Synergistic antifungal activity of Amphotericin B in combination with zinc nanoparticles biosynthesized from leek (Allium ampeloprasum) extract against Candida tropicalis and Cryptococcus neoformans

Background: Fungal infections are emerging as a serious global health concern, especially among immunocompromised patients. Opportunistic species such as Candida tropicalis and Cryptococcus neoformans are responsible for severe systemic infections. Objectives: This experimental in-vitro study aimed to enhance the antifungal activity of Amphotericin B by combining it with biosynthesized ZnO-NPs derived from leek extract. Methods: ZnO-NPs were synthesized using an aqueous leek extract and characterized by UV–Vis, FTIR, AFM, EDX, and FE-SEM analyses. Antifungal activity was tested against C. tropicalis and C. neoformans using the agar-well diffusion method. Results: The biosynthesized ZnO-NPs exhibited uniform morphology and functional groups confirming phytochemical capping. Amphotericin B combined with ZnO-NPs demonstrated a synergistic effect, producing larger inhibition zones than Amphotericin B alone in a concentration-dependent manner (50–3000 µg/ml). Conclusion: Biosynthesized ZnO-NPs enhance the antifungal potency of Amphotericin B, suggesting a promising strategy to improve efficacy and minimize toxicity.