Liver GST Activity Research Articles

Acute toxicity, biochemical and histological of fenitrothion and thiobencarb on fish Nile tilapia (Oreochromis niloticus)

Abstract. Fouad MR, El-Aswad AF, Aly MI. 2022. Acute toxicity, biochemical and histological of fenitrothion and thiobencarb on fish Nile tilapia (Oreochromis niloticus). Nusantara Bioscience 14: 217-226. The results show that the tested fenitrothion and thiobencarb are highly toxic to fish. However, fenitrothion is more toxic (1.6 times) on Oreochromis niloticus (Linnaeus, 1758) than thiobencarb. The determined 96-h LC50 values using a static bioassay system to Nile tilapia fingerlings (8-10 g) were 0.20 and 0.32 mg L-1 for fenitrothion and thiobencarb, respectively. The mortality rate of fish exposed to ½ 96-h LC50 of fenitrothion (0.10 mg/L) and thiobencarb (0.16 mg/L) for four days demonstrated was 20% mortality rate. Fish showed tremors, lethargy, decreased movement, and increased respiratory rhythm. The total activity of AChE in control was 5.61 ±0.03; it was significantly reduced to 4.92 ±0.03 in fenitrothion treatment and 1.13 ±0.02 in thiobencarb treatment. Fenitrothion decreased the specific activity from 0.83 ±0.01 for the control to 0.68 ±0.01, whereas thiobencarb reduced the specific activity to 0.22 ±0.01. Generally, thiobencarb inhibited AChE activity much more than fenitrothion; it produced 80% inhibition, while fenitrothion produced 12.5% inhibition. It showed a significant increase in liver GST and SOD activity of Nile tilapia exposed to the tested pesticides compared to the control. There were no histological alterations in the tissues of the control individuals. It was found that the herbicide thiobencarb affected the gills, kidneys, and liver of Nile tilapia more than the insecticide fenitrothion.

Enzyme biomarker response in Zenaida asiatica from an agricultural area of Campeche, Mexico

Objective: To evaluate the response of CAT, AChE, and GST enzyme biomarkers in Zenaida asiatica from an agricultural area of the municipality of Champotón, Campeche. Design/methodology/approach: The biomarkers AChE, CAT, and GST were analyzed in tissues of 24 birds from backyards and agricultural areas of Champotón, Campeche. The enzymatic activities in the tissues were compared by means of a t test and comparison of means (Tukey p≤0.05), with the Statistica v. 7 software. Results: The highest AChE activity occurred in the brain (p=0.00001), CAT activity in liver (p=0.00001), and GST activity in liver and brain (p=0.001). Study limitations/implications: To evaluate the effect of pesticides on wild birds, a larger number of individuals is required in different agricultural areas. Findings/conclusions: In the tissues of Z. asiatica from agricultural areas, greater activity of the biomarkers AChE, CAT, and GST was found, reflecting the excessive use of pesticides.

Acute and sub‐lethal effects of nitrate on haematological and oxidative stress parameters of juvenile mullet (Mugil liza) in freshwater

This study aimed to evaluate the effects of nitrate (NO3–N) in juvenile mullet in freshwater. Experiment 1 evaluated the LC50-96h of fish at five different NO3–N concentrations (0.01, 85.32, 462.12, 851.25 and 955.25 mg L−1). Experiment 2 evaluated haematological and oxidative stress variables in fish exposed to four NO3–N concentrations (0.01, 8.16, 33.83 and 52.66 mg L−1) for 5 days. The safe concentration for 96 h was 60.61 mg NO3–N L−1. In experiment 2, blood glucose and haematological values were lower in fish subjected to 52.66 mg NO3–N L−1 compared with the other treatments on day 1. On day 5, fish subjected to the two highest NO3–N concentrations had blood glucose and erythrocytes levels as well as gills and liver ACAP values significantly higher than the control group. Fish exposed to 52.66 mg NO3–N L−1 showed reduced GST activity in gills, liver and muscle on day 5 compared with day 1. In general, exposure to nitrate did not induce an increase in the TBARS levels in the tissues evaluated. In conclusion, acute exposure to 52.66 mg NO3–N L−1 impacted the physiological homeostasis of mullets, but it did not cause lipid peroxidation.

