Impact of deltamethrin exposure on mRNA expression levels of metallothionein A, B and cytochrome P450 1A in rainbow trout muscles

Metallothionein as a biomarker of aquatic contamination in fish: An in silico and in vitro approach using zebrafish as experimental model organism

Human activities contaminate aquatic ecosystems with chemicals like metals and pesticides. Fish, sensitive to pollution, are key toxicological models. Metallothionein (Mt) expression, a biomarker for metal contamination, varies depending on the chemical exposure. This study investigated differences in metal affinity for Zn2+ binding sites of proteins and Mt induction by the insecticides dichlorvos (DDPV) and deltamethrin (DTM) in Danio rerio. First, D. rerio Zn-binding protein structures with different cell functions were used to evaluate the difference between the binding scores of five metals with the binding site with highest affinity for Zn2+ through molecular docking and from there to infer the most potent inducers. Cadmium ion was found to have the highest binding score mean for the selected proteins (Cd2+>Cu2+>Pb2+>Mn2+>Cu+>Hg2+), and, thus, cadmium chloride (CdCl2) was used as a positive control for Mt induction in D. rerio larvae. D. rerio embryos were exposed to sublethal concentrations of Cd (100 μg L-1), DDPV (1 mg L-1), and DTM (0.01 μg L-1) up to 96 h post-fertilization (hpf). Larvae exposed to Cd and DDPV showed increased Mt levels, whereas DTM exposure had no effect. Proteomic analyses suggest that Mt induction in D. rerio larvae exposed to Cd follows a distinct mechanism from DDPV exposure. Enrichment analysis supports a possible link between DDPV exposure and oxidative stress-induced Mt expression. In contrast, Cd-induced Mt expression likely involves metal transcription factor activation by Zn2+. These differences in responsiveness highlight the need for careful consideration when using Mt as a biomarker of metal contamination.

Residual levels of dietary deltamethrin interfere with growth and intestinal health in Litopenaeus vannamei

To date, few study explored the damage of chronic dietary exposure to the lipophilic pesticide deltamethrin (DM) in aquatic animals, and it remains unclear whether its toxicity and residue levels would be affected by dietary lipid levels. Therefore, the present study aimed to elucidate the interactions between dietary lipid levels and DM levels in the Pacific white shrimp, focusing on growth performance, antioxidant capacity, and intestinal microbiota. DM has excellent insecticidal activity and has been used worldwide. Previous research has shown that environmental DM poses toxicity risks to aquatic animals. Six different diets were formulated to feed shrimp for 6 weeks with two lipid levels (6.96 %, 10.88 %) and three DM levels (0.2 mg·kg-1, 1 mg·kg-1, 5 mg·kg-1), namely LF0.2, LF1, LF5, HF0.2, HF1, HF5, respectively. Each diet was assigned to three net cages with a total of 18 cages (40 shrimp per tank, average weight (0.382±0.001 g), of which 0.2 mg·kg-1, are grouped in environmental DM control groups. The growth of shrimp was reduced as the dietary DM levels increased. When shrimp were fed a diet containing a high dose of DM, a reduction in their antioxidant capacity was also observed. Enzyme activity and gene expression related to lipid metabolism in hepatopancreas and hemolymph indicated a significant interaction between dietary lipid levels and DM in the lipid metabolism of shrimp. The terms of detoxification-related genes (gst, sult, cyp1a1) were upregulated in shrimp fed the high-dose DM. Additionally, the presence of DM in the diet severely harmed the hepatopancreas and intestinal histological morphology. DM in the diet increased the susceptibility of shrimp to pathogens and induced intestine microbiota dysbiosis, disrupting the balance of inter-species interactions. DM was not detected in the muscle and hepatopancreas of the shrimp after six weeks of exposure. In conclusion, the presence of DM in feed reduced the growth performance and antioxidant capacity of shrimp, damaging intestinal health. DM was rapidly metabolized by shrimp.

Induction of oxidative stress and cardiac developmental toxicity in zebrafish embryos by arsenate at environmentally relevant concentrations

The contamination of water by arsenic (As) has emerged as a significant environmental concern due to its well-documented toxicity. Environmentally relevant concentrations of As have been reported to pose a considerable threat to fish. However, previous studies mainly focused on the impacts of As at environmentally relevant concentrations on adult fish, and limited information is available regarding its impacts on fish at early life stage. In this study, zebrafish embryos were employed to evaluate the environmental risks following exposure to different concentrations (0, 25, 50, 75 and 150 μg/L) of pentavalent arsenate (AsV) for 120 hours post fertilization. Our findings indicated that concentrations ≤ 150 μg/L AsV did not exert significant effects on survival or aberration; however, it conspicuously inhibited heart rate of zebrafish larvae. Furthermore, exposure to AsV significantly disrupted mRNA transcription of genes associated with cardiac development, and elongated the distance between the sinus venosus and bulbus arteriosus at 75 μg/L and 150 μg/L treatments. Additionally, AsV exposure enhanced superoxide dismutase (SOD) activity at 50, 75 and 150 μg/L treatments, and increased mRNA transcriptional levels of Cu/ZnSOD and MnSOD at 75 and 150 μg/L treatments. Concurrently, AsV suppressed metallothionein1 (MT1) and MT2 mRNA transcriptions while elevating heat shock protein70 mRNA transcription levels in zebrafish larvae resulting in elevated malondialdehyde (MDA) levels. These findings provide novel insights into the toxic effects exerted by low concentrations of AsV on fish at early life stage, thereby contributing to an exploration into the environmental risks associated with environmentally relevant concentrations.

Gradual effects of gradient concentrations of perfluorooctane sulfonate on the antioxidant ability and gut microbiota of red claw crayfish (Cherax quadricarinatus)

Perfluorooctane sulfonate (PFOS) is a typical persistent organic pollutant that is characterized by environmental persistence, bioaccumulation, and toxicity. In this study, we investigated the gut microbial response of the red claw crayfish Cherax quadricarinatus after 28 days of exposure to 0 ng/L, 1 ng/L, 10 μg/L, or 10 mg/L of PFOS as a stressor. We measured oxidative stress-related enzyme activities and expression of molecules related to detoxification mechanisms to evaluate the toxic effects of PFOS. We found that PFOS disturbed microbial homeostasis in the gut of C. quadricarinatus, resulting in increased abundance of the pathogen Shewanella and decreased abundance of the beneficial bacterium Lactobacillus. The latter especially disturbed amino acid transport and carbohydrate transport. We also found that the activities of glutathione S-transferase and glutathione peroxidase were positively correlated with the expression levels of cytochrome P450 genes (GST1-1, GSTP, GSTK1, HPGDS, UGT5), which are products of PFOS-induced oxidative stress and play an antioxidant role in the body. The results of this study provided valuable ecotoxicological data to better understand the biological fate and effects of PFOS in C. quadricarinatus.

