Cloning and functional analysis of glutathione peroxidase gene in red swamp crayfish Procambarus clarkii

Effects of ferritin heavy chain on oxidative stress, cell proliferation and apoptosis in geese follicular granulosa cells

1. The ferritin heavy chain (FHC) has a vital impact on follicular development in geese, due to its ability to regulate apoptosis of granulosa cells (GCs) and follicular atresia. However, its specific regulatory mechanisms remain unclear. The present study characterised how FHC regulates oxidative stress, cell proliferation and apoptosis in goose GCs by interfering with and overexpressing the FHC gene.2. After 72 h of interference with FHC expression, the activity of GCs decreased remarkably (p < 0.05), reactive oxygen species (ROS) levels and the expression levels of antioxidant enzyme genes catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) increased significantly (p < 0.05). The overexpression of FHC for 72 h was found to significantly reduce the expression of CAT and SOD genes (p < 0.05).3. Interfering with FHC expression revealed that the expression levels of the cell proliferation gene Aurora kinase A (AURORA-A) were significantly decreased (p < 0.05), while the expression levels of the apoptosis genes B-cell lymphoma-2 (BCL-2) and cysteine aspartate-specific protease 8 (CASPASE 8) increased (p < 0.05). Further research has shown that, when interfering with FHC expression for 72 h, apoptosis rate increased by 1.19-fold (p < 0.05), but the current data showed a lower apoptosis rate after FHC overexpression by 59.41%, 63.39%, and 52.31% at three different treatment times (p < 0.05).4. In conclusion, FHC improved the antioxidant capacity of GCs, promotes GCs proliferation, and inhibits GCs apoptosis of ovarian follicles in Sichuan white geese.

Antioxidation, immunity and hepatopancreatic histology of red swamp crayfish (Procambarus clarkii) subjected to low-temperature aerial exposure stress and re-immersion

Desiccation is a stressful situation that decapods often experience during live transportation. This study investigated the effects of low-temperature aerial exposures (LTAEs) (dry exposure (DL) and moist exposure (ML) at 6 °C) and re-immersion on the antioxidative and immune responses and hepatopancreatic histopathology in P. clarkii. Compared to the control group (normally feeding at 24.0 °C water temperature), the crayfish under LTAEs showed overall severe hepatopancreatic oxidative damage, with significantly increased malondialdehyde (MDA) contents and significantly reduced total antioxidant capacity (T-AOC), and oxidant damage was not fully recovered even after 12 h of re-immersion; the expression of hsp70 was significantly increased within 24-48 h of stress and re-immersion. The activity of hemolymphatic acid phosphatase (ACP) was significantly increased during 24-48 h of the stress and at 12 h of re-immersion; the activity of aspartic aminotransferase (AST) and alanine aminotransferase (ALT) was significantly increased throughout the experiment; and the gene expression of proPO or TLR was significantly increased during 12-48 h of the stress. Severe histopathological changes (lumen dilatation, vacuolation of epithelial cells and reduced cell numbers) were observed in hepatopancreas at 48 h of stress and 12 h of re-immersion. These results indicated that 48 h of low-temperature aerial exposure stress stimulated the non-specific immunity but adversely affected the antioxidation and hepatopancreatic histomorphology of P. clarkii, whereas 12 h of re-immersion was not sufficient to restore crayfish from stress to a normal state.

Immobilization of Superoxide Dismutase in Mesoporous Silica and its Applications in Strengthening the Lifespan and Healthspan of Caenorhabditis elegans

Senescence is a major inductive factor of aging-related diseases in connection with an accumulation of reactive oxygen species (ROS). Therefore, it is important to maintain ROS at an appropriate level to keep homeostasis in organisms. Superoxide dismutase (SOD) is a vital enzyme in defending against oxidative damage in vivo. Because of the defects in the direct application of SOD and SOD mimics, mounting delivery systems have been developed for the efficient applications of SOD to realize antioxidant treatment. Among these systems, mesoporous silica nanoparticles (MSNs) have been widely studied because of various advantages such as desirable stability, low toxicity, and adjustable particle sizes. Herein, SOD was immobilized on MSNs using a physical absorption strategy to construct the nanosystem SOD@MSN. The nematode Caenorhabditis elegans (C. elegans) was selected as the model organism for the subsequent antioxidant and anti-aging studies. The research results suggested the nanosystem could not only be effectively internalized by C. elegans but could also protect the nematode against external stress, thus extending the lifespan and healthspan of C. elegans. Therefore, SOD@MSN could be applied as a promising medicine in anti-aging therapeutics.

