Liver Glutathione S-transferase Research Articles

Consumption of toxic benthic cyanobacteria by two common demersal fish: Growth, antioxidant and liver histopathology responses

Benthic freshwater cyanobacteria have the potential to produce toxins. Compared with more extensively studied plankton species, little is known about the impact of harmful benthic cyanobacteria on aquatic organisms. As demersal fish are usually in direct contact with benthic cyanobacteria, it is important to understand their interactive effects. This study investigated the physio-chemical responses of two demersal fish (Xenocypris davidi and Crucian carp) after exposure to benthic Oscillatoria (producing cylindrospermopsin, 2 × 106 cells/mL) for 7 days. Interestingly, benthic Oscillatoria had less adverse effects on X. davidi than C. carp. The two demersal fish effectively ingested Oscillatoria, but Oscillatoria cell sheathes could not be fully digested in C. carp intestines and led to growth inhibition. Oscillatoria consumption induced oxidative stress and triggered alterations in detoxification enzyme activities in the X. davidi liver. Superoxide dismutase (SOD) and glutathione reductase (GR) activities significantly increased in the C. carp liver, but catalase (CAT) and detoxification enzymes glutathione S-transferase (GST) and glutathione (GSH) activities were insignificantly changed. This suggested that C. carp may have a relatively weak detoxification capacity for toxic Oscillatoria. Oscillatoria ingestion led to more pronounced liver pathological changes in C. carp, including swelling, deformation, and loss of cytoskeleton structure. Simultaneously, fish consumption of Oscillatoria increased extracellular cylindrospermopsin concentration. These results provide valuable insights into the ecological risks associated with benthic cyanobacteria in aquatic ecosystems.

Ameliorative and protective effect of Bergenia ciliata (Haw.) Sternb. extract against acetaminophen-induced hepato-renal damage in rats: B. ciliata and hepato-renal damage

Background: Bergenia ciliata (Haw.) Sternb. is a medicinal plant bestowed with antioxidative phytochemicals and has been traditionally associated with several medicinal and health-promoting properties and used in the management of diseases.Method: The study was undertaken to determine the potential of the extract of the rhizome of Bergenia ciliata (Haw.) Sternb. at 150 and 300 mg/kg body weight (BW) to attenuate the drug-induced oxidative damage in hepatic and renal tissues of Wistar rats. The toxicity was induced by a single oral administration of acetaminophen (APAP).Results: The oral administration of APAP significantly altered the levels of hepatic and renal damage indicators in Wistar rats. The levels of superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione-s-transferase (GST) and total thiols (TTH) decreased significantly in erythrocytes, hepatic and renal tissues. Administration of B. ciliata (150 mg/kg BW) significantly decreased the elevated hepato-renal biomarkers and malondialdehyde (MDA) levels in the tissues whereas significantly increased the levels of SOD, GST and TTH in erythrocytes and liver. The higher dose of B. ciliata (300 mg/kg BW) restored the levels of plasma hepatic and renal biomarkers as well as antioxidant parameters (SOD, GST, GPx, TTH and MDA). It also reversed the histopathological alterations in hepato-renal tissues indicating the protective potential of the extract.Conclusions: Overall, the results indicated that the B. ciliata rhizome extract attenuated the drug-induced hepato-renal toxicity in a dose-dependent manner in Wistar rats and therefore, has the potential for future therapeutic uses.

Fungicides from rice cultivation (tebuconazole and azoxystrobin) alters biochemical and histological markers of hammertoad tadpoles (Boanafaber).

Tebuconazole (TBZ) and azoxystrobin (AZX) are fungicides frequently used in rice cultivation. Despite protecting crops against fungal diseases, these compounds can contaminate the natural environments close to the crops, exerting negative effects on non-target organisms, the present study aimed to characterize the contamination by fungicides of a river that flows in an area dominated by rice cultivation in the north of the state of Santa Catarina, SC, Brazil. Concentrations of TBZ and AZX found in the field were used to evaluate their negative effects on development, biochemical biomarkers and histopatology of the liver of a native tadpole species, the hammerfrog (Boana faber). Tadpoles were exposed for 16 days to the lowest (1.20 μg/L) and highest (2.60 μg/L) concentration of TBZ, lowest (0.70 μg/L) and highest (1.60 μg/L) concentration of AZX, and the mix of both fungicides at lowest and highest concentration of each found in field analyses. Exposure to the lower TBZ concentration and both concentrations of the Mix accelerated the development of tadpoles. AZX caused an increase in the activities of glutathione S-transferase (GST), carboxylesterase (CbE) and glucose-6-phosphate dehydrogenase (G6PDH) in the liver, an increase in the levels of protein carbonyls (PC) in the liver and an increase in the activity of acetylcholinesterase (AChE) in muscle of tadpoles. TBZ, on the other hand, generated an increase in GST, G6PDH, PC and histopathological severity scores in liver and in muscle AChE activity. The effects were more intense in the groups exposed to the Mix of contaminants. No treatment altered brain AChE. The data showed that the fungicides from in rice cultivation found in natural aquatic environments around the crops pose risks to the health of the animals, compromising their metabolism and development.

