GST Enzyme Activity Research Articles

SOURCES OF LIPIDS IN DIETS FOR SILVER CATFISH (Rhamdia quelen) JUVENILES

The purpose of this study was to evaluate different lipid sources in diets for silver catfish juveniles regarding aspects of productive performance, centesimal composition, hepatic histology, biochemical responses, and oxidative stress. A total of 300 juveniles with an initial mean weight of 18.45 ± 1.22g were distributed in 20 net-pens of 1m3, arranged in a 200 m2 masonry tank, for a period of 90 days. The experimental diets were isoprotein (29.05% digestible protein) and isoenergetic (3,250 kcal.kg-1), containing different sources of oils (soybean, sunflower, fish, canola and olive) at a concentration of 3.0%. The animals were distributed in a completely randomized design, with five treatments and four replicates. The data were submitted to ANOVA, and the means, when significant, were compared by the Tukey test at 5% significance level. Visceral fat index was higher for fish fed diets containing sunflower oil (P<0.05). No differences (P>0.05) were observed for the variables of productive performance, centesimal composition, and blood biochemistry. A difference (P<0.05) was observed in hepatic histology, where the treatment with soybean oil had a higher number of hepatocytes. The animals fed with fish oil had a higher TBARS lipid peroxidation and a higher GST enzyme activity (P<0.05). Therefore, the different lipid sources can be used to feed this species without any damage to productive performance. It is not advisable to include sunflower oil, as it provides greater deposition of visceral fat.

Insecticide Resistance Status and Mechanisms of Anopheles sinensis (Diptera: Culicidae) in Wenzhou, an Important Coastal Port City in China.

Although scaled-up interventions and effective control efforts have drastically reduced malaria morbidity and mortality, malaria remains a serious threat to public health worldwide. Anopheles sinensis Wiedemann 1828 is a historically important vector of Plasmodium vivax (Haemosporida: Plasmodiidae) malaria in China. Insecticide resistance has become a major obstacle to vector-borne disease control. However, little is known about the insecticide resistance of An. sinensis in Wenzhou, an important coastal port city in Zhejiang province, China. The aim of this study was to examine insecticide resistance and mechanisms in An. sinensis field mosquito populations. Evidence of multiple insecticide resistance was found in An. sinensis adult female populations. Medium to high frequencies of target site kdr together with fixed ace-1 mutations was detected in both the Ruian and Yongjia populations. Both populations showed an association between kdr L1014 mutation and resistance phenotype when tested against deltamethrin and DDT. Significantly different metabolic enzyme activities were found between the susceptible laboratory strain and field-collected mosquitoes from both Ruian and Yongjia. Both field collected An. sinensis populations exhibited significantly higher P450 enzyme activity compared with the laboratory strain, while the field-collected resistant mosquitoes exhibited various GST and COE enzyme activities. These results indicate multiple resistance mechanisms in An. sinensis field populations. Effective implementation of insecticide resistance management strategies is urgently needed. The data collected in this study will be valuable for modeling insecticide resistance spread and vector-control interventions.

Genome-wide analysis of the Tetrahymena thermophila glutathione S-transferase gene superfamily

The ciliate Tetrahymena thermophila has a rapid response to detoxify xenobiotics, which presents opportunity to study the diversification of Glutathione S-Transferase superfamily. In-silico identification of putative GST genes were resulted with 70 GST genes; 49 TtGSTmu, 7 TtGSTomega, 5 TtGSTtheta, 2 TtGSTzeta, 4 TtMAPEG and 3 TtEF1G. TtGST superfamily has short intron carrying or intronless genes. The most expressed mRNAs of TtGST are limited to 4 members at all life stages. TtGST genes are widely distributed to all five micronuclear chromosomes with the highest diversified members from different classes in chromosome 4. The clustering and the orientation of some TtGSTs in the T. thermophila genome give clues about the recent gene duplication. Analysis of GSH affinity-purified GST proteins with Western blot and activity assay showed GST activity carrying purified TtGST populations. In conclusion, the enhanced genome capacity of TtGST superfamily may have evolved through improved GST enzymatic activity.

