Cis‐urocanic acid inhibits conjunctivitis and blepharitis in rat model of acute eye irritation

Abstract

Purpose In vitro studies have shown anti‐inflammatory and cytoprotective effects of cis‐urocanic acid (cis‐UCA) in human ocular epithelial cells exposed to UV‐B irradiation. In this study, we aimed to investigate the efficacy of topical cis‐UCA against compound 48/80 induced eye irritation in a rat model. Methods Adult Wistar rats in groups of six animals were treated with 1000 µg/ml compound 48/80 in both eyes. Cis‐UCA 0.5% solution, corticosteroid dexamethasone 1 mg/ml (Oftan® Dexa), antihistamine ketotifen 0.25 mg/ml (Zaditen), or PBS was applied in both eyes at time points 0.5, 6, and 12 h after application of compound 48/80. Clinical signs of ocular inflammation were evaluated by scoring from photographs by ophthalmologist 1, 6, 12, and 24 h after the last drug application. Results Cis‐UCA solution attenuated conjunctival hyperemia in compound 48/80 irritated eyes equally well compared to dexamethasone and ketotifen. At time points 12 and 24 h, the mean decrease in severity score was 50% and 40%, respectively, for the cis‐UCA group. Redness of the eyelid margin was prevented best by ketotifen at 1‐h time point, whereas cis‐UCA and dexamethasone almost completely abolished lid redness at 6, 12, and 24 h. Conclusion These results suggest that cis‐UCA has an anti‐inflammatory effect in acute eye irritation, which is comparable to corticosteroid dexamethasone and antihistamine ketotifen.

A randomized phase I clinical study of cis‐urocanic acid eye drops in healthy adult subjects

“…; Jauhonen et al. , ). The ocular as well as systemic safety and tolerability of cis‐UCA in preclinical studies have been very good, and the non‐clinical toxicology data justified the use of cis‐UCA with the planned doses and dosing regimens.…”

“…Moreover, our preliminary results in the compound 48/80‐induced eye irritation model in the rat suggest that cis‐UCA may reduce acute ocular inflammation (Jauhonen et al. ).…”