Can the Herbicide Dicamba Produce Oxidative Stress in the Native South American fish Jenynsia lineata at Environmentally Relevant Concentrations?

Dicamba (DIC) is one of the most applied auxin herbicides worldwide. Sublethal effects in the South American native fish Jenynsia lineata exposed to DIC concentrations close to environmental concentrations (0.03-30µg/L) during 48h were analysed thorough the evaluation of catalase (CAT), glutathione S-transferase (GST), superoxide dismutase (SOD) activities and malondialdehyde (MDA) and H2O2 levels for detecting potential oxidative stress. In gills MDA increased showing oxidative damage probably because of an inefficient antioxidant defense. This response evidenced the important role of gills as an organ of direct contact with waterborne contaminants. In addition, other changes in the biomarkers of oxidative stress were observed such as the inhibition of SOD activities in brain and the inhibition of GST in liver. These results show that short- term exposures to environmentally relevant concentrations of DIC could induce sublethal effects in native fish.

The transient character of mitochondrial uncoupling by the popular fungicide fluazinam is specific for liver

The popular fungicide fluazinam is known to exhibit an unusual cyclic pattern of the protonophoric uncoupling activity in isolated rat liver mitochondria (RLM), with membrane deenergization followed by spontaneous recoupling in the minute scale, which is associated with glutathione conjugation of fluazinam catalyzed by glutathione-S-transferase (GST). Here, we compare the fluazinam effect on RLM with that on rat kidney (RKM) and heart (RHM) mitochondria by monitoring three bioenergetic parameters: oxygen consumption rate, mitochondrial membrane potential and reduction of nucleotides. Only in RLM, the uncoupling activity of fluazinam was transient, i.e. disappeared in a few minutes, whereas in RKM and RHM it was stable in this time scale. We attribute this difference to the increased activity of mitochondrial GST in liver. We report data on the detection of glutathione-fluazinam conjugates by mass-spectrometry, thin layer chromatography and capillary electrophoresis after incubation of fluazinam with RLM but not with RKM, which supports the assumption of the tissue specificity of the conjugation.

CONSUMPTION OF BROCCOLI SPROUTS INCREASED THE ACTIVITY OF GLUTATHIONE-DEPENDENT ANTIOXIDANT ENZYMES IN MURINE LIVER

Aim. The purpose of this work was to investigate effects of the consumption of broccoli sprouts on the activity of antioxidant defense enzymes in the liver of. GPx isoforms. After photo fixation of gels, we determined activity of each isoform densitometrically using ImageJ software. Results were statistically analyzed by ANOVA followed by post-hoc Tukey's test. Data are presented as mean±SEM. Methods. Frozen tissue was homozeniged in lysis buffer, centrifuged and resulted supernatants were used for analysis. Activities of enzymes were determined by using electrophoresis in polyacrylamide gel. After electrophoresis we conducted dyeing of separate gels for detection of superoxide dismutase (SOD), glutathione-S-transferase (GST) or glutathione peroxidase (GPx) isoforms. After photo fixation of gels, we determined activity of each isoform densitometrically using ImageJ software. Results were statistically analyzed by ANOVA followed by post-hoc Tukey's test. Data are presented as mean±SEM. Results. In the hepatic tissue of all four groups of mice, two isoforms of SOD (SOD1 and SOD2) were detected in gels. The intensity of the bands of both isoforms was not significantly different between groups. Three isoforms of GST (GST1, GST2, GST3) were detected in the liver samples. The activity of GST1 did not significantly differ between the experimental groups. Activities of GST2 and GST3 forms were significantly higher in the group “Broccoli” compared to Control and Cafeteria Diet groups. We identified three isoforms of glutathione peroxidase (GPx1, GPx2, GPx3) in liver samples. The activity of GPx isoform 1 was not significantly different between the experimental groups. The activity of GPx2 was significantly higher in the group of mice that consumed Broccoli and Cafeteria Diet + Broccoli compared to Control. GPx2 activity was significantly higher in the Broccoli group compared to the Cafeteria Diet group. Activity of GPx3 was significantly higher in the Broccoli group compared to the Control and Cafeteria Diet group. Conclusions. Cafeteria diet did not significantly affect the activity of SOD isoforms, but led to redistribution of in the activity of GST and GPx isoforms in murine liver. Feeding with broccoli spouts significantly increased the activity of 2 and 3 isoforms of GST and GPx in murine liver compared to values in control mice and mice fed with cafeteria diet. Combination of Broccoli + Cafereria diet had small activating effects on antioxidant enzyme acivity, compared with cafeteria diet.

