Neuroprotective effect of melatonin in experimental optic neuritis in rats

GONZÁLEZ FLEITAS MF; CHIANELLI M; ROSENSTEIN RE; DE LAURENTIIS A; SANDE PH; ARANDA ML; KELLER SARMIENTO MI; DORFMAN D

JOURNAL OF PINEAL RESEARCH

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2016 vol. 60 p. 360 - 372

0742-3098

Optic neuritis (ON) is an inflammatory, demyelinating, and neurodegenerative condition of the optic nerve, which might induce permanent vision loss. Currently, there are no effective therapies for this disorder. We have developed an experimental model of primary ON in rats through a single microinjection of 4.5 μg of bacterial lipopolysaccharide (LPS) into the optic nerve. Since melatonin acts as a pleiotropic therapeutic agent in various neurodegenerative diseases, we analyzed the effect of melatonin on LPS-induced ON. For this purpose, LPS or vehicle were injected into the optic nerve from adult male Wistar rats. One group of animals received a subcutaneous pellet of 20 mg melatonin at 24 h before vehicle or LPS injection, and another group was submitted to a sham procedure. Melatonin completely prevented the decrease in visual evoked potentials (VEPs), and pupil light reflex (PLR), and preserved anterograde transport of cholera toxin β-subunit from the retina to the superior colliculus. Moreover, melatonin prevented microglial reactivity (ED1-immunoreactivity, P