Abstract
OBJECTIVES: Candida albicans is resistant to commercial antifungal agents. Therefore, it is desirable to use material derived from natural sources as an antifungal agent. Essential oil from Citrus limon peel is able to inhibit the growth of C. albicans in vitro. The purpose of this study was to determine the most effective concentration of essential oil from C. limon peel with regards to the inhibition of C. albicans cyto-morphometric changes and biofilm formation in vivo. METHODS: Male Wistar rats weighing 200-300 g were inoculated with C. albicans for 48 h and then given a single dose of oral methylprednisolone as an immunosuppressant. Essential oil from C. limon peel, in a gel form and at three different concentrations (0.39%, 0.78% and 1.56%), was applied twice a day for 2 days. The rats were killed after 48 h and then palatal mucosa tissues were prepared and examined with a scanning electron microscope (SEM) with regards to C. albicans, cyto-morphometric changes and biofilm formation. RESULTS: Essential oil from C. limon peel at a concentration of 1.56% showed the strongest ability to inhibit C. albicans growth when compared to 0.78% and 0.39%. At a concentration of 1.56%, essential oil from C. limon peel disrupted cyto-morphometric changes; cells that were neither in intact nor colonised were evident, the filaments around the cells were smooth, the layer of biofilm had disappeared and there was no evidence of hyphae formation. CONCLUSION: The effect of essential oil from C. limon peel on cyto-morphometric changes and biofilm formation was concentration-dependent. Essential oil from C. limon peel at a dose of 1.56% showed the strongest ability to inhibit cyto-morphometric changes and biofilm formation. These findings demonstrate that essential oil of C. limon peel is a potential antifungal candidate for the treatment of candidiasis.