Resveratrol mediated cancer cell apoptosis, and modulation of multidrug resistance proteins and metabolic enzymes

BackgroundThe degree of intracellular drug accumulation by specific membrane transporters, i.e., MDR1, BCRP, and MRP, and the degree of detoxification by intracellular metabolic enzymes, i.e., CYP3A4 and GST, provide control for cancer chemotherapy through diminishing the propensity of cancer cells to undergo apoptosis which in turn modulates the unresolved and complex phenomenon of multidrug resistance (MDR) for the cancer cells. Hypothesis/PurposeThis study dwells into the interaction details involving ABC-transporters, CYP3A4, GST and cytotoxic effects of resveratrol on different cell lines. MethodsResveratrol was evaluated for its ability modulating the expression and efflux functions of P-gp /MDR1, MRP1, and BCRP in the multidrug-resistant human colon carcinoma cell line, Caco-2, and CEM/ADR5000 cells through flow cytometry and RTPCR technique. ResultsThe resveratrol influenced P-gp and MRP1 efflux functions whereby it increased rhodamine 123 with calcein accumulation in concentration-dependent manner (1 – 500 µM) in the Caco-2 cell lines and inhibited the effluxes of both the substrates also as concentration-dependent phenomenon (10 – 100 µM) in the p-gp overexpressing CEM/ADR5000 cells through FACS (full form). The treatment of drug-resistant Caco-2, and CEM/ADR5000 cells with doxorubicin (DOX) along with 20 µM of resveratrol in the mixture. It increased the cell sensitivity DOX towards the DOX and enhanced the cytotoxicity. The resveratrol inhibited both CYP3A4 and GST enzymatic activity in a concentration-dependent way and induced apoptosis in the resistance cell lines because of increased levels of caspase-3, -8,-6/9 and incremental phosphatidyl serine (PS) exposure as detected by flow cytometry. The treatment of Caco-2 cells with resveratrol showed significantly lower p-gp, MRP1, BCRP, CYP3A4, GST, and hPXR mRNA levels in a 48 h observation. ConclusionThe result confirmed resveratrol mediated inhibition of ABC-transporters’ overall efflux functions, and its expression, and apoptosis as well as metabolic enzymes GST and CYP3A4 activity.

Investigation of the protective effects of horse mushroom (Agaricus arvensis Schaeff.) against carbon tetrachloride-induced oxidative stress in rats.

Wild and cultured mushrooms have been extensively used for food and medicinal purposes all around the world. However, there is limited information on chemical composition, health enhancing effects and contributions on diet of some mushrooms (e.g., Agaricus arvensis) widely distributed in many countries including United Kingdom, Australia, Turkey etc. Therefore, the present study was aimed to analyse the bioactive composition and ameliorative effects of A. arvensis via evaluating in vitro and in vivo antioxidant properties in CCl4 induced rat model. The extract exhibited higher antioxidant capacities in vitro than that of the positive control (Reishi-Shiitake-Maitake standardized extract). Administration of the extract had significant regulative effects in the levels of AST, ALT, LDH, Urea and TRIG levels according to CCl4 group. Additionally, lipid peroxidation and GSH in the brain, kidney and liver tissues was regulated by extract treated groups compared to the CCI4 group. The supplementation of the extract at the dose of 100mg/kg regulated the levels of GST, GR, CAT and GPx enzyme activities in brain and liver, but not in kidney tissue. There was approximately three fold increase in CAT enzyme activity in kidney tissue of extract treated groups compared to Control and CCl4 groups. The extract contained a rich composition of bioactive compounds including phenolics (protocatechuic acid and p-hydroxybenzoic acid), volatile compounds (benzaldehyde, palmitic acid and linoleic acid) and mineral compounds (K, Si, Mg and Na). Data obtained within this study suggests that A. arvensis might be used for food industries in order to obtain nutritional products.

Screening Effects of Methanol Extracts of Diplotaxis tenuifolia and Reseda lutea on Enzymatic Antioxidant Defense Systems and Aldose Reductase Activity.

