Metabolomic analysis for combined hepatotoxicity of chlorpyrifos and cadmium in rats

Precision of in Vivo Pesticide Toxicology Research Can Be Promoted by Mass Spectrometry Imaging Technology

Pesticides are crucial for agricultural production, but their excessive use has become a significant pollution source, leading to increased pesticide residues in the environment and food and posing a threat to human health. In vivo pesticide toxicology research aims to protect humans with detection technology playing a key role. Spatial information plays a crucial role in in vivo pesticide toxicity research. However, current technologies cannot simultaneously analyze the content and spatial information on pesticides in vivo. Mass spectrometry imaging (MSI) technology can address this limitation by simultaneously analyzing the content and spatial distribution of chemicals in vivo with high sensitivity and efficiency, aiding in the discovery of toxic biomarkers and mechanisms. Nevertheless, the limited application of MSI in vivo pesticide toxicology research hinders the accuracy of such research. Therefore, MSI should be promoted to enhance the accuracy of in vivo pesticide toxicology research.

Cadmium exposure and its association with oxidative stress, MT1A methylation, and idiopathic male infertility in Egypt: A case-control study

Idiopathic male infertility, a significant health concern, lacks a clear etiology. Cadmium (Cd), a widespread environmental pollutant known to impact male reproductive health negatively, can accumulate in mussels, a common food source in Egypt. This study investigated the link between ecological Cd exposure, oxidative stress, MT1A methylation, and idiopathic male infertility in two regions of Alexandria. Thirty-three infertile men and 33 fertile controls were included. Cd levels were measured in mussels from the study sites and in participants' blood and semen. Biomarkers reflecting Cd exposure and its effects were assessed. Mussel Cd levels exceeded regulatory limits. Infertile men revealed significantly higher blood and semen Cd levels, reduced semen quality, increased oxidative stress, and elevated MT1A methylation compared to controls. MT1A methylation was inversely correlated with sperm count and is the strongest predictor of idiopathic male infertility, demonstrating the lowest p-value and considerable effect size. This study suggests that environmental Cd exposure, potentially through mussel consumption, may contribute to idiopathic male infertility in Egypt by increasing oxidative stress, inducing epigenetic modifications, and impairing semen quality. These findings underscore the need for further research into the mechanisms underlying Cd-induced male infertility and the development of preventative strategies.

Exposure to chlorpyrifos interferes with intercellular communication in cumulus-oocyte complexes during porcine oocyte maturation

Chlorpyrifos (CPF), a widely used organophosphorus pesticide (OP) to control pests has been verified reproductive toxicity on mammalian oocytes. However, limited information exists on its correlation with the dysfunction of the intercellular communication in cumulus-oocyte complexes (COCs). Herein, our study utilized porcine COCs as models to directly address the latent impact of CPF on the communication between cumulus cells (CCs) and oocytes during in vitro maturation. The results demonstrated that CPF exposure decreased the rate of the first polar body (PB1) extrusion and blocked meiosis progression. Notably, the cumulus expansion of CPF-exposed COCs was suppressed significantly, accompanied by the down-regulated mRNA levels of cumulus expansion-related genes. Furthermore, the early apoptotic level was raised and the expression of BAX/BCL2 and cleaved caspase 3 was up-regulated in the CCs of CPF-exposed COCs (p < 0.05). Moreover, CPF exposure impaired mRNA levels of antioxidant enzyme-related genes, induced higher levels of reactive oxygen species (ROS) and reduced the levels of mitochondrial membrane potential (MMP) in CCs (p < 0.05). Additionally, the integrated optical density (IOD) rate (cumulus/oocyte) of calcein and the expression of connexin 43 (CX43) was increased in CPF treatment groups (p < 0.05). As well, CPF exposure reduced the expression levels of FSCN1, DAAM1 and MYO10, which resulted in a significant decrease in the number and fluorescence intensity of transzonal projections (TZPs). In conclusion, CPF inhibited the expansion of cumulus and caused oxidative stress and apoptosis as well as disturbed the function of gap junctions (GJs) and TZPs, which eventually resulted in the failure of oocyte maturation.

A study on the effectiveness of sodium selenite in treating cadmium and perfluoro octane sulfonic (PFOS) poisoned zebrafish (Danio rerio)

Perfluoro octane sulfonate (PFOS) and cadmium (Cd) are toxic elements in the environment. As a micronutrient trace element, selenium (Se) can mitigate the adverse effects induced by PFOS and Cd. However, few studies have examined the correlation between Se, PFOS and Cd in fish. The present study focused on the antagonistic effects of Se on PFOS+Cd-induced accumulation in the liver of zebrafish. The fish was exposed to PFOS (0.08mg/L), Cd (1mg/L), PFOS+ Cd (0.08 mg/L PFOS+1 mg/L Cd), L-Se (0.07mg/L Sodium selenite +0.08mg/L PFOS+1mg/L Cd), M-Se (0.35mg/L Sodium selenite + 0.08mg/L PFOS+ 1 mg/L Cd), H-Se (1.75 mg/L Sodium selenite + 0.08 mg/L PFOS+ 1mg/L Cd) for 14d. The addition of selenium to fish exposed to PFOS and Cd has been found to have significant positive effects. Specifically, selenium treatments can alleviate the adverse effects of PFOS and Cd on fish growth, with a 23.10% improvement observed with the addition of T6 compared to T4. In addition, selenium can alleviate the negative effects of PFOS and Cd on antioxidant enzymes in zebrafish liver, thus reducing the liver toxicity caused by PFOS and Cd. Overall, the supplementation of selenium can reduce the health risks to fish and mitigate the injuries caused by PFOS and Cd in zebrafish.