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The present study was assessed to determine the acute toxicity and changes in oxidative stress enzymes of Tubifex tubifex and to evaluate the acute toxicity and changes in oxidative stress enzymes, hematological and biochemical parameters, growth parameters of freshwater fish Oreochromis mossambicus during chronic exposure to Quinalphos. The study reveals that the 96h LC50 value of Quinalphos to T. tubifex and O. mossumbicus were 6.28 μg/l and 5.35 μg/l respectively. Besides, the exposed worms and fish also exhibited erratic behavioral responses at the acute level. Acute exposure of Quinalphos to T. tubifex induces alterations in oxidative stress enzymes including catalase (CAT), superoxide dismutase (SOD), glutathione S-transferase (GST), malondialdehyde (MDA), reduced glutathione (GSH), and glutathione peroxidase (GPx). Additionally, chronic exposure of Quinalphos to O. mossumbicus showed increasing the levels of liver CAT, SOD, GST, MDA, aspartate aminotransferase (AST) and alanine aminotransferase (ALT). Sublethal levels of Quinalphos elicited substantial changes in protein, glucose, albumin and creatinine of fish in compare to control. Quinalphos also effects different growth (GSI, SGR, FCR) and hematological parameters (the red blood cell, haemoglobin and haematocrit) of treated fish. Moreover, by using integrated biomarker response (IBR) and biomarker response index (BRI) the change in the health status of pesticide exposed fish was determined. These results indicate that Quinalphos alters the survivability and behavioral responses of T. tubifex and O. mossambicus at the acute level and changes the oxidative stress biomarkers, biochemical and hematological parameters of the fish during chronic exposure.

Rosemary and CoQ10 Alleviated the Detrimental Effects of Concomitant Administration of Acetaminophen and Carbamazepine by Accelerating Their Metabolism and Elimination

BACKGROUND: The interaction of carbamazepine (CBZ) and acetaminophen (APAP) could result in hepatic failure and mortality. This study was conducted to analyzed the potential of rosemary ethanol extract (REE) or coenzyme Q10 (CoQ10) to alleviate the interactions between CBZ and APAP.METHODS: Fourty-eight adult male rats were treated differently based on the assigned groups. Oxidative stress parameters, including malondialdehyde (MDA), glutathione (GSH), glutathione peroxidase (GPx), superoxide dismutase (SOD), catalase, and glutathione S-transferase (GST), and the expression levels of CYP3A4, CYP2E1, IL-6, TNF-α, and IL-1B in the liver were estimated. In addition, the histopathology of liver was examined and the plasma clearance rate of CBZ and APAP was estimated.RESULTS: Combination of CBZ and APAP significantly elevated alanine aminotransferase (ALT) activity and hepatic MDA, and reduced the activities of GPx, GST, and GSH level in liver. The gene expression of CYP3A4 and CYP2E1 was upregulated by CBZ and CoQ10, respectively. The expression of IL-6 has decreased in the groups treated with CBZ alone or in combination with APAP. TNF-α expression was significantly downregulated in the groups treated with CBZ, APAP, REE, CoQ10, or combination CBZ and APAP. The liver from CBZ and APAP combination group showed centrolobular degeneration and necrosis. REE and CoQ10 were able to alleviate most of these detrimental effects. The combined administration of CBZ and APAP extended the plasma clearance time of APAP and CBZ from 6 to 24 and from 9 to 24 hours, respectively.CONCLUSION: REE and CoQ10 alleviated the detrimental effects of the combination of CBZ and APAP through enhancing the cellular antioxidant milieu, induction of metabolizing enzymes, reduction of the plasma half-life of APAP and CBZ preventing their accumulation and potential interaction.KEYWORDS: acetaminophen, antioxidants, carbamazepine, CoQ10, CYP3A4, CYP2E1, glutathione, lipid peroxidation, rosemary