The aim of the study was to investigate the effects of methanol extracts from the flowers and leaves of Diplotaxis tenuifolia and Reseda lutea on the activity of AR, CAT, GST, and GPx. Total phenolic and flavonoid contents of the plant samples were evaluated using Folin-Ciocalteu reagent and aluminum chloride colorimetric methods. Also, the effects of extracts on CAT, GST, GPx, and AR enzyme activities were investigated using kinetic assays. The highest phenolic and flavonoid contents were detected in the methanol extract of D. tenuifolia leaves with 144.49±0.29 mg gallic acid equivalent/L and 250.485±0.002 quercetin equivalent/L, respectively. The best activity profile for GST and GPx were observed in the extract of leaves belonging to D. tenuifolia with IC50 values of 121±0.05 and 140±0.001 ng/mL, respectively. According to the results, methanol extracts from leaves of R. lutea and D. tenuifolia showed no significant activity potential on AR. Moreover, none of the studied extracts demonstrated any reasonable CAT activation potential. The results indicated that leaves of D. tenuifolia had good effect on the antioxidant enzymatic defense system, which it makes it a good constituent of the daily diet.

Modulation of xenobiotic metabolizing enzyme activities in rat liver by co-administration of morin, endosulfan, and 7,12-dimethylbenz[a]anthracene

Morin is a flavonoid which is present in many plants. Endosulfan and 7,12-dimethylbenz[a]anthracene (DMBA) are toxic chemicals that humans are exposed to in their daily lives. In this study, the protective role of morin was investigated in endosulfan and DMBA treated rats. Eight groups, each comprising seven 2.5-month-old adult male Wistar rats (weighing 170–255 g), were used. Endosulfan, morin, and DMBA were administered individually or in combinations, at 5 mg/kg body weight (bw) (three times/week), 25 mg/kg bw (three times/week), and 30 mg/kg bw (once/week for three weeks) via oral gavage, respectively. On day 54 of the administration period, the rats were killed. DMBA + endosulfan co-administration significantly increased CYP1A1-, CYP1A2-, CYP2E-, and GST-associated activities in the rats compared to the control. DMBA + endosulfan + morin significantly increased CYP1A1, CYP1A2, CYP3A, and GST associated activities in the rats relative to the control. Histopathological studies were performed to investigate protective effects of morin on liver damage. The results indicated that DMBA + endosulfan treatment induced liver damage, and morin reduced this damage. These findings suggest that CYP1A, CYP3A, and GST enzyme activities participate in the protective mechanism of morin against endosulfan and DMBA induced toxicity.

The Effects of NPR1 Dependent Salicylic Acid Change in Increasing Salt Tolerance of Soybean Leaves by Acclimation

Non-expressor of Pathogen Related 1 (NPR1) is a regulatory gene of the salicylic acid (SA) signaling pathway, the detailed mechanism of which is still not well understood. This study investigated the effects of NPR1-dependent SA level change on increasing salt tolerance of soybean leaves with acclimation. Salt-sensitive (‘SA88’) and salt-tolerant (‘Erensoy’) soybean (Glycine max L.) plants were treated with increasing NaCl concentrations (25, 50, 75, and 100 mM; acclimation) and with 100 mM NaCl directly (non-acclimation) in two groups. The results showed that acclimation treatment alleviated salt-induced damage in the sensitive cultivar with increasing superoxide anion radical scavenging activity, and decreasing hydrogen peroxide (H2O2) and malondialdehyde (MDA) content. However, the APX, CAT, and GST enzyme activities were increased by acclimation treatment, with the highest increase observed in GST enzymes. Interestingly, the Gmnpr1 gene expression was upregulated in all treatments but was more pronounced in non-acclimation. Furthermore, the highest increase in endogenous SA level was under acclimation treatment in ‘SA88’. In conclusion, the results firstly showed that an acclimation process is useful for increasing salt tolerance in sensitive soybean plants with only ROS-inducted NPR1-independent SA accumulation but not through the NPR1-dependent SA signaling pathway.

Macrofilaricidal Activity of Leaf Extracts of Rauvolfia tetraphylla L. Against Bovine Filarial Parasite Setaria cervi.

