Amelioration of selenite toxicity and cataractogenesis in cultured rat lenses by Vitex negundo.

摘要

PURPOSE: Recent evidence suggests that oxidative stress plays a significant role in the development of cataract. The present study sought to evaluate the efficacy of flavonoid fraction of Vitex negundo (FVN) in preventing the toxicity induced by sodium selenite in vitro culture condition. METHODS: Enucleated rat lenses were maintained in organ culture containing DMEM medium alone (G I), supplemented with 0.1mM sodium selenite (G II), sodium selenite + 20 mug/ml quercetin (G III) and sodium selenite + 50 mug/ml FVN (G IV). Treatment was from the second to fifth day, while selenite administration was done on the third day. After the experimental period, lenses were taken out and the activities of superoxide dismutase (SOD), catalase, Ca(2+) ATPase, levels of reduced glutathione (GSH), calcium, reactive oxygen species (ROS), thiobarbituric acid reactive substances (TBARS), and sulfhydryl content were studied. RESULTS: Morphological examination revealed dense vacuolization and loss of cortical transparency in G II compared to control and treated group. The mean activities of the enzymes SOD, catalase and Ca(2+) ATPase, levels of GSH and sulfhydryl content were significantly reduced in lenses of G II compared to control. In addition, the mean levels of ROS, calcium and TBARS were elevated in G II compared to control. However, these changes were modulated by FVN treatment to further strengthen its protective role over selenite cataract. CONCLUSION: These results suggest that FVN treatment prevented selenite toxicity and cataractogenesis by maintaining antioxidant status, calcium homeostasis, protecting sulfhydryl group, and decreasing oxidative stress in lens, which may be due to its protective effects.