Mechanism of sturgeon intestinal inflammation induced by Yersinia ruckeri and the effect of florfenicol intervention

The mechanism by which Y. ruckeri infection induces enteritis in Chinese sturgeon remains unclear, and the efficacy of drug prevention and control measures is not only poor but also plagued with numerous issues. We conducted transcriptomic and 16 S rRNA sequencing analyses to examine the differences in the intestinal tract of hybrid sturgeon before and after Y. ruckeri infection and florfenicol intervention. Our findings revealed that Y. ruckeri induced the expression of multiple inflammatory factors, including il1β, il6, and various chemokines, as well as casp3, casp8, and multiple tumor necrosis factor family members, resulting in pathological injury to the body. Additionally, at the phylum level, the relative abundance of Firmicutes and Bacteroidota increased, while the abundance of Plesiomonas and Cetobacterium decreased at the genus level, altering the composition of the intestinal flora. Following florfenicol intervention, the expression of multiple apoptosis and inflammation-related genes was down-regulated, promoting tissue repair. However, the flora became further dysregulated, increasing the risk of infection. In conclusion, our analysis of the transcriptome and intestinal microbial composition demonstrated that Y. ruckeri induces intestinal pathological damage by triggering apoptosis and altering the composition of the intestinal microbiota. Florfenicol intervention can repair pathological damage, but it also exacerbates flora imbalance, leading to a higher risk of infection. These findings help elucidate the molecular mechanism of Y. ruckeri-induced enteritis in sturgeon and evaluate the therapeutic effect of drugs on intestinal inflammation in sturgeon.

Biochemical and gene expression alterations due to individual exposure of atrazine, dichlorvos, and imidacloprid and their combination in zebrafish

In environmental toxicology, combined toxicity has emerged as an important concern. Atrazine (ATZ), dichlorvos (DIC), and imidacloprid (IMD) are the major pesticides, extensively used to control insect, flies, mosquitoes, and weed. Here, we investigate whether the exposure to three different types of pesticides individually and in combination for 24 h alters antioxidant enzyme responses in zebrafish (Danio rerio). Oxidative stress parameters (biochemical and mRNA expression), acetylcholinesterase (AChE) activity, and Metallothionein-II (MT-II) mRNA expression levels were measured. Present work includes toxicological assessment of individual and combined (CMD) exposure of ATZ (185.4 µM), DIC (181 µM), IMD (97.8 µ), and CMD (ATZ 92.7 µM + DIC 90.5 µM + IMD 48.9 µM), in the liver, kidney, and brain of adult zebrafish. Lipid peroxidation (LPO), glutathione (GSH) content, AChE, superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) activity along with mRNA expression of SOD, CAT, GPx, and MT-II were evaluated. Briefly, LPO, GSH content, the activity of AChE, and all antioxidant enzymes enhanced significantly in individual exposure, which was further altered in the CMD group. The mRNA expression of SOD, CAT, GPx, and MT-II in the liver and kidney showed significant down-regulation in all exposed groups. In the brain, significant upregulation in mRNA expression of SOD, CAT, GPx, and MT-II was observed in DIC and IMD groups, while ATZ and CMD showed significant downregulation except for GPx. Findings postulate that the CMD group exhibits synergistic toxic manifestation. The present study provides the baseline data on the combined toxic effects of pesticides and suggests regulating the use of pesticides.

In vitro study of deltamethrin-induced extracellular traps in hemocytes of Ruditapes philippinarum

Deltamethrin (DLM), a broad-spectrum pesticide, has been proven to have toxic effects on aquatic organisms. Here, we detected the formation of extracellular traps (ETosis) formation in Manila clam (Ruditapes philippinarum) hemocytes stimulated by three concentrations of DLM (0.01, 0.1 and 1 μg/mL) in vitro, and explored the underlying mechanisms induced by this pesticide. Extracellular DNA structure observation and quantitative results indicated that DLM exposure could obviously induce hemocytes ETosis, especially under high concentration of DLM induction. Moreover, DLM increased the levels of myeloperoxidase (MPO) and reactive oxygen species (ROS) in a dose-dependent manner, and enhanced the mRNA expression of several ROS-related genes. DPI (NADPH oxidase inhibitor) and ABAH (MPO inhibitor) could substantially inhibit DLM-induced extracellular traps (ETs), suggesting that the induced ETs release was caused by the induction of the ROS burst and MPO production. In addition, three concentrations of DLM-induced ETs were also accompanied by mitochondrial dysfunction, such as increasing the production of mitochondrial ROS, leading to a decrease in mitochondrial membrane potential (MMP) and activation of mitochondrial permeability transition pore (MPTP). Taken together, these results will shed new light on the immunotoxicity of DLM in clams and perhaps lays the foundation for health assessment in bivalves.

Pesticides and tremor: An overview of association, mechanisms and confounders

Pesticides are a heterogeneous class of chemicals mainly used for the protection of crops from pests. Because of their very widespread use, acute or/and chronic exposure to these chemicals can lead to a plethora of sequelae inflicting diseases, many of which involve the nervous system. Tremor has been associated with pesticide exposure in human and animal studies. This review is aimed at assessing the studies currently available on the association between the various types of pesticides/insecticides and tremor, while also accounting for potential confounding factors. To our knowledge, this is the first coherent review on the subject. After appraising the available evidence, we call for more intensive research on this topic, as well as intonate the need of implementing future preventive measures to protect the exposed populations and to reduce potential disabilities and social drawbacks.

Dietary α-lipoic acid alleviates deltamethrin-induced immunosuppression and oxidative stress in northern snakehead (Channa argus) via Nrf2/NF-κB signaling pathway

The goal of the study was to determine the ameliorative effects of dietary alpha-lipoic acid (α-LA) on deltamethrin (DEL)-induced immunosuppression and oxidative stress in northern snakehead (Channa argus). The northern snakeheads (15.38 ± 0.09 g) were exposed to DEL (0.242 μg/L) and fed with diets supplemented α-LA at 300, 600, and 900 mg/kg. After the 28-day exposure test, we obtained the following results: i) α-LA alleviates DEL-induced liver injury by reversing the increase of the serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels and liver cytochrome P450 enzymes (Cytochrome P450 (cyp)1a and cyp1b) expression levels. ii) α-LA can reverse the DEL-induced reduction of serum complement 4 (C4), C3, immunoglobulin M (IgM), and lysozyme (LYS) levels and the increase of liver and intestine nuclear factor kappa B (nf-κb) p65, tumor necrosis factor (tnf)-α, interleukin (il)-1β, il-8, and il-6 gene expressions, while il-10 expression levels showed the opposite result. iii) α-LA reversed the reduction of superoxide dismutase (SOD), catalase (CAT), glutathione (GSH), glutathione-S-transferase (GST) and glutathione peroxidase (GSH-Px) levels in the liver and intestine induced by DEL, while malondialdehyde (MDA) showed the opposite result. iv) α-LA reversed the reduction of Cu/Zn sod, nuclear factor erythroid 2-related factor 2 (nrf2), NAD (P)H: quinone oxidoreductase (nqo)1, and heme oxygenase (ho)-1 antioxidant gene expression levels in the liver and intestine induced by DEL. Therefore, our study indicated that optimal α-LA (600 mg/kg) could attenuate DEL-induced toxicity (including liver damage, immunotoxicity, and oxidative stress) in northern snakehead via Nrf2/NF-κB signaling pathway. This is the first research that explores the alleviated effects of α-LA on DEL-induced toxicity damage in fish. This study provides a positive measure to reduce the toxicity damage caused by DEL to aquatic animals, and provides a theoretical basis for exploring the regulation mechanism of α-LA in toxic substances.

