Protective effects of melatonin as an eye drops against selenite-induced cataract in rat pups

Abstract

The aim of the present study is to investigate the possible role of melatonin, when administered as eye drops, in selenite-induced cataractogenesis in rat pups. Sixty Wistar albino rats (13 days old) were allocated into three groups (20 animals each); group A was injected subcutaneously with normal saline and received no other treatment; group B was injected with (40 μmol/g body weight) sodium selenite subcutaneously and treated with 1 drop of melatonin eye drops, specially formulated for this purpose, twice daily for 30 days; and group C was injected with sodium selenite as in group B but treated with a single drop of normal saline twice daily for 30 days. The stage of cataract development was examined with slit-lamp photographs. After 30 days, the pups were sacrificed and their eyeballs enucleated for histological examination. The results demonstrated that melatonin eye drops decreased nuclear cataract formation after 15 and 21 days of treatment, compared to the saline-treated group. Histological evaluations of enucleated lenses revealed that treatment with melatonin drops clearly indicated recovery of the lenticular tissues, which retained their ordinary shape. These findings demonstrate that melatonin, when administered as eye drops, protects the lens of rat pups against selenite-induced cataract.