Antioxidant and non-specific immune defenses in partially freeze-tolerant Xizang plateau frogs, Nanorana parkeri.

The Xizang plateau frog Nanorana parkeri can tolerate brief and partial freezing of their body. To determine the significant role of antioxidant defense and non-specific immune defense in freezing survival of this species, we assayed parameters of oxidative damage, antioxidant defense and non-specific immune enzymes during freezing exposure (-2°C for 12h) in five organs (heart, brain, liver, kidney, and skeletal muscle). The results showed that freezing led to a significant rise in the content of malondialdehyde (MDA) and carbonyl groups (CG) in brain, liver and kidney tissues. The activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX) increased significantly in brain and liver tissues with an augmentation of total antioxidant capacity (T-AOC). Apparent increments in muscle SOD activity and liver GST activity were also observed during freezing exposure. Vitamin C content significantly decreased in liver and kidney but a significant increase occurred in brain. Activities of non-specific immune enzymes, acid phosphatase (ACP) and alkaline phosphatase (AKP), were also assessed. ACP activity was significantly reduced in all five tissues tested whereas AKP activity decreased significantly in four tissues but rose in brain. In summary, freezing is accompanied by oxidative stress in the high-altitude frog, N. parkeri, as documented by increases in the content of MDA and CG in tissues. Freezing exposure also induced tissue-specific changes in the antioxidant defenses showing that activation of antioxidant systems is a part of the survival strategy of this in a high-altitude frog during freezing. Such up-regulation of antioxidant enzymes suggests a particularly important role for them in the liver and brain, serving as an anticipatory mechanism to deal with the ROS challenge during freeze/thaw episodes. Our findings contribute to extending the current understanding of the mechanisms of freeze tolerance in high-altitude frogs.

Vitamin C supplementation in aquaculture activities

Neste estudo, investigaram-se os efeitos de diferentes níveis de vitamina C na dieta de peixes com biomarcadores de estresse oxidativo e parâmetros hematológicos em jundiás. Os juvenis foram divididos em três grupos e alimentados com diferentes quantidades de vitamina C: 1) 0, 2) 500 e 3) 1.000 mg kg-1. Dez peixes por grupo foram coletados em 0, 14 e 28 dias após o início do experimento. A atividade da catalase hepática aumentou no grupo 1 após 28 dias. A atividade da GPx nas brânquias diminuiu em todos os grupos, e a GPx hepática aumentou nos grupos alimentados com vitamina C. A atividade hepática da SOD e os níveis de NPSH nas brânquias e no fígado não foram afetados. Em todos os grupos, a atividade GST diminuiu nas brânquias e aumentou no fígado. Os níveis de peroxidação lipídica diminuíram no fígado e nas brânquias para os grupos 2 e 3. Os resultados deste estudo indicam que ambas as dietas, com 500 ou 1.000 mg/kg de vitamina C, contribuíram para diminuir o dano oxidativo de Rhamdia quelen, sugerindo que a suplementação de vitamina C no presente modelo experimental pode ser útil na aquicultura para superar possíveis mudanças oxidativas induzidas por condições ambientais adversas.

Differential modulation of cellular antioxidant status in zebrafish liver and kidney exposed to low dose arsenic trioxide

Zebrafish were exposed to a nonlethal dose (1/350LC50; 50µg/L) of As2O3 and sampled at 7, 15, 30, 60 and 90 days of treatment. The oxidative stress response was assessed in terms of time-dependent histopathological changes, lipid peroxidation, GSH status, activities of detoxification enzymes and expression of antioxidant genes in liver and kidney. As2O3 treatment enhanced lipid peroxidation except at day 90 in liver and day 30 in kidney. Glutathione depleted significantly in the liver except on day 30; whereas in kidney, it increased initially but thereafter depleted significantly. The liver GST activity was high until day 30, low on day 60 and high on day 90. On the other hand, activity of GST in kidney remained high throughout the exposure. GR activity in liver decreased initially but augmented from 30 days onwards whereas in kidney it remained high until 30 days of exposure. Significant increase in GPx and CAT activities in liver and kidney confirmed oxidative stress in zebrafish which correlated with mRNA expression of antioxidant genes. Upregulation in mRNA level of Cu-Zn Sod in liver and kidney was prominent. Gpx1 upregulation was more conspicuous in kidney as compared to liver while the pattern of Cat expression was almost similar in both the organs. Among the mitochondrial genes, expression of Cox1 was significantly high only after 90 days in liver, while in kidney it enhanced at 7, 30 and 60 days of arsenic exposure. Ucp2 was upregulated in liver after 15 days of exposure but significantly downregulated at day 90; in kidney it remained unchanged at other time points except at day 90. An overall increased expression of Bcl2 further confirmed As2O3 induced oxidative stress in zebrafish liver and kidney. The pattern of mRNA expression of Nrf2 was not uniform and was in accordance to its downstream antioxidant genes. Present findings elucidate that low dose of As2O3 exposure induces a time dependent differential modulation of antioxidant status in liver and kidney of zebrafish in a tissue-specific manner.

