Environmental factors which can influence on eye consist of rub eyeballs, allergic reaction, and solarization (9). An excess of environmental fac- tors, particularly UV exposure, causes oxidative damage to KC corneas because of the failure of KC corneas to process reactive oxygen species (ROS) which leads to corneal thinning and loss of vision (10). The accumulation of ROS can damage cells by reacting with proteins, DNA, and membrane phospholipids (11). The normal cor- nea’s antioxidant enzymes eliminate the ROS be- fore they damage cells; these consist of superox- ide dismutase, glutathione reductase, catalase, and glutathioneperoxidase, but in the disease condi- tion, ROS can devastate cellular defenses and promote cell damage (12).
Abstract: Glutathioneperoxidase (GPX), one of the antioxidant enzymes, exerts a vital role in reducing oxidative damage. GPX1 Pro198Leu (rs1050450) polymorphism has been reported in the development of several cancers, while the results were inconsistent. We thus conducted this meta-analysis to identify the association between GPX1 (rs1050450) polymorphism and cancer risk. 52 eligible publications with 60 case-control studies were included, with 21,296 cancer patients and 30,346 controls. The results in total population suggested there was a significant association between GPX1 (rs1050450) polymorphism and cancer susceptibility in part genetic models (TT vs CT+CC: OR = 1.15, 95% CI = 1.01-1.32, P = 0.042; TT vs CC: OR = 1.15, 95% CI = 1.00-1.31, P = 0.044; T vs C: OR = 1.09, 95% CI = 1.01-1.17, P = 0.02). The stratified analysis by cancer types suggested a positive correlation between GPX1 (rs1050450) polymorphism and the development of bladder cancer (TT+CT vs CC: OR = 1.72, 95% CI = 1.09-2.70, P = 0.019; TT vs CT+CC: OR = 3.56, 95% CI = 1.42-8.94, P = 0.007; TT vs CC: OR = 3.75, 95% CI = 1.41-9.94, P = 0.008; T vs C: OR = 1.941, 95% CI = 1.17-3.22, P = 0.01) as well as head and neck cancer (TT vs CT+CC: OR = 2.19, 95% CI = 1.39-3.46, P = 0.001) and brain cancer (TT+CT vs CC: OR = 1.19, 95% CI = 1.03-1.37, P = 0.018). These results support that GPX1 (rs1050450) polymorphism might be a candidate marker for cancer risk with type-specific effects.
FIGURE 4. G418 increases rGPx-1 but decreases rGPx-1 activity. Recombinant protein was isolated from permanently transfected cells grown in medium with 2% FCS with the addition of selenium (10 ng/ml) and/or G418 (200 g/ml). His-tagged rGPx-1 was isolated using nickel-magnetic beads. Samples were analyzed by Western blot with the mouse anti-human GPx-1 antibody and by in-gel enzyme activity assays.A, Western blot of rGPx-1 iso- lated from cells treated with G418 and those not treated (NT). Various amounts of commercially avail- able human GPx-1 were used as controls on the gel. HPAEC indicates samples from human pulmonary arterial endothelial cells. B, reversed image of an in- gel GPx-1 assay using the same rGPx-1 samples used forA. Commercially available bovine GPx-1 was used as standards for the in-gel assay. Samples were run on SDS/PAGE gel without heat denaturation to pre- serve the active form of the enzyme. C, the in-gel assay is specific for GPx-1 activity. Mercaptosucci- nate (MSA), a GPx-1 inhibitor, blocks the formation of the achromatic bands. Albumin (1 g) was used as a nonspecific protein. D, Western blot or rGPx-1 from cells treated with G418 or selenium. Heat denatur- ation reduces the rGPx-1 to the monomeric form. Most of the rGPx-1 is in the active tetrameric form (non-heated sample).
The aim of the paper was the study of retabolil, compound LES-2222 and testosterone propionate influence on the activity of catalase (CAT) (EC 220.127.116.11) and glutathioneperoxidase (GPO) (EC 18.104.22.168) in the different tissues under food deprivation in rats (Compound LES-2222 – thiopyrano[2,3-d]thiazole derivative (2-(2-Oxo- 5a,11b-dihydro-5H,6H-7-oxa-1,4-dithia - 3 - aza- cyclopenta[c]phenanthren-3-yl) - N- (3 - trifluoro methyl-phenyl)-acetamide) was synthesized at the Department of Pharmaceutical, Organic and Bioorganic Chemistry, Danylo Halytsky Lviv National Medical University). 12-14
Flavonoids from Dolichos biflorus Linn. were isolated and screened for antioxidant activity on rabbits fed high fat diet (HFD). Methanolic extract of Dolichos biflorus was fractionated with hexane, chloroform, ethylacetate and methanol. Ethylacetate fraction which showed maximum flavonoid yield, were fractionated by column chromatography and estimated for flavonoids (total phenol) content. High fat diet rabbits showed significant decreased activities of tissue enzymatic and non enzymatic antioxidant. High fat diet induces the oxidative stress in cell by producing reactive oxygen species. Antioxidant Enzymes such as Superoxide dismutase, Catalase, Glutathioneperoxidase, Glutathione-s-transferase, and non enzymatic antioxidant Glutathione showed enhanced activities on administration of isolated flavonoids from Dolichos biflorus in high fat diet rabbits. Hence it is concluded that flavonoids isolated from Dolichos biflorus were found to have protective action against high fat diet induced oxidative stress in different tissues in rabbits.
