Efficacy of cobalt chelates CTC-23 & CTC-96 for treatment of recurrent stromal ocular herpes simplex infection in a rabbit model

Purpose : Herpes simplex virus (HSV) causes infections in humans that can lead to permanent scarring and loss of vision as well as blindness. The virus, after primary infection of a host, becomes senescent; recurrent disease is possible from latent virus. In this project, we use an animal model to evaluate various tetradentate Co^III chelates with nitrogenous axial ligands for efficacy treating such reactivations. Methods: Normal 3-5 Ib NZW rabbits were intracorneally infected with HSV-1, strain RE. The animals were monitored until resolution, then irradiated with a single dose of 250 mJ ultraviolet (UV)-B radiation. Those animals presenting with stromal keratitis were arbitrarily divided into groups receiving for 5 days, varying doses of: one of two CTC compounds, triflurothymidine/prednisilone (TFT/Pred; current treatmentof choice) or 0,9% physiologic saline. The animals were followed in a double-blind fashion and monitored for severity/resolution of the HSV-1 via biomicroscropic (slitlamp) examination as well as viral culture techniques (ELISAs, plaque and infectivity assays). Results: By day 10 post-infection the lowest concentration of CTC-23, 5 μg/ml, had eliminated virus and stromal symptomatology from the eyes of about half the animals, while at 25 u.g/ml, all eyes were virus-free by day 12. CTC-96 and TFT/Pred were more effective still, eliminating virus and stromal symptomatology from every eye by day 10 at both 5 and 10 ug/ml. Conclusions: We conclude that CTC compounds 23 and 96 were effective antiviral agents against herpes simplex type 1, strain RK.