RNA-Seq and 16S rRNA Analysis Revealed the Effect of Deltamethrin on Channel Catfish in the Early Stage of Acute Exposure

Deltamethrin (Del) is a widely used pyrethroid insecticide and a dangerous material that has brought serious problems to the healthy breeding of aquatic animals. However, the toxicological mechanisms of Del on channel catfish remain unclear. In the present study, we exposed channel catfish to 0, 0.5, and 5 μg/L Del for 6 h, and analyzed the changes in histopathology, trunk kidney transcriptome, and intestinal microbiota composition. The pathological analyses showed that a high concentration of Del damaged the intestine and trunk kidney of channel catfish in the early stage. The transcriptome analysis detected 32 and 1837 differentially expressed genes (DEGs) in channel catfish trunk kidneys after exposure to 0.5 and 5 μg/L Del, respectively. Moreover, the KEGG pathway and GO enrichment analyses showed that the apoptosis signaling pathway was significantly enriched, and apoptosis-related DEGs, including cathepsin L, p53, Bax, and caspase-3, were also detected. These results suggested that apoptosis occurs in the trunk kidney of channel catfish in the early stage of acute exposure to Del. We also detected some DEGs and signaling pathways related to immunity and drug metabolism, indicating that early exposure to Del can lead to immunotoxicity and metabolic disorder of channel catfish, which increases the risk of pathogenic infections and energy metabolism disorders. Additionally, 16S rRNA gene sequencing showed that the composition of the intestinal microbiome significantly changed in channel catfish treated with Del. At the phylum level, the abundance of Firmicutes, Fusobacteria, and Actinobacteria significantly decreased in the early stage of Del exposure. At the genus level, the abundance of Romboutsia, Lactobacillus, and Cetobacterium decreased after Del exposure. Overall, early exposure to Del can lead to tissue damage, metabolic disorder, immunotoxicity, and apoptosis in channel catfish, and affect the composition of its intestinal microbiota. Herein, we clarified the toxic effects of Del on channel catfish in the early stage of exposure and explored why fish under Del stress are more vulnerable to microbial infections and slow growth.

Effects of acute deltamethrin exposure on kidney transcriptome and intestinal microbiota in goldfish (Carassius auratus)

As a widely used synthetic pyrethroid insecticide, deltamethrin (DM) causes serious health problems to aquatic organisms. However, the comprehensive understanding of the adverse effect of DM on aquatic organisms has received limited attention. In this study, goldfish (Carassius auratus) were exposed to 0 (control group), 0.2 and 2 µg/L DM for 96 h. The kidney transcriptome and intestinal microbiota were investigated. Comparative transcriptome analysis identified 270 and 711 differentially expressed genes (DEGs) in goldfish kidneys after exposure to 0.2 and 2 µg/L DM, respectively. KEGG pathway analysis revealed that the apoptosis pathway was markedly regulated and the regulation of programmed cell death was significantly enriched by the GO analysis. Several apoptosis-related genes including cathepsin L and cytochrome c were also detected. These results indicated that apoptosis occurred in the goldfish kidney after acute exposure to sublethal concentration of DM. Besides, some immune and drug metabolism-related DEGs were identified, indicating that exposure to DM caused immunotoxicity and metabolic disruption in goldfish. Additionally, 16 S rRNA gene sequencing analysis revealed a remarkable alteration in the composition of the intestinal microbial community of DM-treated goldfish. At the phylum level, the abundance of Proteobacteria, Firmicutes and Fusobacteria was increased, whereas the abundance of Bacteroidetes was reduced significantly after DM exposure. At the genus level, the abundance of Aeromonas, Cetobacterium, Dielma and Pseudorhodobacter was reduced, whereas Akkermansia was increased after DM exposure. In summary, exposure to DM could induce apoptosis and immunotoxicity in goldfish kidneys and affect the composition of the intestinal microbiota in goldfish. This study provides a comprehensive analysis of the adverse effect of DM exposure on the goldfish and will be helpful for understanding the toxicological mechanisms of DM in fish.

Peroxiredoxin alleviates the fitness costs of imidacloprid resistance in an insect pest of rice

Chemical insecticides have been heavily employed as the most effective measure for control of agricultural and medical pests, but evolution of resistance by pests threatens the sustainability of this approach. Resistance-conferring mutations sometimes impose fitness costs, which may drive subsequent evolution of compensatory modifier mutations alleviating the costs of resistance. However, how modifier mutations evolve and function to overcome the fitness cost of resistance still remains unknown. Here we show that overexpression of P450s not only confers imidacloprid resistance in the brown planthopper, Nilaparvata lugens, the most voracious pest of rice, but also leads to elevated production of reactive oxygen species (ROS) through metabolism of imidacloprid and host plant compounds. The inevitable production of ROS incurs a fitness cost to the pest, which drives the increase or fixation of the compensatory modifier allele T65549 within the promoter region of N. lugens peroxiredoxin (NlPrx) in the pest populations. T65549 allele in turn upregulates the expression of NlPrx and thus increases resistant individuals' ability to clear the cost-incurring ROS of any source. The frequent involvement of P450s in insecticide resistance and their capacity to produce ROS while metabolizing their substrates suggest that peroxiredoxin or other ROS-scavenging genes may be among the common modifier genes for alleviating the fitness cost of insecticide resistance.

Comparison of imidacloprid, propiconazole, and nanopropiconazole effects on the development, behavior, and gene expression biomarkers of the Pacific oyster (Magallana gigas)

Coastal areas are final recipients of various contaminants including pesticides. The effects of pesticides on non-target organisms are often unclear, especially at environmentally relevant concentrations. This study investigated the impacts of insecticide imidacloprid (IMI) and fungicide propiconazole (PRO), some of the most detected pesticides in the Arcachon Bay in France. This work also included the research of propiconazole nanoformulation (nanoPRO). The effects were assessed studying the development of the early life stages of the Pacific oyster (Magallana gigas). Oyster embryos were exposed for 24, 30, and 42 h (depending on the endpoint) at 24 °C to environmentally relevant concentrations of the two pesticides as well as to nanoPRO. The research focused on sublethal endpoints such as the presence of developmental malformations, alterations of locomotion patterns, or changes in the gene expression levels. No developmental abnormalities were observed after exposure to environmental concentrations detected in the Arcachon Bay in recent years (maximal detected concentration of IMI and PRO were 174 ng/L and 29 ng/L, respectively). EC₅₀ of PRO and nanoPRO were comparable, 2.93 ± 1.35 and 2.26 ± 1.36 mg/L, while EC₅₀ of IMI exceeded 200 mg/L. IMI did not affect larval behavior. PRO affected larval movement trajectory and decreased average larvae swimming speed (2 μg/L), while nanoPRO increased the maximal larvae swimming speed (0.02 μg/L). PRO upregulated especially genes linked to reactive oxygen species (ROS) production and detoxification. NanoPRO effects on gene expression were less pronounced - half of the genes were altered in comparison with PRO. IMI induced a strong dose-response impact on the genes linked to the detoxification, ROS production, cell cycle, and apoptosis regulation. In conclusion, our results suggest that current pesticide concentrations detected in the Arcachon Bay are safe for the Pacific oyster early development, but they might have a small direct effect via altered gene expressions, whose longer-term impacts cannot be ruled out.

