Therapeutic effects of selenium nanoparticles versus selenium on experimentally induced diabetic retinopathy via modulation of TLR4 / NF- _k B P65 / VEGF / connexin 43 signaling

Diabetic retinopathy is the most prevalent microvascular consequences of diabetes mellitus that can result in vision loss. Nanotechnology has been widely used in the treatment of ophthalmic diseases. Selenium is a naturally occurring compound that has antioxidant and anti-inflammatory effects. This study aimed at comparing the possible ameliorating effect of selenium versus Nano-selenium on streptozotocin-induced diabetic retinopathy in rats. Sixty adult male albino-Wister rats were divided randomly into six groups; control, Selenium+ve, Nanoselenium+ve, diabetic, DR-Se treated group, and DR-NS treated group. Animals were anesthetized and sacrificed at the end of study. Eyes were removed and prepared for biochemical, histological, and immunohistochemical studies. The results showed that the diabetic group had an apparent decrease in retinal thickness, loss of photoreceptors, dilated congested blood vessels in retinal layers. Additionally, a significant increase in malondialdehyde and significant decrease in Total Antioxidant Capacity were detected. Significant increase in surface area fraction of vascular endothelial growth factor, nuclear factor kappa B, Glial fibrillary acidic protein immune stained cells were noticed, and significant decrease in connexin 43 expression was also detected. Improvement in all mentioned parameters in DR-Se and DR-NS groups was noticed. Our study suggested that Selenium, whether in its regular or nano form, holds promise for alleviating diabetic retinopathy in rats on biochemical, histological, and immunohistochemical basis.