Reduced body condition and enzymatic alterations in frogs inhabiting intensive crop production areas

Parameters indicative of general condition and health were compared amongst adult frogs inhabiting uncultivated lands and fields subjected to agricultural practices typical of the humid pampas of Argentina. Whereas no significant differences existed in the parasite load and external malformations prevalence rate of adult frogs from either environments, a reduced condition factor was clearly demonstrated in frogs from agricultural lands. This conclusion was reached for four frog species of different life habits: the terrestrial fossorial Rhinella fernandezae, the terrestrial Leptodactylus latinasus, the semi-aquatic Leptodactylus ocellatus, and the arborescent Hypsiboas pulchellus. A distinct pattern of enzymatic modifications was furthermore observed in L. ocellatus and H. pulchellus from agricultural lands, including elevated hepatic activities of catalase and cholinesterase, and an inhibition of liver GST activity. Further studies should investigate the causes and consequences of the systematically low condition factor observed in frogs from agricultural fields of the humid pampas of Argentina.

Sublethal effects of pesticide mixtures on selected biomarkers of Carassius auratus

In the present study, the in vivo effects of commercial propoxur alone and in combination with isoprocarb and chlorpyrifos on acetylcholinesterase and glutathione S-transferases activities in goldfish ( Carassius auratus) were investigated. Brain and muscle AChE activity was significantly inhibited (88% and 85% at most, respectively) by propoxur after 5 d of exposure at concentrations between 141 and 2263 μg/L, bell-shaped concentration–response curves were obtained. In most cases, time dependence was apparent. Under insecticide mixture exposure (binary mixture propoxur/isoprocarb and ternary mixture propoxur/isoprocarb/chlorpyrifos), the inhibition of AChE activity was significant in all cases and linear concentration–response relationships were observed. Propoxur (alone and in combination) significantly inhibited gill GST activity, and both mixtures also induced significant inhibition of liver GST activity. However, concentration and time dependence were not apparent. AChE is likely to be more informative than GST and seems to be a good biomarker to diagnose exposure to anticholinesterase pesticides in wild populations of this species.

Antidiabetic and antioxidant effect of Panax ginseng

The present study was conducted to investigate the biochemical and immunomodulatory effects of Panax ginseng (Araliaceae) roots on diabetic, obese and obese diabetic rats. In this regard, 120 rats were divided into eight groups; control, normal treated, diabetic, treated diabetic, obese, treated obese, obese diabetic and treated obese diabetic groups. Blood glucose, serum IL-6 and TNF-α level showed highly significant increase (P<0.005) in diabetic, obese and obese-diabetic groups (non-treated groups) as compared with the control group. These values showed highly significant decrease after treatment (22.5mg/kg b.w. orally/day) with Ginseng extract (P<0.005). Plasma insulin level showed highly significant increases (P<0.005) in both obese and obese-diabetic groups while in the diabetic group it showed a highly significant decrease (P<0.005) as compared with the control group. On the contrary, both of the treated obese and treated obese-diabetic groups showed significant decreases in plasma insulin level, (P<0.05) while the treated diabetic group showed a highly significant increase (P<0.005) as compared with non-treated groups. Serum triglyceride-Total cholesterol -LDL-cholesterol level increased highly significantly (P<0.005) in non-treated groups as compared with the control group while it decreased highly significantly in treated groups as compared with non-treated groups, but HDL-cholesterol level showed highly significant decreases in non-treated groups as compared with the control groups and showed highly significant increases (P<0.005) in the treated groups toward normal value as compared with non-treated groups. GST, GSH, SOD and GSH-PX activity in both liver and kidney tissue showed significant decreases (P<0.05) in non-treated groups as compared with the control group. These results showed significant increases in both of treated diabetic and treated obese-diabetic groups and a non-significant increase in the treated obese group as compared with non-treated groups. MDA (malondialdehyde) levels showed highly significant increase (P<0.005) in the diabetic and obese diabetic groups. After treatment with ginseng significant decreases in MDA levels were observed. In conclusion, Panax ginseng has antidiabetic and antioxidant properties