Investigation of the effect of N-acetylcysteine on aluminum phosphide toxicity in rats

Aluminum Phosphide (ALP) is one of the most dangerous pesticides. When it comes into contact with water, it emits Phosphine (PH3) gas, which causes poisoning and death in many people. The purpose of this study is to look into the role of N-acetylcysteine in the treatment of aluminum phosphide toxicity in rats. In this study, 30 male Wistar rats were fed with aluminum phosphide orally. After 15 minutes, N-acetylcysteine was administered intraperitoneally. The antioxidant enzymes glutathione S-Transferase (GST), Superoxide Dismutase (SOD), Catalase (CAT), glutathione (GSH), Aspartate Aminotransferase (AST), Alanine Transaminase (ALT), and Alkaline Phosphatase (ALK) were studied in blood plasma. CAT, GST, and GSH concentrations in plasma, liver, and kidneys of rats infected with aluminum phosphide decreased, while AST, ALT, and ALK concentrations increased. The levels of all enzymes studied approached normal after N-acetylcysteine administration, and the rats survived for up to 12-15 hours. According to the findings of this study, N-acetylcysteine (NAC) at a dose of 10 mg/kg improves hepatic manifestations and prevents liver necrosis, so it can be considered a potential therapeutic agent in the treatment of this poisoning.

Effects of white mustard (Sinapis alba) oil on growth performance, immune response, blood parameters, digestive and antioxidant enzyme activities in rainbow trout (Oncorhynchusmykiss)

A study was conducted to evaluate the effects of dietary supplementation of white mustard (Sinapis alba) oil (WMO) on growth performance, immune responses, digestive and antioxidant enzyme activities in juvenile rainbow trout (Oncorhynchus mykiss). For this purpose, fish (initial weight: 25.77 ± 0.13 g) were divided into four experimental groups in triplicate and fed ad libitum twice a day with diets containing WMO at 0 (control), 0.5, 1, and 1.5% of diet for 9 weeks. Three fish from each tank (n:9 per treatment) were sampled on 21st, 42nd, and 63rd days for further analyses. At the end of the feeding period, fish were challenged with Aeromonas hydrophila and Yersinia ruckeri in two separate experimental setups. Results showed that final weight, weight gain, and specific growth rate were significantly increased in all experimental groups compared to the control. Feed conversion ratio was similar among treatments. Respiratory burst and potential killing activity decreased in all experimental groups compared to the control (P < 0.05). Lysozyme and myeloperoxidase activities were elevated in all experimental groups at the end of the experiment compared to the control (P < 0.05). Cytokine gene expressions in the head kidney and intestine were elevated in all experimental groups compared to that of the control in general (P < 0.05). Hematological responses of the experimental fish groups were similar to that of the control (P > 0.05). Pepsin and trypsin levels decreased in all experimental groups (P < 0.05). In terms of antioxidant enzyme activities, significant improvement in liver superoxide dismutase, catalase, and glutathione s-transferase activities in all treatment groups were determined (P < 0.05). In addition, a significant decline in liver lipid peroxidation levels was recorded in all treated groups at all sampling times compared to the control (P < 0.05). At the end of this feeding trial, no significant differences (P > 0.05) were observed in survival against A. hydrophila among experimental groups compared to the control (P > 0.05). However, increased survival against Y. ruckeri was determined in experimental fish groups (P < 0.05). This study suggests that white mustard oil had a favorable effect on the overall health and growth of rainbow trout.

Effects of dietary pantothenic acid on growth, antioxidant ability and innate immune response in juvenile black carp