cDNA Characterization and Expression of Selenium-Dependent CqGPx3 Isoforms in the Crayfish Cherax quadricarinatus under High Temperature and Hypoxia

Glutathione peroxidase 3 (GPx3) is the only extracellular selenoprotein (Sel) that enzymatically reduces H2O2 to H2O and O2. Two GPx3 (CqGPx3) cDNAs were characterized from crayfish Cherax quadricarinatus. The nerve cord CqGPx3a isoform encodes for a preprotein containing an N-terminal signal peptide of 32 amino acid residues, with the mature Sel region of 192 residues and a dispensable phosphorylation domain of 36 residues. In contrast, the pereiopods CqGPx3b codes for a precursor protein with 19 residues in the N-terminal signal peptide, then the mature 184 amino acid residues protein and finally a Pro-rich peptide of 42 residues. CqGPx3 are expressed in cerebral ganglia, pereiopods and nerve cord. CqGPx3a is expressed mainly in cerebral ganglia, antennulae and nerve cord, while CqGPx3b was detected mainly in pereiopods. CqGPx3a expression increases with high temperature and hypoxia; meanwhile, CqGPx3b is not affected. We report the presence and differential expression of GPx3 isoforms in crustacean tissues in normal conditions and under stress for high temperature and hypoxia. The two isoforms are tissue specific and condition specific, which could indicate an important role of CqGPx3a in the central nervous system and CqGPx3b in exposed tissues, both involved in different responses to environmental stressors.

Going Forward and Back: The Complex Evolutionary History of the GPx

Simple Summary

Glutathione peroxidases (GPxs) are considered as one of the main antioxidant enzymes, which reduce peroxides into less toxic compounds. This family of enzymes is found in most eukaryotic organisms, but it is highly divergent regarding its structure, catalytic mechanism, and substrate usage. Furthermore, it is still unclear how these enzymes are dispersed in the animal kingdom. Through robust phylogenetic and sequence analyses, we show that all GPx genes originated from a common ancestor and evolved independently across different kingdoms. In Metazoa, GPx genes expanded into three main groups before the rise of bilaterian animals, and they were further expanded in vertebrates. These expansions allowed GPx enzymes to diversify, not only structurally, but also functionally. Our study contributes to the understanding of how this abundant class of antioxidant enzymes evolved. The evolution of GPxs appears to be a continuous process, leading to the diversification of their functions.

Abstract

There is large diversity among glutathione peroxidase (GPx) enzymes regarding their function, structure, presence of the highly reactive selenocysteine (SeCys) residue, substrate usage, and reducing agent preference. Moreover, most vertebrate GPxs are very distinct from non-animal GPxs, and it is still unclear if they came from a common GPx ancestor. In this study, we aimed to unveil how GPx evolved throughout different phyla. Based on our phylogenetic trees and sequence analyses, we propose that all GPx encoding genes share a monomeric common ancestor and that the SeCys amino acid was incorporated early in the evolution of the metazoan kingdom. In addition, classical GPx and the cysteine-exclusive GPx07 have been present since non-bilaterian animals, but they seem to have been lost throughout evolution in different phyla. Therefore, the birth-and-death of GPx family members (like in other oxidoreductase families) seems to be an ongoing process, occurring independently across different kingdoms and phyla.

New Galantamine Derivatives with Inhibitory Effect on Acetylcholinesterase Activity

BACKGROUND

Inhibitors of acetylcholinesterase (AChE) are used to treat many disorders, among which are neurodegenerative upsets, like Alzheimer's disease (AD). One of the limited licensed AChE inhibitors (AChEIs) used as drugs is the natural compound galantamine (Gal).

OBJECTIVE

As Gal is a toxic compound, here we expose data about its four derivatives in hybrid peptide-norgalantamine molecules, which have shown 100 times lower toxicity.

METHODS

Four newly synthesized galantamine derivatives have been involved in docking analysis made by Molegro Virtual Docker. Biological assessments were performed on ICR male mice. The change in short and long-term memory performance was evaluated by passive avoidance test. AChE activity and levels of main oxidative stress parameters: lipid peroxidation, total glutathione (GSH), enzyme activities of catalase (CAT), superoxide dismutase, and glutathione peroxidase were measured in brain homogenates.