Leaf extracts of Rauvolfia tetraphylla were evaluated for antifilarial potential using Setaria cervi as target parasite. Four extracts were tested these were hexane, chloroform, acetone and methanol. The activity was assessed by means of worm motility assay, MTT reduction and GST enzyme inhibition assay using female worms of Setaria cervi. DEC was used as a standard drug. Methanol extract exhibited significant activity among all the extracts with percentage of reduction 89.28% at 10mg/ml concentration. DEC was comparitively less active than methanolic extract with 79.22% activity at the same dose. The IC50 value for methanolic extract was found to be 0.03mg/ml, which was better than the standard DEC i.e. 2.84mg/ml. The methanol extract significantly inhibited the GST enzyme activity of Setaria worms as compared to untreated worms with percentage of inhibition value of 56.41% at 10mg/ml. The most active methanol extract was finally explored for cell viability study by using trypan blue dye exclusion test. The methanolic extract significantly killed the oocytes of Setaria worms as all the oocytes stained blue in treated worms and unstained in control oocytes. The findings indicate that the methanolic extract has potent macrofilaricidal ativity.

Evaluating the hepatoprotective efficacy of Aloe vera polysaccharides against subchronic exposure of aflatoxins B1

Abstract The objective of this study was to evaluate the hepatoprotective effect of Aloe vera polysaccharides (APs), the main bioactive components in Aloe vera gel, against AFB 1 -induced hepatotoxicity in a subchronic AFB 1 -exposed rat model and to investigate the possible underlying mechanisms. As a result, APs effectively restrained the loss of appetite, impairment of organs, attenuated serum aminotransferases and TBIL levels, and ameliorated histopathological alterations in AFB 1 -intoxicated rats. Co-administration of APs markedly down-regulated the hepatic expression of IL-1β and IL-6, and significantly inhibited the generation of MDA and the decrease in antioxidants (GSH, SOD, CAT and GSH-Px). Furthermore, APs significantly inhibited the AFB 1 -dependent elevation in gene expression, synthesis and activities of CYP1A2/3A4 enzymes, and evidently enhanced GST enzyme activity, thus decreasing the hepatotoxicity of AFB 1 . These results indicated that APs bear protective efficacy against AFB 1 -induced subchronic hepatotoxicity, which can be attributed to its anti-oxidative and anti-inflammatory capacities, and its ability to regulate the generation and excretion of toxic AFBO. This work poses importance for developing hepatoprotective functional food from Aloe vera , which would conduce to people under chronic exposure of AFB 1 in developing countries.

Protective effect of Silybum marianum and Taraxacum officinale extracts against oxidative kidney injuries induced by carbon tetrachloride in rats

The protective effect of the extracts of the plants Silybum marianum and Taraxacum officinale by carbon tetrachloride (CCl4) was researched. Sixty-six female Wistar albino rats were divided into six groups: Control, Silybum marianum, Taraxacum officinale, CCl4, Silybum marianum+ CCl4, Taraxacum officinale+CCl4. The Silybum marianum and Taraxacum officinale extracts were administered as 100 mg/kg/day by gavage. The CCl4 was administered as 1.5 mL/kg (i.p.). At the end of the trial period, in the serums obtained from the animals, in the CCl4 group it was found that the MDA level increased in the kidney tissue samples as well as in the ALP and GGT enzyme activities. It was also found that the GSH level and the GST enzyme activities decreased (p<.05). The microscopic evaluations showed that the CCl4 caused a serious hydropic degeneration, coagulation necrosis, and mono-nuclear cell infiltration in the kidney cell. In the animals where CCl4 and Silybum marianum and Taraxacum officinale extracts were applied together, it was found that the serum ALP and GGT enzyme activities decreased and that the MDA level decreased in the kidney tissue, and that the GSH level and GST enzyme activities increased. It was observed that the histopathological changes caused by the CCl4 toxicity were corrected by applying the extracts. Eventually, it was determined that the Silybum marianum was more effective. Silybum marianum and Taraxacum officinale extracts which were used against histopathological changes in the kidney caused by toxication showed a corrective effect, which were supported by biochemical parameters.