Hepatic and extrahepatic expression of glutathione S-transferase isozymes in mice and its modulation by naturally occurring phenolic acids

A simple plant phenolic acid, protocatechuic acid and a polyphenol, tannic acid are potential chemopreventive agents which inhibited the chemically induced carcinogenesis in many experimental models. We previously demonstrated that those compounds modulate the activity of xenobiotic detoxifying enzymes, including GST in mouse liver, kidney and epidermis. Intraperitoneal (i.p.) treatment with protocatechuic acid in the dose of 80 mg/kg for three consecutive days increased the GST activity in liver and kidney. In case of tannic acid the same effect was observed in kidney after i.p. administration of the single dose of 80 mg/kg. Topical application of phenolic acids resulted in enhancement of epidermal GST activity. The focus of this study was to further investigate the effects of these phenolic acids on the protein levels of GST isozymes in the same tissues using the treatment protocols used in our previous studies. The results confirmed the expression of GST alfa, mu, pi and theta in mouse liver, kidney and epidermis. Treatment with protocatechuic acid resulted in an increase of the expression of GST class mu in liver, but did not affect this isoform in skin and kidney. This compound inhibited the level of kidney GST pi by 35%. Tannic acid decreased the expression of GST mu, alpha and theta in liver. Application of the equimolar doses of both phenolic acids on mouse skin resulted in reduced level of the GST alpha protein. The results of our study indicate that, although moderate, the effect of protocatechuic acid and tannic acid on GST subunits in mice may play certain role in biological activity of these compounds. Of special importance could be the increased expression of GST mu in liver which is involved in detoxification of many carcinogens including polycyclic aromatic hydrocarbons.

Biochemical, physiological, and histological changes in the neotropical fish Prochilodus lineatus exposed to diesel oil

Toxicity tests were conducted simulating a diesel oil spill in a tropical environment and juveniles of Prochilodus lineatus were exposed to the water-soluble fraction of diesel oil (WSD) for 6, 24, 96 h, and 15 days. The results showed the activation of biotransformation pathways for xenobiotics, through a time-dependent increase of liver GST activity. WSD caused a decrease in hematocrit and hemoglobin content, very likely due to hemolysis. Furthermore, an increase in glucose levels was observed after acute exposure to WSD. A possible lack of cortisol response could also be associated with WSD, since a reduction in plasma cortisol was seen in fish exposed to the petroleum product for 15 days. Moreover, the occurrence of lesions in the gills and even more severe lesions in the liver, should lead to functional damage to both organs, interfering thus directly with fundamental processes for the maintenance of homeostasis in this fish.

Field studies of eelpout (Zoarces viviparus L.) from Polish coastal waters (southern Baltic Sea)

The aim of the presented studies was to detect the possible effects of contaminants on the physiological and biochemical parameters of eelpout females from the southern Baltic. Eeelpout was sampled in Polish coastal waters during November 2001, 2002 and 2003. The integrated studies included measurements of selected biomarkers in fish as well as the analysis of female reproductive capacity and fry malformation frequencies in relation to environmental conditions in examined areas. The mean values of relative fecundity (RF) and embryo somatic (ESI) indexes were the highest at the reference site. The frequency of females carrying dead and malformed fry was the highest at selected sites from the outer and inner part of the Gulf of Gdansk. The highest mean activity levels of muscular AChE were noted in fish sampled at the reference site and one site from the outer part of the gulf, whereas liver GST activity was the highest in samples from other site from the outer part of the gulf and the reference site. The results of trace metals analyses in fish muscle and liver did not indicate any substantial differences in the mean tissue concentrations between samples from contaminated sites and the reference site. The concentrations of PCBs, HCHs and DDTs in liver were markedly higher at three contaminated sites in comparison with the other sites. A similar pattern was observed in muscle tissue. Based on the preceding evidence, it cannot be concluded unequivocally that these studies on the physiology, biochemistry and contaminant concentrations of eelpout females provide evidence that the contaminants present in the coastal areas of the Polish part of the southern Baltic Sea have a harmful impact on this species.

