Objective:To examine the effect of compound ketotifen eye drops(CKF,containing 0.1% ketotifen and 0.000 5% dexamethasone) on experimental acute allergic conjunctivitis in rats.Methods:27 male Wistar rats were immunized by intraperitoneal injection of egg albumin and were randomized into three groups: CKF,0.1% ketotifen (KF) and 0.000 5% dexamethasone (DM) Rats in each group received the respective eye drops in one eye and vehicle in the other eye 60,45,30,15 min before and 15,30 min after challenge.Immediately before challenge,the rats were injected intravenously with Evans Blue(EB).The challenge was performed by topical instillation of egg albumin,and 60 min later,the animals were killed and the dye was extracted from the eyes.The intensity of EB extravasation was determined by spectrophotometry at 620nm and inhibitory rates were calculated.Results:CKF,KF and DM suppressed EB extravasation significantly.The inhibitory rate was 53.98%±15.57% for CKF,27.91%±28.36% for KF and 11.90%±34.16% for DM.CKF was more effective than both KF and DM on inhibiting dye vascular leakage in the eyes (P＝0.028,0.004,respectively).Conclusion:These data clearly indicate that the compound of ketotifen eye drops has potential as a topical ocular formulation for anti-allergic disease.

Objective　To develop a rapid，sensitive and reliable high-performance gas chromatography to evaluate the fluconazole (FCZ) bioavailability after topically applied FCZ in-situ gelling ophthalmic delivery system to the rabbit eyes.Methods　A megabore capillary column（30m long and inner diameter of 0.530 mm） with a 0.88-μm-thick bonded liquid phase was used.Detector was nitrogen-selective type.Tears adsorbed to the filter paper was directly by methanol with no evaporation stage prior to analysis.Aqueous humors was extracted by ethyl acetate.Results　The duration of each analysis was less 10 min and the minimum detectable concentration was 0.01μg/ml.The assay was linear from 0.1 to 20 μg/ml.The average recoveries from tears and aqueous humors were 99.0% and 94.8%，respectively.Conclusion　This method can be used to determine rabbit tears and aqueous humors levels of fluconazole and was practicable approach for evaluating intraocular pharmacokinetics after topically applied to rabbit eyes.

Lymphocytic choriomeningitis virus/physiology* ; Allosteric Regulation ; Nucleotidyltransferases

Antiviral Agents/pharmacology* ; COVID-19 ; Coronavirus 3C Proteases ; Humans ; Lactams ; Leucine ; Molecular Docking Simulation ; Molecular Dynamics Simulation ; Nitriles ; Proline ; Protease Inhibitors/pharmacology* ; SARS-CoV-2

A new coronavirus (SARS-CoV-2) has been identified as the etiologic agent for the COVID-19 outbreak. Currently, effective treatment options remain very limited for this disease; therefore, there is an urgent need to identify new anti-COVID-19 agents. In this study, we screened over 6,000 compounds that included approved drugs, drug candidates in clinical trials, and pharmacologically active compounds to identify leads that target the SARS-CoV-2 papain-like protease (PLpro). Together with main protease (M
Antiviral Agents/therapeutic use* ; Binding Sites ; COVID-19/virology* ; Coronavirus Papain-Like Proteases/metabolism* ; Crystallography, X-Ray ; Drug Evaluation, Preclinical ; Drug Repositioning ; High-Throughput Screening Assays/methods* ; Humans ; Imidazoles/therapeutic use* ; Inhibitory Concentration 50 ; Molecular Dynamics Simulation ; Mutagenesis, Site-Directed ; Naphthoquinones/therapeutic use* ; Protease Inhibitors/therapeutic use* ; Protein Structure, Tertiary ; Recombinant Proteins/isolation & purification* ; SARS-CoV-2/isolation & purification*

The global COVID-19 coronavirus pandemic has infected over 109 million people, leading to over 2 million deaths up to date and still lacking of effective drugs for patient treatment. Here, we screened about 1.8 million small molecules against the main protease (M^pro) and papain like protease (PL^pro), two major proteases in severe acute respiratory syndrome-coronavirus 2 genome, and identified 1851M^pro inhibitors and 205 PL^pro inhibitors with low nmol/l activity of the best hits. Among these inhibitors, eight small molecules showed dual inhibition effects on both M^pro and PL^pro, exhibiting potential as better candidates for COVID-19 treatment. The best inhibitors of each protease were tested in antiviral assay, with over 40% of M^pro inhibitors and over 20% of PL^pro inhibitors showing high potency in viral inhibition with low cytotoxicity. The X-ray crystal structure of SARS-CoV-2 M^pro in complex with its potent inhibitor 4a was determined at 1.8 Å resolution. Together with docking assays, our results provide a comprehensive resource for future research on anti-SARS-CoV-2 drug development.
Humans ; Antiviral Agents/chemistry* ; COVID-19 ; COVID-19 Drug Treatment ; High-Throughput Screening Assays ; Molecular Docking Simulation ; Protease Inhibitors/chemistry* ; SARS-CoV-2/enzymology* ; Viral Nonstructural Proteins

Emerging and re-emerging RNA viruses occasionally cause epidemics and pandemics worldwide, such as the on-going outbreak of the novel coronavirus SARS-CoV-2. Herein, we identified two potent inhibitors of human DHODH, S312 and S416, with favorable drug-likeness and pharmacokinetic profiles, which all showed broad-spectrum antiviral effects against various RNA viruses, including influenza A virus, Zika virus, Ebola virus, and particularly against SARS-CoV-2. Notably, S416 is reported to be the most potent inhibitor so far with an EC of 17 nmol/L and an SI value of 10,505.88 in infected cells. Our results are the first to validate that DHODH is an attractive host target through high antiviral efficacy in vivo and low virus replication in DHODH knock-out cells. This work demonstrates that both S312/S416 and old drugs (Leflunomide/Teriflunomide) with dual actions of antiviral and immuno-regulation may have clinical potentials to cure SARS-CoV-2 or other RNA viruses circulating worldwide, no matter such viruses are mutated or not.
Animals ; Antiviral Agents ; pharmacology ; therapeutic use ; Betacoronavirus ; drug effects ; physiology ; Binding Sites ; drug effects ; Cell Line ; Coronavirus Infections ; drug therapy ; virology ; Crotonates ; pharmacology ; Cytokine Release Syndrome ; drug therapy ; Drug Evaluation, Preclinical ; Gene Knockout Techniques ; Humans ; Influenza A virus ; drug effects ; Leflunomide ; pharmacology ; Mice ; Mice, Inbred BALB C ; Orthomyxoviridae Infections ; drug therapy ; Oseltamivir ; therapeutic use ; Oxidoreductases ; antagonists & inhibitors ; metabolism ; Pandemics ; Pneumonia, Viral ; drug therapy ; virology ; Protein Binding ; drug effects ; Pyrimidines ; biosynthesis ; RNA Viruses ; drug effects ; physiology ; Structure-Activity Relationship ; Toluidines ; pharmacology ; Ubiquinone ; metabolism ; Virus Replication ; drug effects