Triclosan (TCS) and Triclocarban (TCC) cause lifespan reduction and reproductive impairment through oxidative stress-mediated expression of the defensome in the monogonont rotifer (Brachionus koreanus)

Triclosan (TCS) and Triclocarban (TCC) are used as antimicrobial agents and have been widely dispersed and detected in the marine environment. However, the toxicities of TCS and TCC have been poorly investigated in marine invertebrates. In this study, the effects of TCS and TCC on mortality, population growth, lifespan, and fecundity were examined in the monogonont rotifer (Brachionus koreanus) using cellular ROS levels, GST enzymatic activity, and gene expression of defensomes. The median lethal concentration (LC50) of TCS (393.1μg/L) and TCC (388.1μg/L) was also determined in the same species. In TCS- and TCC-exposed B. koreanus, growth retardation and reduced fecundity were observed and were shown to have a potentially deleterious effect on the life cycle of B. koreanus. In addition, time-dependent increases in ROS content (%) and GST enzymatic activity were shown in response to TCS and TCC exposure. Additionally, transcript levels of detoxification proteins (e.g., CYPs), antioxidant proteins (e.g., GST-sigma, Cu/ZnSOD, CAT), and heat shock proteins (Hsps) were modulated in response to TCS and TCC exposure over a 24h period. Our results indicate that TCS and TCC induce oxidative stress and transcriptional regulation of detoxification, antioxidant, and heat shock proteins, resulting in changes in lifespan and fecundity.

Expression profile of eight glutathione S-transferase genes in Crassostrea ariakensis after exposure to DSP toxins producing dinoflagellate Prorocentrum lima

In this study, changes in eight GSTs mRNA level including GST-α, GST-σ, GST-ω, GST-π, GST-μ, GST-ρ, GST-θ and microsomal GST (mGST) in the oyster Crassostrea ariakensis after exposure to Prorocentrum lima have been evaluated by quantitative real-time PCR. Additionally, the contents of five GST isoforms were detected by ELISA. After exposure to P. lima at density of 2 × 105 cells/L, mGST mRNA significantly increased in gill, while GST-σ was induced in digestive gland. After exposure to P. lima at density of 2 × 106 cells/L, GST-ω and mGST expressions increased in gill, whereas GST-α and GST-σ were induced in digestive gland. The GST content and activity in oysters exposed to P. lima also showed a different pattern when the different isoforms and organs were compared. After exposure to P. lima (2 × 106 cell/L), GST-π increased in gill but decreased in digestive gland. The total GST enzyme activity increased in gill, while remained unchanged in digestive gland. These various regulation of GST gene expressions indicated that the GSTs isoenzymes might play divergent physiological roles in the detoxification of DSP toxins in C. ariakensis.

Proteomic profiling of gill GSTs in Mytilus galloprovincialis from the North of Portugal and Galicia evidences variations at protein isoform level with a possible relation with water quality

Glutathione transferases (GSTs) are key for xenobiotic detoxification at the molecular level across phyla. These enzymes are therefore likely to be part of the defence mechanisms used by marine organisms, such as mussels, that thrive in highly polluted environments. Taking this hypothesis into account, we used proteomics to characterize the profile of GSTs from the gills of marine mussel Mytilus galloprovincialis in order to discriminate natural mussel populations exposed to different levels of pollution.Samples were collected between Cabo Home (Spain) and Matosinhos (Portugal) covering a north-south transect of approximately 122 Km of the Atlantic Ocean along the Western Coast of the Iberian Peninsula. GSTs from mussel gills were extracted and purified by affinity chromatography with glutathione as the binding substrate to the solid medium. We studied the abundance of GST isoforms by two-dimensional gel electrophoresis and matrix assisted laser desorption/ionization-time of flight mass spectrometry and assessed total activity.Eleven putative individual GSTs from classes Mu, Pi and Sigma were identified by proteomics. Few variations were observed in total GST activity of post-mitochondrial samples between sampling sites, with animals from Matosinhos (polluted site) showing highest GST activity and Cabo Home (clean site) showing lowest. This contrasts with the increased number of differences in the individual GST isoforms. Each mussel population showed unique GST proteomic profiles. Based on the results we conclude that proteomics surpasses the conventional GST enzymatic activity method to discriminate natural mussel populations and has potential application in environmental monitoring. It is reasonable to suggest that the GST proteomic profiles observed may reflect differences in contamination levels.

Glutathione Transferases Responses Induced by Microcystin-LR in the Gills and Hepatopancreas of the Clam Venerupis philippinarum.