The effect of long-term depuration on phase I and phase II biotransformation in mullets (Mugil cephalus) chronically exposed to pollutants in River Douro Estuary, Portugal

Pollutants such polycyclic aromatic hydrocarbons (PAHs) are released into the environment by urban communities and industries and the enzymes that catalyse the biotransformation of pollutants play a key role regarding the accumulation of these compounds in fish species inhabiting these areas. In this study the relationship between phase I (EROD activity) and phase II (GST activity) and PAH metabolites was measured in grey mullet (Mugil cephalus) after capture in the Douro estuary, and after long-term depuration in an unpolluted laboratory environment. The results showed a significant decrease in EROD activity after 1 month and in bile metabolites after 4 months in captivity, with both maintaining reduced levels at 4 and 8 months depuration. Liver GST activity did not showed significant changes. This study provides evidence that Douro estuary waters contain bioavailable PAHs that can be associated with the induction of cytochrome P450, and that mullets have the ability to metabolise and eliminate PAHs.

Inhibition of PhIP-induced mammary carcinogenesis in female rats by ingestion of freeze-dried beer

This study evaluated the modulating effect of non-alcoholic constituents of beer on 2-amino-1-methyl-6-phenylimidazo[4,5- b]pyridine (PhIP)-induced mammary carcinogenesis. Female Sprague–Dawley (SD) rats at 6 weeks of age were divided into four groups ( n=26–30) and fed either a high fat diet or high fat diets containing 1, 2 or 4% freeze-dried beer (FD beer). One week after the start of feeding, rats received PhIP at a dose of 85 mg/kg by gavage four times weekly for 2 weeks. There were no differences in the body weights or diet intakes of rats between the control and the experimental groups. Weekly observation of palpable tumors indicated that tumor incidence and tumor multiplicity in the 2 and 4% FD beer groups were lower than in the control group throughout the experiment. Neoplastic lesions were pathologically examined at the end of the 22-weeks experiment. Tumor development was inhibited by FD beer intake in a dose-dependent manner. Tumor incidence (38.5%) and tumor multiplicity (0.8±0.4) for the group fed with a diet containing 4% FD were significantly reduced as compared with the control group (73.3% and 1.8±0.7). Supplementation with FD beer for 3 weeks together with the PhIP treatments resulted in increased liver GST activity, decreased liver CYP1A2 activity and a decrease in the number of DNA adducts in the mammary tissue, though these values were not significant. In conclusion, our results suggest that intake of FD beer may reduce the risk of carcinogenesis caused by heterocyclic amines.

CYP1A and phase II responses of Scophthalmus maximus upon long-term repeated exposure to B(a)P and B(a)P-PCB77 mixtures

In a controlled laboratory experiment, fish in two treatment groups were exposed to B(a)P or B(a)P+PCB77 repeatedly over 1 year. Fish were held in a flow-through system and sampled on day 0, week 3, and on months 3, 6, 9, and 12. Each sampling (except week 3) was followed by exposure in water under static conditions. Exposure was terminated by restoring the flow-through within a maximum period of 24 h. Hepatic CYP1A remained significantly induced in juveniles even 3 months after the first exposure. The induction response in liver was more persistent in comparison to the gill response in juveniles. Sex influenced CYP1A expression in both organs of control fish and in both exposure groups. Suppression of CYP1A occurred in females even under repeated exposure. Liver GST activity showed sex differences, control females having higher activities than control males on the same sampling day. GST activity showed increases and decreases under both exposures possibly indicating the overriding influence of some other factors. Increased levels of fluorescent aromatic compounds (FACs) were detected in bile only in females exposed to B(a)P and PCB77 for 9 months. Liver UDPGT activity, length, weight, and condition showed no differences related to exposure or gender. The study was supported by Norwegian Research Council and the Ministry of Oil and Energy in Norway.

