Pentoxifylline treats Aspergillus fumigatus keratitis by reducing fungal burden and suppressing corneal inflammation

Macrophage Membrane-Coated Nanoparticles for the Delivery of Natamycin Exhibit Increased Antifungal and Anti-Inflammatory Activities in Fungal Keratitis

This study aims to explore the efficacy and safety of macrophage membrane-coated nanoparticles for the delivery of natamycin (NAT) in the therapy of fungal keratitis (FK). Macrophage membranes were isolated and identified by immunofluorescence staining (IFS). NAT was encapsulated into poly(lactic-co-glycolic acid) (PLGA). Fungal stimulated macrophage membranes (M1) or unstimulated membranes (M) were separately mixed and sonicated with PLGA nanoparticles. The biocompatible nanoparticles (PLGA-NAT, PLGA-NAT@M, and PLGA-NAT@M1) were characterized with zeta-sizer analysis, transmission electron microscopy (TEM), and Western blot. Drug encapsulation and loading efficiency and the release of NAT in the nanoparticles were detected by ultraviolet spectrophotometry. The cytotoxicity, ocular surface toxicity and irritability, and systemic safety of nanoparticles with different concentrations were assessed. In vitro, we examined the antifungal properties of the nanoparticles. The eye surface retention time, drug release, and curative effects on FK were evaluated in vitro and in vivo. IFS results showed the separation of the macrophage membrane and nucleus. The prepared nanoparticles had a typical "core-shell" structure and uniform nanometer size, and the membrane proteins were retained on the membrane allowing to exert functional effects of macrophage. The loading efficiencies of PLGA-NAT@M and PLGA-NAT@M1 were 7.6 and 6.7%, respectively. The encapsulation efficiencies of PLGA-NAT@M and PLGA-NAT@M1 were 51.2 and 41.5%, respectively. PLGA-NAT@M and PLGA-NAT@M1 could gradually release NAT and reduce the clearance of the ocular surface. Macrophage membranes enhanced the antifungal activity of PLGA-NAT. Furthermore, the membrane coated with macrophage increased the biocompatibility and decreased the corneal toxicity of nanoparticles. In vivo, PLGA-NAT@M1 significantly alleviated the severity of FK. In vitro, PLGA@M and PLGA@M1 reduced the protein levels of inflammatory cytokines after fungal stimulation. The prepared PLGA-NAT@M1 has good physical properties and biosafety. It could evade ocular surface clearance, release NAT gradually, and achieve high antifungal and anti-inflammatory efficiencies to FK. Macrophage membrane-coated nanoparticles clinically have high application potential to the treatment of FK.

Licochalcone A Ameliorates Aspergillus fumigatus Keratitis by Reducing Fungal Load and Activating the Nrf2/HO-1 Signaling Pathway

Fungal keratitis (FK) is a blinding corneal infectious disease. The prognosis is frequently unfavorable due to fungal invasion and an excessive host inflammatory response. Licochalcone A (Lico A) exhibits a broad spectrum of pharmacological activities, encompassing antifungal, anti-inflammatory, antioxidation, and antitumor properties. However, the role of Lico A has not yet been studied in FK. In this study, we discovered that Lico A could disrupt Aspergillus fumigatus (A. fumigatus) biofilms, inhibit fungal growth and adhesion to host cells, induce alterations of hyphal morphology, and impair the cell membrane and cell wall integrity and mitochondrial structure of A. fumigatus. Lico A can alleviate the severity of FK in mice, reduce neutrophil infiltration and fungal load, and significantly decrease the pro-inflammatory cytokines in mouse corneas infected with A. fumigatus. In vitro, we also demonstrated that Lico A increased the expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) around the nucleus in human corneal epithelial cells (HCECs) stimulated with A. fumigatus. We verified that the anti-inflammatory effect of Lico A is associated with the activation of the Nrf2/HO-1 axis. These results indicated that Lico A could provide a protective role in A. fumigatus keratitis through its anti-inflammatory and antifungal activities.

Activation of AMPK/mTOR-Driven Autophagy and Suppression of the HMGB1/TLR4 Pathway with Pentoxifylline Attenuates Doxorubicin-Induced Hepatic Injury in Rats

Despite being an effective chemotherapeutic agent, the clinical use of doxorubicin (DOX) is limited by several organ toxicities including hepatic injury. Pentoxifylline (PTX) is a methylxanthine derivative with marked anti-inflammatory and anti-apoptotic features. It is unknown, however, whether PTX can mitigate DOX-evoked hepatotoxicity. This study aims to explore the potential hepatoprotective impact of PTX in DOX-induced hepatic injury and the underlying molecular mechanisms. Histopathology, immunohistochemistry, and ELISA were used to examine liver tissues. The current findings revealed that PTX administration to DOX-intoxicated rats mitigated the pathological manifestations of hepatic injury, reduced microscopical damage scores, and improved serum ALT and AST markers, revealing restored hepatic cellular integrity. These favorable effects were attributed to PTX's ability to mitigate inflammation by reducing hepatic IL-1β and TNF-α levels and suppressing the pro-inflammatory HMGB1/TLR4/NF-κB axis. Moreover, PTX curtailed the hepatic apoptotic abnormalities by suppressing caspase 3 activity and lowering the Bax/Bcl-2 ratio. In tandem, PTX improved the defective autophagy events by lowering hepatic SQSTM-1/p62 accumulation and enhancing the AMPK/mTOR pathway, favoring autophagy and hepatic cell preservation. Together, for the first time, our findings demonstrate the ameliorative effect of PTX against DOX-evoked hepatotoxicity by dampening the hepatic HMGB1/TLR4/NF-κB pro-inflammatory axis and augmenting hepatic AMPK/mTOR-driven autophagy. Thus, PTX could be utilized as an adjunct agent with DOX regimens to mitigate DOX-induced hepatic injury.

Pseudolaric acid B exerts an antifungal effect and targets SIRT1 to ameliorate inflammation by regulating Nrf2/NF-κB pathways in fungal keratitis

Fungal keratitis (FK) is a vision-threatening infection. We aimed to explore the antifungal and anti-inflammatory effects of pseudolaric acid B (PAB) on FK and the underlying mechanisms involved. Network pharmacology utilized to acquire the potential target genes, and silent information regulator 1 (SIRT1) was consistently downregulated in Gene Expression Omnibus dataset and clinical samples. Molecular docking analysis showed that PAB and SIRT1 had good binding activity. No toxicity was observed in vivo and in vitro with a PAB concentration below 0.3 μM. PAB exerted its antifungal activity by destroying the integrity of hyphae, and alleviated the severity of FK in rats by decreasing clinical scores, fungal burden and inhibiting inflammatory cell infiltration. PAB increased SIRT1 to regulate the crosstalk between nuclear factor erythroid 2-related factor 2 (Nrf2) and nuclear factor kappa-B (NF-κB), decreasing the levels of inflammatory cytokines tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6; and pattern recognition receptors, C-type lectin domain containing 7A (Dectin-1), lectin-like oxidized low-density lipoprotein receptor 1 (LOX-1), toll like receptor (TLR)-2, and TLR4 both in vivo and in vitro. However, this anti-inflammatory effect of PAB was abolished by the SIRT1 inhibitor EX527. This study provides new evidence that PAB has antifungal and anti-inflammatory effects in FK and may provide a novel therapeutic strategy for the treatment of FK.