Effects of glyphosate on immune responses and haemocyte DNA damage of Chinese mitten crab, Eriocheir sinensis

Sub-acute toxicity of the herbicide glufosinate-ammonium exposure in adult red swamp crayfish (Procambarus clarkii)

Glufosinateammonium (GLA) is one of the most widely used agricultural herbicides. It is frequently detected in surface waters near farmland and may pose a risk to non-target aquatic species. This study aimed to explore the toxicity of subacute GLA exposure in crayfish. Adult red swamp crayfish were exposed to GLA (0, 1, 10, and 100 mg/L) for 21 days. Bioaccumulation, oxidative stress, nonspecific immunity, and the expression of genes encoding xenobiotic detoxification-related enzymes were examined. The results showed GLA accumulation and hepatopancreatic histopathological changes (dilation of hepatic tubules and vacuolation of hepatocytes) in the exposed crayfish. GLA exposure induced ROS production, inhibited glutathione expression, and catalase activity in the crayfish hepatopancreas, as well as inhibited immunoenzyme expression (acid phosphatase, alkaline phosphatase, and lysozyme) in the hemolymph. In addition, the total hemocyte number decreased, and the proportion of hemocyte subsets changed significantly. Superoxide dismutase first increased and then decreased with increasing GLA dosage. GLA promoted the expression of biotransformation enzymes (cypb5, gst) in the hepatopancreas. Our results suggest that subacute GLA exposure caused structural damage to the hepatopancreatic tissue and decreased antioxidant capacity and non-specific immunity in crayfish. These findings provide insight into the toxicity of herbicides on non-target organisms.

Effect of glyphosate-based herbicide roundup on hemato-biochemistry of Labeo rohita (Hamilton, 1822) and susceptibility to Aeromonas hydrophila infection

In the present study, comprehensive research was executed to investigate the salient toxic effects of glyphosate herbicide in static water system by evaluating the haemato-biochemical profiles of Labio rohita. A challenge study against Aeromonas hydrophila was conducted to determine disease susceptibility of the fish, treated to varying concentrations of commercial-grade glyphosate herbicide. A static range finding bioassay and definitive test revealed that the 96-h LC50 value of glyphosate was 10.16 mg L-1. The experimental fish were subjected to three sub-lethal concentrations of 2.06, 1.03, and 0.63 mg l-1 for 28 days and changes were documented bi-fortnightly to study haemato-biochemical alterationsin the fish. Significantly (p < 0.05) low values in red blood corpuscles (RBC), hemoglobin (Hb), and hematocrit value (Hct) were documented. In contrast, a significant (p < 0.05) escalation in white blood corpuscles (WBC) was documented in comparison to the control. Biochemical and stress markers such as blood glucose, total protein, and alkaline phosphatase (ALP) were significantly (p < 0.05) low, whereas serum glutamate pyruvate transaminase (SGPT) and serum glutamate oxaloacetate transaminase (SGOT) escalated significantly (p < 0.05). Chronic exposure to glyphosate, on the other hand, had the least effect on the Na+ and K+ ions. Further, a challenge assay against A. hydrophila at three sub-lethal glyphosate concentrations demonstrated a synergistic impact that reduced the fish survivability. The findings conclude that persistent low glyphosate concentrations in aquatic ecosystems show significant pathophysiological changes in L. rohita, with increased vulnerability to infections. Altogether, our findings indicate the need to further study the possible assessment for a sustainable bio-remediation technique, mitigation of the detrimental effects of glyphosate exposure in fish, and recommendation of an acceptable residue concentration of the glyphosate in aquatic ecosystem.