All three strains of laboratory rats used in this study reacted on the injection of Cd, but not on the exposition to Cd in water. Ognjanovic et al. (2003) observed increased activity of antioxidant defense enzymes: copper zinc containing superoxide dismutase, catalase, glutathioneperoxidase, gluta- thione reductase, and glutathione S-transferase as a response of male Wistar rats to acute exposure to Cd (0.4 mg Cd/kg of body mass). For glutathione reductase activity, the increase has been observed with the increase of applied Cd concentration for all three strains, in agreement with the literature (Ognjanovic et al. 2003; Flora et al. 2008). In the case of GST activity, a more complex dependence was observed. This could be explained by differ- ent function of these enzymes. In GST measure- ment, strain LE appeared as the most sensitive to Cd exposition – the increase of GST activity was significant already after the intraperitoneal ap- plication of 0.6 mg per 100 g body weight.
(OH). These oxidants can cause oxidation of sulphydryl groups in membrane protein, crystallins and as those of enzymes. Protein precipitation due to the formation of high molecular weight (HMW) aggregates is as a result of oxidation of crystallins. There are no proven and reputable results showing the sequesnce of different oxidative modifications in the lens. However the lens contains several protective mechanisms against oxidizing agents. These include glutathione reductase glutathioneperoxidase, catalase, superoxide dismutase, and ascorbic acid.
The implication of these results is that the process of lipid peroxidation, i.e. the oxidative deterioration of polyunsaturated fatty acids, which usually result in the formation of hydroperoxides, short-chain aldehydes, ketones, and other oxygenated molecules may be a common occurrence in many human subjects who are constantly exposed to even trace quantities of kerosene. That is a process that has been highlighted through results obtained from numerous studies as being responsible for the development of a number of diseases; examples being atherosclerosis,  diabetes,  cancer  and may be one of the main contributing factors in aging.  Moreover, free radical-mediated lipid peroxidation has been identified as being a critical event that is involved in disease states such as brain dysfunction, cardiovascular disease, and cancer as well as in the degenerative processes associated with aging. Enzymatic antioxidants such as superoxide dismutase and glutathioneperoxidase protect cell membranes from lipid peroxidation.  Furthermore, Voss and Siems  have linked an imbalance between free radical generation and the defense system in the pathogenesis of not only atherosclerosis and diabetes
ABSTRACT: In the present study, the effects of sub-lethal sub-chronic doses of ibuprofen, diclofenac, and car- bamazepine alone, and in combination (concentration range 0.02–60 µg/l), on the early life stages of tench (Tinca tinca) were investigated. The lower concentrations of pharmaceuticals tested (0.02, 0.2, 2 µg/l) represent the concentration values of these substances commonly present in surface waters or effluents from wastewater treat- ment plants. Multiple biomarkers of biotransformation, antioxidant defence systems, and lipid peroxidation were determined in fish after 35 days of exposure. The evaluated pharmaceuticals induced oxidative stress in fish both alone and in combination with each other. Generally, 60 µg/l of each single pharmaceutical influenced the activity of antioxidant enzymes significantly (P < 0.05), whereas the same concentration of these pharmaceuticals in combi- nation (1 : 1 : 1) did not have any impact on the activity of these enzymes. However, changes in biotransformation and antioxidant enzymes were apparent if lower concentrations of these pharmaceuticals were administered in the mixture. Significant changes (P < 0.05) in the activities of glutathione reductase, glutathioneperoxidase, and glutathione-S-transferase were observed even at environmental concentration ranges. A significant effect (P < 0.05) on lipid peroxidation levels was found only in the experimental group exposed to carbamazepine.
After three weeks of extract administration rats were anesthetized and blood samples were collected by sino-orbital puncture. Serum separated was used for all biochemical estimations.Animals were autopsied and liver was excised carefully and washed in saline.Tissue homogenate was prepared in 0.1M Tris-HCl buffer( pH 7.4) and used for the determination of lipid peroxides (LPO), reduced glutathione (GSH), glutathioneperoxidase(GPx),glutathione S-tranferase (GST), catalase (CAT) and superoxide dismutase(SOD).
