Abstract
Background and  Aims: Oral infections caused by Candida species are increasing worldwide. One of the common topical treatments related to oral candidiasis is nystatin, which has anti-fungal and antimicrobial activity. Common anti-fungal treatments have many side effects and cause drug resistance and repeated recurrence of Candida infection. The use of plant extracts can be a suitable alternative to synthetic drugs such as nystatin. The aim of this study was to compare the anti-fungal effect of Nigella Sativa with nystatin on Candida albicans.
Materials and Methods: An experimental study was conducted by referring to the Scientific and Industrial Research Organization of Iran and the standard strain of Candida albicans with PTCC5027 was provided. Ethanol soaking method was used to obtain the Nigella sativa ethanolic extract. Fungal suspension with 0.5 McFarland concentration was cultured in a broth medium. To investigate the anti-candida properties of the Nigella sativa Linn ethanolic extract , Disk diffusion technique was done in a Potato dextrose agar by uniformly inoculating the fungal suspension on the culture medium of potato dextrose agar then using a 100 μl micropipette, the Nigella sativa Linn extract with a concentration of 100 mg/ml and Nystatin in a dose of 0.06 mg was poured on a sterile blank disk and put in the plates and , subsequently the growth inhibition zone of the extract was measured. By diluting the extract and nystatin to  0.09, 0.19, 0.39, 0.78, 1.56, 3.12, 6.25, 12.5, 25.50 the Minimum Inhibitory Concentration (MIC) and the Minimum fungicidal concentration (MFC) were obtained using both Microdilution broth and Macrodilution broth. Each experiment was repeated 3 times and the obtained data were statistically analyzed using SPSS ver:25 software and t-test exam.
Results: The length of the inhibition zone measured from the Nigella sativa Linn extract was 19.5mm respectively and the length of the inhibition zone obtained by Nystatin was 24.5 mm respectively. Studying the results of the dilution test in both techniques concluded from the Nigella sativa Linn extract showed that the Nigella sativa Linn ethanolic extract at a concentration of 1.56 mg /ml has the least Minimum Inhibitory Concentration (MIC) and at a concentration of 3.12 mg/ml it has the lowest Minimum Fungicidal Concentration (MFC). Statistical analysis (T-test) showed that the difference in length of the Nigella sativa Linn inhibition zone with Nystatin (P <0.05) was significant.
Conclusion: According to our findings, it seems that the Nigella sativa Linn ethanolic extract is quite effective on the growth of Candida albicans and has an antifungal effect. However, the antifungal effect of Nystatin is significantly higher than the Nigella sativa Linn ethanolic extract.