Achillea taygetea
The ethyl acetate extract of A. taygetea demonstrated significant
inhibitory effects on obligate anaerobic pathogens, with MIC values
ranging from 0.04 mg / ml (P. micra ) to 0.60 mg / ml (F.
nucleatum ). The effect on facultative anaerobic streptococci varied,
with S. oralis inhibited at 0.60 mg / ml, S. sobrinusinhibited at a minimum of 5.00 mg / ml, and the inhibitory
concentrations observed in S. mutans tests were attributed to the
effects of DMSO. Among the remaining pathogens listed in Table 1, all
except S. aureus (MIC = 2.50 mg / ml) showed resistance to the
extract. The MBC values ranged from 0.15 mg / ml (P. micra ) to
5.00 mg / ml (S. aureus ), except for S. sobrinus , which
was not eliminated in the test.
In the biofilm plate assay, the tested S. mutans strain showed
strong inhibition in biofilm formation at a concentration of 5.00 mg /
ml. The lower cutoff value was calculated at an optical density (OD595)
of 0.143. In the presence of 2.50 mg / ml of the ethyl acetate extract,
biofilm production fell into the C2 category. Figure 2 indicates that
lower concentrations did not affect biofilm formation, as all absorbance
values were higher than the high cutoff value (OD595 =
0.428).