Effects of C60, a Fullerene, on the Activities of Glutathione S-Transferase and Glutathione-Related Enzymes in Rodent and Human Livers

The effects of C60, a fullerene, on the activities of glutathione 5-transferase (GST), glutathione peroxidase (GSH-Px) and glutathione reductase (GR) in rodent and human livers were investigated. the GST activity in rat liver towards frans-4-phenyl-3-buten-2-one and that in mouse liver towards ethacrynic acid were inhibited by C60- the GST activity towards 1,2-dichloro-4-nitrobenzene, isomerase activity of GST towards androst-5-ene-3,17-dione, GSH-Px activity and GR activity were not affected by C60 a kinetic study using purified mouse GST-π with ethacrynic acid (25-100 μM) as the substrate revealed that C60 was a non-competitive inhibitor of the enzyme with a Ki = 48.8 ± 0.25 μM and a Ki = 47.9 ±0.18 μM. However, C60 did not inhibit the activity of purified mouse GST-π towards l-chloro-2,4-dinitrobenzene. Thus, the inhibition by C60 appears to be substrate-specific. In human liver, C60 inhibited the GST activity towards ethacrynic acid, and moderately inhibited GSH-Px and GR activities.

Alterations in isoforms of glutathione S-transferase in liver and kidney of cadmium exposed rhesus monkeys: purification and kinetic characterization.

Exposure of animals to cadmium (Cd) (25 mg kg(-1) body wt day(-1)) for 10 weeks resulted in preferential accumulation of the metal in liver and kidney. Cd accumulation concomitantly increased zinc (Zn) concentration in both the organs. However, significant decrease in copper level was observed in liver, whereas kidney showed increase in copper (Cu) level. Cd exposure resulted in decreased total GST activity in liver (63%) and kidney (41%) as compared to control group monkeys on normal diet (group I). On isoelectric focusing (IEF) control liver GST segregated into thirteen isoenzymes, while in Cd-treated experimental animals (group II) liver GST resolved into nine isoenzymes. Similarly kidney GST from control animals separated into seven isoenzymes as compared to four isoenzymes from Cd-treated animals. Kinetic analysis showed that Cd exposure did not alter the affinity constant (Km) of GST for GSH and CDNB whereas maximal velocity (Vmax) for these substrates decreased as compared to controls in both the organs, indicating inhibition in GST synthesis by Cd. Cd resulted in a noncompetitive type of inhibition with respect to GSH in vitro. On isoelectric focussing GST of liver and kidney in group II resolved into nine and four isoenzymes as compared to thirteen and seven in group I, showing loss of four basic isoenzymes in case of liver and three isoenzymes in case of kidney. Monkey liver and kidney expressed all the three classes of GST isoenzymes i.e. alpha, mu and pi, which were serologically identical to human alpha, mu and pi GSTs.

Pesticides as activators of mouse liver microsomal glutathione S-transferase

Selected sulfhydryl-reactive pesticides activate mouse liver microsomal glutathione S-transferase (GST m) assayed in purified form free from cytosolic transferases (GST cs) with 1-chloro-2,4-dinitrobenzene as the substrate. Maximum activations were as follows: 1315% for N-ethylmaleimide (positive control) at 1 m M, 374% for chloranil at 0.01 m M, 272% for EPTC sulfoxide at 10 m M, 255% for captan at 0.1 m M, 228% for acrolein at 1 m M, and 152% for methyl isothiocyanate at 10 m M. Pesticides which showed little or no activation were alachlor, atrazine, tetramethrin, and tridiphane. The toxicological relevance of GST m activation was examined with the aforementioned activators plus EPTC and allyl alcohol. Experiments were conducted in vitro or in vivo with washed microsomes (which contain not only GST m but also some GST cs) and the post-mitochondrial supernatant fraction with its high GST c activity. These studies established that GST m, either unactivated or activated, was not a significant contributor to overall mouse liver GST activity.