Characterization of Herbal Antifungal Agent, Origanum vulgare against Oral Candida spp. Isolated from Patients with Candida-Associated Denture Stomatitis: An In vitro Study

BACKGROUND: Candida Associated Denture Stomatitis is the prevalent fungal pathosis in denture wearers, especially in immunocompromized patients. Existing antifungal agents are ineffective since the Candida species become resistant and also, they become toxic. Origanum vulgare is a herbal plant with high anti-fungal activity against Candida of blood and urine origin. However, it has never been explored against Candida from oral cavity. MATERIALS & METHODOLOGY: Dry leaves of the plant were purchased and authenticated. Oil extraction was done using Hydro-distillation method. Clinical isolates of Candida from denture wearers was speciated using CHROMagar. Well Diffusion test was used to confirm the antifungal activity. Hydro-distillation & Maceration methods of extraction were compared. MIC/MFC was determined using CSLI guidelines. Infra-Red Spectroscopy was used to identify the active functional group. RESULTS: O.vulgare showed 30±3mm of zone of inhibition as against 19mm for fluconazole. The suitable extraction method was Hydro-distillation. MIC & MFC were found to be 0.024% and 0.097% respectively which was much lesser than for fluconazole (0.25%). The active functional group had chemically similar structure as Carvacrol, usually found in antifungal herbs. CONCLUSION: within the limitations of the study, it was concluded that (a)O.vulgare is anticandidal for clinical isolates of oral Candida, (b) Hydro-distillation is an effective method as compared to Maceration (c) MIC & MFC are much lower than that of fluconazole (d) the major functional group was structurally similar to Carvacrol.