Trends of ocular fungal infections in North China (2001-2020)

Ebselen improves fungal keratitis through exerting anti-inflammation, anti-oxidative stress, and antifungal effects

Fungal keratitis is a severely vision-threatening corneal infection, where the prognosis depends on both fungal virulence and host immune defense. Inappropriate host responses can induce substantial inflammatory damage to the cornea. Therefore, in the treatment of fungal keratitis, it is important to concurrently regulate the immune response while efforts are made to eliminate the pathogen. Ebselen is a widely studied organo-selenium compound and has been demonstrated to have antifungal, antibacterial, anti-inflammatory, and oxidative stress-regulatory properties. The effectiveness of ebselen for the treatment of fungal keratitis remains unknown. In this study, ebselen was demonstrated to produce a marked inhibitory effect on Aspergillus fumigatus (A. fumigatus), including spore germination inhibition, mycelial growth reduction, and fungal biofilm disruption. The antifungal activity of ebselen was related to the cell membrane damage caused by thioredoxin (Trx) system inhibition-mediated oxidative stress. On the contrary, ebselen enhanced the antioxidation of Trx system in mammalian cells. Further, ebselen was proven to suppress the expressions of inflammatory mediators (IL-1β, IL-6, TNF-α, COX-2, iNOS, and CCL2) and reduce the production of oxidative stress-associated indicators (ROS, NO, and MDA) in fungi-stimulated RAW264.7 cells. In addition, ebselen regulated PI3K/Akt/Nrf2 and p38 MAPK signaling pathways, which contributed to the improvement of inflammation and oxidative stress. Finally, we verified the therapeutic effect of ebselen on mouse fungal keratitis. Ebselen improved the prognosis and reduced the fungal burden in mouse corneas. Expressions of inflammatory mediators, as well as the infiltration of macrophages and neutrophils in the cornea were also obviously decreased by ebselen. In summary, ebselen exerted therapeutic effects by reducing fungal load and protecting host tissues in fungal keratitis, making it a promising treatment for fungal infections.

Plumbagin inhibits fungal growth, HMGB1/LOX-1 pathway and inflammatory factors in A. fumigatus keratitis

To investigate the anti-inflammatory and antifungal effects of plumbagin (PL) in Aspergillus fumigatus (A. fumigatus) keratitis, the minimum inhibitory concentration (MIC), time-killing curve, spore adhesion, crystal violet staining, calcium fluoride white staining, and Propidium Iodide (PI) staining were employed to assess the antifungal activity of PL in vitro against A. fumigatus. The cytotoxicity of PL was assessed using the Cell Counting Kit-8 (CCK8). The impact of PL on the expression of HMGB1, LOX-1, TNF-α, IL-1β, IL-6, IL-10 and ROS in A. fumigatus keratitis was investigated using RT-PCR, ELISA, Western blot, and Reactive oxygen species (ROS) assay. The therapeutic efficacy of PL against A. fumigatus keratitis was assessed through clinical scoring, plate counting, Immunofluorescence and Hematoxylin-Eosin (HE) staining. Finally, we found that PL inhibited the growth, spore adhesion, and biofilm formation of A. fumigatus and disrupted the integrity of its cell membrane and cell wall. PL decreased IL-6, TNF-α, and IL-1β levels while increasing IL-10 expression in fungi-infected mice corneas and peritoneal macrophages. Additionally, PL significantly attenuated the HMGB1/LOX-1 pathway while reversing the promoting effect of Boxb (an HMGB1 agonist) on HMGB1/LOX-1. Moreover, PL decreased the level of ROS. In vivo, clinical scores, neutrophil recruitment, and fungal burden were all significantly reduced in infected corneas treated with PL. In summary, the inflammatory process can be inhibited by PL through the regulation of the HMGB-1/LOX-1 pathway. Simultaneously, PL can exert antifungal effects by limiting fungal spore adhesion and biofilm formation, as well as causing destruction of cell membranes and walls.

The Effectiveness and Safety of Intravitreal Injections of Voriconazole in the Treatment of Fungal Endophthalmitis: A Systematic Review

Background: Fungus endophthalmitis is a rare and serious infection that is treated with systemic and topical antifungal drugs. There is no clear consensus on the treatment of fungal endophthalmitis with intravitreal injections (IVIs) of voriconazole. This systematic review aims to summarize the literature on IVIs of voriconazole for fungal endophthalmitis. Methods: We conducted a systematic review of the literature to determine the effectiveness and safety of IVIs of voriconazole in the treatment of fungal endophthalmitis. We searched databases such as PubMed and Embase using the following search terms "Endophthalmitis" AND "Intravitreal Injections" AND "Voriconazole" with date limits of January 1, 1900, to December 31, 2022. We included all reports on humans, which described clinical outcomes of IVIs of voriconazole in the treatment of fungal endophthalmitis, including randomized controlled trials (RCTs) and case series. A descriptive synthesis of the data was conducted with a pooling of data for interventions. Results: One RCT and 21 retrospective studies were analyzed in this review. In these reports, a wide range of heterogeneous treatment regimens was used, including IVI in combination with other drugs, systemic therapy in combination with other agents, and surgery. Combined with other treatments, intravitreal voriconazole results in a favorable anatomical and clinical cure that was well tolerated. Conclusions: Reports on IVIs of voriconazole for fungal endophthalmitis demonstrate a heterogeneous approach to treatment. Of these, IVIs of voriconazole in anatomical and clinical outcomes appeared to be highly effective, although more data on its safety are needed.