An 8-week feeding study was conducted to examine how dietary pantothenic acid (PA) affects growth, antioxidant ability and innate immunity in juvenile black carp (Mylopharyngodon piceus). Juvenile fish (7.35 ± 0.06 g) were fed diets with PA at 0, 5, 10, 20, 40 and 80 mg/kg, respectively. The highest weight gain (WG), specific growth rate (SGR) and protein efficiency ratio (PER) were obtained with 10 mg/kg dietary PA (p < 0.05), as well as the lowest feed conversion ratio (FCR). Adequate dietary PA (10 and 20 mg/kg) markedly upregulated neuropeptide Y (NPY), orexin (ORX) and ghrelin (GRL) and downregulated cholecystokinin (CCK) in the brain of these animals (p < 0.05). Intestinal sodium-dependent multivitamin transporter (SMVT) expression and α amylase, trypsin, chymotrypsin and lipase activities were all improved after supplementation of PA at 10 or 20 mg/kg (p < 0.05). In addition, adequate dietary PA (10 and 20 mg/kg) significantly increased the activities of antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX) and glutathione reductase (GR), as well as the amounts of reduced glutathione (GSH) and total antioxidant capacity (T-AOC) in the liver of these animals (p < 0.05). Meanwhile, liver glutathione S-transferase (GST) activity and malondialdehyde (MDA) amounts levels were both markedly decreased with dietary PA at 10 or 20 mg/kg (p < 0.05). Furthermore, adequate dietary PA significantly elevated the mRNA amounts of NFE2-related nuclear factor 2 (Nrf2) and downregulated Kelch-like-ECH-associated protein 1a (Keap1a) and Keap1b (p < 0.05), and remarkably upregulated innate defense molecules, including lysozyme (LYZ), natural resistance-associated macrophage protein (NRAMP), liver-expressed antimicrobial peptide 2 (LEAP-2), hepcidin (HEPC), complement 3 (C3) and complement 9 (C9) in the liver (p < 0.05). Meanwhile, elevated dietary PA resulted in increased LYZ activity and C3 content and decreased aspartate aminotransferase (ALT) and aspartate aminotransferase (AST) activities in serum samples from juvenile black carp compared with the groups fed PA-deficient diets (p < 0.05). Moreover, 10, 20 and 40 mg/kg PA-containing diets starkly downregulated intestinal interleukin 8 (IL-8) and IL-11 at the mRNA level in comparison with the PA-deficient diet (0 mg/kg) (p < 0.05). However, PA supplementation at 10, 20 or 40 mg/kg resulted in increased intestinal zonula occludens-1 (ZO-1), ZO-2, ZO-3, claudin 3, claudin 4, claudin 8, claudin 15 and occludin mRNA levels in M. piceus in comparison with the 0 mg/kg PA group (p < 0.05). Jointly, the above findings suggested adequate dietary PA (10 and 20 mg/kg) enhances feed utilization and growth performance, as well as antioxidant capacities and non-specific immune reactions in juvenile M. piceus.

The effects of dietary exposure to Magnéli phase titanium suboxide and titanium dioxide on rainbow trout (Oncorhynchus mykiss)

Magnéli phase titanium suboxides (Magnéli TiOx) are promising, novel materials with superior properties compared to TiO2, they are substoichiometric titanium oxides with the chemical formula TinO2n-1 (where n ≥ 1). In this study, for the first time, subchronic effects of dietary intake of Magnéli TiOx were evaluated and compared with TiO2 particles of similar size, in concentrations 0.1% and 0.01% of feed. The experiment consisted of 38 d of an exposition period and 14 d of a depuration period. Minor effects on plasma biochemical profile and morphological parameters were recorded. A reduced count of leukocytes was found in the blood of both Magnéli TiOx and TiO2 exposed fish, suggesting immunotoxic effects. Erythrocytosis was specific for Magnéli TiOx. Indices of oxidative stress, namely increased lipid peroxidation in liver, increased activity of superoxide dismutase in liver, kidney and gills and glutathione S-transferase (GST) in gills, as well as decreased activity of ceruloplasmin and GST in liver were found predominantly in fish exposed to TiO2. Histopathological examination revealed increased lipid-like vacuolation in the liver, the presence of hyaline droplets in renal tubules and multiplication of mucous glands in the epidermis in both tested substances and intestine damage in TiO2 groups.Overall, in Magnéli TiOx exposed groups, fewer adverse effects compared to TiO2 expositions were recorded. Their wider practical implementation in place of TiO2 is therefore beneficial.

Effect of a Sub-Chronic Oral Exposure of Broccoli (Brassica oleracea L. Var. Italica) By-Products Flour on the Physiological Parameters of FVB/N Mice: A Pilot Study.

