Berberine Ameliorates Ocular Surface Inflammation And Apoptosis By Modulating The NF-κB Signaling Pathway In Mouse Models Of Dry Eye

Objective:to study the therapeutic effects and mechanism of berberine on ocular surface injury of dry eye.Methods:the model of dry eye of experimental animals was established by subcutaneous injection of 0.2%scopolamine in the drying environment.At the early stage,the experimental mice can be divided into six groups,namely,the Normal group,Dry Eye group,Solvent group,three berberine local point eye treatment groups with concentration gradient of 0.5 mg/ml,1 mg/ml,2 mg/ml(6 mice in each group),respectively.The phenol red line method and Oregon green dextran(OGD)staining are used to observe the type tear secretion and corneal barrier function,and to select the optimal treatment concentration of berberine.After determining the optimal treatment concentration of berberine,the optimal treatment concentration is selected as the medication administration group of berberine.The iodate Schiff staining(PAS)is used to observe the conjunctival goblet cells density is in each group,apoptosis of corneal epithelial cells in situ TUNEL staining.Immunofluorescence and Western Blotting are used to detect MMP-3,MMP-9,Caspase-8,a marker of apoptosis in the conjunctiva,and CD4 positive T cells in the conjunctiva.qRT-PCR detectes dry eye related inflammatory factors(IL-1α、IL-1β、IL-6、IL-17、IFN-γ、TNF-α)in the conjunctiva.Western Blotting observes the protein expression in NF-κB signaling pathway.Results:the local berberine treatment could effectively increase the amount of tear secretion in mice and protect the function of corneal epithelial barrier.The treatment group with 2mg/ml berberine had the best effect.The application of berberine locally reverses the decrease of conjunctival goblet cells density of dry eye,inhibits the expression of MMP-3 and MMP-9 in corneal epithelium,effectively alleviates the corneal and conjunctival epithelial cells apoptosis,effectively inhibits the CD4+T cells invasion and the expression of its mediated inflammatory cytokines IL-17 and IFN gamma in ocular surface,and can inhibit activation predominate of IKK,NF-kappa B in the signaling pathway NF-kappa B to play the role of the anti-inflammator.Conclusions:the application of berberine locally can inhibit activation of NF-κB signaling pathway and ocular surface inflammation mediated by CD4+T cells,effectively reverse the ocular surface injury of dry eye mice and restore their tear secretion.