ABSTRACT: The present study was to investigate the antioxidant activity of aqueous bark extract of Spondias pinnata (Linn. f.) Kurz (Family: Anacardiaceae) in streptozotocin-induced diabetic rats. The antioxidant activity was evaluated by the activities of liver enzymes, antioxidant enzymes, and the extent of lipid peroxidation (LPO) in the liver of streptozotocin (STZ) -diabetic rats. S. pinnata extract decreased the LPO by 17%, activities of alanine aminotransferase, aspartate aminotransferase, and alkaline phosphatase decreased by 20%, 17% and 36% respectively (P<0.05). The liver reduced glutathione, activities of glutathione reductase, glutathioneperoxidase, and glutathione S-transferase of plant extract treated diabetic rats were increased by 43%, 44%, 69% and 52% respectively (P<0.05). The light microscopic appearance of the liver tissue in S. pinnata treated rats has corroborated the biochemical results. The present investigation revealed that the bark extract of S. pinnata exerts significant in-vivo antioxidant activities in diabetic rats.
Oxidative stress–an imbalance between the generation of reactive oxygen species (ROS) and the compensatory re- sponse from the endogenous antioxidant network, has been demonstrated to play a pivotal role in diabetic vascu- lar complications . Therefore, it has been proposed that scavengers of oxidative stress may have a positive ef- fect in alleviating diabetes as well as reduce its secondary complications. Antioxidants like superoxide dismutase (SOD), catalase (CAT), glutathioneperoxidase (GPX) and reduced glutathione (GSH) effectively forms a defensive alliance against the onslaught of ROS protecting cells from oxidative damage. Reports have shown variation in the ac- tivities of antioxidant enzymes in diabetic rats. Although reductions of enzyme activities have been reported, some studies also demonstrated an increase and no change in enzyme activities. Possible reasons for the contradictory reports are variation in disease severity, duration, tissue specificity or other experimental conditions .
Both glutathioneperoxidase-overexpressing and knock-out mice have been studied in the context of focal cerebral ischemia/reperfusion. Overexpression reduces necrotic and apoptotic cell death, astrocytic/microglial activation and inflammatory cell infiltration (Ishibashi et al., 2002; Weisbrot- Lefkowitz et al., 1998). In contrast, intracerebroventricular infusion of exogenous glutathioneperoxidase failed to improve outcome from global forebrain ischemia/reperfusion (Yano et al., 1998). This difference might be attributable to differences in model type (focal versus global) or intracellular bioavailability of glutathioneperoxidase when administered intracerebroventricularly. The progeny of cross-breeding a glutathioneperoxidase knock-out and a Cu,Zn-SOD overexpressor caused a loss of protection that was otherwise afforded by overexpression of Cu,Zn-SOD (Crack et al., 2001). However, the glutathioneperoxidase knockout alone was insufficient to worsen cerebral ischemia/reperfusion injury (Crack et al., 2001), consistent with overlap in function with catalase. Cumulatively, these data implicate an important role for glutathioneperoxidase in brain ischemia/reperfusion, although the relative contributions of glutathioneperoxidase and catalase have not been clarified.
Medicinal and Aromatic plants, a gift of nature produce a diverse array of primary and secondary metabolites known as phytochemicals that have antioxidant properties. Hence the present study is aimed at investigating the Antioxidant potential and phytochemical screening in Ocimum americanum. The powdered plant sample of Ocimum americanum was extracted with various buffers and the extracts were analysed for the enzymatic and nonenzymatic antioxidants. The Ocimum americanum was found to exhibit all the enzymatic antioxidants like catalase, peroxidase, superoxide dismutase, glutathioneperoxidase, and polyphenol oxidase and nonenzymatic antioxidants like ascorbic acid, α-tocopherol, reduced glutathione and polyphenol. Phytochemical screening of aqueous and ethanolic extract of the leaves of Ocimum americanum was carried out. The present study reveals that the leaf part of Ocimum americanum appears to be a good source of antioxidants and phytochemicals.
