Table 1.
Summary of plants used in this study and their putative antifungal actives.
Fig 1.
Checkerboard assay layout on a 96-well plate.
Two extracts were combined in concentrations starting at the calculated MIC90 and in subsequent 2-fold diluted concentrations. Antifungal used as control was econazole at 30 µg/mL. Solvent control used 70% ethanol. Growth control was C. albicans inoculum with RPMI 1640 media with no treatment. Columns 9 and 10 contained only one extract at concentrations starting at the calculated MIC90 and 2-fold serially diluted.
Table 2.
MIC90 and MIC50 for each plant extract against C. albicans in broth microdilution measured with OD530.
Table 3.
Calculated FIC Index scores of plant extract combinations against C. albicans according to MIC90 and MIC50.
Fig 2.
Heatmap matrices of FICI values for each plant extract combination.
(A) MIC90 values and (B) MIC50 values. Green indicates strongly synergistic and red indicates strongly antagonistic. Synergistic = FICI < 0.5, additive = 0.5 ≤ FICI < 1, neutral = 1 ≤ FICI < 2, antagonistic = FICI ≥ 2.
Fig 3.
Comparison of antifungal activity as % inhibition of C. albicans growth between plant extracts and their putative active compounds.
Antifungal activity of (A) berberine and H. canadensis, (B) eucalyptol and E. globulus, and (C) punicalagin and P. granatum. For all data points n = 3. Bars represent ±S.D.
Table 4.
Calculated FIC Index scores of pure compound or fraction combinations of select extracts against C. albicans according to MIC50 and MIC90 in mg/mL.