Evaluation of Umbelliferone's antifungal efficacy against multidrug-resistant Candida albicans: A combined in-vitro and in-silico approach investigating mechanisms of action and therapeutic potential.

The rise of multidrug-resistant Candida albicans poses a significant threat to public health, emphasizing the need for novel antifungal therapies. In this context, plant-derived compounds have emerged as promising candidates, owing to their diverse medicinal properties, including antifungal activity. In the current study, the compound was isolated and purified from Evolvulus alsinoides through fractionation and High-Performance Thin-Layer Chromatography (HPTLC) and characterized using High-Resolution Mass Spectrometry (HRMS), Fourier Transform Infrared Spectroscopy (FTIR), and Nuclear Magnetic Resonance Spectroscopy (NMR) and identified as umbelliferone. The compound exhibited potent anti-candidal activity against both antifungal-susceptible (K1) and multidrug-resistant (K2) strains of C. albicans. The efficacy of the compound revealed the significant inhibitory effects with zones measuring 16 ± 0.57 mm and 14 ± 0.57 mm against K1 and K2 strains, respectively at 1 mg concentration. Furthermore, the minimum inhibitory concentrations were determined to be 125 μg/mL for K1 strain and 175 μg/mL for K2 strain. In-silico studies revealed that umbelliferone met Lipinski's rule requirements and demonstrated favourable ADMET properties as it showed the least binding energy of -6.1 and -5.6 kcal/mol against dihydrofolate reductase (DHFR) and lanosterol 14α-demethylase (ERG11) respectively of the Candida proteins. The molecular dynamics study demonstrated that the DHFR-umbelliferone complex remains stable over time and under physiological conditions throughout a 100 ns simulation. Additionally, gene expression studies revealed that the umbelliferone significantly reduces the expression of DFR1 codes for the protein DHFR with a 0.7-fold decrease in K1 and a 0.5-fold decrease in K2 when compared to the control. These findings highlight umbelliferone as a promising antifungal agent against multidrug-resistant C. albicans, offering a new avenue for drug discovery and development.