Synergistic/antagonistic toxicity characterization and source-apportionment of heavy metals and organophosphorus pesticides by the biospectroscopy-bioreporter-coupling approach

Many anthropogenic chemicals are manufactured and eventually enter the surrounding environment, threatening food security and human health. Considering the additive or synergistic effects of pollutant mixtures, there is an expanding need for rapid, cost-effective and field-portable screening methods in environmental monitoring. This study used a recently developed biospectroscopy-bioreporter-coupling (BBC) approach to investigate the binary toxicity of Ag(I), Cr(VI) and four organophosphorus pesticides (dichlorvos, parathion, omethoate and monocrotophos). Ag(I) and Cr(VI) altered the toxicity mechanisms of pesticides, explained by the synergistic or antagonistic effect of Ag/Cr-induced cytotoxicity and pesticide-induced genotoxicity. The discriminating Raman spectral peaks associated with organophosphorus pesticides were 1585 and 1682 cm-1, but 750, 1004, 1306 and 1131 cm-1 were found in heavy metal and pesticide mixtures. More spectral alterations were related to pesticides rather than Ag(I) or Cr(VI), hinting at the dominant toxicity mechanisms of pesticides in mixtures. Ag(I) supplement significantly increased the levels of reactive oxygen species induced by organophosphorus pesticides, attributing to the increased permeability of cell membrane and entrance of toxic substances into the cells by the oligodynamic actions. This study lends deeper insights into the interactions between microbes and pollutant mixtures, offering clues to assess the cocktail effects of multiple pollutants comprehensively.

Trace metals with heavy consequences on bees: A comprehensive review

The pervasiveness of human imprint on Earth is alarming and most animal species, including bees (Hymenoptera: Apoidea: Anthophila), must cope with several stressors. Recently, exposure to trace metals and metalloids (TMM) has drawn attention and has been suggested as a threat for bee populations. In this review, we aimed at bringing together all the studies (n = 59), both in laboratories and in natura, that assessed the effects of TMM on bees. After a brief comment on semantics, we listed the potential routes of exposure to soluble and insoluble (i.e. nanoparticle) TMM, and the threat posed by metallophyte plants. Then, we reviewed the studies that addressed whether bees could detect and avoid TMM in their environment, as well as the ways bee detoxify these xenobiotics. Afterwards, we listed the impacts TMM have on bees at the community, individual, physiological, histological and microbial levels. We discussed around the interspecific variations among bees, as well as around the simultaneous exposure to TMM. Finally, we highlighted that bees are likely exposed to TMM in combination or with other stressors, such as pesticides and parasites. Overall, we showed that most studies focussed on the domesticated western honey bee and mainly addressed lethal effects. Because TMM are widespread in the environment and have been shown to result in detrimental consequences, evaluating their lethal and sublethal effects on bees, including non-Apis species, warrants further investigations.

Impacts of cadmium on male fertility: Lessons learnt so far

Cadmium (Cd) is one of the most dangerous heavy metals in the world. Globally, toxicities associated with cadmium and its attendant negative impact on humans and animals cannot be under-estimated. Cd is a heavy metal, and people are exposed to it through contaminated foods and smoking. Cd exerts its deleterious impacts on the testes (male reproductive system) by inducing oxidative stress, spermatogenic cells apoptosis, testicular inflammation, decreasing androgenic and sperm cell functions, disrupting ionic homeostasis, pathways and epigenetic gene regulation, damaging vascular endothelium and blood testes barrier. In association with other industrial by-products, Cd has been incriminated for the recent decline of male fertility rate seen in both man and animals. Understanding the processes involved in Cd-induced testicular toxicity is vital for the innovation of techniques that will help ameliorate infertility in males. In this review, we summed up recent studies on the processes of testicular toxicity and male infertility due to Cd exposure. Also, the usage of different compounds including phytochemicals, and plant extracts to manage Cd reprotoxicity will be reviewed.

Exposure to the herbicide butachlor activates hepatic stress signals and disturbs lipid metabolism in mice

Butachlor is a systemic herbicide widely applied on wheat, rice, beans, and different other crops, and is frequently detected in groundwater, surface water, and soil. Therefore, it is necessary to investigate the potential adverse health risks and the underlying mechanisms of hepatotoxicity caused by exposure to butachlor in invertebrates, other nontarget animals, and public health. For this reason, a total of 20 mice were obtained and randomly divided into two groups. The experimental mice in one group were exposed to butachlor (8 mg/kg) and the mice in control group received normal saline. The liver tissues were obtained from each mice at day 21 of the trial. Results indicated that exposure to butachlor induced hepatotoxicity in terms of swelling of hepatocyte, disorders in the arrangement of hepatic cells, increased concentrations of different serum enzymes such as alkaline phosphate (ALP) and aspartate aminotransferase (AST). The results on the mechanisms of liver toxicity indicated that butachlor induced overexpression of Apaf-1, Bax, Caspase-3, Caspase-9, Cyt-c, p53, Beclin-1, ATG-5, and LC3, whereas decreases the expression of Bcl-2 and p62 suggesting abnormal processes of apoptosis and autophagy. Results on different metabolites (61 differential metabolites) revealed upregulation of PE and LysoPC, whereas downregulation of SM caused by butachlor exposure in mice led to the disruption of glycerophospholipids and lipid metabolism in the liver. The results of our experimental research indicated that butachlor induces hepatotoxic effects through disruption of lipid metabolism, abnormal mechanisms of autophagy, and apoptosis that provides new insights into the elucidation of the mechanisms of hepatotoxicity in mice induced by butachlor.

