Abstract
Purpose:
To investigate the biological effects of (-)-epigallocatechin gallate (EGCG), catechins combination {(-)-epicatechin (EC), (-)-epigallocatechin (EGC), (-)-epicatechin gallate (ECG), (+)-gallocatechin (GC)}, catechins combination (GC, EGC, and EC), and green tea extract Theaphenon® E on sodium iodate-induced retinal degeneration in rats.
Methods:
Adult Sprague-Dawley rats were injected intravenously with single dose of 40 mg/kg sodium iodate and administered intra-gastrically with EGCG, catechins combination (EGCG, GC, EGC, and EC), catechins combination (GC, EGC, and EC), and Theaphenon® E. Controls were injected i.v. with normal saline or 40 mg/kg sodium iodate. After in vivo examination of the retinas by confocal scanning laser ophthalmoscopy (CSLO) and spectral domain optical coherence tomography (SD-OCT), the rats were sacrificed for biochemical and histological analyses, including determination of Superoxide dismutase (SOD), glutathione peroxidase (GPx), caspase 3 mRNA, and 8-Iso-PGF2α concentration in the retina.
Results:
CSLO revealed decrease in hyporeflective blots in the retina after treatment with EGCG, catechins combination (EGCG, GC, EGC, and EC), and Theaphenon® E. Concomitant protective effects of these catechins were observed in histological preparations with reduction retinal lesion. Expressions of SOD, GPx, caspase 3 and 8-Iso-PGF2α in the retina were reduced, indicating strong anti-oxidant effects of the catechins.
Conclusions:
EGCG, catechins combination (EGCG, GC, EGC, and EC) and Theaphenon® E attenuated sodium iodate-induced retinal degeneration in rats, supporting the notion that catechins may alleviate oxidative stress in the retina.