Effects of some probable antioxidants on selenite-induced cataract formation and oxidative stress-related parameters in rats

The effect of several natural and synthetic compounds on selenite-induced c ataract was investigated in rat pups. Simultaneous determination of glutath ione S-transferase (GST), selenium dependent glutathione peroxidase (Se-GPx ), catalase (CAT), superoxide dismutase (SOD) activities and malondialdehyd e (MDA) levels were carried out in the lens, erythrocyte and plasma. The re sults showed that propolis, diclofenac, vitamin C (Vit-C) and quercetin pre vented cataract formation to the extent of 70, 60, 58.4, and 40%, respectiv ely. Standardized extract of Ginkgo biloba (Egb 761) did not affect the cat aract formation. Selenite treatment caused a significant decrease in the ac tivity of erythrocyte SOD. This was accompanied by a simultaneous increase in the levels of MDA either in lens and in plasma. A significant increase w as shown in erythrocyte GST (substrate ethacrynic acid; eaa), and GPx activ ities and lens GST (substrate chlorodinitro benzene; cdnb) activity. Antiox idant treatment caused significant changes in enzyme activities and MDA lev els. There was no effect of selenite and antioxidants on total body weight increase during the course of the study. Blood parameters did not correlate to lens parameters following selenite treatment. Our results suggest that antioxidant supplementation following selenite exposure may prevent the cat aract formation and may enhance antioxidant defence of blood and lens. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.