Department of Biology and Biotechnology, An-Najah National University, Nablus, Palestine
Preferred Abstract (Original):
To assess the clinical utility of the crude ethanolic extract of the leaves of Varthemia iphionoides
(Compositae), minimal inhibitory concentrations eJ'v1Ies) were determined using agar dilution technique.
Accordingly, The MICs of of this plant extract ranged from 0.0313-1 mg/ml for three clinical Staphylacaccus
aureus strains and ATCC strains of Bacillus subtilis and Staphylococcus epidermidis, whereas Escherichia
coli studied in this report was fOlUld to exhibit higher 1v1Ie value (4 mg/ml). The effect of combinations of
ethanolic extract of Varthemia iphionoides and cefotaxime was investigated by means of fractional inhibitory
concentration (FIe) indices. Using the FIe indices, synergistic interactions were observed against B. subtilis
(ATCC 6633) and S. aureus strains (FIC indices of 0.75-0.875); while combinations against E. cali and
S. epidermidis (ATCC 25923) exhibited antagonistic interactions (FIC indices of 2.5 to 16.4). Synergy was
confirmed at cefotaxime concentrations corresponding to 1/2 MIC and an ethanol extract concentrations
corresponding to 1/41v1IC and lower.
Key words: Varthemia iphionoides . Medicinal plants . Antibacterial activity . Herb-drug interactions
. Plant extracts