Pseudolaric Acid B Ameliorates Fungal Keratitis Progression by Suppressing Inflammation and Reducing Fungal Load

Abstract

This study aimed to determine the mechanisms of antifungal and anti-inflammation effects of pseudolaric acid B (PAB) on Aspergillus fumigatus (A. fumigatus) keratitis. In vitro MIC assay and crystal violet staining were conducted to evaluate the efficacy of PAB against A. fumigatus. PAB inhibited A. fumigatus growth and inhibited the formation of fungal biofilms in a dosedependent manner. Molecular docking analysis revealed that PAB possesses strong binding properties with Rho1 of A. fumigatus, which is devoted to encoding (1,3)-β-D-glucan of A. fumigatus. RT-PCR results also showed that Rho1 was inhibited by PAB. In vivo, PAB treatment reduced clinical scores, fungal load, and macrophage infiltration, which were increased by A. fumigatus in mice corneas. In addition, PAB treatment suppressed the expression of Mincle, p-Syk, and cytokines (TNF-α, MIP2, iNOS, and CCL2) in infected corneas and in RAW264.7 cells, which were tested by RT-PCR, Western blot, and enzyme-linked Immunosorbent Assay. Notably, trehalose-6,6-dibehenate, an agonist of Mincle, pretreatment reversed the regulatory function of PAB in RAW 264.7 cells. Moreover, flow cytometry showed that PAB upregulated the ratio of M2/M1 macrophages in A. fumigatus-infected corneas and RAW264.7 cells. In conclusion, PAB produced antifungal activities against A. fumigatus and decreased the inflammatory response in mouse A. fumigatus keratitis.

Silica nanoparticles containing nano-silver and chlorhexidine to suppress Porphyromonas gingivalis biofilm and modulate multispecies biofilms toward healthy tendency

“…Stained biofilms were treated with 30% acetic acid for 5 min. The absorbance was detected at 590 nm according to previous studies [ 50 ]. All experiments were conducted at least three replicates in sextuplicate.…”