Antidermatophytic Activity of Benzophenanthridine Alkaloids Against Trichophyton mentagrophytes

Abstract

Dermatophytoses caused by filamentous fungi of the genus Trichophyton are a widespread group of mycoses; their treatment is significantly complicated by the long-standing issue of increasing microbial resistance to standard antifungal drugs. The aim of this study was to evaluate the antidermatophytic activity of benzophenanthridine alkaloids against a pathogenic strain of Trichophyton mentagrophytes and to determine the mechanisms of their fungicidal action. Isolated and purified alkaloid fractions containing sanguinarine and chelerythrine were investigated. The research methodology included determining the minimum inhibitory and minimum fungicidal concentrations using the broth microdilution method, assessing the kinetics of microbial death, and conducting electron microscopy analysis of ultrastructural changes in fungal cells following exposure to the bioactive compounds. The experiment demonstrated that benzophenanthridine alkaloids possess pronounced antifungal activity, completely inhibiting mycelial growth and sporulation of Trichophyton mentagrophytes at ultra-low concentrations. Electron microscopy revealed profound destructive changes, manifested as a loss of cell wall integrity, damage to the cytoplasmic membrane, and the induction of intracellular organelle lysis. The study concludes that benzophenanthridine alkaloids are highly effective and represent a promising basis for the development of new, potent antifungal agents. The findings support the rationale for conducting further preclinical trials of these plant-derived compounds in topical formulations for the treatment of dermatophytoses.