In vitro prevention by ACE inhibitors of cataract induced by glucose

Objectives: To study, the anticataract activity of lisinopril and enalapril on cataract induced by glucose, in goat lenses. Materials and Methods: Goat lenses were incubated in artificial aqueous humor containing 55 mM glucose (cataractogenesis) with lisinopril or enalapril in different concentrations at room temperature for 72 h. Biochemical parameters studied in the lens were electrolytes (Na+, K+), Na+-K+-ATPase activity, malondialdehyde (MDA) and proteins. Results: Glucose induced opacification of goat lens began 8-10 hrs after incubation and was complete in 72-80 hrs. Cataractous lenses showed higher Na+, MDA (P< 0.001), lower Na+-K+-ATPase activity, and water-soluble protein content. Lenses treated with lisinopril or enalapril in concentrations of 1, 5, and 10 ng/ml showed higher protein (total and water soluble proteins) content and prevented formation and progress of cataract by glucose, as evidenced by biochemical parameters. Conclusion: The anticataract activity of lisinopril and enalapril may be because of the antioxidant and free radical scavenging activity, as evidenced by a decrease in MDA in treated lenses. Further in-vitro and in-vivo studies in various experimental models and long term clinical trials are required to validate the anticataract activity of ACE-inhibitors.