Mediation of oxidative stress toxicity induced by pyrethroid pesticides in fish

Organophosphate and organochlorine pesticides are banned in most countries because they cause high toxicity and bioaccumulation in non-target organisms. Pyrethroid pesticides have been applied to agriculture and aquaculture since the 1970s to replace traditional pesticides. However, pyrethroids are approximately 1000 times more toxic to fish than to mammals and birds. Fish-specific organs such as the gills and their late metabolic action against this type of pesticide make fish highly susceptible to the toxicity of pyrethroid pesticides. Oxidative stress plays an important role in the neurological, reproductive, and developmental toxicity caused by pyrethroids. Deltamethrin, cypermethrin, and lambda-cyhalothrin are representative pyrethroid pesticides that induce oxidative stress in tissues such as the gills, liver, and muscles of fish and cause histopathological changes. Although they are observed in low concentrations in aquatic environments such as rivers, lakes, and surface water they induce DNA damage and apoptosis in fish. Pyrethroid pesticides cause ROS-mediated oxidative stress in fish species including carp, tilapia, and trout. They also cause lipid peroxidation and alter the state of DNA, proteins, and lipids in the cells of fish. Moreover, changes in antioxidant enzyme activity following pyrethroid pesticide exposure make fish more susceptible to oxidative stress caused by environmental pollutants. In this review, we examine the occurrence of pyrethroid pesticides in the aquatic environment and oxidative stress-induced toxicity in fish exposed to pyrethroids.

Exposure to Dichlorodiphenyldichloroethylene (DDE) and Metallothionein Levels in Rats Fed with Normocaloric or High-Fat Diet: A Review

The growing number of studies on metallothioneins (MTs), cysteine-rich metal-binding proteins, have been disclosing new functions of these proteins. Thanks to their inducibility, they were considered to play a pivotal role in regulating trace metals homeostasis and in detoxification from heavy metals; nowadays, it is known that they are involved in various physiological and pathological processes, such as regulation of apoptosis, elimination of free radicals, and protection of nucleic acids against toxic insults. MT induction has been demonstrated following stress factors other than heavy metals, such as endocrine-disrupting chemicals, insecticides, and herbicides. However, retrieved data are often controversial: in some cases, xenobiotics elicit MT expression and synthesis; under different conditions, they lead to a decrease in cellular MT content. This review describes the MT response to dichlorodiphenyltrichloroethane (DDT) contamination in mammalian tissues. In particular, attention focuses on changes in MT expression, synthesis, and localization in rat liver, kidneys, and testes following oral administration of dichlorodiphenyldichloroethylene (DDE), the main metabolite of DDT, under normal dietary conditions or in combination with a high fat diet potentially able to increase the cellular uptake of this lipophilic pesticide. The potential connection between MT expression and synthesis, lipophilic substances and trace metals availability is also discussed.

Deltamethrin toxicity: A review of oxidative stress and metabolism

Deltamethrin is widely used worldwide due to its valuable insecticidal activity against pests and parasites. Increasing evidence has shown that deltamethrin causes varying degrees of toxicity. Moreover, oxidative stress and metabolism are highly correlated with toxicity. For the first time, this review systematically summarizes the deltamethrin toxicity mechanism from the perspective of oxidative stress, including deltamethrin-mediated oxidative damage, antioxidant status, oxidative signaling pathways and modulatory effects of antagonists, synergists and placebos on oxidative stress. Further, deltamethrin metabolism, including metabolites, metabolic enzymes and pathways and deltamethrin metabolite toxicity are discussed. This review will shed new light on deltamethrin toxicity mechanisms and provide effective strategies to ensure pest control and prevention of human and animal poisoning.

Combined effects of DDE and hyperlipidic diet on metallothionein expression and synthesis in rat tissues

Metallothionein is well known for its detoxificant and anti-oxidant properties and has been shown to be effective to prevent hydroxyl radical-generated DNA degradation. The purpose of this investigation was to analyze the combined effect of two factors promoting cellular oxidative-stress, that is, the administration of the pesticide dichloro-diphenyl-dichloroethylene (DDE) and a high fat diet, on metallothionein expression and synthesis in rat liver and kidney. DDE is the main metabolite of dichloro-diphenyl-trichloroethane (DDT), and is commonly found in the food chain and in all tissues of living organisms, carried by the fats. Male Wistar rats were fed with a standard (N) or a high fat (HF) diet and exposed to DDE (10 mg/kg body mass, N + DDE and HF + DDE groups) or vehicle (corn oil, N, and HF groups) via gavage every day for 28 days. Tissues histology was determined by light microscopy analysis; differences in metallothionein gene expression and synthesis by real-time PCR and western blot, respectively. Finally, protein cellular localization was established by immunocytochemistry. The results showed a different involvement of metallothionein in defending tissues from HF- and DDE-induced oxidative stress, suggesting that hepatic and renal cells use different strategies against pro-oxidant species. In both cell types a marked increase in the metallothionein content was observed in the nucleus, with a concomitant drop of the cytoplasmatic protein, either under HF- and DDE-stress conditions; however, no synergistic or additive effects were observed between the action of fats and pesticide. These findings reinforce the role of metallothionein in protecting DNA from oxidative damage.

Imidacloprid exposure cause the histopathological changes, activation of TNF-α, iNOS, 8-OHdG biomarkers, and alteration of caspase 3, iNOS, CYP1A, MT1 gene expression levels in common carp (Cyprinus carpio L.)

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IMI toxication was evaluated with three different methods.

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Pathological lesions were observed after IMI exposure in gills, liver and brain.

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IMI exposure induced iNOS, 8-OHdG and TNF-α activation in gills, liver and brain.

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IMI exposure caused upregulation iNOS, caspase 3 and MT1 expressions in brain.

Imidacloprid (IMI) is a neonicotinoid that is widely used for the protection of crops and carnivores from insects and parasites, respectively. It is well known that imidacloprid exposure has a harmful effect on several organisms. However, there is little information about imidacloprid toxicity in aquatic animals, particularly fish. Thus, in the current study, we assessed the histopathological changes; activation of iNOS, 8-OHdG and TNF-α; and expression levels of caspase 3, iNOS, CYP1A and MT1 genes in the common carp exposed to imidacloprid. For this purpose, fish were exposed to either a low dose (140 mg/L) or a high dose (280 mg/L) of imidacloprid for 24 h, 48 h, 72 h and 96 h. After IMI exposure, we detected hyperplasia of secondary lamellar cells and mucous cell hyperplasia in the gills, as well as hydropic degeneration in hepatocytes and necrosis in the liver. Moreover, 8-OHdG, iNOS and TNF-α activation was found particularly in the gills and liver but also moderately in the brain. Transcriptional analysis showed that caspase 3 expression was altered low dose and high doses of IMI for 72 h and 96 h exposure (p < 0.05), iNOS expression was up-regulated with both low and high doses of IMI and in a time-dependent manner (p < 0.05, p < 0.01, p < 0.001), CYP1A expression was not significantly changed regardless of the dose of IMI and exposure time (p > 0.05) except with low and high doses of IMI for 96 h (p < 0.05), and lastly, MT1 gene expression was up-regulated only in the brain with low doses of IMI for 96 h and high doses of IMI for 48 h, 72 h and 96 h exposure (p < 0.05, p < 0.01). Our results indicated that acute IMI exposure moderately induce apoptosis in the brain but caused severe histopathological lesions, inflammation, and oxidative stress in the gills, liver, and brain of the common carp.

