Objectives
Plant extracts are important natural resources that may have antimicrobial and antibiofilm effects against pathogens. This study was conducted to investigate the
in vitro
antimicrobial activities of methanol extracts of some medicinal plants (
Achillea nobilis
subspecies
neilreichii
(A. Kern.) Velen.,
Aetheorhiza bulbosa
(L.) Cass,
Allium paniculatum
L,
Asphodelus aestivus
Brot.,
Ballota nigra
L.,
Cistus laurifolius
L.,
Cistus salviifolius
L.,
Dioscorea communis
(L.) Caddick and Wilkin,
Galium verum
L.,
Hypericum triquetrifolium
Turra,
Paliurus spina-christi
Mill.,
Primula vulgaris
Huds. subspecies
rubra
(Sm.) Arcang.,
Ranunculus arvensis
L. and
Teucrium polium
L.) from Balıkesir province in Türkiye.
Materials and Methods
Preliminary antimicrobial activity screening was conducted for all extracts. Antibiofilm activity studies were conducted on mature
Candida albicans
biofilms. Moreover, the cytotoxicities of
A. paniculatum
flower extract on A549 and Vero cell lines were determined using a colorimetric tetrazolium-based assay.
Results
A. paniculatum
flower,
P. vulgaris
root,
C. laurifolius, C. salviifolius,
and
A. nobilis
displayed good activity [minimum inhibitory concentrations (MIC): 9.75, 156, 312, 312 and 312 µg/mL, respectively] against
C. albicans
American Type Culture Collection 10231. Biofilm studies were conducted on these plant extracts. The methanol extract of
A. paniculatum
flower decreased the number of
C. albicans
[colony-forming unit (CFU)/mL] in mature biofilm statistically at 32 x MIC and higher concentrations (
p
< 0.01).
A. paniculatum
flower extract had a cytotoxic effect (killing more than 50% of cells) at high concentrations, and its effect on Vero cells was similar to that on A549 cells.
Conclusion
This study demonstrated the importance of the methanol extract of
A. paniculatum
flower as a natural alternative against
C. albicans
infections, including biofilms.