Optimization of antifungal activity of tea tree oil for specific treatment of oral candidiasis

Abstract

Candidiasis is a type fungal infection that usually grow at warm and moist area such as mucosal epithelial lining of human body’s part. The most common cause of candidiasis is due to overgrowth of normal microbiota such as candida species. The overgrowth is triggered under circumstances such as in immunologically weak patient. The present commercialized antifungal drug can be used to cure this disease. However, these antifungal agents causing unwanted side effect on patients, so alternative natural remedy such as tea tree essential oil is studied on its antifungal activities. In this project, 4 different types of agar medium were chosen to screen and isolate the dominant strains with similar colony morphology (macroscopic examination) namely Saboraud dextrose agar, Malt extract agar, Tryptic soy agar and LB agar. Besides, microscopic examinations were done to identify the desired Candida species. Identification test were done on the isolated strain for further confirmation. Based on the test, the isolated strain UniMAP X is presumed to be Candida albicans. In the qualitative analysis, the tea tree essential oil was tested and indicated the presence of terpenoid, tannin, saponin, phenol and high antioxidant activity which highly potential to be the alternative antifungal agent. Three parameters (diameter of disc diffusion, incubation temperature and pH of agar medium) were studied using DoE software to optimize the antifungal activities of tea tree oil against the isolated microorganisms responsible for oral candidiasis. Result of Analysis of Variance (ANOVA) shown that the designed model was significant to describe the antifungal activities on the isolated strain. In conclusion, it was found that 8 mm disc diffusion diameter in agar plate pH 5.50 at temperature 36.41 °C was the optimized condition to improve the antifungal activity of tea tree essential oil against the isolated strain UniMAP X.