M.A. EMAN, S.M. EMAN

Biophysics and Laser Science Unit, Research Institute of Ophthalmology, Giza, Egypt. P.O. Box: 90. Tel: (+2) 35718305, Fax: (+2) 35752688

Abstract. Alpha-lipoic acid (LA) is well known as a powerful antioxidant. The effect of LA against streptozotocin (STZ)-induced diabetic cataract in rabbits was investigated. Twenty New Zealand albino rabbits were divided into 4 groups. Group I served as the control one. The other three groups (II, III, and IV) received a single intravenous injection of STZ (50 mg/kg body weight). After the onset of diabetes, cataract was developed within 12 to 13 weeks in group II. Groups III and VI received a daily dose of 150 mg/day of LA for 8 weeks and 16 weeks after induction of diabetes, respectively. The activity of Na⁺-K⁺ATPase was measured in lens membrane. Soluble lens proteins were extracted and the following techniques were carried out: estimation of total soluble protein, gel filtration chromatography and sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). The results indicated a decrease in total soluble lens protein and Na⁺-K⁺ATPase activity, increase in molecular weight of all protein fractions and changes in the electrophoretic mobility of lens proteins in diabetic cataract group. These changes were reduced in rabbits treated with LA particularly the long period (16 weeks). It is concluded that LA treatment was associated with delayed the development and progression of streptozotocin-induced diabetic cataract in rabbits.
Key words: lens proteins, alpha-lipoic acid, electrophoresis, streptozotocin.

Corresponding author’s e-mail: e.aly@hotmail.com

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