Assessment of 8-hydroxy-2-deoxyguanosine activity, gene expression and antioxidant enzyme activity on rainbow trout (Oncorhynchus mykiss) tissues exposed to biopesticide

The goal of this study was to determinate toxicity mechanism of biopesticide with antioxidant enzymes parameters such as superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase (CAT) and malondialdehyde (MDA) levels, oxidative DNA damage (8-hydroxy-2-deoxyguanosine (8-OHdG)), transcriptional changes of heat shock protein 70 (HSP70), and cytochromes P4501A (CYP1A), sod, cat, and gpx in liver and gill tissues of Oncorhynchus mykiss. For this aim, plant-based (natural pesticides, azadirachtin (AZA)) and synthetic pesticides (deltamethrin (DLM)) were exposed on the fish at different concentrations (0.0005 and 0.00025ppm of DLM; 0.24 and 0.12ppm of AZA) for 21 days. According to the results of the study, the activity of SOD, CAT and GPx decreased, but malondialdehyde (MDA) level and activity of 8-OHdG increased in the gill and liver of rainbow trout (p<0.05). Additionally sod, cat and gpx were down regulated; HSP70 and CYP1A were up regulated for transcriptional observation. The downwards regulation of antioxidant (sod, cat and gpx) and the upregulation of HSP70 and CYP1A was obvious with doses of AZA or DLM (p<0.05). The findings of this study suggest that biopesticide can cause biochemical and physiological effects in the fish gill and liver by causing enzyme inhibition, an increase in 8-OHdG levels and changes in both transcriptional parameters (sod, cat, gpx, HSP70 and CYP1A). We found that excessive doses of plant-based pesticide are nearly as toxic as chemical ones for aquatic organisms. Moreover, 8-OHdG, HSP70 and CYP1A used as a biomarker to determinate toxicity mechanism of biopesticide in aquatic environment.

Transcriptional responses in the hepatopancreas of Eriocheir sinensis exposed to deltamethrin

Deltamethrin is an important pesticide widely used against ectoparasites. Deltamethrin contamination has resulted in a threat to the healthy breeding of the Chinese mitten crab, Eriocheir sinensis. In this study, we investigated transcriptional responses in the hepatopancreas of E. sinensis exposed to deltamethrin. We obtained 99,087,448, 89,086,478, and 100,117,958 raw sequence reads from control 1, control 2, and control 3 groups, and 92,094,972, 92,883,894, and 92,500,828 raw sequence reads from test 1, test 2, and test 3 groups, respectively. After filtering and quality checking of the raw sequence reads, our analysis yielded 79,228,354, 72,336,470, 81,859,826, 77,649,400, 77,194,276, and 75,697,016 clean reads with a mean length of 150 bp from the control and test groups. After deltamethrin treatment, a total of 160 and 167 genes were significantly upregulated and downregulated, respectively. Gene ontology terms "biological process," "cellular component," and "molecular function" were enriched with respect to cell killing, cellular process, other organism part, cell part, binding, and catalytic. Pathway analysis using the Kyoto Encyclopedia of Genes and Genomes showed that the metabolic pathways were significantly enriched. We found that the CYP450 enzyme system, carboxylesterase, glutathione-S-transferase, and material (including carbohydrate, lipid, protein, and other substances) metabolism played important roles in the metabolism of deltamethrin in the hepatopancreas of E. sinensis. This study revealed differentially expressed genes related to insecticide metabolism and detoxification in E. sinensis for the first time and will help in understanding the toxicity and molecular metabolic mechanisms of deltamethrin in E. sinensis.

Biomarker response and hypothalamus-pituitary-interrenal axis functioning in Arctic charr from Bjørnøya (74°30' N), Norway, with high levels of organohalogenated compounds

The populations of Arctic charr (Salvelinus alpinus) residing in Lake Ellasjøen at Bjørnøya Island in the Norwegian Arctic (74° 30'N, 19° 00'E) possess substantially higher levels of organohalogenated compounds (strongly dominated by polychlorinated biphenyls, PCBs) than conspecifics residing in other, proximate lakes on the island. In the present study we sampled large (<400g), immature charr from Lake Ellasjøen (high PCB levels) and Lake Laksvatn (reference lake, low PCB levels) by hook and line for an immediate blood sampling, and blood and tissue sampling after a 1h confinement stressor. This was done in order to investigate possible effects of pollutants on an acute stress performance in a high-latitude fish species by comparing muscle PCB levels, hepatic cytochrome P4501A (CYP1A) biomarker activation and functioning of the hypothalamus-pituitary-interrenal (HPI) axis between these two populations of Arctic charr. As expected sum PCB muscle levels were 8-fold higher on a wet weigh basis, and 19-fold higher on a lipid weight basis, in charr from Ellasjøen than in charr from Laksvatn. This was accompanied by a 3.5-fold higher liver cyp1a mRNA abundance in the Ellasjøen charr compared to Laksvatn charr. Brain transcript levels encoding glucocorticoid receptor 1 and 2 (GR2) and corticotropin-releasing factor, and pituitary transcript levels encoding GR2 and proopiomelanocortin A1 and A2 were higher in Ellasjøen charr than in Laksvatn charr, while interrenal transcript levels encoding melanocortin 2 receptor and steroidogenic acute regulatory protein were lower. There were no differences in plasma cortisol concentration between the two charr populations immediately after capture and one hour after confinement. The strong biomarker response to OHCs and altered mRNA abundances of key genes related to HPI axis functioning in the Ellasjøen charr suggest endocrine disruptive effects of OHCs in this charr population. Possible ecological implications are not known, but it cannot be excluded that a slower growth rate in Ellasjøen charr compared to Laksvatn charr due to an increased metabolic demand associated with the activation of xenobiotic defense and detoxification systems may have contributed to the lower body mass of Ellasjøen charr compared to Laksvatn charr.

