Retinal Protective Effect of Avocado Soybean (ASB) Versus Glibenclamide in Streptozotocin-Induced Diabetic Rats.

Introduction: Diabetic retinopathy is a neurodegenerative, microvascular, and sight-threatening impact of chronic uncontrolled diabetes. Avocado/soybean (ASB), a relatively new nutraceutical mixture, has acquired a significant role as a natural substitutional therapy for numerous diseases. Glibenclamide (Gli), a potent sulfonylurea, was confirmed as a diabetic therapy. Aim of the Study: To explore the protective effects of ASB versus glibenclamide on the diabetic rats' retina induced by streptozotocin (STZ). Materials and Methods: Forty rats were categorized into four groups: Normal control, Diabetic Control, Diabetes+Avocado soybean, and Diabetes+Glibenclamide. Retinal specimens were processed for histological, immunohistochemical, ultrastructural studies. Morphometrical and statistical studies were also performed. Results: Diabetic retinal specimens demonstrated evident disorganization of the retinal layers, degenerated retinal pigment epithelium, photoreceptors, and outer nuclear layers with appearance of empty spaces and multiple vacuolations. Most of ganglion cells were lost, others appeared with pycnotic nuclei. Together with a highly significant decrease (P< 0.001) of the total thickness, and the thickness of the outer and inner nuclear layers of the rats' retina, and the number of the ganglion cells. Immune expression of TNF-α, VEGF, caspase-3, and vimentin illustrated a highly significant elevation (P< 0.001). Ultrastructural findings of retinal pigmented cell layer illustrated; swollen degenerated mitochondria with cytoplasmic vacuolation. Degenerated photoreceptors, ganglion cells have indented irregular nucleus, destructed nuclear membrane, and vacuolated cytoplasm. ASB amends the diabetic retinopathy changes, structurally and immunohistochemically, more than glibenclamide Conclusion: ASB has a more, retinal-protective efficacy on DR, than glibenclamide. [ABSTRACT FROM AUTHOR]