Prevention of Selenite-induced Cataract by L-Cysteine and Vitamin C in Rats

Background: Development of a drug which could prevent or delay the onset or progression of cataract will help to reduce the number of people getting blind due to cataract worldwide. This study was undertaken to evaluate the clinical and biochemical changes of the crystalline lens and gel-electrophoresis of water soluble proteins in a selenite- induced cataract and to assess the preventive role of L-Cysteine and vitamin C in rat as an animal model. Methods: Cataracts were induced in rats by administration of sodium selenite. In control group, saline was injected subcutaneously (SC). In experimental groups (groups 2-5), sodium selenite (20 μmol/kg) was injected SC. Rats in group 3 received SC injections of 0.1 ml of vitaminC (0.3 mM), in group 4 received SC injection of 0.1 ml of L-cysteine (0.05 μmol) and those in group 5 received SC injection of 0.1 ml of L-cysteine (0.1 μmol). The development of cataract was assessed clinically. Then, the lenses were checked for total and soluble protein concentrations and eletrophoretic pattern (SDS-PAGE). Results: Sodium selenite could induce cataract and cause biochemical and eletrophoretic changes in the lens. L-cysteine and vitamin C were highly effective in preventing or minimizing selenite-induced cataract and in maintaining near-normal total protein and soluble protein concentrations of the lens. These reagents were also effective in restoring the near normal pattern of lens proteins in SDS-PAGE. L-cystein was more effective than vitamin C in prevention of cataract but the difference was not statistically significant. Conclusions: Our results showed that cataractous and biochemical changes of the crystalline lens proteins due to selenite can be minimized or prevented by L-cysteine and vitamin C.