Losartan delays the progression of streptozotocin-induced diabetic cataracts in albino rats.

The ocular renin-angiotensin system has become an interesting target for ocular diseases because it has been implicated in various ocular diseases such as diabetic retinopathy, glaucoma, age-related macular degeneration, uveitis, and hypertensive cataracts. In the present study, we explored the effect of topically and orally administered losartan (an angiotensin receptor blocker) on streptozotocin-induced diabetic cataract in albino rats. Topical treatment with losartan modulated neither the blood glucose level nor the polyol content but oral treatment with losartan decreased both. Topical and oral treatment with losartan significantly increased the antioxidants (glutathione, glutathione peroxidase, superoxide dismutase, and catalase), decreased the lipid peroxidant malondialdehyde, and restored soluble protein, and insoluble protein and various ions (Na+ , K+ , and Ca2+ ) in the lens; however, topical treatment had a better effect than oral treatment. These findings demonstrate that topical administration of losartan significantly reduces the risk of cataract formation without affecting either the blood glucose level or polyol contents.