Translation, ribosome biogenesis, and oxidative damage caused by chlorpyrifos exposure to common carp (Cyprinus carpio L.) liver: application of combined RNA-seq with sRNA-seq in risk evaluation of environmental toxicant chlorpyrifos

Pesticide chlorpyrifos (CPF) is a widespread environmental pollutant gaining attention as it is highly injurious to aquatic life. Although the toxicity of CPF is well characterized, but the mechanism of toxic response especially, the hepatotoxicity remained unclear. In this study, we performed integrated analysis, including micro-RNA (miRNA) and small RNA (sRNA) to analyze CPF exposure responding genes and enrichment pathways. A total of 23,742 expressed genes were detected and out of these expression levels of 1746 were changed significantly. Majority of them participated in protein biosynthesis, nucleotide binding, and oxidation-reduction activities. In extensive analysis of micro-RNA (miRNA) expression profiles by comparing CPF treated carp with control, we identified 214 novel miRNAs with CPM > 5 in at least one sample. The miRNAs have the same change in direction compared with overlapped mRNA pairs in upregulated genes, suggesting potential positive correlation. As a whole, we detected many differently expressed genes (DEGs) and miRNAs, which may be used as the biomarkers for the detection of CPF pollution in water and aquatic product safety. However, their functions are required to be deeply analyzed, especially more samples or time pointed data are needed to illustrate their concrete mechanism.

Iprodione and/or chlorpyrifos exposure induced testicular toxicity in adult rats by suppression of steroidogenic genes and SIRT1/TERT/PGC-1α pathway

There is cumulative evidence that iprodione (IPR) fungicide and chlorpyrifos (CPF) insecticide are endocrine disruptors that can evoke reproductive toxicity. Yet, the underlying mechanisms are still unclear. Besides, the outcomes of their co-exposure to male sexual behavior and male fertility are still unknown. The effects of IPR (200 mg/kg b.wt) and CPF (7.45 mg/kg b.wt) single or mutual exposure for 65 days on sexual behavior, sex hormones, testicular enzymes, testis, and accessory sex gland histomorphometric measurements, apoptosis, and oxidative stress biomarkers were investigated. In addition, expression of nuclear receptor subfamily group A (NR5A1), 17β-hydroxysteroid dehydrogenase (HSD17B3), silent information regulator type-1 (SIRT1), telomerase reverse transcriptase (TERT), and peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) genes has been assessed. Our results revealed that the individual or concurrent IPR and CPF exposure significantly disturb the sexual behavior, semen characteristics, testicular enzymes, and male hormones level. Oxidative stress caused by IPR and CPF activates apoptosis by inducing Caspase-3 and reducing Bcl-2. Downregulation of HSD17B3, NR5A1, and SIRT1/TERT/PGC-1α pathway was evident. Of note, most of these disturbances were exaggerated in rats co-exposed to IPR and CPF compared to IPR or CPF alone. Conclusively, our findings verified that IPR and CPF possibly damage the male reproductive system, and concurrent exposure should be avoided.

Role of Autophagy in Cadmium-Induced Hepatotoxicity and Liver Diseases

Cadmium (Cd) is a toxic pollutant that is associated with several severe human diseases. Cd can be easily absorbed in significant quantities from air contamination/industrial pollution, cigarette smoke, food, and water and primarily affects the liver, kidney, and lungs. Toxic effects of Cd include hepatotoxicity, nephrotoxicity, pulmonary toxicity, and the development of various human cancers. Cd is also involved in the development and progression of fatty liver diseases and hepatocellular carcinoma. Cd affects liver function via modulation of cell survival/proliferation, differentiation, and apoptosis. Moreover, Cd dysregulates hepatic autophagy, an endogenous catabolic process that detoxifies damaged cell organelles or dysfunctional cytosolic proteins through vacuole-mediated sequestration and lysosomal degradation. In this article, we review recent developments and findings regarding the role of Cd in the modulation of hepatotoxicity, autophagic function, and liver diseases at the molecular level.

Puerarin Attenuates Cadmium-Induced Neuronal Injury via Stimulating Cadmium Excretion, Inhibiting Oxidative Stress and Apoptosis

Cadmium (Cd) is a potential pathogenic factor in the nervous system associated with various neurodegenerative disorders. Puerarin (Pur) is an isoflavone purified from the Chinese medical herb, kudzu root, and exhibits antioxidant and antiapoptotic properties in the brain. In this study, the detailed mechanisms underlying the neuroprotective potential of Pur against Cd-induced neuronal injury was evaluated for the first time in vivo in a rat model and in vitro using primary rat cerebral cortical neurons. The results of the in vivo experiments showed that Pur ameliorated Cd-induced neuronal injury, reduced Cd levels in the cerebral cortices, and stimulated Cd excretion in Cd-treated rats. We also observed that the administration of Pur rescued Cd-induced oxidative stress, and attenuated Cd-induced apoptosis by concomitantly suppressing both the Fas/FasL and mitochondrial pathways in the cerebral cortical neurons of rats both in vivo and in vitro. Our results demonstrate that Pur exerted its neuroprotective effects by stimulating Cd excretion, ameliorating Cd-induced oxidative stress and apoptosis in rat cerebral cortical neurons.

A review on genotoxicity in connection to infertility and cancer

Genotoxicity has been identified as the main cause of infertility and a variety of cancers. The mechanisms affect the structure, quality of the information or the segregation of DNA and are not inherently correlated with mutagenicity. The concept of genotoxicity, the chemical classes that cause genetic damage and the associated mechanisms of action are discussed here. Hazardous effects of pharmaceuticals, cosmetics, agrochemicals, industrial compounds, food additives, natural toxins and nanomaterials are, in large part, identified by genotoxicity and mutagenicity tests. These are critical and early steps in industrial and regulatory health assessment. Though several in vitro experiments are commonly used and approval by regulatory agencies for commercial licensing of drugs, their accuracy in human predictions for genotoxic and mutagenic effects is frequently questioned. Treatment of real and functional genetic toxicity problems depends in detail on the knowledge of mechanisms of DNA damage in the molecular, subcellular, cellular and tissue or organ system levels. Current strategies for risk assessment of human health need revisions to achieve robust and reliable results for optimizing their effectiveness. Additionally, computerized methods, neo-biomarkers leveraging '-omics' approaches, all of which can provide a convincing genotoxicity evaluation to reduce infertility and cancer risk.

