Antifungal Potential of Flavonoids Against Drug-Resistant Fungal Pathogens

Review Article

Abstract

Invasive fungal infections represent a critical global health challenge characterized by expanding at-risk patient cohorts, unacceptable mortality rates, and progressive resistance across conventional antifungal classes. The therapeutic arsenal remains constrained by end-organ toxicities, narrow empirical spectra, unfavorable pharmacokinetics, and a sparse developmental pipeline. Plant secondary metabolites, particularly polyphenolic flavonoids, provide structurally versatile chemical scaffolds with broad-spectrum antimycotic potential against high-priority pathogens including Candida, Aspergillus, Cryptococcus, and emergent filamentous moulds. Flavonoids exert multimodal fungicidal and fungistatic pressure through simultaneous biological targets: disrupting fungal plasma membrane integrity via sterol destabilization, compromising cell wall architecture through β-glucan and chitin dysregulation, uncoupling mitochondrial electron transport chains, inducing endogenous reactive oxygen species generation, suppressing nucleic acid and protein biosyntheses, impeding cell division cycles, inhibiting dimorphic yeast-to-hyphal phenotypic shifts, and dampening ATP-binding cassette or major facilitator superfamily efflux pumps. When co-administered with conventional polyenes, azoles, or echinocandins, flavonoids systematically reverse multidrug-resistant phenotypes, showing marked in vitro and in vivo chemosensitization and synergy. Nevertheless, translational hurdles such as poor aqueous solubility, rapid systemic phase II clearance, variable membrane permeation, and sub-micromolar stability impede direct clinical deployment. Overcoming these pharmacokinetic constraints demands rationally engineered nano-formulations, polymeric encapsulation, and semisynthetic structural optimization. Exploiting bioactive flavonoids as standalone scaffolds or synergistic clinical adjuvants provides a viable therapeutic paradigm to alleviate fungal morbidity, restore conventional drug susceptibility, and forestall antimicrobial resistance development worldwide.