A major cellular mechanism to reduce oxidative stress is via the nuclear factor E2-related factor 2 (Nrf2)-anti- oxidant response element (ARE) signaling pathway. Nrf2 is a transcription factor that regulates the expression of genes coding for antioxidant, anti-inflammatory, and de- toxifying proteins [9, 10]. In the absence of stress condi- tions, Nrf2 localizes in the cytoplasm where it interacts with the actin-binding protein, Kelch-like ECH- associated protein 1 (Keap1), leading to its ubiquitina- tion and proteasomal degradation . On the other hand, when signals from ROS target the Nrf2-Keap1 complex, Nrf2 dissociates from Keap1 and translocates into the nucleus inducing transcription of a wide range of proteins, such as heme oxygenase-1 (HO-1), super- oxide dismutase-1 (SOD-1), glutathioneperoxidase-1 (GPx1), and catalase (CAT), that play an important role in protecting cells against oxidative stress-induced dam- age [12–14]. In addition to its involvement in antioxi- dant and detoxifying responses, Nrf2 also plays an important role in inflammation. Recent studies have shown crosstalk between Nrf2 and nuclear factor-κB (NF-κB) signaling pathways under stress . NF-κB is an inflammatory transcription factor that, when translo- cated to the nucleus, initiates the transcription of proin- flammatory molecules including cytokines (IL-1, IL-6, TNF-α), cyclooxygenase-2 (COX-2), and others . It can be activated by oxidative stress or inhibited by the presence of antioxidant agents. Specifically, the activa- tion of Nrf2 prevents the overproduction of proinflam- matory mediators, whereas its inhibition is associated with enhanced expression of NF-ĸB [17–19]. Overall, the aforementioned findings indicate that the interaction between these two pathways is closely related to the oxi- dative/inflammatory state of the cell and thus to its survival.
degenerative diseases , thus natural antioxidants, flavo- noids and phenolic compounds have gained considerable attention. Structurally, phenolic compounds contain a con- jugated ring with a hydroxyl group, and can act as an anti- oxidant by preventing free radical-mediated diseases. Plant antioxidant capacity is characterized by quenching free rad- icals such as lipid peroxy radicals, singlet oxygen and super- oxide anions . Combinatorial methods are required to explore the antioxidant tendency of natural resources be- cause no single assay can reflect all antioxidants in a mixed assay or the complex nature of phytochemicals. Adedapo et al.  reported the scavenging abilities of plant extracts against free radicals in a complex assay system to eradicate the radical-related pathological diseases. Toxic compounds of drugs and xenobiotics are metabolized by the gluta- thione system (reduced glutathione, glutathione reductase, glutathioneperoxidase and glutathione-S-transferase). Ad- ministration of C. opaca reduced CCl 4 toxicity, thereby in-
hydrogenase (LD), and glutathioneperoxidase (GSH-px) at the end of the experiment in comparison with the initial values (Table 1). However, the initial value of calcium con- centration was significantly higher in comparison with the values in the control and Cremophor group. The activity of LD was significantly higher at the end of the experi- ment even in comparison with the control and Cremophor groups. The administration of Cremophor induced the same changes in LD, phosphate, and Fe; in addition, a de- crease in potassium and albumin concentrations could be observed at the end of the experiment. In the control group, an increase in sodium and GSH and a decrease in urea and phosphates were apparent. These changes were statistically significant only in comparison with the corresponding ini- tial values. The other observed changes were only transient without any permanent trends.
concentration and purity were determined from OD260/ 280 readings (ratio > 1.8) using a NanoDrop ND-1000 UV spectrophotometer (NanoDrop Technologies, Wilmington, DE, USA). After determining the RNA concentration, 1 μg of total RNA was reverse-transcribed into cDNA using PrimeScript™ RT Reagent Kit (TaKaRa Biotechnology, Dalian, Liaoning, China) according to the manufacturer’s guidelines. Real-time PCR was performed on an ABI StepOnePlus™ Real-Time PCR System (Applied Biosystems, Grand Island, NY, USA) according to the manufac- turer’s instructions. The primers were designed using the Primer-Blast (http://www.ncbi.nlm.nih.gov). The pri- mer sequences for the target and reference genes (copper- and zinc-containing superoxide dismutase (Cu/Zn-SOD), manganese-containing superoxide dismutase (Mn-SOD), glutathioneperoxidase1 (GPX1), thioredoxin (TXN), thioredoxin 2 (TXN2) and β-actin) are given in Table 2. Briefly, the reaction mixture was prepared using 2 μL of cDNA (50 μg/mL), 0.4 μL of forward primer (20 μmol/L), 0.4 μL of reverse primer (20 μmol/L), 10 μL of SYBR Premix Ex Taq™ (TaKaRa Biotechnology, Dalian, Liaoning, China), 0.4 μL of ROX Reference Dye (TaKaRa Biotech- nology, Dalian, Liaoning, China) and 6.8 μL of double- distilled water. Each sample was tested in duplicate. RT- qPCR consisted of a pre-run at 95 °C for 30 s and 40 cycles of denaturation at 95 °C for 5 s, followed by a 60 °C annealing step for 30 s. The conditions of the melting curve analysis were as follows: one cycle of denaturation at 95 °C for 10 s, followed by an increase in temperature from 65 °C to 95 °C at a rate of 0.5 °C/s. The relative levels of mRNA expression were calculated using the 2 -ΔΔC T method , in which the β-actin gene was