Antifungal efficacy of a novel nitric oxide releasing solution in the presence of keratin

Introduction Nitric oxide (NO)–based therapeutics represent a promising modality for overcoming the challenges of treating dermatophyte infections within keratinized tissues. Methods This study evaluated the antifungal activity of a nitric oxide–releasing solution (NORS) against clinical isolates of Trichophyton mentagrophytes, Trichophyton tonsurans, and Epidermophyton floccosum, comparing MIC and MFC profiles to efinaconazole and assessing keratin associated inhibition relative to terbinafine. Results NORS demonstrated potent fungicidal activity across all species, with MIC90 and MFC90 values consistently at 0.005 μg/mL. Unlike terbinafine, whose efficacy decreased significantly in keratin-rich environments, NORS retained antifungal activity in the presence of human nail keratin. Discussion These results support further clinical evaluation of NO-based antifungals as potential treatments for onychomycosis and tinea pedis.