A multi-method approach was employed to compare the responses of Glutatione Transferases (GSTs) in the gills and hepatopancreas of Venerupis philippinarum to microcystins (MCs) toxicity. In this way, using the cytosolic fraction, the enzymatic activity of GSTs, superoxide dismutase (SOD), serine/threonine protein phosphatases (PPP2) along with the gene expression levels of four GST isoforms (pi, mu, sigma1, sigma2) were investigated in both organs of the clams exposed for 24 h to 10, 50 and 100 μg L−1 of MC-LR. Cytosolic GSTs (cGSTs) from both organs of the high dose exposed clams were purified by glutathione-agarose affinity chromatography, characterized kinetically and the changes in the expression of cGSTs of the gills identified using a proteomic approach. MC-LR caused an increase in GST enzyme activity, involved in conjugation reactions, in both gills and hepatopancreas (100 μg L−1 exposure). SOD activity, an indicator of oxidative stress, showed significantly elevated levels in the hepatopancreas only (50 and 100 μg L−1 exposure). No significant changes were found in PPP2 activity, the main target of MCs, for both organs. Transcription responses revealed an up-regulation of sigma2 in the hepatopancreas at the high dose, but no significant changes were detected in the gills. Kinetic analysis evidenced differences between gills of exposed and non-exposed extracts. Using proteomics, qualitative and quantitative differences were found between the basal and inducible cGSTs. Overall, results suggest a distinct role of GST system in counteracting MCs toxicity between the gills and the hepatopancreas of V. philippinarum, revealing different roles between GST isoforms within and among both organs.

Transcriptional responses of glutathione transferase genes in Ruditapes philippinarum exposed to microcystin-LR.

Glutathione Transferases (GSTs) are phase II detoxification enzymes known to be involved in the molecular response against microcystins (MCs) induced toxicity. However, the individual role of the several GST isoforms in the MC detoxification process is still unknown. In this study, the time-dependent changes on gene expression of several GST isoforms (pi, mu, sigma 1, sigma 2) in parallel with enzymatic activity of total GST were investigated in gills and hepatopancreas of the bivalve Ruditapes philippinarum exposed to pure MC-LR (10 and 100 µg/L). No significant changes in GST enzyme activities were found on both organs. In contrast, MC-LR affected the transcriptional activities of these detoxification enzymes both in gills and hepatopancreas. GST transcriptional changes in gills promoted by MC-LR were characterized by an early (12 h) induction of mu and sigma 1 transcripts. On the other hand, the GST transcriptional changes in hepatopancreas were characterized by a later induction (48 h) of mu transcript, but also by an early inhibition (6 h) of the four transcripts. The different transcription patterns obtained for the tested GST isoforms in this study highlight the potential divergent physiological roles played by these isoenzymes during the detoxification of MC-LR.

Trichinella spiralis: Low vaccine potential of glutathione S-transferase against infections in mice

We have previously reported that Trichinella spiralis glutathione-S-transferase (TsGST) gene is an up-regulated gene in intestinal infective larvae (IIL) compared to muscle larvae (ML). In this study, the TsGST gene was cloned, and recombinant TsGST (rTsGST) was produced. Anti-rTsGST serum recognized the native TsGST by Western blotting in crude antigens of ML, adult worm (AW) and newborn larvae (NBL) of T. spiralis, but not in ML excretory–secretory (ES) antigens. Expression of TsGST was observed in all different developmental stages (IIL, AW, NBL and ML). An immunolocalization analysis identified TsGST in the cuticle, stichosome and genital primordium of the parasite. The rTsGST had GST enzymatic activity. After a challenge infection with T. spiralis larvae, mice immunized with rTsGST displayed a 35.71% reduction in adult worms and a 38.55% reduction in muscle larvae. The vaccination of mice with rTsGST induced the Th1/Th2-mixed type of immune response with Th2 predominant (high levels of IgG1) and partial protective immunity against T. spiralis infection.

