Antifungal Effects of Thymol-Loaded Chitosan Nanocomposite Alone and in Combined with Nystatin Against Candida Albicans, a Major Cause of Oral Candidiasis

Abstract

Objectives: Oral candidiasis is the most common oral infection that affects the oral mucosa. The most common oral thrush is caused by the fungus Candida albicans, but it can also be caused by Candida glabrata or Candida tropicalis. This study aimed to evaluate the antifungal effect of thymol-loaded chitosan nanocomposite in comparison with nystatin control drug on C. Albicans. Material and Methods: The obtained nanocomposite was characterized by scanning electron microscope (SEM), nanosizer-Zetasizer, and Fourier-transform infrared spectroscopy. Anti-Candida effects of thymol-loaded chitosan nanocomposite were assessed by evaluating the minimum inhibitory concentrations (MICs) and minimum fungicidal concentrations (MFCs) using broth microdilution method, according to the modified M60 protocol on yeasts, proposed by the Clinical and Laboratory Standards Institute. Results: Based on the results of SEM analysis, thymol-loaded chitosan nanocomposite with synthesized chitosan base shows a spherical shape. According to the size of the synthesized nanoparticles, the results showed that the size of nanoparticles varies from 100 to 600 nm, while most nanoparticles were between 200 and 300 nm with an average size of 295 nm. The lowest and the best MIC and MFC were related to the combination of nanoparticles + nystatin with 0.158 and 0.208 µg/ml, respectively. The results showed that the combination of nanoparticles + nystatin in comparison with nystatin group as a controlled drug showed a significant anti-Candida effect. Conclusion: The findings of the present in vitro study showed that thymol-loaded chitosan nanocomposite particularly along with nystatin showed promising antifungal effect against C. albicans as the main cause of oral candidiasis. Nevertheless, further investigations are required to elucidate the precise mechanism as well as systemic toxicity, especially in clinical settings.