Abstract
PURPOSE: The objective of the investigation was to study possible inhibition of oxidative stress and cataract formation by caffeine in vivo. METHODS: Oxidative stress and consequent cataract formation was induced by intraperitoneal administration of a single dose of sodium selenite (1.16 μmol) to Sprague-Dawley rat pups on day 9 postnatally. In experiments designed to inhibit such cataract formation, the pups were pretreated intraperitoneally with caffeine (5.15 μmol), starting 2 days prior to the administration of selenite and continuing such treatment till day 21, when the experiments were terminated. The extent of tissue damage caused by the selenite was assessed biochemically by measurements of the levels of GSH and ATP in the isolated lenses. Cataract formation and its prevention were monitored by examining the eye with pen light illumination and subsequent photography of the isolated lenses. RESULTS: Injection of selenite led to a significant loss of lens clarity because of cataract formation. In the group treated with caffeine, the formation of cataract was significantly prevented. In the caffeine-untreated group, the levels of lens GSH and ATP were substantially lower than in the caffeine-treated group. The levels of GSH decreased from a value of ∼8.2 μmol to ∼2 μmol/g wet weight of the lens. The content of ATP decreased from ∼2.5 μmol to about ∼ 1 μmol. In the case of caffeine-treated group, these decreases were significantly prevented from taking place, the corresponding values of GSH and ATP being ∼5.8 and ∼1.6 μmol/g, respectively. CONCLUSION: Over all, the results suggest that caffeine can exert a significant preventive effect against cataract formation induced by agents generating reactive oxygen species such as sodium selenite.