Melatonin and its bioisosteres as potential therapeutic agents for the treatment of retinopathy of prematurity

We conducted a study on the impact of intraperitoneal injections of melatonin and its three bioisosteres (compounds 1–3) on the development of oxygen‐induced retinopathy in newborn rats during a 21‐day experiment. It was demonstrated that melatonin and its analogues 1–3 effectively reduce the total protein concentration in the vitreous body of rat pups, decrease concentration of VEGF‐A, and lower the level of oxidative stress (as indicated by normalization of antioxidant activity in the vitreous body). Melatonin and its analogues 1–3 equally normalize the level of VEGF‐A. Analogues 1 and 2 even exceed melatonin in their ability to reduce protein influx into the vitreous body. However, analogue 2 had no effect on antioxidant activity, while analogues 1 and 3 caused a significant increase in this parameter, with analogue 3 even slightly exceeding melatonin. Thus, it can be concluded that analogues 1–3 are comparable to melatonin and can be utilized as potential therapeutic agents for the treatment of retinopathy of prematurity. Administration of melatonin and 3 its bioisosters efficiently normalize VEGF‐A and total protein levels and antioxidant activity in vitreous body of newborn rat pups (in oxygen‐induced retinopathy model). Novel melatonin analogues could be used as new metabolically stable therapeutic agents for the treatment of retinopathy of prematurity.