Neurotoxic responses in brain tissues of rainbow trout exposed to imidacloprid pesticide: Assessment of 8-hydroxy-2-deoxyguanosine activity, oxidative stress and acetylcholinesterase activity

The extensive use of imidacloprid, a neonicotinoid insecticide, causes undesirable toxicity in non-targeted organisms including fish in aquatic environments. We investigated neurotoxic responses by observing 8-hydroxy-2-deoxyguanosine (8-OHdG) activity, oxidative stress and acetylcholinesterase (AChE) activity in rainbow trout brain tissue after 21 days of imidacloprid exposure at levels of (5 mg/L, 10 mg/L, 20 mg/L). The obtained results indicated that 8-OHdG activity did not change in fish exposed to 5 mg/L of imidacloprid, but 10 mg/L and 20 mg/L of imidacloprid significantly increased 8-OHdG activity compared to the control (p < 0.05). An immunopositiv reaction to 8-OHdG was detected in brain tissues. The brain tissues indicated a significant increase in antioxidant enzyme activities (superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx)) compared to the control and there was a significant increase in malondialdehyde (MDA) levels (p < 0.05). High concentrations of imidacloprid caused a significant decrease in AChE enzyme activity (p < 0.05). These results suggested that imidacloprid can be neurotoxic to fish by promoting AChE inhibition, an increase in 8-OHdG activity and changes in oxidative stress parameters. Therefore, these data may reflect one of the molecular pathways that play a role in imidacloprid toxicity.

Consecutive emamectin benzoate and deltamethrin treatments affect the expressions and activities of detoxification enzymes in the rainbow trout (Oncorhynchus mykiss)

Rainbow trout (Oncorhynchus mykiss) subjected to three consecutive, alternating treatments with emamectin benzoate (EMB) and deltamethrin (DM) during outbreaks of Caligus rogercresseyi in a farm located in southern Chile (Hornopiren, Chiloé), were studied to determine the effects of these treatments on the protein and enzymatic activity levels of cytochrome P450 1A (CYP1A), flavin-containing monooxygenase (FMO) and glutathione S-transferase (GST) in different tissues. Consecutive and alternating EMB/DM treatments resulted in a 10-fold increase and 3-fold decrease of CYP1A protein levels in the intestine and gills, respectively. Notably, CYP1A activity levels decreased in most of the analyzed tissues. FMO protein and activity levels markedly increased in the kidney and the intestine. GST was up-regulated in all tissues, either as protein or enzyme activity. When comparing consecutive EMB/DM treatments against previous studies of EMB treatment alone, CYP1A activity levels were similarly diminished, except in muscle. Likewise, FMO activity levels were increased in most of the analyzed tissues, particularly in the muscle, kidney, and intestine. The increases observed for GST were essentially unchanged between consecutive EMB/DM and EMB only treatments. These results indicate that consecutive EMB/DM treatments in rainbow trout induce the expression and activity of FMO and GST enzymes and decrease CYP1A activity. These altered activities of detoxification enzymes could generate imbalances in metabolic processes, synthesis, degradation of hormones and complications associated with drug interactions. It is especially important when analyzing possible effects of consecutive antiparasitic treatments on withholding periods and salmon farming yields.

Five metal elements homeostasis-related genes in Synechogobius hasta: Molecular characterization, tissue expression and transcriptional response to Cu and Fe exposure

Two isoforms of Cu transporter (CTR1 and CTR2) and metallothionein (MT1 and MT2), and divalent metal ion transporter 1 (DMT1) were cloned and characterized in Synechogobius hasta, respectively. The protein sequences of S. hasta CTRs possessed two methionine-rich regions (MxM and MxxxM) and three transmembrane regions. At the C-terminus, CTR1 contained a sequence of conserved cysteine and histidine residues (HCH), while CTR2 did not contain the conserved sequence. The protein sequence of S. hasta DMT1 possessed all the characteristic features of DMT1, including twelve conserved hydrophobic cores of transmembrane domains. The protein sequences of S. hasta MTs were highly conserved in the total number of cysteine residues and their locations. mRNA of the five genes were expressed in a wide range of tissues but the levels were relatively higher in the liver. Cu exposure tended to up-regulate the mRNA expressions of CTR2, DMT1, MT1 and MT2. However, Fe down-regulated the Cu-induced increase of CTR2 and DMT1 mRNA levels. For the first time, our study cloned and characterized CTR1, CTR2, DMT1, MT1 and MT2 genes in S. hasta and determined their tissue-specific expression, and also the transcriptional change by Cu and Fe exposure, which shed new light on the CuFe relationship and help to understand the basic mechanisms of Cu and Fe homeostasis in fish.

Pollution by metals and toxicity assessment using Caenorhabditis elegans in sediments from the Magdalena River, Colombia

The Magdalena River is the most important river in Colombia, supplying over 70% of the population of fish and drinking water, and it also is the main river transportation way of the country. It receives effluents from multiple sources along its course such as contaminant agricultural and industrial discharges. To evaluate the toxicity profile of Magdalena River sediments through endpoints such as survival, locomotion, and growth, wild type strains of Caenorhabditis elegans were exposed to aqueous extracts of the sediments. To identify changes in gene expression, GFP transgenic strains were used as reporter genes. Physiological and biochemical data were correlated with metal concentration in the sediments, identifying patterns of toxicity along the course of the river. Levels of some metals such as Cd, Cu, and Ni were above TEC and PEC limits. Effects in survival, growth, and locomotion were observed in most of the samples, and changes in gene expression were evident in the genes mtl-2, sod-4, and gst-1 using fluorescence expression. Cadmium and lead were the metals which were primarily associated with sediment toxicity, and the sampling sites with the highest increased expression of stress response genes were Barrancabermeja and Girardot. However, the diverse nature of toxic profiles observed in C. elegans in the study area showed the pervasiveness of different types of discharges throughout the river system.

Cloning, characterization and cadmium inducibility of metallothionein in the testes of the mudskipper Boleophthalmus pectinirostris

Metallothioneins (MTs) are cysteine-rich, low molecular weight, and heavy metal-binding protein molecules. MT participates in metallic homeostasis and detoxification in living animals due to its abundant cysteine. In order to investigate the functions of MT during spermiogenesis in the mudskipper (Boleophthalmus pectinirostris), we identified the MT complete which contains: an 83bp 5' untranslated region, a 110bp 3' untranslated region, and a 183bp open reading frame. The protein alignment between MT sequences of other species shows a high similarity and a strong identity in cysteine residues vital for the metal-binding affinity of MT. The localizations of MT were mainly in the cytoplasm of germinal cells, indicating a role in spermatogenesis and testis protection. After the cadmium (Cd) exposure, the testis presents abnormal morphology and MT mRNA expression, both of which indicate a sensitive response of testis MT to Cd. Therefore, we suggest that MTs play an important role in spermatogenesis and testes protection against Cd toxicity in B. pectinirostris.

Effects of subchronic exposure to glyphosate in juvenile oysters (Crassostrea gigas): From molecular to individual levels

Glyphosate-based herbicides are extensively used and can be measured in aquatic ecosystems, including coastal waters. The effect of glyphosate on non-target organisms is an issue of worldwide concern. The aim of this study was to investigate the effects of subchronic exposure to glyphosate in juvenile oysters, Crassostrea gigas. Yearling oysters were exposed to three concentrations of glyphosate (0.1, 1 and 100μgL(-1)) for 56days. Various endpoints were studied, from the individual level (e.g., gametogenesis and tissue alterations) to the molecular level (mRNA quantification), including biochemical endpoints such as glutathione-S-transferase (GST) and catalase activities and malondialdehyde content. No mortality and growth occurred during the experiment, and individual biomarkers revealed only slight effects. The levels of gene expression significantly increased in oysters exposed to the highest glyphosate concentration (GST and metallothioneins) or to all concentrations (multi-xenobiotic resistance). These results suggested an activation of defence mechanisms at the molecular level.

