New pharmacological properties of Medicago sativa and Saponaria officinalis saponin-rich fractions addressed to Candida albicans

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. INTRODUCTIONCandida albicans is probably the best known and at the same time the most effective opportunistic fungal pathogen of humans and animals. It constitutes a commensal microflora in the gastrointestinal and genitourinary tracts of .70 % of humans. However, in certain circumstances C. albicans could be pathogenic to critically ill, immunocompromised patients or even to healthy persons. It causes a diverse range of pathologies -from local cutaneous and mucosal infections (e.g. candidiasis of nail shafts and nails, oropharyngeal candidiasis, intestinal candidiasis) to lifethreatening systemic infections, such as candidaemia, fungal pneumonia, meningitidis or endocarditis (Cannon et al., 2009;Kabir et al., 2012;Kabir & Ahmad, 2013;Sardi et al., 2013; Tlamçani & Er-rami, 2013). Endogenous candidaemia and the carrier state are the main mechanisms of Candida spp. spread and transmission, although exogenous infections are also possible (Mathé & van Dijck, 2013;Sardi et al., 2013). The pathogenicity and high invasiveness of C. albicans arise from the broad range of its virulence factors. These include tissue-damaging hydrolytic enzymes: proteases (mainly secreted aspartic proteinases), phospholipases and haemolysins, but first of all the agents/abilities contributing to its strong adherence (e.g. two main C. albicans adhesions: agglutinin-like sequence and hyphal wall protein-1), biofilm formation and the transformation of morphological forms (yeast-to-hyphal). Also, the ability of C. albicans to survive in various anatomical body sites and to evade host defences seems to be essential (Chai et al., 2009;Chandra et al., 2001;Gropp et al., 2009;Sardi et al., 2013).Invasive candidiasis usually results from tissue colonization by yeast and formation of biofilm -the structured multicellular microbial communities embedded in a self-...

Phytochemical investigation and antimicrobial assessment of Bellis sylvestris leaves

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Antibacterial effect of Medicago sativa extract on the common bacterial in sinusitis infection

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