Low-dose cadmium stress increases the bioaccumulation and toxicity of dinotefuran enantiomers in zebrafish (Danio rerio)?

Co-occurrence of pesticides and heavy metals has attracted extensive attention. The enantioselective behaviors of dinotefuran to aquatic organisms have not been reported, and the effects of cadmium (Cd) was absent, which were investigated in this study at environmentally relevant concentrations. The enantioselective accumulation and elimination of dinotefuran enantiomers were observed in zebrafish, and it had tissue specificity. The S-dinotefuran concentrations were higher than R-dinotefuran in heads and viscera, but it was opposite in muscles. There existed competition between S-dinotefuran and R-dinotefuran, and the existence of S-dinotefuran might decrease the accumulation and elimination of the R-dinotefuran in zebrafish. When co-exposure to Cd and dinotefuran, the accumulation concentrations of dinotefuran enantiomers increased in zebrafish at the initial stage, which were opposite latterly. The accumulation concentrations of R-dinotefuran in R + Cd treatment in fish were 3.4 times higher than those in R-dinotefuran treatment, and the enantiomer fraction (EF) values changed from 0.484 to 0.195. The oxidative stress of S-dinotefuran on zebrafish was highest, followed by rac- and R-dinotefuran. Co-exposure to Cd led to toxicity increase for R-dinotefuran, the malonaldehyde (MDA) content decreased significantly in R + Cd treatment during 7-28 days, while obvious declination of MDA contents was found on the 28th day in R-dinotefuran treatment. Furthermore, compared to R-dinotefuran treatment, Cd increased the relative expression of cz-sod (3.4 times), cas3 (1.6 times) and p53 (5.7 times) in R + Cd treatment. The co-exposure of Cd might alter the environmental behaviors and toxicity effects of dinotefuran enantiomers in zebrafish, including the enantioselectivity. The effects of Cd on accumulation and toxicity of R-dinotefuran were greater than those on S-dinotefuran. Thus, it is necessary to consider the effects of coexistent metals to chiral pesticides in ecological risk. SUMMARIZES: The enantioselective accumulation and elimination of dinotefuran enantiomers had tissue specificity. Cd increased the accumulation and toxicity of R-dinotefuran in zebrafish.

Ecological and toxicological assessments of anthropogenic contaminants based on environmental metabolomics

There has long been a great concern with growing anthropogenic contaminants and their ecological and toxicological effects on living organisms and the surrounding environment for decades. Metabolomics, a functional readout of cellular activity, can capture organismal responses to various contaminant-related stressors, acquiring direct signatures to illustrate the environmental behaviours of anthropogenic contaminants better. This review entails the application of metabolomics to profile metabolic responses of environmental organisms, e.g. animals (rodents, fish, crustacean and earthworms) and microorganisms (bacteria, yeast and microalgae) to different anthropogenic contaminants, including heavy metals, nanomaterials, pesticides, pharmaceutical and personal products, persistent organic pollutants, and assesses their ecotoxicological impacts with regard to literature published in the recent five years. Contaminant-induced metabolism alteration and up/down-regulation of metabolic pathways are revealed in typical organisms. The obtained insights of variations in global metabolism provide a distinct understanding of how anthropogenic contaminants exert influences on specific metabolic pathways on living organisms. Thus with a novel ecotechnique of environmental metabolomics, risk assessments of anthropogenic contaminants are profoundly demonstrated.

Untargeted metabolite profiling of liver in mice exposed to 2-methylfuran

Furan, a significant food contaminant, was found in many cooked foods. In most cooked foods, furan has been found to be coexisted with some alkylated derivatives such as 2-methylfuran. 2-methylfuran was found to be potent hepatotoxins. Little toxicological data is available for 2-methylfuran. The objective of this study was to investigate metabolite changes in the liver samples from mice fed with 2-methylfuran by untargeted metabolomic approach. Metabolomic analysis was conducted by using gas chromatography coupled with mass spectrometry (GC-MS). Twenty-four metabolites were identified as differential metabolites. The important metabolic pathway was linoleic acid metabolism, glycine, serine, and threonine metabolism, methane metabolism, ascorbate, and aldarate metabolism, valine, leucine, and isoleucine biosynthesis, arachidonic acid metabolism, alanine, aspartate, and glutamate metabolism, aminoacyl-tRNA biosynthesis, cysteine, and methionine metabolism, inositol phosphate metabolism, and pyruvate metabolism. These newly identified pathways provide evidence for investigating toxic mechanism of 2-methylfuran. PRACTICAL APPLICATION: Furan in foods has caused public health concern for its hepatotoxicity and hepatic carcinogenicity in rodents. The metabolomics method was constructed to find more biomarkers to study underlying hepatotoxic mechanisms of 2-methylfuran. It will offer important information for official limits of 2-methylfuran in foods.

Chlorpyrifos inhibits sperm maturation and induces a decrease in mouse male fertility

BACKGROUND

Pesticides, especially organophosphorus pesticides such as chlorpyrifos (CPF), play an important role in modern agriculture. Studies have shown that pesticide residues are an important cause of male reproductive injury in mammal.

AIM

The aim of this study was to evaluate the reproductive damage caused by CPF in male mice and investigate the underlying mechanisms.

METHODS

In vivo, C57BL/6 mice (6-8 weeks old) were treated with CPF for 14, 70, and 80 days by intraperitoneal injection, intragastric administration, and dietary supplementation, respectively. Then, sperm from the cauda epididymidis was cultured in vitro to confirm the deleterious effects of CPF.

RESULTS

The in vivo results indicated that, after treatment with CPF by dietary supplementation and intraperitoneal injection, the expression of reproduction-related genes in the mouse testes was altered, although the mice were fertile and the testes presented no morphological abnormalities. Notably, mating experiments revealed that the fertility of male mice was decreased following CPF administration by gavage. Sperm motility within the cauda epididymidis declined significantly after CPF treatment, which was accompanied by a decrease in sperm density, upregulation of relative reactive oxygen species (ROS) levels, and downregulation of glutathione reductase activity. In vitro incubation experiments showed that sperm rapidly lost their capacity for linear movement; the relative ROS levels also increased significantly, while the mitochondrial membrane potential (MMP) showed a significant decrease. However, the integrity of the plasma membrane was not affected by CPF administration.

