antifungal effect of citrus reticulata essential oil and extracts on candida species

Objective: this in vitro study evaluated the antifungal activity of citrus reticulata (tangerine) peel essential oil and extracts against various candida species.methods: the essential oil and aqueous and alcoholic extracts of citrus reticulata were prepared at 50% and 90% concentrations. candida albicans, candida glabrata, and candida krusei were cultured on sabouraud dextrose agar with turbidity standardized to 0.5 mcfarland. growth inhibition zones were measured and compared to 0.2% chlorhexidine (positive control) and normal saline (negative control). the minimum inhibitory concentration (mic) and minimum fungicidal concentration (mfc) of the 90% essential oil were also determined against the microorganisms.results: the 50% essential oil and both 50% and 90% concentrations of aqueous and alcoholic extracts showed no antifungal activity. the 90% essential oil produced inhibition zones of 6.5 ± 0.5 mm for c. albicans, 10.5 ± 0.5 mm for c. glabrata, and 10.0 ± 1.0 mm for c. krusei, all significantly smaller than those of chlorhexidine (17.0 ± 0.2 mm, 15.0 ± 0.3 mm, and 17.0 ± 0.2 mm, respectively; p<0.05). mic values were 1/8 for c. albicans, 1/32 for c. glabrata, and 1/4 for c. krusei (based on 90% concentration). the essential oil was fungicidal only against c. albicans (mfc: 1/2 concentration) and fungistatic against the other two species.conclusions: the 90% citrus reticulata essential oil effectively formed inhibition zones against c. albicans, c. glabrata, and c. krusei, although to a lower extent than chlorhexidine. the 90% citrus reticulata essential oil had a fungicidal effect only on c. albicans.