Study of Antifungal Synergism Effects of Chitosan with Thymol, Carvacrol and Isothiocyanate against Candida albicans

Background and Aim: Prevalence of drug resistance in Candida albicans hinders common treatments with conventional antifungal drugs. A stockpile of research is being done to discover novel antifungal drugs. Chitosan has emerged as a promising antimicrobial and biodegradable polymer with various medical applications. The significant antimicrobial potential of some of the secondary metabolites from plants has been confirmed in several studies. Thymol, Carvacrol, and Isothiocyanate are three plant secondary metabolites with strong antifungal properties. In this study, the synergistic effect of Thymol, Carvacrol, and Isothiocyanate with chitosan against C. Albicans was tested. Materials and Methods: The minimum inhibitory concentration and synergistic effects of chitosan with Thymol, Carvacrol, and Isothiocyanate were assessed in checkerboard assay. The minimum fungicidal concentrations against C. Albicans, time-kill assay, and growth curve were tested subsequently. Results: The results of the checkerboard test confirmed the synergistic effects of chitosan with all three investigated plant metabolites. The Chitosan- Thymol combination represented the most effective antifungal activities against C. Albicans based on the time-kill and growth curve assay results. Conclusion: Chitosan- Thymol combination can be a promising compound for control of C. Albicans. Chitosan- Thymol combination sharply declined the number of viable cells during the first two hours. This ability can be tested in further studies as a biopolymer or nano-capsulated drug.