Brassica by-products are a source of natural bioactive molecules such as glucosinolates and isothiocyanates, with potential applications in the nutraceutical and functional food industries. However, the effects of oral sub-chronic exposure to broccoli by-product flour (BF) have not yet been evaluated. The objective of this pilot study was to analyse the effects of BF intake in the physiological parameters of FVB/N mice fed a 6.7% BF-supplemented diet for 21 days. Glucosinolates and their derivatives were also quantified in plasma and urine. BF supplementation significantly decreased (p < 0.05) the accumulation of perirenal adipose tissue. Furthermore, mice supplemented with BF showed significantly lower (p < 0.01) microhematocrit values than control animals, but no impact on the general genotoxicological status nor relevant toxic effects on the liver and kidney were observed. Concerning hepatic and renal antioxidant response, BF supplementation induced a significant increase (p < 0.05) in the liver glutathione S-transferase (GST) levels. In BF-supplemented mice, plasma analysis revealed the presence of the glucosinolates glucobrassicin and glucoerucin, and the isothiocyanates sulforaphane and indole-3-carbinol. Overall, these results show that daily intake of a high dose of BF during three weeks is safe, and enables the bioavailability of beneficial glucosinolates and isothiocyanates. These results allow further testing of the benefits of this BF in animal models of disease, knowing that exposure of up to 6.7% BF does not present relevant toxicity.

Effects of melatonin and N-acetylcysteine on aluminum phosphide poisoning in rats.

Aluminum phosphide (ALP) poisoning is one of the deadliest types of poisoning in the world. The antioxidant properties of melatonin and N-acetylcysteine and their effects on reducing cell death have been identified. The aim of this study was to evaluate the effects of N-acetylcysteine and melatonin in the treatment of aluminum phosphide poisoning in rats. Fifty male Wistar rats weighing 200-250 g were tested in five groups of ten. The first group was the control group; the second group received (10 mg/kg) of ALP, the third group received (10 mg/kg) of ALP and (10 mg/kg) of melatonin, the fourth group received (10 mg/kg) of ALP and (10 mg/kg) of N-acetylcysteine, and the last group received (10 mg/kg) of ALP and (10 mg/kg) of melatonin and N-acetylcysteine. The plasma of samples was isolated, and the activity of antioxidant enzymes (glutathione S-transferase (GST), Superoxide dismutase (SOD), and catalase (CAT)) was analyzed. The concentrations of CAT, GST, Glutathione, GSH were decreased in plasma, liver, and kidneys of mice treated with aluminum phosphide; also, the concentrations of aspartate aminotransferase (AST), ALT, and AlK were increased (P < 0.05), while the activity of SOD did not change significantly (P > 0.05). Treatment with N-acetylcysteine and melatonin led to an increase in the activity of CAT, GST, and GSH in plasma, liver, and kidney. After the administration of N-acetylcysteine and melatonin to mice, the levels of all enzymes were close to normal, and the mice survived for 12-15 hours after administration. The administration of N-acetylcysteine (NAC) and melatonin at a dose of 10 mg/kg improves hepatic manifestations and prevents liver necrosis; also, they are considered potential therapeutic agents in the treatment of this poisoning.

A typical enzyme activity for glutathione conjugation indicates exposure of pacu to pollutants

Abstract Functional enzyme assays to detect sublethal poisoning of Neotropical fish are paramount. Accordingly, we assayed a glutathione S-transferase (GST) activity in liver and kidney cytosols from Piaractus mesopotamicus injected with methyl parathion or benzo[a]pyrene using the substrate 1-chloro-2,4-dinitrobenzene (CDNB), which is the usual substrate for assaying a known general activity of GST. Since the most reactive substrate is required to reveal specific changes in enzyme activity, we also used two alternative substrates, 1,2-dichloro-4-nitrobenzene (DCNB) and ethacrynic acid (ETHA). Activities with CDNB or ETHA did not change. However, assays with DCNB showed that methyl parathion caused a decrease in GST activity in the liver on the 24th, 48th and 96th hour after the injection. DCNB also revealed that GST activity in the liver increased seven days after benzo[a]pyrene injection, coming down to normal after fourteen days. Benzo[a]pyrene, but not methyl parathion, increased the activities with DCNB in cytosol from the kidney seven and fourteen days after the injection. Thus, a decreased liver GST activity assayed with DCNB corresponded to contamination of P. mesopotamicus with methyl parathion. The increase of this GST activity in the liver and the kidney correlates to pacu contamination with polycyclic aromatic hydrocarbons.

