Rutin prevents retinal ganglion cell death and exerts protective effects by regulating transforming growth factor-β2/smad2/3akt/PTEN signaling in experimental rat glaucoma

Abstract

Purpose: To investigate the protective effect of rutin against glaucoma in a rat model, and the mechanisms involved. Methods: Sprague-Dawley rats were injected hypertonic saline in the limbal vein for elevation of intraocular pressure (IOP). Rats in the treatment group were administered rutin at doses of 12.5, 25 or 50 mg/kg orally and daily for 21 days. Results: Rutin markedly (p < 0.05) reduced IOP and prevented loss of retinal ganglion cells (RGCs). The expression of apoptotic pathway proteins, i.e., Bcl-xL, Bcl-2, Bad and Bax were significantly (p < 0.05) regulated by rutin. Moreover, rutin caused a substantial decrease in TGF-β2 expression, and also down-regulated p-Smad2 and p-Smad3 dose-dependently (p < 0.05). Raised levels of collagen I, fibronectin and elastin were effectively down-regulated. Rutin substantially up-regulated the Akt pathway involved in cell survival, and markedly improved the survival of RGCs subjected to hypoxia in vitro (p < 0.05). Conclusion: These results reveal that rutin exerts protective effect against glaucoma in a rat model via a mechanism involving regulation of the TGF-β2/Smad2/3Akt/PTEN signaling pathways. Thus, rutin has potentials for use in the management of glaucoma.