Role of Fish Oil on Amelioration of Injured Cornea and Lens of Diabetic and Hypercholesterolemic Male Wistar Rats

Abstract

The association between diabetes and hypercholesterolemia and cataract represents the main public health problem. Little information about the biochemical changes in lens during the progress of disease parallel with lens ultrastructure. Also, the interrelationship between lens and cornea and the dramatic effects of both diseases in cornea was still not clearly illustrated. Our objective was designed to the role of diabetes and hypercholesterolemia in the development of lens and corneal damages and the ameliorated role of fish-oil-treatment. Sixtyfour male albino rats of Wistar strain were arranged into eight groups (n=8). These are control, fish oil-supplementation, diabetes (single ip stretozotocin of 40 mg/kg body weight in citrate buffer pH 4.6), diabetes and fish oil, hypercholesterolemia (fed on diet rich of 3% cholesterol), hypercholesterolemia and fish oil, diabetes and hypercholesterolemia, diabetes and hypercholesterolemia and fish oil. Treatments were carried out for 16 weeks. Rats were sacrificed and lenses and cornea were separated. Lenses were examined biochemically for glycated protein, endothellin, adhesion molecules and zinc and iron contents as well as scanning electron microscopy. Cornea was examined at light and transmission electron microscopy.The lens of diabetic and/or hypercholesterolemia exhibited apparent increase of carbonylated proteins and glycation end products, endothelin-1, adhesion molecules (ICAM-1 & VCAM-1), zinc and iron parallel with disorganized ball and socket and degeneration of lens fibers. The cornea of both diabetic and or hypercholesterolemic possessed damage of corneal epithelium, hyalinization and degeneration of both Bowman's and stromal collagenous layers associated with diffuse leukocytic inflammatory cells in the peripheral collagenous stromal layers and degeneration of endothelium lining the Descemet's membrane. Hypercholesterolemia showed the least dramatic effect in comparison with diabetes. Fishoil supplementation ameliorated the lens and corneal structure and improved the biochemical changes.The author finally concluded that the amelioration role of fish oilsupplementation attributed to the reduction of glycated proteins, endothelin-1, adhesion molecules and lens zinc and iron contents which reflected in the structural components of lens fibers as well as improved the elementary structures of cornea.