Baicalein Protects Against Aspergillus fumigatus Keratitis by Reducing Fungal Load and Inhibiting TSLP-Induced Inflammatory Response

Invest Ophthalmol Vis Sci. 2021 May 3;62(6):26. doi: 10.1167/iovs.62.6.26.


Purpose: To investigate the antifungal and anti-inflammatory effects of baicalein on Aspergillus fumigatus (A. fumigatus) keratitis and the underlying mechanisms.

Methods: The noncytotoxic antifungal concentration of baicalein was determined using CCK8, cell scratch assay, minimum inhibitory concentration, biofilm formation, scanning electron microscopy, propidium iodide uptake test and adherence assay in vitro and Draize test in vivo. In fungal keratitis (FK) mouse models, clinical score and plate count were used to evaluate FK severity, and myeloperoxidase assay and immunofluorescence staining were performed to examine neutrophil infiltration and activity. Real-time PCR, ELISA, and Western blot were performed to explore the anti-inflammatory activity of baicalein and the underlying mechanisms in vivo and in vitro.

Results: Baicalein at 0.25 mM (noncytotoxic) significantly inhibited A. fumigatus growth, biofilm formation, and adhesion in vitro. In A. fumigatus keratitis mice, baicalein mitigated FK severity, reduced fungal load, and inhibited neutrophil infiltration and activity. Baicalein not only suppressed mRNA and protein levels of proinflammatory factors IL-1β, IL-6, and TNF-α, but also inhibited the expression of thymic stromal lymphopoietin (TSLP) and TSLP receptor (TSLPR) in vivo and in vitro. In HCECs, mRNA and protein levels of IL-1β, IL-6, and TNF-α were significantly lower in the TSLP siRNA-treated group, while higher in the rTSLP-treated group than in the corresponding control. Baicalein treatment significantly inhibited rTSLP induced the expression of IL-1β, IL-6, and TNF-α.

Conclusions: Baicalein plays a protective role in mouse A. fumigatus keratitis by inhibiting fungal growth, biofilm formation, and adhesion, and suppressing inflammatory response via downregulation of the TSLP/TSLPR pathway.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antifungal Agents / therapeutic use*
  • Aspergillosis / drug therapy*
  • Aspergillosis / metabolism
  • Aspergillosis / microbiology
  • Aspergillus fumigatus / drug effects
  • Aspergillus fumigatus / isolation & purification
  • Aspergillus fumigatus / ultrastructure
  • Blotting, Western
  • Cells, Cultured
  • Cytokines / antagonists & inhibitors*
  • Cytokines / genetics
  • Cytokines / metabolism
  • Disease Models, Animal
  • Enzyme-Linked Immunosorbent Assay
  • Epithelium, Corneal / drug effects
  • Epithelium, Corneal / metabolism
  • Eye Infections, Fungal / drug therapy*
  • Eye Infections, Fungal / metabolism
  • Eye Infections, Fungal / microbiology
  • Female
  • Flavanones / therapeutic use*
  • Inflammation / drug therapy*
  • Keratitis / drug therapy*
  • Keratitis / metabolism
  • Keratitis / microbiology
  • Mice
  • Mice, Inbred C57BL
  • Microbial Sensitivity Tests
  • Microscopy, Electron, Scanning
  • Real-Time Polymerase Chain Reaction
  • Thymic Stromal Lymphopoietin


  • Antifungal Agents
  • Cytokines
  • Flavanones
  • baicalein
  • Thymic Stromal Lymphopoietin