In vitro study of antifungal effect of walnut (Juglans regia L.) leaf extract on the Malassezia furfur fungus

Malassezia furfur is the cause of pityriasis versicolor. Phenolic compounds in the walnut leaf have antimicrobial effects. The purpose of this study was to examine the antifungal effects of alcoholic and aqueous extracts of walnut leaf on M. furfur, in vitro. Alcoholic and aqueous extracts of walnut leaf were prepared by simple distillation and Rotary method and then we studied the antifungal effects of these extracts on M. furfur by using disc and Well method, in vitro. Then the minimum inhibitory concentration (MIC) and minimal fungicidal concentration (MFC) were determined. SPSS18 software, two-way ANOVA and Bonferroni test were used for data analysis. The largest growth inhibition zone diameters for water, ethanolic and methanolic extracts were 30, 28.66and 46.33 mm, respectively, that were observed at a concentration of 110 mg/ml. MIC of aqueous extract for M. furfur was 25×103 mg/ml and its MFC was 5×104 mg/ml. The MIC and MFC of walnut leaf ethanolic extract were 6250 and 125×102 mg/ml, respectively. Also MIC and MFC of methanolic extract were 25×103 and 5×103 mg/ml, respectively. Statistical results showed that extracts had a different effect on the diameter of inhibition zones and increased concentration of the extracts led to increased inhibition zone diameters (p<0.05). According to the results of this study, extracts of walnut leaf can be a promising therapy in the future for the treatment of infections caused by M. furfur.