http://nopr.niscair.res.in/handle/123456789/7458 Search the Channel search http://nopr.niscair.res.in/simple-search http://nopr.niscair.res.in/handle/123456789/10864 Title: Induction of oxidative stress and histopathological changes by sub-chronic doses of triazophos <br/> <br/>Authors: Jain, Smita; Mythily, S; Ahmed, Rafat S; Arora, Vinod K; Banerjee, B D <br/> <br/>Abstract: The effect of triazophos (O, O-diethyl O-1-phenyl-1 H-1, 2, 4-triazol-3-yl phosphorothioate), a widely used insecticide was studied on the induction of oxidative stress and histological alterations at sub-chronic doses in male albino rats. Oral administration of triazophos at concentrations of 1.64, 3.2 and 8.2 mg/kg body wt for 30 days produced dose as well as time-dependent increase in the lipid peroxidation (determined by malondialdehyde levels) and glutathione-S-transferase (GST) activity in serum with a concomitant decrease in ferric reducing ability of plasma (FRAP) and blood glutathione (GSH) content. Histopathological examination of liver of triazophos-treated rats showed significant and progressive degenerative changes as compared to control, which could be due to induction of oxidative stress. However, no significant histopathological changes were observed in spleen, kidney and brain at either dose of triazophos with respect to control. These results indicated that oral administration of triazophos was associated with enhanced lipid peroxidation and compromised antioxidant defence in rats in dose and time-dependent manner. Thus the present study demonstrated for the first time the role of oxidative stress as the important mechanism involved in the stimulation of hepatic histo-architectural alterations at sub-chronic doses of triazophos in rats. <br/> <br/>Page(s): 388-392 Sun, 28 Nov 2010 22:58:59 GMT http://nopr.niscair.res.in/handle/123456789/10863 Title: Cadmium-induced oxidative stress in <i>Saccharomyces cerevisiae</i> <br/> <br/>Authors: Muthukumar, Kannan; Nachiappan, Vasanthi <br/> <br/>Abstract: The present study was undertaken to determine the effect of cadmium (Cd) on the antioxidant status of the yeast<i style=""> Saccharomyces cerevisiae</i>. <i style="">S. cerevisiae</i> serves as a good eukaryotic model system for the study of the molecular mechanisms of oxidative stress. We investigated the adaptative response of <i style="">S. cerevisiae</i> exposed to Cd. Yeast cells could tolerate up to 100 μM Cd and an inhibition in the growth and viability was observed. Exposure of yeast cells to Cd showed an increase in malondialdehyde and glutathione. The activities of catalase, superoxide dismutase and glutathione peroxidase were also high in Cd-exposed cells. The incorporation of Cd led to significant increase in iron, zinc and inversely the calcium, copper levels were reduced. The results suggest that antioxidants were increased and are involved in the protection against macromolecular damage during oxidative stress; presumably, these enzymes are essential for counteracting the pro-oxidant effects of Cd. <br/> <br/>Page(s): 383-387 Sun, 28 Nov 2010 22:58:59 GMT http://nopr.niscair.res.in/handle/123456789/10862 Title: Effect of exogenous H₂O₂ on antioxidant enzymes of <i>Brassica juncea</i> L. seedlings in relation to 24-epibrassinolide under chilling stress <br/> <br/>Authors: Kumar, Manish; Sirhindi, Geetika; Bhardwaj, Renu; Kumar, Sandeep; Jain, Gagandeep <br/> <br/>Abstract: Hydrogen peroxide is most stable molecule among reactive oxygen species, which play a vital role in growth and development of plant as signaling molecule at low concentration in response to various abiotic and biotic stresses. Exogenous application of H₂O₂ is known to induce chilling tolerance in plants. Brassinosteroids are plant steroid hormones known for their anti-stress properties. In this study, effect of exogenous H₂O₂ on antioxidant defense system of <i>Brassica juncea</i> L. seedlings was investigated in 24-epibrassinolide (24-EBL) treated and untreated seedlings under chilling stress. The surface sterilized seeds of <i>B. juncea</i> L. were germinated in petriplates containing different concentrations of H₂O₂ alone and in combination with 10^-8M 24-EBL. Chilling treatment (4 ºC) was given to 10-days old seedlings grown in different treatments for 6 h daily up to 3 days. 24 h recovery period was given to chilling treated seedlings by placing at 25ºC ± 2ºC and harvested for antioxidant enzymes on 14^th day after sowing (DAS). Treatment of 24-EBL in combination with H₂O₂ (15 and 20 mM) helped in reducing the toxicity of seed and seedlings due to H₂O₂ exposure on their germination rate, shoot and root length respectively. 24-EBL treatment at seed and seedling stage helped in alleviating the toxic effect of H₂O₂ through antioxidant defense system by increasing the activities of various enzymes involved in antioxidant defense system such as catalase (CAT, E.C. 1.11.1.6), ascorbate peroxidase (APOX, E.C. 1.11.1.11), and superoxide dismutase (SOD, E.C. 1.15.1.1). In conclusion, exogenous pretreatment of H₂O₂ to seeds of <i>B. juncea </i>L. adapted the seedlings to tolerate chilling stress, which was further ameliorated in combination of H₂O₂ with 24-EBL. <br/> <br/>Page(s): 378-382 Sun, 28 Nov 2010 22:58:59 GMT http://nopr.niscair.res.in/handle/123456789/10861 Title: Assessing the relationship among physicochemical properties of proteins with respect to hydrophobicity: A case study on AGC kinase superfamily <br/> <br/>Authors: Banerjee, Amit Kumar; Manasa, B Poorna; Murty, Upadhyayula Suryanarayana <br/> <br/>Abstract: Understanding the protein structures is crucial, as it is involved in every cellular activity. Several experimental techniques, such as X-Ray crystallography, nuclear magnetic resonance and electron microscopy are available to gain insight about the structure and function of a protein molecule. Gigantic data on protein structural and sequential information is deposited in various repositories regularly which provide us the scope for more theoretical studies. Hydrophobicity always plays a vital role in tertiary structure formation and behavior of a protein molecule. This study focuses on elucidating influence of several physicochemical properties on hydrophobicity of AGC kinase proteins. AGC kinase superfamily is selected due to its tremendous structural and functional variability and sequence data availability. A combined data mining and stochastic approach confirmed that out of 47 parameters, transmembrane tendency influences the target variable most, followed by percent buried residues, GRAVY (Grand Average Hydropathicity) and aliphatic index. Calculating the influence of different physicochemical parameters and their interrelation will aid tremendously in the future of protein science. <br/> <br/>Page(s): 370-377 Sun, 28 Nov 2010 22:58:59 GMT