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 instillation on cataract progression was examined in 12-month-old Wistar rats fed a 25% galactose diet. Vit. E-containing liposomes prepared with dipalmitoylphosphatidylcholine and dioleoylphosphatidylcholine (7:3 w/w) were instilled into both eyes twice a day. Lenses of galactose-fed rats showed suture accentuation at 6 months of feeding and opacities in the cortex and nuclei at 8 months. 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 months of feeding; increased LPO, galactitol, and water contents and decreased GSH content at 8 months. Sera of galactose-fed rats had increased Vit. E and cholesterol concentrations at 6 months of feeding. The liposome instillation increased lens Vit. E content with attenuation of the increased lens LPO content and the decreased lens GSH content but did not affect the changes in lens galactitol and water contents and serum Vit. E and cholesterol concentrations. These results indicate that instilled Vit. E-containing liposomes 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.