RESULTS

Our experimental data revealed that the new hybrid molecules did not impair memory performance in healthy mice. Two of the compounds demonstrated better than Gal AChE inhibitory activity in the brain. None of them changed the level of lipid peroxidation products, one of the compounds increased GSH levels, and all of them increased CAT enzyme activity.

CONCLUSION

The new galantamine-peptide hybrids demonstrated a potential for inhibition of AChE and antioxidant activity and deserve further attention.

Ultrasonic-assisted extraction of polysaccharides from Auricularia auricula and effects of its acid hydrolysate on the biological function of Caenorhabditis elegans

The present study was designed to explore the in vivo-antioxidant capacity and the probable mechanism of AAPs-H, prepared from Auricularia auricula polysaccharides with the optimal extraction conditions by Box-Behnken design and acid hydrolysis, using Caenorhabditis elegans as a model organism. The effects of AAPs-H on the locomotion behavior, life span, antioxidant-related enzymes activities, and antioxidants levels in C. elegans were studied. Furthermore, the potentials of AAPs-H in up-regulating the expression of antioxidant-related genes in C. elegans, such as skn-1, sod-3 and sir-2.1, were also discussed. AAPs-H demonstrated a highly significant protective effect against the damage caused by paraquat, could significantly increase U-Turn frequency of worms (p < 0.01), extend their lifespan, enhance antioxidant systems including GR by 63.96% (p < 0.05), GSH-Px by 71.16% (p < 0.01), SOD by 78.65% (p < 0.01) and CAT by 98.52% (p < 0.01), increase the level of GSH by 28.12% (p < 0.05), and decrease the level of MDA by 39.29% (p < 0.01). The qRT-PCR results showed that AAPs-H could up regulate mRNA expression levels of skn-1, sod-1, sod-2, sod-3 and sir-2.1 in wild-type C. elegans (>1.6 fold) when treated with the concentration of 0.4 mg/mL (p < 0.05 or p < 0.01). Our studies provide evidence that AAPs-H improves antioxidant defense system, and up-regulation of oxidative stress related genes for prevention of stress damage in C. elegans.

The feeding of dietary Codonopsis pilosula polysaccharide enhances the immune responses, the expression of immune-related genes and the growth performance of red swamp crayfish (Procambarus clarkii)

Polysaccharides have many functions in aquatic animals and are widely used as immunopotentiators. However, despite the emergence of serious diseases, few studies have explored the effects of Codonopsis pilosula polysaccharide (CPP) on crustaceans. We studied the effects of CPP on the growth performance, nonspecific immunity, antioxidant activity and disease resistance of red swamp crayfish (Procambarus clarkii). Healthy crayfish (5.80 ± 0.1 g) were fed diets supplemented with 0% (control), 0.05%, 0.1%, 0.15%, 0.20%, and 0.30% CPP for 8 weeks. At the end of the 8-week feeding trial, the optimal final body weight (FBW), weight gain (WG), specific growth rate (SGR), and feed conversion ratio (FCR) were observed in the crayfish fed the diets with 0.15% and 0.20% CPP, followed by those fed the diet with 0.30% CPP and then those fed the diet with 0.10% CPP, whereas the values of these parameters were obtained with the control crayfish (P < 0.05). The crayfish fed the diets with 0.15% and 0.20% CPP exhibited a significantly higher total hemocyte count (THC) and significantly increased phenoloxidase (PO), lysozyme (LZM), hemocyte (Hc), acid phosphatase (ACP) and alkaline phosphatase (AKP) compared with those belonging to the other groups (P < 0.05). The crayfish fed the diets with 0.15% and 0.2% CPP exhibited significantly higher total superoxide dismutase (T-SOD) and glutathione peroxidase (GPx) activities, a significantly increased total antioxidant capacity (T-AOC) and a significantly lower malondialdehyde (MDA) content compared with the other groups (P < 0.05), which indicated that antioxidant capacity was significantly induced by the CPP-supplemented diets. Significantly upregulated expression of immune-related genes (anti-lipopolysaccharide factors (alf), peroxiredoxin (prx5), cathepsin B (ctsb), mitochondrial manganese superoxide dismutase (mtMnsod), cyclophilin A (cypa), glutathione peroxidase (gpx), Toll-like receptor 3 (tlr3), and heat shock protein 70 (hsp70)) was detected in the crayfish fed the diets supplemented with 0.15% and 0.20% CPP diet compared with the levels observed in the control crayfish. These results showed that dietary CPP supplementation greatly improved the growth, immunity and antioxidant capacities of crayfish, and according to the observed results, 0.15%-0.2% is the recommended optimal level of CPP dietary supplementation for crayfish.