Boric acid supplementation affects antioxidant activity in ovariectomized female rats

This study aimed to investigate the protective effect of boric acid (BA) supplementation against oxidative stress (OS) in ovariectomized rats. A total of 48 nonpregnant female Wistar albino rats (180-250 g) were used in the experiment. The rats were divided into six equal groups (n = 8): Control, OVX, OVX + 5 mg/kg BA (OVX + BA5), OVX + 10 mg/kg BA (OVX + BA10), 5 mg/kg BA (BA5), and 10 mg/kg BA (BA10). The rats were intraperitoneally anesthetized with a combination of ketamine hydrochloride (85 mg/kg) and xylazine (10 mg/kg) and underwent a bilateral ovariectomy. Supplementation with 5 mg/kg and 10 mg/kg BA via oral gavage was started 2 weeks after ovariectomy and continued for 20 days. Catalase (CAT), glutathione S-transferase (GST), glutathione peroxidase (GPx), glutathione (GSH), and malondialdehyde (MDA) levels in the liver, kidney, and brain tissues of rats were analyzed by the spectrophotometric method. MDA concentrations in the liver tissue was increased in the OVX rats compared to the control group (p &lt;0.05). Liver GST activity was significantly decreased in the OVX rats, but it was increased with 5 mg/kg and 10 mg/kg BA supplementation (p &lt;0.05). Mean kidney GSH, GPx, and CAT activities in the OVX rats were increased with 5 mg/kg and 10 mg/kg BA supplementation (p &lt;0.05). In the brain tissue, GST activity was increased in the OVX rats treated with 10 mg/kg BA (p &lt;0.05). These results indicate that BA supplementation can enhance antioxidant defense mechanisms against OS after ovariectomy in female rats.

Impacts of some metal ions on glutathione s-transferase in the liver of Chalcalburnus tarichi: an endemic species of Lake Van.

Glutathione-S-transferase (GSTs) is a multifunctional enzyme that provides homeostasis by catalyzing the first step of the formation of mercapturic acid, the end product in detoxification metabolism. They can prevent reactive electrophilic compounds from harming the body by covalently binding the same type of compounds to each other. In this study, we determined the in vitro inhibitory effects of metal ions such as Cu2+, Cd2+, Ag+, and Co2+ on GST enzyme activity. For this aim, GST was purified from C. tarichi Pallas liver with 37.36% yield and 29.304 EU/mg specific activity using the chromatographic method. The Vmax values of liver GST were determined for CDNB and GSH to be 1.245 and 0.562 EU/mL, respectively, and the Km values were found 0.89 and 0.06 mM, respectively, using the Lineweaver-Burk plot. The effects of the metal ions at different concentrations on in vitro GST activity were studied. The IC50 values were determined for Cu+2, Cd+2, Ag+, and Co+2 as 0.163, 0.235, 0.00021, and 0.446 mM, respectively. The Ki constants were determined as 0.049 ± 0.009, 0.117 ± 0.031, 0.002 ± 0.0007, and 0.893 ± 0.3 mM, respectively. Ag+ showed the best inhibitory effect among the studied metal ions. Cd2+, Cu2+ and Co2+ showed a competitive inhibition mechanism, while Ag+ was noncompetitive.

Evaluation of the acute toxic effects of crude oil on intertidal mudskipper (Boleophthalmus pectinirostris) based on antioxidant enzyme activity and the integrated biomarker response

With the development of marine oil industry, oil spill accidents will inevitably occur, further polluting the intertidal zone and causing biological poisoning. The muddy intertidal zone and Boleophthalmus pectinirostris were selected as the research objects to conduct indoor acute exposure experiments within 48 h of crude oil pollution. Statistical analysis was used to reveal the activity changes of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione S-transferase (GST) in the gills and liver of mudskipper. Then, integrated biomarker response (IBR) indicators were established to comprehensively evaluate the biological toxicity. The results showed that the activities of SOD, CAT and GST in livers were higher than those in gills, and the maximum induction multipliers of SOD, CAT and GPx in livers appeared earlier than those in gills. Both SOD and GPx activities were induced at low pollutant concentrations and inhibited at high pollutant concentrations. For the dose-effect, the change trends of CAT and SOD were roughly inversed. There was substrate competition between GPx and CAT, with opposite trends over time. The activating mechanism of GST was similar to that of GPx, and the activation time was earlier than that of GPx. In terms of dose-effect trends, the IBR showed that the antioxidant enzymes activities in biological tissues were induced by low and inhibited by high pollutant concentrations. Overall, SOD and GPx in gills and CAT and GST in livers of the mudskippers were suitable as representative markers to comprehensively analyze and evaluate the biotoxicity effects of oil pollution in the intertidal zone. The star plots and IBR values obtained after data standardization were consistent with the enzyme activity differences, which can be used as valid supplementary indexes for biotoxicity evaluation. These research findings provide theoretical support for early indicators of biological toxicity after crude oil pollution in intertidal zones.

