Accepted 20 March, 2008 |
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The active
components of leaves of Mangifera indica L. were
extracted using cold water and organic solvents (acetone and
methanol) and were tested against Staphylococcus aureus,
Streptococcus pyogenase, Streptococcus pneumoniae, Bacillus
cereus, Escherichia coli, Pseudomonas aerugenosa, Proteus
mirabilis, Salmonella typhi and Shigella flexnerri
using the agar well (cup plate) diffusion method. Both the
acetone and methanol extracts inhibited the growth of gram
positive bacteria, with acetone extract exerting more
activities on all the gram positive bacteria with zone of
inhibition between 15 - 16 mm, and a gram negative bacterium
S. typhi (14 mm) at 250 mg/ml. Whereas, water extract was
not active on any of the bacterial pathogens tested at any
of the concentration of the extract used. The activities of
the plant extracts on the inhibited pathogens using the zone
of inhibition were not as effective as the standard
commercial antibacterial disks of gentamicin and
erythromycin (t = 2.23, p < 0.05). Increased temperature (60
and 100°C for 1 h) had a multiplier effect on the activity
of the extracts, but alkaline pH decreased the activity.
Preliminary phytochemical analysis revealed the presence
of tannins, glycosides, saponins and phenols. The
MIC and MBC of the extracts was in the range of 12.5 - 75
and 25 - 175 mg/ml respectively. There is a basis for the
traditional use of the plant as a local health remedy.
Key
words:
Antibacterial activity, MIC, MBC, gram-positive bacteria,
gram-negative bacteria, Mangifera indica, extract. |