Phenotypic expression and polymorphism of Glutathione S Transferase gene in materno-fetal dyads with idiopathic fetal growth restriction

IntroductionIncidence of fetal growth restriction (FGR) in India is quite high, and FGR has been found to be associated with various non-infectious diseases including coronary artery disease, diabetes mellitus and metabolic syndrome. Moreover, 40% of FGR is termed idiopathic (IFGR) for which cause is not known. Oxidative stress, which is postulated to have a role in FGR, is modulated by polymorphism of antioxidant genes. This study aims to examine association of GST polymorphism and enzymatic activity with incidence of FGR. Materials and methods150 unrelated live births participated as dyads (mother and neonate). 75 consecutive IFGR materno-fetal dyads (referred subsequently as IFGR mother and IFGR neonate) were recruited as cases. Polymorphic analysis of GSTT1 and GSTM1 were carried out by multiplex PCR. Glutathione-S-transferase activity in serum was measured using 1-chloro-2, 4-dinitrobenzene (CDNB) as substrate. ResultsIncidence of GSTT1 null type is significantly higher in IFGR fetus and their mothers (p < 0.01). Incidence of GSTM1 null type is significantly higher in IFGR fetus (p = 0.001). GST activity levels in mothers giving birth to IFGR babies was about 50% of the values found in the control group (p < 0.001). The GST activity levels in control group was found to be 50% higher than the FGR babies (p = 0.001). ConclusionOur results show that there is definite association between polymorphism of GST genes and incidence of IFGR. Simultaneously, our study also found a correlation between maternal GST activity and fetal weight.

Biomarker responses in Corbicula fluminea to the presence of dioxin-like polychlorinated biphenyls and seasonal changes

PCBs are potential genotoxicants and inductors of increased levels of ROS and oxidative stress in both humans and wildlife. In this study, biotransformation parameters and antioxidant (AO) enzymes were analyzed in the Asian clam, Corbicula fluminea, with respect to the presence of dioxin-like PCBs (dl-PCBs) in the environment. For this purpose, clams were collected from three localities with different environmental conditions. Sediments from each locality and clam tissues were analyzed for the presence of dl-PCBs. Biological responses included changes in the expression of fish CYP1A immunoreactive protein, changes in the activities of AO enzymes, SOD, CAT, GR and GPx, and the phase II biotransformation enzyme GST. Clams from the locality with the highest ΣWHO–TEQ values for sediment dl-PCBs had the highest ΣWHO–TEQ values for tissue dl-PCBs and the highest level of fish CYP1A immunoreactive protein expression. The correlations found between the concentrations of dl-PCBs and AO and GST activities revealed both concentration-dependent inhibitory and stimulatory effects. The activities of GPx, GR and GST were very sensitive to environmental xenobiotics, including dl-PCBs. The obtained results indicate that the activities of these enzymes were fine-tuned to provide optimized antioxidant responses. We also observed seasonal changes in GST and AO enzyme activities in Asian clam. The highest levels of activity were observed in spring as compared to summer or autumn. CDA, which was performed in order to classify the different clam populations, revealed a coordinated rearrangement of the clams’ metabolic components that were probably aimed at compensating for environmental fluctuations. The presented data reveal the sensitivity of C. fluminea to the presence of dl-PCBs in the environment and support the use of this clam as a sentinel species for biomonitoring studies.

Sublethal gamma irradiation affects reproductive impairment and elevates antioxidant enzyme and DNA repair activities in the monogonont rotifer Brachionus koreanus

To examine the effects of gamma radiation on marine organisms, we irradiated several doses of gamma ray to the microzooplankton Brachionus koreanus, and measured in vivo and in vitro endpoints including the survival rate, lifespan, fecundity, population growth, gamma ray-induced oxidative stress, and modulated patterns of enzyme activities and gene expressions after DNA damage. After gamma radiation, no individuals showed any mortality within 96h even at a high intensity (1200Gy). However, a reduced fecundity (e.g. cumulated number of offspring) of B. koreanus at over 150Gy was observed along with a slight decrease in lifespan. At 150Gy and 200Gy, the reduced fecundity of the rotifers led to a significant decrease in population growth, although in the second generation the population growth pattern was not affected even at 200Gy when compared to the control group. At sub-lethal doses, reactive oxygen species (ROS) levels dose-dependently increased with GST enzyme activity. In addition, up-regulations of the antioxidant and chaperoning genes in response to gamma radiation were able to recover cellular damages, and life table parameters were significantly influenced, particularly with regard to fecundity. DNA repair-associated genes showed significantly up-regulated expression patterns in response to sublethal doses (150 and 200Gy), as shown in the expression of the gamma-irradiated B. koreanus p53 gene, suggesting that these sublethal doses were not significantly fatal to B. koreanus but induced DNA damages leading to a decrease of the population size.