N-acetylcysteine Inhibits and Eradicates Candida albicans Biofilms

摘要

N-acetylcysteine (NAC) is used in the treatment of chronic bronchitis that attributed to its mucus dissolving properties. Its ability to reduce biofilm formed by different types of bacteria was proven previously in many studies. Therefore we examined its effect on C. albicans biofilms by testing its effect alone and in combination with ketoconazole using Tissue culture plate assay method (TCP). NAC effects on C. albicans morphology and the texture of biofilms were determined using Scanning electron microscope (SEM). It was found that the inhibitory effect of NAC was concentration dependent. NAC reduced C. albicans adherence by ≥32.8% while ketoconazole reduced adherence by ≥25% in comparison to control. Also, it showed higher disruptive effect (50-95%) than ketoconazole (22-80.7%) on mature biofilms. Using NAC and ketoconazole in combination, a significant inhibitory effect (P<0.01) on both adherence and mature biofilms (54-100%) was seen. NAC reduced the amount of biofilm mass in all tested Candida in concentrations at which their growth was not affected. NAC and ketoconazole combinations showed complete eradication to mature biofilms formed in most of the tested strains. NAC can inhibit C. albicans growth, inhibit dimorphism, which is an important step in biofilm formation, and change the texture of the formed biofilms, what makes NAC an interesting agent to be used as an inhibitor for biofilm formation by C. albicans.