Proposed model for binding of permethrin and deltamethrin insecticides with ct-DNA, a structural comparative study

In this work, the interaction of two synthetic pyrethroid insecticides, permethrin (PER) and deltamethrin (DEL), with ct-DNA has been studied by cyclic voltammetry (CV), circular dichroism (CD), competitive fluorescence, atomic force microscopy (AFM), UV-vis spectroscopy, thermodynamic measurements, Fourier-transform infra-red (FT-IR), high performance liquid chromatography (HPLC) and two-layered ONIOM (our N-layered integrated molecular orbital+molecular mechanics) (DFT B3LYP, 6-31++G(d, p):UFF) molecular modeling methods. The last four methods were also utilized to study the binding of DEL with DNA. The results revealed that the PER may interact through partial intercalation and groove binding process while the PER only interacts through groove binding. Finally, the insecticides structure effect on interaction is discussed.

Transcriptional responses in Atlantic salmon (Salmo salar) exposed to deltamethrin, alone or in combination with azamethiphos

Recently, Atlantic salmon (Salmo salar) fish farmers have applied a combination of deltamethrin and azamethiphos in high-concentration and short-duration immersion treatment to improve protection against sea-lice (Lepeophtheirus sp.). In this work we aimed to study the effects of deltamethrin, alone or in combination with azamethiphos, on the transcription of stress and detoxification marker genes. Atlantic salmon kept at 12°C (one group was also kept at 4-5°C) were treated with deltamethrin alone or in combination with azamethiphos for a total of 40min, and gill and liver tissue harvested for transcriptional analysis 2 and 24h post treatment. No lethality was observed during the experiment. The result showed that deltamethrin, alone or in combination with azamethiphos, affected the transcriptional levels of several oxidative stress markers, including MnSOD (SOD2) and HSP70 (HSPA8) in the liver, and GPX1, CAT, MnSOD, HSP70 and GSTP1 in the gills. Significant responses for CASP3B, BCLX, IGFBP1B and ATP1A1 (Na-K-ATPase a1b) by some of the treatments suggest that the pharmaceutical drugs may affect apoptosis, growth and ion regulation mechanisms. In fish kept at 4-5°C, different effects were observed, suggesting a temperature-dependent response. In conclusion, the observed responses indicate that short-term exposure to deltamethrin has a profound effect on transcription of the evaluated markers in gills and liver of fish. Co-treatment with azamethiphos appears to have small mitigating effects on the transcriptional response caused by deltamethrin exposure alone.

Modulatory effects of deltamethrin-exposure on the immune status, metabolism and oxidative stress in gilthead seabream (Sparus aurata L.)

Deltamethrin, a sintetic pyrethroid, is the insecticide that has been replacing recently to others like organochlorines, organophosphates and carbamates which are less toxic for birds and mammals, although, unfortunately, all of them are highly toxic to various non-targeted aquatic organisms including fish. In the present study, the consequences of the exposition of gilthead seabream (Sparus aurata L.) specimens to sublethal bath dose of deltamethrin (0.1 ppb) on organo-somatic indexes, immunity, seric metabolic parameters, oxidative stress and liver histology were determined after 1, 3, 7 and 14 days of exposure. Deltamethrin alters gilthead seabream immune status, the hepato-somatic index and various seric metabolic parameters since the first exposure day while important progressive deleterious morphological changes in liver were also observed. However, no statistically significant deviation was detected in the expression of oxidative stress-related genes whilst the expression of cytochrome P450 gene was up-regulated in head-kidney and liver of exposed fish. Overall, the present results indicate severe immunotoxicological and metabolic effects of deltamethrin in gilthead seabream, the species with the highest rate of production in Mediterranean aquaculture. In general, the values obtained for the tested parameters during the trial seem to indicate that specimens try to adapt to this adverse situation although the continuous presence of the toxic impede the hypothetic recovery of homoeostasis. The use of deltamethrin in the proximities of seabream farms should be carefully considered.

Goose fat, a promising nutrient for fish feeding, activates antioxidant enzymes in rainbow trout, Oncorhynchus mykiss

The objective of this experiment was to test effects of different dietary lipids in rainbow trout feeding on the activity and expression of antioxidant enzymes, superoxide dismutase (SOD), glutathione peroxidase (GPx) and glutathione S-transferase (GST). Four iso-nitrogenous and iso-lipidic casein-gelatin based experimental diets were formulated. The sources of dietary lipids were cod liver oil (CO, rich in polyunsaturated fatty acids), goose fat (GF, rich in saturated fatty acids and monounsaturated fatty acids), soybean oil (SO, rich in linoleic acid), and a blend of CO, GF and SO. Dietary treatments had no significant effect on growth performance and survival was not affected. SOD, GPx and GST enzymes had the maximum activity in GF diet. However qPCR data showed that SOD and GPx mRNA levels were minimum in GF group. Overall data showed that rainbow trout liver enzymes were activated upon GF diet probably activating the enzyme structure itself without stimulating gene expression.

New cytochrome P450 1B1, 1C1, 2Aa, 2Y3, and 2K genes from Chinese rare minnow (Gobiocypris rarus): Molecular characterization, basal expression and response of rare minnow CYP1s and CYP2s mRNA exposed to the AHR agonist benzo[a]pyrene

Cytochrome P450 (CYP450) genes play an important role in catalyzing oxidative metabolism of toxicants. Recently, CYP1 subfamily were discovered and reported in fish, however, little is known regarding the CYP2 isoforms in fish. In the present study, the cDNA fragments of CYP 1B1 and 1C1 and CYP2Aa, 2Y3, and 2K of rare minnow were cloned and exhibited a high amino acid sequence identity compared with their zebrafish orthologs. Basal expression showed CYP1C1 and CYP 2Aa expression were observed in all eight tissues analyzed (liver, gill, intestine, kidney, spleen, brain, skin, and muscle). CYP 1A, and 1B1 expression was found in all tissues except for muscle and skin. However, CYP 2Y3 was expressed in liver, spleen, intestine and muscle whereas CYP 2K in liver, kidney and intestine. 4 and 100μgL(-1) Benzo[a]pyrene (BaP) induced patterns showed that CYP 1A, 1B1 and 1C1 expression in liver, gill, and intestine was strongly up-regulated (p<0.05). Furthermore, CYP 2Y3 was strongly induced in liver from BaP treatments (p<0.05). The high induction on mRNA level of CYP1s and CYP 2Y3 by BaP could be associated with catalyzing detoxification and indicated that CYP2s may also be potential biomarker to screen AHR agonist. The high responsiveness of CYP1 and 2 genes suggested Chinese rare minnow is feasible to screen and assess pollution with AHR agonist.

