Enhancement of Fluconazole Antifungal Efficacy by Repurposed Statins against Candida albicans: Multilevel in Silico, In Vitro, and Ex Vivo Experimental Validation Supporting Adjunct Antifungal Therapy

Background: The increasing incidence of antifungal resistance in Candida albicans necessitates the identification of alternative therapeutic strategies. Drug repurposing offers a promising approach to accelerate antifungal discovery using agents with established safety profiles. Statins, widely used as lipid-lowering drugs, have recently attracted attention for their potential antifungal activity. Objective: This study aimed to evaluate the antifungal repositioning potential of statins, with particular emphasis on fluvastatin, against Candida albicans using an integrated in silico, in vitro, and ex vivo approach. Methods: Molecular docking studies were performed using Molecular Operating Environment (MOE) to assess the binding affinity of statins against key fungal enzymes, including lanosterol 14-α-demethylase (CYP51), HMG-CoA reductase, dihydrofolate reductase (DHFR), and thioredoxin reductase (TRR). In vitro antifungal activity was evaluated through growth inhibition assays, while synergistic interactions with fluconazole were assessed. Ex vivo studies were conducted to examine membrane permeability and antifungal efficacy under physiologically relevant conditions. Results: Docking analysis revealed that fluvastatin exhibited the highest binding affinity toward all targeted enzymes, indicating a multi-target inhibitory mechanism. In vitro assays confirmed dose-dependent growth inhibition of C. albicans, with fluvastatin demonstrating superior antifungal potency compared to other statins. Notably, fluvastatin showed synergistic activity when combined with fluconazole, resulting in enhanced antifungal efficacy at reduced concentrations. Ex vivo studies further supported its superior membrane permeability and sustained antifungal activity. Conclusion: The strong concordance among computational, biological, and ex vivo findings positions fluvastatin as a promising antifungal repositioning candidate. Its multi-target mechanism and synergistic potential with fluconazole highlight its relevance for future preclinical and clinical evaluation, emphasizing the value of drug repurposing and combination therapy in addressing antifungal resistance