Synergistic Antifungal Bioassay of Neem Leaves Extract with Essential Oils against Dermatophytes

Abstract

Introduction: The neem plant is also known as a panacea in dentistry due to its antimicrobial properties and plays vital role in the cosmetic industry as it is extensively used in cosmetic preparations for hair and skin care. Objective: The present study was carried out to evaluate the synergistic activity of essential oils in combination with neem leaves ethanolic extracts. Methods: The antifungal activity of neem leaves (Azadirachta indica) ethanolic extracts in combination with A. indica, Eucalyptus citriodora and Cymbopogon martini essential oils was conducted by agar well diffusion method followed by M38-A2 broth microdilution method on pathogenic dermatophytes strains; Microsporum gypseum, Trichophyton mentagrophytes and T. rubrum. Neem leaves extract was obtained by treating the matured green leaves with ethanol. Moreover, HPLC analysis was performed to narrate the terpenoid content having extensively noted antifungal spectrum. The potent antimycotic fluconazole taken as a positive control. Result: The result exhibited that there was overall growth retardation of the dermatophytes at minimum inhibitory concentration between 125 to 250 μg/mL for leaves extract and between 0.078 to 5.0 μL for selected essential oils. The range of minimum inhibitory concentration (MIC) of fluconazole was found between 0.25 and 0.50 μg/mL. Conclusion: Neem leaves ethanolic extracts analysis showed the possible existence of terpenoids in extracts that are recognized having extensive biological action. The outcomes of this study showed a novel report on the therapeutic potential of neem leaves extract with A. indica, E. citriodora and C. martini to control dermatophytosis. The neem leaf extract and antifungal herbal oil in combination have been proven to improve and broad-spectrum antifungal activity and they can be formulated in suitable formulations for the effective treatment of mycosis.