Biomarkers of Planarian Dugesia japonica in Response to Herbicide Glyphosate Exposure

As the worldwide top-selling herbicide, glyphosate is ubiquitously distributed in the natural environment, and its influence on the ecological safety and human health has being increasingly concerned. In this study, mRNA expressions of GPX and three heat shock protein genes in freshwater planarian Dugesia japonica in response to glyphosate were determined, and two oxidative stress parameters were measured. The results suggested that GPX activity can be used as a more sensitive biomarker in contrast with GPX gene expression, and mRNA expressions of Hsp70, Hsp90 genes are more sensitive than Hsp40 for planarians in response to glyphosate stress. Besides, the deduced T-AOC as well as varied GPX activity and mRNA expression levels of Hsps also indicated that glyphosate exposure would inhibit antioxidation and induce oxidative stress in D. japonica, while specific antioxidant systems and stress proteins tried to protect cells by their own regulation. The results of this study will be helpful to elucidate the stress response mechanisms of freshwater planarians to herbicide glyphosate.

Effects of hesperidin on the growth performance, antioxidant capacity, immune responses and disease resistance of red swamp crayfish (Procambarus clarkii)

We evaluated the effects of hesperidin on the nonspecific immunity, antioxidant capacity and growth performance of red swamp crayfish (Procambarus clarkii). A total of 900 healthy crayfish were randomly divided into six groups: the control group (fed the basal diet) and the HES25, HES50, HES75, HES100 and HES150 groups, which were fed the basal diet supplemented with 25, 50, 75, 100 and 150 mg kg^-1 hesperidin, respectively. The feeding experiment lasted 8 weeks. The results indicated that compared with the control group, the crayfish groups supplemented with 50-150 mg kg^-1 hesperidin had a decreased feed conversion ratio (FCR) and increased final body weight (FBW), specific growth rate (SGR) and weight gain (WG) (P < 0.05). The protein carbonyl content (PCC), reactive oxygen species (ROS) level and malondialdehyde (MDA) level in the hepatopancreas and hemocytes were significantly lower, while the total antioxidant capacity (T-AOC), glutathione peroxidase (GPx) activity, and superoxide dismutase (SOD) activity were significantly higher in the crayfish groups supplemented with 50-150 mg kg^-1 hesperidin than in the control group. Supplementation with 50-150 mg kg^-1 hesperidin significantly increased the activities of acid phosphatase (ACP), alkaline phosphatase (AKP), lysozyme (LZM), and phenoloxidase (PO) compared with the control group (P < 0.05); upregulated the mRNA expression of cyclophilin A (CypA), extracellular copper-zinc superoxide dismutase (ecCuZnSOD), GPxs, crustin, astacidin, Toll3 and heat shock protein 70 (HSP70) (P < 0.05); and decreased crayfish mortality following white spot syndrome virus (WSSV) infection. These findings indicate that dietary hesperidin supplementation at an optimum dose of 50-150 mg kg^-1 may effectively improve nonspecific immunity, antioxidant capacity and growth performance in crayfish.

Glutathione peroxidase 3 in the mud crab Scylla paramamosain: Characterization and regulation under nitrite stress

Glutathione peroxidases (GPx) are parts of the enzymatic antioxidant system that can eliminate the peroxides produced as effect of reactions of molecules with reactive oxygen species (ROS). In this study, a selenium-dependent glutathione peroxidase 3 cDNAs (designated as SpGPx3) was obtained from the mud crab Scylla paramamosain. The open reading frame (ORF) of SpGPx3 was 639 bp, which encoded a putative protein of 212 amino acids. SpGPx3 protein contained a characteristic GPx signature motif, and an active site motif. Mud crabs were exposed to 20 mg L^-1 nitrite for 72 h. Quantitative real-time PCR analysis revealed that the SpGPx3 mRNA was distributed abundantly in mud crab. The transcript levels of antioxidant enzyme genes (SpGPx3, SpSOD and SpCAT) were obviously induced after acute nitrite exposure. After knockdown of the SpGPx3 level, the mortality of mud crabs and malondialdehyde (MDA) content significantly increased under nitrite stress. These results suggested that SpGPx3 played an important role in protecting organisms against oxidative stress.

