Effect of nystatin and licorice on yeasts isolated from the oral lesions of patients with cancer under chemotherapy (in vitro study)

Oral candidiasis is one of the most common manifestations of patients with cancer under chemotherapy. Due to many side effects of chemical antifungal products and various advantages of herbal extracts like licorice, this study was performed to compare the antifungal effects of nystatin and licorice on yeasts isolated from oral mucosa of patients with cancer receiving chemotherapy.

In this in vitro study, a total number of 30 patients with oral candidiasis who received chemotherapy were examined. The samples were prepared by using swabs taken from the lesions, and after 48 h, they were transferred and cultured on Sabouraud dextrose agar. The antifungal effect of licorice was compared with nystatin using agar disk diffusion method. These data were entered in SPSS statistical software and were analyzed with Kruskal–Wallis and Mann–Whitney tests. (α = 5%).

Four types of candida were identified among all 30 oral lesions (Candida albicans, Candida glabrata, Candida stellatoidea, and Candida SP). The mean inhibition zone diameter around nystatin showed a significant difference (P < 0.001) between C. albicans (9.486), C. glabrata (8.627), C. stellatoidea (7.00), and C. sp (7.06) but the inhibition zone diameter around licorice was almost zero in all groups.

Licorice extracts did not show any antifungal effects whereas nystatin showed the most antifungal effect against C. albicans.