CONCLUSIONS

The above data indicated that exposure to CPF reduces sperm motility by disrupting mitochondrial function and increasing the level of oxidative stress during sperm maturation, thereby reducing the fecundity of male mice.

Metabolomic biomarkers in urine of rats following long-term low-dose exposure of cadmium and/or chlorpyrifos

Heavy metals and pesticides can be easily enriched in food chains and accumulated in organisms, thus pose significant threat to human health. However, their combined effects for long-term exposure at low dose has not been thoroughly investigated; especially there was no biofluid biomarker available to noninvasively diagnose the toxicosis of the combined exposure of the two chemicals at their low levels. In this study, we investigated the change of urine metabolites of rats with 90-day exposure to heavy metal cadmium (Cd) and/or organophosphorus pesticide chlorpyrifos (CPF) using gas chromatography-mass spectrometry (GC-MS)-based metabolomics approach. Our results showed that the interaction of Cd and CPF mainly displayed an antagonistic effect. We identified the panels of metabolite biomarkers in urine: benzoic acid and mannose were unique biomarkers for Cd exposure; creatinine and N-phenylacetyl glycine were unique biomarkers for CPF exposure; anthranilic acid, ribitol, and glucose were unique biomarkers for Cd plus CPF exposure. Our results suggest that 90-day exposure to Cd and/or CPF could cause a disturbance in energy and amino acid metabolism. And urine metabolomics analysis can help understand the toxicity of low dose exposure to mixed environmental chemicals.

Identification of metabolite biomarkers in serum of rats exposed to chlorpyrifos and cadmium

Chlorpyrifos (CPF) and cadmium (Cd) are widespread environmental pollutants, which are often present in drinking water and foods. However, the combined effects of CPF and Cd were not entirely clear at present. There was also no biomarker available to diagnose the poisoning of the two chemicals at low dose for long-term exposures. In this study, we investigated the change of serum metabolites of rats with subchronic exposure to CPF, Cd, and CPF plus Cd using gas chromatography-mass spectrometer-based metabolomics approach. We performed a stepwise optimization algorithm based on receiver operating characteristic to identify serum metabolite biomarkers for toxic diagnosis of the chemicals at different doses after 90-day exposure. We found that aminomalonic acid was the biomarker for the toxicity of Cd alone administration, and serine and propanoic acid were unique biomarkers for the toxicities of CPF plus Cd administrations. Our results suggest that subchronic exposure to CPF and Cd alone, or in combination at their low doses, could cause disturbance of energy and amino acid metabolism. Overall, we have shown that analysis of serum metabolomics can make exceptional contributions to the understanding of the toxic effects following long-term low-dose exposure of the organophosphorus pesticide and heavy metal.

The State-of-the Art of Environmental Toxicogenomics: Challenges and Perspectives of "Omics" Approaches Directed to Toxicant Mixtures

The last decade witnessed extraordinary advances in “omics” methods, particularly transcriptomics, proteomics and metabolomics, enabling toxicologists to integrate toxicokinetics and toxicodynamics with mechanistic insights on the mode-of-action of noxious chemicals, single or combined. The toxicology of mixtures is, nonetheless, a most challenging enterprise, especially for environmental toxicologists and ecotoxicologists, who invariably deal with chemical mixtures, many of which contain unknowns. Despite costs and demanding computations, the systems toxicology framework, of which “omics” is a major component, endeavors extracting adverse outcome pathways for complex mixtures. Still, the interplay between the multiple components of gene expression and cell metabolism tends to be overlooked. As an example, the proteome allocates DNA methyltransferases whose altered transcription or loss of function by action of chemicals can have a global impact on gene expression in the cell. On the other hand, chemical insult can produce reactive metabolites and radicals that can intercalate or bind to DNA as well as to enzymes and structural proteins, compromising their activity. These examples illustrate the importance of exploring multiple “omes” and the purpose of “omics” and multi-“omics” for building truly predictive models of hazard and risk. Here we will review the state-of-the-art of toxicogenomics highlighting successes, shortcomings and perspectives for next-generation environmental toxicologists.

Combination of Patulin and Chlorpyrifos Synergistically Induces Hepatotoxicity via Inhibition of Catalase Activity and Generation of Reactive Oxygen Species

Patulin (PAT) is the most common food-borne mycotoxin found in fruits and fruit-derived products, while chlorpyrifos (CPF) is a widely used pesticide on fruit and other crops. On the basis of the residue data, certain types of fruits can be contaminated simultaneously by patulin and chlorpyrifos. However, there are no available data about the combined toxicity. Since liver is a possible toxic target of both patulin and chlorpyrifos, we tested whether the combination exposure can cause enhanced hepatotoxicity using both cell culture and animal models. Results showed that the combination resulted in synergistic cytotoxicity in vitro and significantly enhanced liver toxicity in vivo. Mechanistically, PAT inhibited catalase activity via PIG3 induction, while CPF decreased catalase expression. These two mechanisms were converged in response to the combination, leading to enhanced inactivating catalase and boosted reactive oxygen species generation. The finding implicated that it is necessary to consider the combined toxicity in safety assessment of these food-borne contaminants.