λ cyhalothrin induced toxicity and potential attenuation of hematological, biochemical, enzymological and stress biomarkers in Cyprinus carpio L. at environmentally relevant concentrations: A multiple biomarker approach

The present study was aimed to evaluate the toxic effects of a commonly used synthetic pyrethroid, λ cyhalothrin on the common carp, Cyprinus carpio L. The results depicted that 96 h LC50 value of λ cyhalothrin to the fish was 1.48 μg l−1. During 45 days of chronic exposure a significant reduction (p < 0.05) in the RBC, hemoglobin, and hematocrit value of fish was observed in λ cyhalothrin treated fish. Blood glucose, cholesterol and creatinine levels increased significantly, while total protein and albumin were significantly decreased (p < 0.05) in the exposed fish. Moreover, alanine aminotransferase and aspartate aminotransferase levels in the blood also increased significantly (p < 0.05) in the treated fish. In gills and liver, glutathione S-transferase (GST) and glutathione peroxidase (GPx) and in liver GST exhibited a significant initial augmentation followed by a subsequent reduction while catalase (CAT), superoxide dismutase (SOD), and malondialdehyde (MDA) level increased markedly with incrementing concentrations of λ cyhalothrin in both the organs. Acetylcholinesterase (AchE) activity in both gills and liver decreased in exposed fish upon addition λ cyhalothrin. However, the hazardous effects of λ cyhalothrin on C. carpio were characterized and portrayed by the development of integrated biomarker response (IBR), and biomarker response index (BRI). GUTS-SD and IT modeling were implied for a better interpretation of the toxicity. These results indicate that exposure to λ cyhalothrin alters the survivability at the acute level and the activity of hematological, plasma biochemical as well as enzymological and stress parameters (in gills and liver) at the sublethal level in C. carpio.

Identification of triterpenoids and hepatoprotective property of Fructus Rosa roxburghii against alcohol-induced liver injury by regulating keap1- Nrf2 signaling

Background Fructus Rose roxburghii is a popular edible fruit with high nutritional and medicinal value, which was effective on anti-alcohol and liver-protection in southwest China.Purpose The aim of this study was to determine main chemical composition of the extract enriched in triterpenoids from Fructus R. roxburghii (TFRr) using UPLC-MS/MS and to investigate the hepatoprotective effects and molecular mechanisms of TFRr in mice with alcohol-induced liver injury.Methods TFRr were isolated from 75% ethanol extract of Fructus R. roxburghii and chemical constituents of TFRr were analyzed using UPLC-MS/MS. Male Kun-Ming mice were randomly divided into two experimental groups (TFRr groups (50 mg/kg) and TFRr groups (100 mg/kg)) and two control groups (normal control group and 53% ethanol group). Liver injury in mice was induced by oral administration with Lieber-DeCarli liquid diet mixing with 53% ethanol. After 10 days of treatment, the mice were weighed and treated with inhaling diethyl ether to anesthetize, then, the blood and liver tissue samples were gathered for molecular analysis and histological examination. The alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in mice serum and the superoxide dismutase (SOD) activity, glutathione peroxidase (GSH) activity and malondialdehyde (MDA) levels in mice liver were detected by Elisa kits. Western blot analysis was carried out to detect the protein expression levels of nuclear factor-erythroid-related factor-2 (Nrf2), heme oxygenase-1 (HO-1), glutamate-cysteine ligase catalytic subunit (GCLC), glutamate-cysteine ligase regulatory subunit (GCLM), SOD1, glutathione S-transferase (GST) and Keap1 in liver tissues.Results Five triterpenoids (kaji-ichigoside F1, rosamultin, tormentic acid, roxburic acid, and pomonic acid) from TFRr extract were identified. TFRr treatment diminished the effects of LPS on the serum levels of AST and ALT in mice as well as MDA, SOD and GSH in liver. In addition, the protein expression levels of Nrf2 target genes, consisting of HO-1, SOD1, GST, GCLM, and GCLC were significantly upregulated by TFRr suggesting TFRr significantly attenuates the alcohol-induced liver injury by Keap1-Nrf2 signaling pathway.Conclusions These results show TFRr has the profoundly protective roles against ethanol-induced liver injury in mice models via Nrf2-Keap1 signaling pathway. Our results suggested that it is rationale to explore the application of extract enriched with active triterpenoids from Fructus Rosa roxburghii in the development of liver protectants.