Publications (15) View all
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Article: Rutin ameliorates free radical mediated cataract by enhancing the chaperone activity of α-crystallin.
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ABSTRACT: BACKGROUND: Cataract, the leading cause of blindness, is associated with oxidative damage and protein modification in the lens. The present study was carried out to assess the efficacy of rutin on rat-lens crystallins in selenite-induced in-vivo cataract models. METHODS: Eight-day-old Sprague-Dawley rat pups were grouped as control (G I), experimental (G II) and rutin-treated (G III). The rat pups in G II, and G III received a single subcutaneous injection of sodium selenite (4 μg/g body weight) and G I received a single subcutaneous injection of sterile water on the 10th day. The treatment groups (G III) were administered with rutin (1 μg/g body weight) respectively from the 8th to 15th day. Cataract was visualized from the 16th day. Lens crystallins (α, β, and γ) were isolated by size exclusion chromatography. Chaperone activity of isolated crystallins was measured by heat, DTT, and oxidation-induced aggregation and refolding assays. Concentration of total protein (soluble and insoluble) and SDS-PAGE analysis of soluble proteins were also done. RESULTS: Treatment with rutin prevented the loss of α crystallin chaperone property, and protein insolubilization prevailed during selenite-induced cataract. CONCLUSIONS: These results suggest the therapeutic potential of rutin, a bioflavonoid, against selenite-induced cataract, which has been reported in this paper for the first time. The work assumes significance, as this is a novel approach in modulating the chaperone activity of lens crystallins in selenite-induced cataract by a natural product.Albrecht von Graæes Archiv für Ophthalmologie 02/2013; · 2.17 Impact Factor -
Article: Prevention of selenite induced oxidative stress and cataractogenesis by luteolin isolated from Vitex negundo.
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ABSTRACT: Free radical mediated oxidative stress plays a crucial role in the pathogenesis of cataract and the present study was to determine the efficacy of luteolin in preventing selenite induced oxidative stress and cataractogenesis in vitro. Luteolin is a bioactive flavonoid, isolated and characterized from the leaves of Vitex negundo. Lenses were extracted from Sprague-Dawley strain rats and were organ cultured in DMEM medium. They were divided into three groups with eight lenses in each group as follows: lenses cultured in normal medium (G I), supplemented with 0.1mM sodium selenite (G II) and sodium selenite and 2 μg/ml luteolin (G III). 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 various parameters were studied. The antioxidant potential of luteolin was assessed by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity. In the selenite induced group, morphological examination of the lenses showed dense cortical opacification and vacuolization. Biochemical examinations revealed a significant decrease in activities of antioxidant enzymes and enzymes of the glutathione system. Additionally decreased glutathione level and increased reactive oxygen species (ROS) and thiobarbituric acid reactive substances (TBARS) were observed. Luteolin treatment abated selenite induced oxidative stress and cataractogenesis by maintaining antioxidant status, reducing ROS generation and lipid peroxidation in the lens. These finding demonstrated the anticataractogenic effect of luteolin by virtue of its antioxidant property, which has been reported in this paper for the first time.Chemico-biological interactions 02/2012; 196(1-2):30-8. · 2.46 Impact Factor -
Article: Amelioration of selenite toxicity and cataractogenesis in cultured rat lenses by Vitex negundo.
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ABSTRACT: 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. 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 μg/ml quercetin (G III) and sodium selenite + 50 μg/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. 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. 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.Albrecht von Graæes Archiv für Ophthalmologie 01/2011; 249(5):685-92. · 2.17 Impact Factor -
Article: Analysis on the alterations of lens proteins by Vitex negundo in selenite cataract models.
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ABSTRACT: Cataract is the leading cause of blindness and is associated with oxidative damage and protein modification in the lens. In the present study, we have employed proteomic and microscopic approaches to investigate the attenuation of selenite cataract by the flavonoids from Vitex negundo (FVN). To demonstrate this attenuation, Sprague-Dawley rat pups were divided into control (G I), selenite induced (G II), and selenite + FVN treated (G III). Cataract was induced by single subcutaneous injection of sodium selenite (4 mg/Kg bodyweight) on the 10th day and FVN (1 mg/Kg bodyweight) administered intraperitoneally from the 8th to the 15th day. Our study indicated that chaperone property of α-crystallin and soluble protein levels were reduced in the selenite induced group. Post translational modifications identified by two dimensional-polyacrylamide gel electrophoresis (2D-PAGE) and immunoblot analysis revealed the loss of cytoskeletal proteins in selenite induced group. Damage of lenticular membrane and abnormal fiber structure were observed by electron microscopy. The results of this study suggest that FVN modulated selenite induced cataractogensis in rat pups by preventing loss of chaperone property, various changes in lens proteins, and lens structure, further strengthening its protective role.Molecular vision 01/2011; 17:1239-48. · 2.20 Impact Factor -
Article: Isorhamnetin-3-glucoside alleviates oxidative stress and opacification in selenite cataract in vitro.
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ABSTRACT: Oxidative stress has long been recognized as an important mediator in the pathogenesis of cataract and the goal of this study was to determine the efficacy of isorhamnetin-3-glucoside (IR3G) in alleviating the toxicity induced by sodium selenite in in vitro culture condition. IR3G is the bioactive flavonoid isolated and characterized from the leaves of Cochlospermum religiosum. Enucleated rat lenses were maintained in organ culture containing M-199 medium alone (G-I), supplemented with 0.1 mM selenite (G-II) and selenite + 25 microg/ml IR3G (G-III). Treatment to G-III was from the second to fifth day while selenite administration to G-II & III was done on the third day. The antioxidant potential of the compound was assessed by Cu(2+) induced lipoprotein diene formation and superoxide scavenging assays. Morphological examination of the lenses also gave a supporting data. Antioxidant enzymes-superoxide dismutase (SOD), catalase and concentration of reduced glutathione (GSH) were significantly lower, while TBARS showed an increase in G-II than that in G-III and G-I lenses. Activity of Ca(2+)-ATPase was decreased and level of calcium was increased in G-II than G-III and G-I lenses. These data suggest that IR3G is able to significantly retard selenite cataract in vitro by virtue of its antioxidant property.Toxicology in Vitro 09/2010; 24(6):1662-9. · 2.78 Impact Factor
