Characterization and enhanced antibiofilm activity of Annona muricata extract in combination with fluconazole against Candida albicans

Abstract

Introduction: Candida albicans biofilm formation contributes significantly to antifungal resistance, necessitating new treatment strategies. Annona muricata Lin., a traditional herbal remedy, has shown promise in combating microbial infections. This study evaluated the antibiofilm activity of the methanol extract of A. muricata leaves, alone or combined with fluconazole, against C. albicans.

Methods: Phytochemicals in the methanol extract were analyzed using LC-MS, biofilm metabolic activity was assessed with the XTT assay, and morphological changes were examined via scanning electron microscopy (SEM). Molecular docking evaluated the binding of compounds in the A. muricata extract to the Sap3 receptor (PDB: 2H6T).

Results: LC-MS identified 17 phytochemicals in the methanol extract. The extract showed dose-dependent inhibition of biofilm formation, reaching ~60% inhibition at 240 μg/ml. Fluconazole inhibition increased from 32% to 76% as concentrations rose from 15 to 240 μg/ml. The combination of A. muricata and fluconazole enhanced inhibition, ranging from 74% to 78% at 15–240 μg/ml. SEM analysis revealed altered biofilm morphology and loss of cell integrity with the combination treatment. Phytochemicals showed high binding affinity (−9.7 to −8.0 kcal/mol) for the Sap3 enzyme, suggesting therapeutic potential.

Conclusion: These findings suggest that compounds in the A. muricata methanol extract synergize with fluconazole at sub-inhibitory concentrations to suppress C. albicans biofilm formation. This paves the way for antifungal treatments that may mitigate fluconazole resistance using this plant extract.