Evaluation of antifungal activity of blended cinnamon oil and usnic acid nanoemulsion using candidiasis and dermatophytosis models

Abstract

Abstract Fungal infections are one of the most important health issues facing by people since a long time. The objective of the present study was to evaluate antifungal activity of a prepared blended cinnamon oil and usnic acid nanoemulsion (CUN) using candidiasis and dermatophytosis models both in vitro and in vivo. In vitro activity was performed using cup plate method; minimum inhibitory concentrations (MICs) and minimum fungicidal concentrations (MFCs) were determined using brain heart infusion (BHI). In vivo antifungal activity was determined on cutaneous candidiasis in rats and on dermatophytosis guinea pig model. In vitro study of CUN exhibited maximum antifungal activity after 48 h. The maximum zone of inhibition was 1.19 cm for CUN (10 mg/mL), which was near to the fluconazole (1 mg/mL) i.e. 1.82 cm. The MIC of CUN for C. albicans and T. mentagrophytes were 60 and 55 μg/mL, respectively, which was more than cinnamon oil and usnic acid solution (CUS). In vivo study of CUN in cutaneous candidiasis model showed significant antifungal activity. The log colony forming unit per infected site of CUN was 1.36 in comparison to untreated control group (3.91). However, the clinical efficacy profile of CUN on dermatophytosis guinea pig model was more than the standard drug (41.3%) and CUS (35.6%). Its mycological efficacy was 81.4%, which was greater than standard drug (79.6%) and CUS (74.5%). Thus, the present study substantiated that CUN can be used as a feasible formulation for topical application against fungal infections.