Glutathione Might Attenuate Cadmium-Induced Liver Oxidative Stress and Hepatic Stellate Cell Activation

The liver is a major organ involved in cadmium (Cd)-induced oxidative damage. Following liver injury, hepatic stellate cells (HSCs) are activated to participate in the wound healing process, but also facilitate liver fibrosis. Previous studies have observed fibrogenic effects of Cd on liver. However, the oxidative stress mechanisms of Cd-induced HSC activation as well as whether administration of glutathione (GSH) alleviates this activation, remain unclear. In this study, 24 rats were divided randomly into four experimental groups: control, GSH-treated, Cd-treated, and Cd + GSH-treated. After 4 weeks, the liver injury index, HSC-specific activation markers, oxidative stress-related antioxidants, and enzyme activities and signals were measured. Cd uptake and the generation of reactive oxygen species (ROS) in hepatocytes were detected by mass cytometry and fluorescence microscopy, respectively. Levels of aspartate aminotransferase, xanthine oxidase, γ-glutamyl transpeptidase, and α-smooth muscle actin (αSMA) were significantly increased in Cd-treated rats. Activated HSCs positive for αSMA expression and excess collagen deposition were detected in the Cd-treated group. In contrast, activities of the antioxidant enzymes superoxide dismutase, glutathione peroxidase, and catalase were reduced. Supplementation with GSH reversed some of the Cd-induced effects and increased the protein level of phosphorylated (p)-P65 while decreasing p-JNK. Pretreatment with GSH lowered Cd uptake and ROS generation in hepatocytes in vitro. These results indicate that administration of GSH was effective in attenuating Cd-induced oxidative stress via decreasing Cd uptake, restoring the activities of oxidative enzymes, activating NF-κB, inhibiting the JNK signaling pathway, and preventing excessive ROS generation and HSC activation.

(3Z)-5-Chloro-3-(Hydroxyimino)indolin-2-one attenuates hyperglycemia, increased hepatic glycogen content and hepatic damage induced by malathion acute exposure in rats

BACKGROUND

Organophosphorus pesticides (OP's) are heavily constituted in agriculture, gardens, home and veterinary and although it is useful, there are concerns about the environment, safety and health of human and animals. In this study, we investigated the effects of a new oxime, (3Z)-5-Chloro-3-(Hydroxyimino)indolin-2-one (OXIME) against the alterations induced by malathion, an OP insecticide, acute exposure on markers of hepatic damage, glucose homeostasis, oxidative stress in rats cholinesterase (ChE) activity in rats.

METHODS

Adult male Wistar rats were divided into four groups: Control; Malathion; OXIME; and Malathion+OXIME. Twelve hours after co-treatment with malathion (250 mg/kg, i.p.) and/or OXIME (50 mg/kg, i.g.), the plasma and liver samples were collected for biochemical analyses.

RESULTS

The OXIME blocked the increase of plasma markers of hepatic function (AST and ALP) and the enzymatic inhibition of catalase and glutathione reductase in the liver of malathion-treated rats. Moreover, the hepatic cholinesterases inhibition induced by malathion acute exposure was suppressed by OXIME treatment. As assessed, a single dose of OXIME lowered the glycemia levels and hepatic glycogen content enhanced by malathion.

CONCLUSIONS

This study suggests promise effects of (3Z)-5-Chloro-3-(Hydroxyimino) indolin-2-one against the hyperglycemia and the hepatic damage induced by malathion acute exposure, as well as its use as a ChE activity reactivator.

The effect of diosmin against liver damage caused by cadmium in rats

A total of 40, male Wistar Albino, 2-3-months-old rats were used and divided into four groups. Control group received the vehicle alone, diosmin group received 100 mg/kg.bw diosmin, the cadmium group received 200 ppm cadmium, cadmium plus diosmin group received 200 ppm cadmium, and 100 mg/kg.bw diosmin for 30 days. Some biochemical parameters (aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, and lactate dehydrogenase) and oxidative stress parameters (malondialdehyde [MDA], nitric oxide [NO], superoxide dismutase [SOD], catalase [CAT], gluthatione peroxidase [GSH-Px], and glutathione [GSH]) were analyzed in the samples. Histo-pathological findings were evaluated in the liver. The body weights and liver weights of the animals were measured. The MDA and NO levels and biochemical enzyme activities examined were increased, whereas SOD, CAT, and GSH-Px activities and GSH levels decreased in cadmium-exposed group. There were also negative changes in body weight, liver weight, and liver tissue histo-phathology. Positive improvements were observed in all these parameters evaluated of the group co-administered cadmium and diosmin. PRACTICAL APPLICATIONS: Cadmium is one of the common environmental pollutants. Diosmin is a type of flavonoid found mainly in citrus fruits. It can also be produced from hesperidine. This compound is used for medical purposes and also has strong antioxidant properties. One of the toxic effects mechanisms of cadmium is oxidative stress and causes liver damage with different pathways. This compound can be used as a supporting agent in addition to the main treatment options against liver damage in case of exposure to possible cadmium. This flavonoid can also be taken with food for prophylactic purposes.

Puerarin prevents cadmium-induced hepatic cell damage by suppressing apoptosis and restoring autophagic flux

Cadmium (Cd) is a common heavy metal contamination that is highly toxic to liver. Puerarin (PU), a potent free radical scavenger, has been shown to exert cytoprotective effect in numerous pathological processes. However, whether PU affords protection against Cd-induced hepatotoxicity remains unclear to be known. Here, we aimed to investigate the protective effect of PU on Cd-induced hepatotoxicity in an immortalized mouse hepatocyte line, AML-12. First, Cd-induced cytotoxicity in AML-12 cells was obviously ameliorated by PU treatment. Also, Cd-induced apoptotic cell death was markedly alleviated by PU treatment, evidenced by two methods. Simultaneously, Cd-elevated malondialdehyde and reactive oxygen species levels were significantly reduced by PU administration, demonstrating the antioxidant effect of PU against Cd exposure. Moreover, Cd-induced blockage of autophagic flux in AML-12 cells was obviously restored by PU treatment, evidenced by immunoblot analysis of autophagy marker proteins and tandem fluorescent-tagged LC3 method. Resultantly, Cd-induced autophagosome accumulation was significantly alleviated by PU treatment. In conclusion, these observations demonstrate that PU treatment alleviates Cd-induced hepatic cell damage by inhibiting apoptosis and restoring autophagy activity, which is intimately related with its antioxidant activity.

