Polyphenolic characterization and antifungal properties of Urtica urens L. extracts against Candida strains: A natural approach to fungal control

Abstract

Urtica urens is classified within the Rosales subfamily and belongs to the Urticaceae family. Its well-documented health benefits are primarily attributed to its phenolic compounds. This study investigates the polyphenol, flavonoid, and condensed tannin content of Urtica urens L. (U. urens L.) extracts obtained using aqueous ethanol and water as solvents. The antifungal activity of ethanol and aqueous extracts derived from the aerial parts of Urtica urens L. was assessed in vitro against various Candida species (C. parapsilosis, C. albicans, C. tropicalis, C. metapsilosis, C. orthopsilosis, C. glabrata). Three methods were employed: the well diffusion method, disc diffusion method, and microdilution method. The findings revealed that the ethanol extract contained the highest levels of polyphenols. Both ethanol and aqueous extracts exhibited antifungal activity against the Candida strains tested. However, the aqueous extract demonstrated superior antifungal efficacy compared to the ethanol extract. The sensitivity of the strains to the extracts was concentration-dependent, with inhibition observed from a concentration of 1 g/mL. The ethanol extract displayed significant inhibitory activity (90.58%, 92.24%, and 91.33%, respectively) against C. metapsilosis, C. glabrata, and C. orthopsilosis, surpassing its activity against other strains. These findings suggested that U. urens L. extracts have potential as natural alternatives to chemical additives for controlling fungal diseases in plants.