Molecular Characterization and Gene Expression of Glutathione Peroxidase 1 in Tor tambroides Exposed to Temperature Stress

Temperature is an abiotic factor that affects various biological and physiological processes in fish. Temperature stress is known to increase the production of reactive oxygen species (ROS) that subsequently cause oxidative stress. Fish is known to evolve a system of antioxidant enzymes to reduce ROS toxicology. Glutathione peroxidase (GPx) family consists of key enzymes that protect fish from oxidative stress. In this study, full-length GPx1 cDNA (GenBank accession no. KY984468) of Tor tambroides was cloned and characterized by rapid amplification of cDNA ends (RACE). The 899-base-pair (bp) GPx1 cDNA includes a 576-bp open reading frame encoding for 191 amino acids, plus 28 bp of 5'-untranslated region (UTR) and 295 bp of 3'-UTR. Homology analysis revealed that GPx1 of T tambroides (Tor-GPx1) shared high similarity with GPx1 sequences of other fish species. The phylogenetic construction based on the amino acid sequence showed that Tor-GPx1 formed a clade with GPx1 sequences of various fish species. Real-time polymerase chain reaction (PCR) was performed to assess the levels of GPx1 gene expression in the liver and muscle of T tambroides under thermal stress. The results indicated that GPx1 gene expression was down-regulated under decreased temperature. However, there was no significant difference between GPx1 gene expression in fish exposed to high temperature and control. Our study provides the first data regarding GPx gene expression in T tambroides under thermal stress.

In Vivo and In Vitro Antioxidant Activities of Methanol Extracts from Olive Leaves on Caenorhabditis elegans

The aim of this study was to evaluate the antioxidant activities of extracts from olive leaves (EOL). The main contents of EOL were determined by colorimetric methods. The antioxidant activities were assessed by measuring the scavenging free radicals in vitro. To investigate the antioxidant activity in vivo, we detected the survival of Caenorhabditis elegans, under thermal stress. Subsequently the reactive oxygen species (ROS) level, activities of antioxidant enzymes, the expression of HSP-16.2 and the translocation of daf-16 were measured. The results showed that, polyphenols was the main component. EOL could well scavenge DPPH and superoxide anion radicals in vitro. Compared to the control group, the survival rate of C. elegans treated with EOL was extended by 10.43%, under heat stress. The ROS level was reduced, while the expression of hsp-16.2 was increased to protect the organism against the increasing ROS. The level of malondialdehyde (MDA) also decreased sharply. The activities of inner antioxidant enzymes, such as catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GSH-PX) were potentiated, which might have had a correlation with the DAF-16 transcription factor that was induced-turned into the nuclear. Therefore, EOL showed a strong antioxidant ability in vitro and in vivo. Hence, it could be a potential candidate when it came to medicinal and edible plants.

Effects of environmental stress on shrimp innate immunity and white spot syndrome virus infection

The shrimp aquaculture industry is plagued by disease. Due to the lack of deep understanding of the relationship between innate immune mechanism and environmental adaptation mechanism, it is difficult to prevent and control the diseases of shrimp. The shrimp innate immune system has received much recent attention, and the functions of the humoral immune response and the cellular immune response have been preliminarily characterized. The role of environmental stress in shrimp disease has also been investigated recently, attempting to clarify the interactions among the innate immune response, the environmental stress response, and disease. Both the innate immune response and the environmental stress response have a complex relationship with shrimp diseases. Although these systems are important safeguards, allowing shrimp to adapt to adverse environments and resist infection, some pathogens, such as white spot syndrome virus, hijack these host systems. As shrimp lack an adaptive immune system, immunization therapy cannot be used to prevent and control shrimp disease. However, shrimp diseases can be controlled using ecological techniques. These techniques, which are based on the innate immune response and the environmental stress response, significantly reduce the impact of shrimp diseases. The object of this review is to summarize the recent research on shrimp environmental adaptation mechanisms, innate immune response mechanisms, and the relationship between these systems. We also suggest some directions for future research.

