Taurine protects against retinal and optic nerve damage induced by endothelin-1 in rats via antioxidant effects

• Main Authors: Agarwal, P. (Author), Agarwal, R. (Author), Iezhitsa, I. (Author), Ismail, N. (Author), Nor Arfuzir, N. (Author), Sidek, S. (Author)
• Format: Article
• Language: English
• Published: Wolters Kluwer Medknow Publications 2018
• Subjects: animal experiment; animal model; animal tissue; antioxidant activity; Article; caspase 3; catalase; controlled study; endothelin 1; endothelin-1; enzyme linked immunosorbent assay; glutathione; histopathology; immunohistochemistry; immunoprecipitation; malonaldehyde; morphometry; nerve injury; neuroprotection; nonhuman; optic nerve; oxidative stress; rat; retina; retina nerve cell; superoxide dismutase; taurine
• Online Access: View Fulltext in Publisher; View in Scopus

 Endothelin-1 (ET-1), a potent vasoconstrictor, is involved in retinal vascular dysregulation and oxidative stress in glaucomatous eyes. Taurine (TAU), a naturally occurring free amino acid, is known for its neuroprotective and antioxidant properties. Hence, we evaluated its neuroprotective properties against ET-1 induced retinal and optic nerve damage. ET-1 was administered intravitreally to Sprague-Dawley rats and TAU was injected as pre-, co-or post-treatment. Animals were euthanized seven days post TAU injection. Retinae and optic nerve were examined for morphology, and were also processed for caspase-3 immunostaining. Retinal redox status was estimated by measuring retinal superoxide dismutase, catalase, glutathione, and malondialdehyde levels using enzyme-linked immuosorbent assay. Histopathological examination showed significantly improved retinal and optic nerve morphology in TAU-treated groups. Morphometric examination showed that TAU pre-treatment provided marked protection against ET-1 induced damage to retina and optic nerve. In accordance with the morphological observations, immunostaining for caspase showed a significantly lesser number of apoptotic retinal cells in the TAU pre-treatment group. The retinal oxidative stress was reduced in all TAU-treated groups, and particularly in the pre-treatment group. The findings suggest that treatment with TAU, particularly pre-treatment, prevents apoptosis of retinal cells induced by ET-1 and hence prevents the changes in the morphology of retina and optic nerve. The protective effect of TAU against ET-1 induced retinal and optic nerve damage is associated with reduced retinal oxidative stress. © 2018 Medknow Publications. All Rights Reserved.