Chlorpyrifos Suppresses Neutrophil Extracellular Traps in Carp by Promoting Necroptosis and Inhibiting Respiratory Burst Caused by the PKC/MAPK Pathway

Neutrophil extracellular traps (NETs) are reticular structures formed by myeloperoxidase (MPO), histones, and neutrophil elastase (NE) that are released from neutrophils in response to pathogenic stimuli. Chlorpyrifos (CPF) is wildly used as an organophosphorus pesticide that causes a range of toxicological and environmental problems. Exposure to CPF can increase the production of neutrophils in carps, and this increase can be considered a biomarker of water pollution. To explore a relationship between NETs and CPF and its mechanism of influence, we treated neutrophils from the blood of carp with 1 μg/mL phorbol 12-myristate 13-acetate (PMA), 0.325 mg/L CPF, or 20 μM necrostatin-1 (Nec-1). The production of MPO and NETs was reduced in the CPF+PMA group compared with that in the PMA group. CPF can cause an increase in reactive oxygen species (ROS), while inhibiting respiratory burst caused by PMA stimulation. We found that the expression levels of protein-coupled receptor 84 (gpr84), dystroglycan (DAG), proto-oncogene serine/threonine kinase (RAF), protein kinase C (PKC), and mitogen-activated protein kinase 3 (MAPK3) in the CPF+PMA group were lower than those in the PMA group, indicating that the PKC-MAPK pathway was suppressed. The expression levels of cylindromatosis (CYLD), mixed lineage kinase domain-like pseudokinase (MLKL), receptor-interacting serine-threonine kinase 1 (RIP1), and receptor-interacting serine-threonine kinase 3 (RIP3) were increased, and the expression levels of caspase 8 were reduced by CPF, indicating that CPF may cause necroptosis. The addition of Nec-1 restored the number of NETs in the CPF+PMA group. The results indicate that CPF reduced the production of NETs by inhibiting respiratory burst and increasing necroptosis. The results contribute to the understanding of the immunotoxicological mechanism of CPF and provide a reference for comparative medical studies.

Chlorpyrifos- and Dichlorvos-Induced Oxidative and Neurogenic Damage Elicits Neuro-Cognitive Deficits and Increases Anxiety-Like Behavior in Wild-Type Rats

The execution of agricultural activities on an industrial scale has led to indiscriminate deposition of toxic xenobiotics, including organophosphates, in the biome. This has led to intoxication characterized by deleterious oxidative and neuronal changes. This study investigated the consequences of oxidative and neurogenic disruptions that follow exposure to a combination of two organophosphates, chlorpyrifos (CPF) and dichlorvos (DDVP), on neuro-cognitive performance and anxiety-like behaviors in rats. Thirty-two adult male Wistar rats (150–170 g) were randomly divided into four groups, orally exposed to normal saline (NS), DDVP (8.8 mg/kg), CPF (14.9 mg/kg), and DDVP + CPF for 14 consecutive days. On day 10 of exposure, anxiety-like behavior and amygdala-dependent fear learning were assessed using open field and elevated plus maze paradigms, respectively, while spatial working memory was assessed on day 14 in the Morris water maze paradigm, following three training trials on days 11, 12, and 13. On day 15, the rats were euthanized, and their brains excised, with the hippocampus and amygdala removed. Five of these samples were homogenized and centrifuged to analyze nitric oxide (NO) metabolites, total reactive oxygen species (ROS), and acetylcholinesterase (AChE) activity, and the other three were processed for histology (cresyl violet stain) and proliferative markers (Ki67 immunohistochemistry). Marked (p ≤0.05) loss in body weight, AChE depletion, and overproduction of both NO and ROS were observed after repeated exposure to individual and combined doses of CPF and DDVP. Insults from DDVP exposure appeared more severe owing to the observed greater losses in the body weights of exposed rats. There was also a significant (p ≤0.05) effect on the cognitive behaviors recorded from the exposed rats, and these deficits were related to the oxidative damage and neurogenic cell loss in the hippocampus and the amygdala of the exposed rats. Taken together, these results provided an insight that oxidative and neurogenic damage are central to the severity of neuro-cognitive dysfunction and increased anxiety-like behaviors that follow organophosphate poisoning.

Metabolomic analysis of serum from rats following long-term intake of Chinese sausage

Introduction

Owing to the contamination of chemical pollutants, especially nitrosamines and their precursors, in Chinese sausage, long-term intake of Chinese sausage may have potential health effects.

Objection

This study investigated the effects of long-term intake of Chinese sausage with different contaminations of N-nitrosodimethylamine (NDMA) on rat liver and the potential biomarkers in the serum.

Methods

Serum metabolomic analysis was performed by gas chromatography–mass spectrometry at weeks 7, 17, 25, and 33; simultaneously, liver histopathological examination was conducted and its relationship with the serum metabolomics was also investigated.

Results

In the study, long-term intake of Chinese sausage with different NDMA contents induced significant changes in serum metabolites and liver histopathology in rats. Metabonomic analysis showed that seven metabolites – β-alanine, 3-aminoisobutyric acid, aminooxyacetic acid, D-alanyl-D-alanine, pelargonic acid, palmitic acid (PA), and linoleic acid (LA) – in three sausage diet groups were significantly decreased at four time points, where three other metabolites were notably increased, which included putrescine, ethanolamine phosphate, and taurine. Among the various treatments, the NDMA (sausage-free) group demonstrated the most remarkable changes. Phenylalanine was decreased followed by an increase, and tyrosine persistently declined, both of which were elevated in the NDMA group. In addition, the histopathological result was consistent with that of the serum metabolomic analysis, and the changes in serum metabolites in each sausage diet group and the NDMA group were consistently associated with disorders of lipids, amino acid, and energy metabolism.

