Artesunate Treats Aspergillus fumigatus Keratitis by Inhibiting Fungal Activity and Activating Autophagy Pathway to Reduce Corneal Inflammation.

PURPOSE: The purpose of this study was to investigate the therapeutic effect of artesunate (ART) on fungal keratitis (FK).

METHODS

The antifungal properties of ART against Aspergillus fumigatus (A. fumigatus) were confirmed by minimum inhibitory concentration (MIC), biofilm formation inhibition test, propidium iodide fluorescence, and calcium fluorescence white test. The levels of HSP90, BrlA, AbaA, WetA, CnaA, and CrzA were detected by quantitative reverse transcription PCR (qRT-PCR). Cell counting kit 8 (CCK-8) was used to detect the cytotoxicity of ART on RAW 264.7 cells and human corneal epithelial cells (HCECs). Clinical corneal score, hematoxylin and eosin (H&E) staining, and corneal fungal plate counts were used to evaluate the therapeutic effect of ART on FK in mice. The qRT-PCR, ELISA, and Western blot were used to investigate the effect of ART on inflammatory mediator expression during fungal infection.

RESULTS

ART inhibited the growth of A fumigatus, biofilm formation, and conidium adhesion in vitro, and destroyed fungal cell walls and cytomembrane. In vivo, ART effectively reduced corneal fungal load. ART could reduce the inflammation of the cornea by reducing the accumulation of inflammatory cells and down-regulating the expression of TNF-α, IL-1β, and IL-6. ART could activate the autophagy pathway to play an anti-inflammatory role in FK by increasing the expression of Beclin-1 and LC3B.

CONCLUSIONS

ART inhibits fungal growth by inhibiting biofilm formation, destroying fungal cell walls and membranes, and reducing the expression of HSP90 and calcineurin-related factors, and activates the autophagy pathway to reduce the expression of TNF-α, IL-1β, and IL-6 in FK by upregulating the protein expression of Beclin-1 and LC3B. ART has therapeutic potential for FK.