Preventive effect of vitamin E-containing liposome instillation on cataract progression in 12-month-old rats fed a 25% galactose diet

The preventive effect of vitamin E (Vit. E)-containing liposome instillatio n on cataract progression was examined in 12-month-old Wistar rats fed a 25 % galactose diet. Vit. E-containing liposomes prepared with dipalmitoylphos phatidylcholine and dioleoylphosphatidylcholine (7:3 w/w) were instilled in to both eyes twice a day. Lenses of galactose-fed rats showed suture accent uation at 6 months of feeding and opacities in the cortex and nuclei at 8 m onths. Two months of Vit. E-containing liposome instillation, starting at 6 months of galactose feeding, retarded this cataract progression. Lenses of galactose-fed rats had increased Vit. E, lipid peroxide (LPO), galactitol, and water contents and decreased reduced glutathione (GSH) content at 6 mo nths of feeding; increased LPO, galactitol, and water contents and decrease d GSH content at 8 months. Sera of galactose-fed rats had increased Vit. E and cholesterol concentrations at 6 months of feeding. The liposome instill ation increased lens Vit. E content with attenuation of the increased lens LPO content and the decreased lens GSH content but did not affect the chang es in lens galactitol and water contents and serum Vit. E and cholesterol c oncentrations. These results indicate that instilled Vit. E-containing lipo somes retard cataract progression in 12-month-old rats fed a 25% galactose diet, mainly by the antioxidative and membrane-stabilizing actions of Vit. E contained in the liposomes.