Comparative In Vitro Antifungal Activities of Zingiber officinale, Justicia carnea, Hibiscus sabdariffa Nanosynthesized Extracts against Uropathogenic Candida albicans

Abstract: Urogenital infections caused by Candida species (candiduria) are a growing public health concern, exacerbated by the rise of antifungal-resistant strains. This necessitates the search for novel, effective antifungal agents, with medicinal plants being a promising source. Ethanol, chloroform, and hot water (aqueous) extracts of Zingiber officinale (rhizome), Justicia carnea (leaf), and Hibiscus sabdariffa (calyx) sourced from Akure, Ondo State, were prepared and tested at 200 mg/ml against uropathogenic Candida albicans isolated from midstream urine samples of patients attending government hospitals in Ondo State. The Minimum Inhibitory Concentration (MIC) and Minimum Fungicidal Concentration (MFC) were determined for the active extracts using a broth microdilution method. Green synthesis of silver nanoparticles (AgNPs) using H. sabdariffa was also characterized and assessed. The hot water extract of J. carnea and the ethanol extract of H. sabdariffa demonstrated the largest zones of inhibition (29.00±0.58 mm) against the isolate. The hot water extract of Z. officinale also showed significant activity, with a peak inhibition of 18.67±0.33 mm. Nanoparticles synthesized with H. sabdariffa showed potent activity, peaking at 24.00±0.58 mm. Z. officinale aqueous extract exhibited the most potent fungicidal activity, with an MFC of 100 mg/ml. The broad-spectrum fungicidal activity of Z. officinale and H. sabdariffa aqueous extracts highlights their potential as therapeutic agents. These findings indicate that nanosynthesized and polar extracts of these indigenous plants offer a viable alternative for developing novel antifungal therapeutics against multidrug-resistant candiduria.