Anti-otomycotic potential of nanoparticles of Moringa oleifera leaf extract: an integrated in vitro, in silico and phase 0 clinical study

Abstract

Otomycosis is a serious superficial mycotic infection of the outer ear canal caused by some pathogenic species of Candida and Aspergillus. The infection remains a challenge to clinicians owing to the incomplete efficacy of market-available antifungal agents and high recurrence rates. The Moringa oleifera leaf ethanol extract showed efficacy against Candida albicans SC5314, compared to Nystatin® as a reference with MIC values of 7 and 718.33 μg ml^-1, respectively. The extract was mixed with lecithin and chitosan to give Moringa core/shell giant nanoparticles, with a good zeta potential (+59.2 mV), a suitable entrapment efficiency (61%) and an enhanced release reaching up to 90% at 8 h. Clinical isolates from oomycote patients were identified via DNA sequencing as Candida parapsilosis, Aspergillus niger and Aspergillus flavus, and the effect of the prepared nanoparticles was tested against them via disk diffusion assay to give inhibition zones of 75, 55 and 55 mm, compared to Nystatin® with 35, 25 and 20 mm, respectively. Interestingly, patients treated with the Moringa-loaded nanoparticles experienced improvement within 1 week with no recurrence for more than 3 months. To have some insight into the bioactive components in the Moringa extract, LC-HRMS-based identification has been employed which led to the annotation of 27 compounds. Subsequent comprehensive in silico investigation suggested some alkaloids to be responsible for the activity targeting the fungal 14-α-demethylase enzyme (CYP51B). Our study revealed that Moringa extract-loaded nanoparticles attained an enhanced antifungal efficacy compared to Nystatin® and therefore they can be employed against invasive and drug-resistant otomycotic infections.