Treculia africana
is a plant that is used in traditional medicine for the treatment
of diverse ailments. To investigate the scientific basis for the use of the plant, the antimicrobial
activities/potency of the root and stem bark extracts were evaluated against common gram
negative and gram positive bacteria as well as yeast. The chemical constituents of the plant in
addition to the effect of temperature and pH on its antimicrobial potencies were investigated.
The phytochemical constituents of the dried powdered plant parts were extracted using aqueous
and organic solvents (acetone and ethanol). The antimicrobial activity of the concentrated
extracts was evaluated by determining the diameter of zone of inhibition against both gram
negative and gram positive bacteria and yeast, using the disc diffusion technique. Phytochemical
studies revealed the presence of glycosides, anthraquinone, free aglycone, saponin, steroids and
polyphenols. The extracts were active against both gram positive and gram negative bacteria.
The activities of the plant extracts were not affected at varied temperatures (4°C, 30°C, 60°C and
100°C), but decreased at alkaline pH. Minimum inhibitory concentration (MIC) and minimum
bactericidal concentration (MBC) of the extracts on the test organisms revealed lowest MIC and
MBC against
Salmonella paratyphi
,
Salmonella typhi
and
Bacillus subtilis
with highest MIC
and MBC exhibited against
Staphylococcus aureus
. Generally, there was significant difference
(p<0.05) in the antimicrobial activities of the test extracts and control antibiotics, with the
control antibiotics exerting broader antimicrobial activity.
Treculia africana demonstrated broad
spectrum antibacterial activity and a potential source of new classes of antibiotics that could be
useful for infectious disease chemotherapy and control.