Antioxidant enzymes and their role in phoxim and carbaryl stress in Caenorhabditis elegans

Pesticide exposure can induce oxidative stress and cause changes to antioxidant enzymes in living organisms. In the present study, the effects of phoxim (an organophosphorus insecticide) and carbaryl (a carbamate insecticide) on antioxidant enzyme activity and gene expression were investigated in the model organism Caenorhabditis elegans. The results show that phoxim exposure can induce superoxide dismutase (SOD) and catalase (CAT) activities and decrease glutathione peroxidase (GPx) activity at lower concentrations. The expression levels of sod-3, sod-5, ctl-1, gpx-6, and gpx-8 were up-regulated after treatment with phoxim. The mRNA expression levels of sod-5, ctl-1 and gpx-6 were increased approximately 70-, 170- and 130-fold, respectively, in the 0.25mM treatment group compared to the control group. Carbaryl exposure decreased SOD activity and induced CAT and GPx activities. The addition of carbaryl up-regulated the expression of sod-5, ctl-1, ctl-3 and gpx-8. Specifically, ctl-1 expression increased approximately 10-fold, and gpx-8 expression increased <30-fold in the 0.5mM treatment group relative to the control group. The transcript level of sod-5 increased >20-fold, and ctl-3 increased approximately 10-fold in the 1mM treatment group. The functions of the antioxidant enzymes during oxidative stress caused by the two insecticides were investigated using deletion mutants. The LC₅₀ values phoxim for the of sod-3 (tm760), sod-5 (tm1146), ctl-1 (ok1242), ctl-3 (ok2042) and gpx-8 (tm2108) mutant strains were lower than those observed for the N2 strain. The LC₅₀ values of carbaryl for the ctl-1 (ok1242), ctl-3 (ok2042) and gpx-6 (tm2535) deletion mutant strains decreased in comparison to the N2 strain. The results suggest that these two insecticides caused oxidative stress and changed altered the antioxidant enzyme activities and their gene expressions in C. elegans. The sod-3, sod-5, ctl-1, ctl-3, gpx-6, and gpx-8 encoding enzymes may play roles in defending cells from oxidative stress caused by these two insecticides.

Molecular characterization of a novel nitric oxide synthase gene from Portunus trituberculatus and the roles of NO/O2(-)- generating and antioxidant systems in host immune responses to Hematodinium

Increasing evidences have established that the nitric oxide synthase (NOS) and NADPH oxidase (NOX) play important roles in host defense system by catalyzing the production of nitrogen oxide (NO) and superoxide anions (O2(-)), respectively. While, there are limited studies to explore the roles of NOS/NOX enzymes in crustacean immunity, and no studies as yet were attempted to elucidate their functions in host immune responses to parasites. In the present study, we cloned a full-length cDNA of NOS and two partial cDNA fragments of NOX and GPx from the economic valuable crab Portunus trituberculatus. The full-length cDNA of NOS was 4002 bp in length that encoded 1203 amino acids containing motifs of the NOS protein and conserved domains. The phylogenetic analysis showed that the NOS protein sequence was clustered together with those of crustacean species in the phylogenetic tree. All of the three novel genes showed high mRNA transcripts in the immune-related tissues (e.g. hemocytes, hepatopancreas) of P. trituberculatus. Striking fluctuation in the transcripts of the critical NO/O2(-)- generating/scavenging related genes (NOS, NOX, CuZnSOD, CAT, GPx) as well as in the enzymatic activities of NOS, NOX, SOD, CAT and GPx were observed in the hemocytes and hepatopancreas of P. trituberculatus post challenged with the parasitic dinoflagellate Hematodinium, indicating that the NO/O2(-)- generating and the antioxidant systems played vital roles in the crustacean innate immunity against the parasitic intrusion. The results indicated a novel respect of the host-parasite interaction between the crab host and the parasitic dinoflagellate Hematodinium.

Toxic effects of ionic liquid 1-octyl-3-methylimidazolium bromide on the antioxidant defense system of freshwater planarian, Dugesia japonica

The activities of antioxidant enzymes and the levels of glutathione (GSH) and malondialdehyde (MDA) were determined when freshwater planarian Dugesia japonica was exposed to different concentrations of 1-octyl-3-methylimidazolium bromide ([C8mim]Br) for one, three, and five days. The results showed that superoxide dismutase (SOD) activity began to increase in all treated groups after three days of exposure, while catalase (CAT) activity was inhibited after the first day, but increased notably on the fifth day except for the lowest concentration group. The activity of glutathione peroxidase (GPX) was induced from the first day of exposure and increased significantly after five days in all treated groups. During the experiment, the levels of intracellular GSH in all treated groups were higher than that of the control group. Changes in MDA suggest that [C8mim]Br is toxic to D japonica and may result in lipid peroxidation in planarian. Our results also indicate that GPX as well as GSH seem to be more sensitive biomarkers of oxidative stress compared with SOD and CAT.