Synthesis and biological evaluation of novel bromophenol derivatives as carbonic anhydrase inhibitors

Here, we provide an alternative synthesis of the natural bromophenol 3,4-dibromo-5-(2,3-dibromo-4,5-dihydroxybenzyl)-6-(ethoxymethyl)benzene-1,2-diol (3) and the first synthesis of (4,5-dihydroxy-2-methylphenyl)(3,4-dihydroxyphenyl)methanone (18) and its brominated derivatives 19-21. The compounds were characterized and tested against the two most studied members of the pH regulatory enzyme family, carbonic anhydrase (CA). The inhibitory potencies of the novel compounds and two natural bromophenols 2, 3 were analyzed at the human isoforms hCA I and hCA II as targets and the KI values were calculated. The KI values of the novel compounds were measured in the range of 13.7-32.7 mM for the hCA I isozyme and 0.65-1.26 mM for the hCA II isozyme. The structurally related compound 14 was also tested in order to understand the structure–activity relationship, and the clinically used sulfonamide acetazolamide (AZA)was tested for comparison reasons. All of the compounds exhibited competitive inhibition with 4-nitrophenylacetate as substrate. The compounds showed strong inhibitory activity against hCA I, being more effective as compared to the clinically used AZA (KI: 36.2 mM), but rather less activity against hCA II.

Protective role of melatonin supplementation against nicotine-induced liver damage in mouse

The present study was carried out to determine histopathological effects of nicotine, one of the most significant components of tobacco, on mouse liver and ameliorative effect of melatonin on liver damage. A total of 140 mature Swiss Albino mice ( Mus musculus) were divided into four experimental groups: control group, nicotine group, melatonin group and nicotine + melatonin group. Each group was further subdivided into seven groups (five mice each) according to the time of killing (12 h and days 1, 3, 5, 7, 14 and 21 after drug administration). In nicotine and nicotine + melatonin groups, 3 mg/kg of nicotine was injected intraperitoneally every day until killing. The nicotine + melatonin group was additionally injected with 10 mg/kg of melatonin after 30 min of nicotine injection. The melatonin group was injected only with 10 mg/kg of melatonin every day until killing. All the treatments were given 2 h before sunset, when melatonin receptors were active. After the last injection, five mice from each group were killed at 12th hour and on days 1, 3, 5, 7, 14 and 21; the livers were removed for histopathological processing by light microscopy. The histopathological results revealed time-dependent degeneration in the livers of mice in nicotine group. Regenerative changes in the nicotine and melatonin groups were observed when compared with nicotine groups.

In vitro and in vivo studies on degradation of quinalphos in rats

A pharmacokinetic in vitro and in vivo degradation study has been carried out in rat to evaluate the deleterious effects of exposure to quinalphos on a target population. Degradation of quinalphos in simulated gastric and intestinal phases has been investigated. The metabolic intermediates of quinalphos in serum and urine of albino rats at different time intervals were identified after dosing the animals with 5 mg kg(-1) body weight. All the samples were lyophilised, extracted and analysed by HPLC and GC-MS. The rate of degradation of quinalphos was accelerated in the presence of the enzymes pepsin and pancreatin contained in the gastric and intestinal simulations, respectively. Quinalphos oxon, O-ethyl-O-quinoxalin-2-yl phosphoric acid, 2-hydroxy quinoxaline and ethyl phosphoric acid are among the important metabolites identified both in in vitro and in vivo investigations. In simulated in vitro study some isomerised derivatives which were missing in the blood and urine of treated animals were identified. This could possibly be either due to non-formation or faster decay of the isomerised derivatives because of slightly different conditions prevailing in the two cases. The results also indicate that the metabolites, 2-hydroxy quinoxaline and oxon, which are more toxic than the parent compound, seem to persist for a longer time.

Salicylic acid derivatives: synthesis, features and usage as therapeutic tools

INTRODUCTION

In the field of medicinal chemistry, there is a growing interest in the use of small molecules. Although acetyl salicylic acid is well known for medical applications, little is known about other salicylic acid derivatives, and there is serious lack of data and information on the effects and biological evaluation that connect them.

AREAS COVERED

This review covers the synthesis and drug potencies of salicylic acid derivatives. After a brief overview of the information on salicylic acid and its features, a detailed review of salicylic acids as drugs and prodrugs, usage as cyclooxygenase inhibitors, properties in plants, synthesis and recent patents, is developed.

EXPERT OPINION

Salicylic acid research is still an important area and innovations continue to arise, which offer hope for new therapeutics in related fields. It is anticipated that this review will guide the direction of long-term drug/nutraceutical safety trials and stimulate ideas for future research.

In vitro enzymatic response of Turkish native chicken "Gerze" to heavy metal exposure

Glucose-6-phosphate dehydrogenase (G6PD) was purified and characterized from the Turkish native chicken, Gerze, erythrocytes for the first time, and some characteristics were investigated. Purification procedure consisted of ammonium sulphate fractionation and affinity chromatography on 29, 59-ADP Sepharose-4B. The enzyme was purified 1063.22-fold with a yield of 43.27% and specific activity of 93.5 EU/mg proteins. Kinetic parameters of the enzyme were determined with glucose-6-phosphate (G6P) as substrate and purified enzyme had an apparent K(M) and V(max) values of 0.222 mM and 0.097 U/ml, respectively. The same parameters were determined with NADP(+) and the K(M) and V(max) values were 0.0603 mM and 0.153 U/ml, respectively. The following metals, Cd(+2), Pb(+2), Hg(+2), Cu(+2), Zn(+2) and Fe(+3) showed inhibitory effects on the enzyme. Cd(+2) and Pb(+2) exhibited the strongest inhibitory action. Hg(+2) and Cu(+2) were moderate inhibitors, whereas Zn(+2) and Fe(+3) showed weaker actions. All tested metals inhibited the enzyme in competitive manner.

Molecular cloning and expression of novel metallothionein (MT) gene in the polychaete Perinereis nuntia exposed to metals

To report a novel metallothionein (MT) gene and evaluate its potency as a biomarker, we clone this MT gene and measured the expression levels in the metal-exposed polychaete Perinereis nuntia. Accumulated metal contents and metallothionein-like proteins (MTLPs), which have been recognized as potential biomarkers, were compared with the relative mRNA expressions of the MT gene of P. nuntia (Pn-MT). In addition, the metal-binding affinity was estimated by recombinant Pn-MT protein. Pn-MT having high cysteine residues with three metal response elements in the promoter region closely clusters with those of other invertebrates. The accumulation patterns of metals were dependent on the exposure times in lead (Pb), cadmium (Cd), and copper (Cu) exposure. Particularly, both MTLP levels and relative mRNA expressions of MT were increased with accumulated metal contents and exposure time in P. nuntia exposed to Pb and Cd. There was no significant modulation of the Pn-MT gene in polychaetes exposed to Zn and As. However, the metal-binding ability of the recombinant Pn-MT protein provides a clear evidence for a high affinity of MT to several metal elements. These results suggest that Pn-MT would play an important role in the detoxification and/or sequestration of specific metals (e.g., Pb and Cd) in P. nuntia and have potential as a molecular biomarker in the monitoring of the marine environment using a polychaete.