Conclusion

This work indicates that excessive NDMA content in sausage may cause liver damage.

Ayurveda metallic-mineral 'Bhasma'-associated severe liver injury

Ayurveda Bhasma is a metallic-mineral preparation homogenised with herbal juices or decoctions and modified with heat treatment to apparently detoxify the heavy metals. It is widely recommended for the treatment of many disease conditions by practitioners of complementary and alternative medicine in the absence of good quality clinical trial evidence on its safety and efficacy. Heavy metal-induced liver injury is widely reported in the literature, and heavy metal adulteration of non-Bhasma-related Ayurveda and herbal products has been well described. We report a patient who developed severe liver injury requiring listing for liver transplantation for improved survival, after consumption of Bhasma for dyspepsia. This case describes the first documented case and toxicology analysis of Ayurveda Bhasma associated with severe drug-induced liver injury. Physicians must be alert regarding patient's use of supposedly safe Ayurveda Bhasma that may promote acute severe liver injury in the absence of other known aetiologies.

Alpha lipoic acid protects against chlorpyrifos-induced toxicity in Wistar rats via modulating the apoptotic pathway

The chronic exposure to chlorpyrifos (CPF) pesticide induces several human disorders including hepatotoxicity. Alpha-lipoic acid (ALA) is a natural antioxidant compound found in plants and animals. The present study aimed to investigate the possible protective effect of ALA against CPF-induced hepatotoxicity and the possible underlying molecular mechanism. Thirty-two male Wistar rats were divided into: Normal rats received only vehicle; ALA group received ALA (10 mg/kg, i.p.); CPF group received CPF (18 mg/kg, s.c.) and CPF-ALA group received CPF (18 mg/kg, s.c.) once daily for 14 days. The present results demonstrated that administration of ALA significantly improved liver functions (p < 0.05) and limited the histopathological lesions induced by CPF in liver tissues. Furthermore, ALA decreased hepatic malondialdehyde contents while increased the glutathione peroxidase, catalase, superoxide dismutase and acetylcholinesterase activities. Interestingly, ALA showed significant antiapoptotic effects through downregulation of Bax and Caspase-3 expression levels. In conclusion, ALA possess protective effects against CPF-induced liver injury through attenuation of apoptosis and oxidative stress.

¹H-NMR-Based Metabonomics of the Protective Effect of Coptis chinensis and Berberine on Cinnabar-Induced Hepatotoxicity and Nephrotoxicity in Rats

Coptis chinensis Franch has been used in Traditional Chinese Medicine (TCM) for treating infectious and inflammatory diseases for over two thousand years. Berberine (BN), an isoquinoline alkaloid, is the main component of Coptis chinensis. The pharmacological basis for its therapeutic effects, which include hepatoprotective effects on liver injuries, has been studied intensively, yet the therapy of liver injuries and underlying mechanism remain unclear. We investigated the detoxification mechanism of Coptis chinensis and berberine using metabolomics of urine and serum in the present study. After the treatment with Coptis chinensis and berberine, compared with the cinnabar group, Coptis chinensis and berberine can regulate the concentration of the endogenous metabolites. PLS-DA score plots demonstrated that the urine and serum metabolic profiles in rats of the Coptis chinensis and berberine groups were similar those of the control group, yet remarkably apart from the cinnabar group. The mechanism may be related to the endogenous metabolites including energy metabolism, amino acid metabolism and metabolism of intestinal flora in rats. Meanwhile, liver and kidney histopathology examinations and serum clinical chemistry analysis verified the experimental results of metabonomics.

Synergistic Effects of Heavy Metals and Pesticides in Living Systems

There is a widespread repeated exposure of the population to the pesticides and heavy metals of occupational and environmental origin. Such population is forced to undergo continuous stress imposed by combined exposure of the heavy metals and different classes of the pesticides used in agricultural as well as health practices. The existing reports from several workers have indicated that heavy metals and pesticides in combination may lead more severe impact on the human health when compared to their individual effects. Such a combination of pesticides and heavy metals may also change or influence the detection of exposure. Several studies in past have shown the synergistic toxic effects of heavy metals and pesticides. Such evaluations have revealed the synergistic interactions of various heavy metals and pesticides in animals as well as humans. The aim of the present article is to provide a synthesis of existing knowledge on the synergistic effects of heavy metal and pesticides in living systems. The information included in this article may be useful for different environment protection agencies and policy makers to consider the combined effects of heavy metals and pesticides on humans while designing strategies toward environmental protection and safety regulations about human health.

Toxicological interactions of pesticide mixtures: an update

Pesticides can interact with each other in various ways according to the compound itself and its chemical family, the dose and the targeted organs, leading to various effects. The term interaction means situations where some or all individual components of a mixture influence each other's toxicity and the joint effects may deviate from the additive predictions. The various mixture effects can be greatly determined by toxicokinetic and toxicodynamic factors involving metabolic pathways and cellular or molecular targets of individual pesticides, respectively. However, the complexity of toxicological interactions can lead to unpredictable effects of pesticide mixtures. Interactions on metabolic processes affecting the biotransformation of pesticides seem to be by far the most common mechanism of synergism. Moreover, the identification of pesticides responsible for synergistic interactions is an important issue for cumulative risk assessment. Cholinesterase inhibiting insecticides (organophosphates and N-methylcarbamates), triazole fungicides, triazine herbicides, and pyrethroid insecticides are overrepresented in the synergistic mixtures identified so far. Since the limited available empirical evidence suggests that synergisms at dietary exposure levels are rather rare, and experimentally occurred at unrealistic high concentrations, synergism cannot be predicted quantitatively on the basis of the toxicity of mixture components. The prediction of biological responses elicited by interaction of pesticides with each other (or with other chemicals) will benefit from using a systems toxicology approach. The identification of core features of pesticide mixtures at molecular level, such as gene expression profiles, could be helpful to assess or predict the occurrence of interactive effects giving rise to unpredicted responses.