Pyruvate ophthalmic drops: anticataract effect in naphthalene- treated albino rats and aqueous humor concentration in albino rabbits

ABSTRACT

This study was performed to determine the cataract-preventive effect of pyruvate ophthalmic drops in naphthalene-treated albino rats and the in vivo corneal pyruvate penetration in albino rabbits. The anticataract effect of topical pyruvate was evaluated in comparison with placebo eye drops in albino rats treated with naphthalene for three weeks. The levels of reduced glutathione [GSH], malondialdehyde [MDA] and insoluble protein fraction were measured in rat lenses of both groups. Also, pyruvate level was measured in aqueous humor after single ocular instillation in albino rabbits. Reduced glutathione, malondialdehyde and insoluble lens protein fraction were maintained in pyruvate-treated group, while they were significantly changed from normal values in the placebo-treated group. In ocular kinetic studies in rabbits, basal aqueous pyruvate level was 500 +/- 40 microM and increased to 1400 +/- 100 microM after ophthalmic application of a single drop of pyruvate 10% solution. Maintenance of GSH, MDA and insoluble protein fraction indicate the anticataract effect of topical pyruvate drops in naphthalene-treated rats. Also, significant concentration of pyruvate achieved in aqueous humor indicate good corneal penetrability of pyruvate and high ocular bioavailability: