1. Therapeutic effect of oxidized bletilla striata polysaccharide-natamycin eye drops on fungal keratitis.
- Author
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Tian X, Ji X, Zhang R, Long X, Lin J, Zhang Y, Zhan L, Luan J, Zhao G, and Peng X
- Subjects
- Animals, Mice, RAW 264.7 Cells, Eye Infections, Fungal drug therapy, Cornea, Aspergillus fumigatus drug effects, Oxidation-Reduction, Antifungal Agents pharmacology, Antifungal Agents chemistry, Antifungal Agents therapeutic use, Anti-Inflammatory Agents chemistry, Anti-Inflammatory Agents pharmacology, Anti-Inflammatory Agents therapeutic use, Cell Survival drug effects, Natamycin pharmacology, Natamycin therapeutic use, Keratitis drug therapy, Keratitis microbiology, Orchidaceae chemistry, Polysaccharides chemistry, Polysaccharides pharmacology, Ophthalmic Solutions chemistry, Mice, Inbred C57BL
- Abstract
Objective: Fungal keratitis (FK) usually develops to a poor clinical prognosis due to the fungal invasion and excessive inflammatory reaction. In order to enhance the therapeutic effect of natamycin (NAT), we used the anti-inflammatory biological polysaccharide bletilla striata polysaccharide (BSP) combined with NAT to prepare a new eye drop -- oxidized bletilla striata polysaccharide-natamycin (OBN)., Methods: UV-vis, FT-IR, and fluorescence spectroscopy were used to identify the synthesis of OBN. Biocompatibility of OBN was determined by CCK-8, scratch assay, and corneal toxicity test. RAW264.7 cells and C57BL/6 mice were stimulated with A. fumigatus and treated with PBS, OBN, or NAT. The anti-inflammatory activity of OBN was detected by RT-PCR and ELISA. In mice with FK, the clinical scores were used to evaluate the effect of OBN; HE staining was performed to assess the corneal pathological changes; MPO assay and immunofluorescence staining were used to investigate neutrophil infiltration., Results: OBN was synthesized by combining oxidized bletilla striata polysaccharide (OBSP) with NAT through Schiff base reaction. OBN did not affect cell viability at a concentration of 160 μg/mL in HCECs, RAW264.7 cells, and mouse corneas. OBN versus NAT significantly improved the prognosis of A. fumigatus keratitis by reducing disease severity, neutrophil infiltration, and expression of inflammatory factors in vivo . Additionally, OBN treatment down-regulated the mRNA and protein expression levels of inflammatory factors IL-1β, TNF-α, and IL-6 in RAW264.7 and mouse models., Conclusion: OBN is a compound prepared by covalently linking OBSP to the imino group of NAT through Schiff base reaction. OBN treatment down-regulated inflammation and improved the prognosis of mice with A. fumigatus keratitis., Competing Interests: Declaration of conflicting interestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
- Published
- 2025
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