Antibacterial activity of the spice extract
Although this is the first time that plants used in this
work are studied for their activities vis-à-vis multiresistant
bacteria, plants belonging to some of the genus
studied herein, like the Aframomum genus are well
documented for their antimicrobial activity [6]. Some
antibacterial compounds, such as acridone and chelerythrine
have previously been isolated from the fruits of
F. leprieurii [14,30]. The antimicrobial activity of P.
brazzeana and S. zenkeri is mainly due to some sulfur
compounds. In fact, sulfur compounds with antimicrobial
properties have previously been isolated from the
two plants [7,31]. Several alkaloids of the genus Piper
proved to be responsible for the activity of P. guineense
[32]. The detection of this class of secondary metabolites
in the extract studied herein can explain the observed
activities. According to Krishnaiah et al. [16], the antimicrobial
activity of I. cylindricum can be due to the
presence of tannins in this plant. However, tannins were
not detected in the extract of I. cylindricum as found in
the present work (Table 2), suggesting that other classes
of secondary metabolites might be responsible for the
antibacterial activity of this plant.