Abstract
The antifungal activity of the saponin-rich fractions (SFs) from Medicago sativa (aerial parts and roots) and Saponaria officinalis (used as a well-known source of plant saponins) against Candida albicans reference and clinical strains, their yeast-to-hyphal conversion, adhesion, and biofilm formation was investigated. Direct fungicidal/fungistatic properties of the tested phytochemicals used alone, as well as their synergy with azoles (probably resulting from yeast cell wall instability) were demonstrated. Here, to the best of our knowledge, we report for the first time the ability of saponin-rich extracts of M. sativa and S. officinalis to inhibit C. albicans germ tube formation, limit hyphal growth, reduce yeast adherence and biofilm formation, and eradicate mature (24 h) Candida biofilm. Moreover, M. sativa SFs (mainly obtained from aerial parts), in the range of concentrations which were active modulators of Candida virulence factors, exhibited low cytotoxicity against the mouse fibroblast line L929. These properties seem to be very promising in the context of using plant-derived SFs as potential novel antifungal therapeutics supporting classic drugs or as ingredients of disinfectants.
- Abbreviations:
- EPS
- extracellular polymeric substance
- GTF
- germ tube form
- Ks
- saponin-rich fraction alone as a negative control
- Km
- medium alone as a negative control
- M
- saponin-rich fraction of Medicago sativa aerial parts
- Mr
- saponin-rich fraction of Medicago sativa roots
- MTT
- 3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide
- S
- saponin-rich fraction of Saponaria officinalis
- SF
- saponin-rich fraction
- XTT
- 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide sodium salt