The effects of a polystyrene nanoplastic on the immune response and gut microbiota of Eriocheir sinensis and its post-recovery state

Although there is increasing concern about the toxicity of nanoplastics, the effects of nanoplastic exposure and subsequent recovery on immune responses, as well as antioxidant responses and gut microbiota, in crustaceans are rarely reported. In this study, the nonspecific immunity and antioxidant defense of Eriocheir sinensis were evaluated after acute exposure to various concentrations (0, 2.5, 5, 10 and 20 mg/L) of 75-nm polystyrene nanoplastics (PS-NPs) for 48 h, as well as after 7 days of recovery from the nanoplastic environment. The results showed that, after 48 h of exposure, nanoplastics were observed in the gills, hepatopancreas and gut. However, no nanoplastics were found in the gut after 7 days of recovery. Under nanoplastic-induced stress, Hc, Relish, proPO, and LITAF mRNA levels increased in the gills and hepatopancreas for 48 h. Expression of the myd88, Hc, Relish and proPO genes decreased in the gills during the 7-day recovery period. Exposure to nanoplastics for 48 h and recovery for 7 days significantly decreased the activities of lysozyme (LZM) alkaline phosphatase (AKP), total superoxide dismutase (SOD) and phenoloxidase (POD) and, glutathione peroxidase (GPX) in the hepatopancreas. Meanwhile, the relative abundance of pathogens exposed to 10 mg/L nanoplastics for 48 h increased at the species level, and these pathogens decreased significantly in the 7-day recovery period. These results suggested that exposure to nanoplastics for 48 h affected the activities of immune system enzymes and expression of immune-related genes in Eriocheir sinensis and altered the diversity and composition of their gut microbiota. E. sinensis could not recover from damage to the hepatopancreas within a 7-day recovery period. The results of this study provided insight into the effects of nanoplastics on crustaceans and it filled a gap in research on crustacean recovery after exposure to nanoplastics.

Effects of Prometryn Exposure on Hepatopancreas Oxidative Stress and Intestinal Flora in Eriocheir sinensis (Crustacea: Decapoda)

There is growing evidence that long-term exposure to prometryn (a widely used herbicide) can induce toxicity in bony fish and shrimp. Our previous study demonstrated its 96 h acute toxicity on the crab Eriocheir sinensis. However, studies on whether longer exposure to prometryn with a lower dose induces toxicity in E. sinensis are scarce. Therefore, we conducted a 20 d exposure experiment to investigate its effects on the hepatopancreas and intestine of E. sinensi. Prometryn reduce the activities of antioxidant enzymes, increase the level of lipid peroxidation and cause oxidative stress. Moreover, long-term exposure resulted in immune and detoxification fatigue, while short-term exposure to prometryn could upregulate the expression of genes related to immunity, inflammation and detoxification. Prometryn altered the morphological structure of the hepatopancreas (swollen lumen) and intestine (shorter intestinal villi, thinner muscle layer and thicker peritrophic membrane). In addition, prometryn changed the species composition of the intestinal flora. In particular, Bacteroidota and Proteobacteria showed a dose-dependent decrease accompanied by a dose-dependent increase in Firmicutes at the phylum level. At the genus level, all exposure groups significantly increased the abundance of Zoogloea and a Firmicutes bacterium ZOR0006, but decreased Shewanella abundance. Interestingly, Pearson correlation analysis indicated a potential association between differential flora and hepatopancreatic disorder. Phenotypic abundance analysis indicated that changes in the gut flora decreased the intestinal organ's resistance to stress and increased the potential for opportunistic infection. In summary, our research provides new insights into the prevention and defense strategies in response to external adverse environments and contributes to the sustainable development of E. sinensis culture.

Cytotoxicity induced by abamectin in hepatopancreas cells of Chinese mitten crab, Eriocheir sinensis: An in vitro assay

Toxic effects of abamectin on non-target aquatic organisms have been well documented due to its extensive use in both agricultural and aquacultural areas. However, knowledge of the abamectin induced cytotoxicity in crustacean hepatopancreas is still incomplete. In this study, we investigated the cytotoxic effects of abamectin on hepatopancreas cells of Chinese mitten crab, Eriocheir sinensis by an in vitro assay. The results showed that abamectin inhibited cell viability with elevated reactive oxygen species (ROS) and malondialdehyde (MDA) levels in a dose-dependent manner. Increased olive tail moment (OTM) values and 8-hydroxy-2'-deoxyguanosine (8-OHdG) contents indicate the DNA damage under abamectin exposure. The up-regulation of the typical apoptosis-related protein BCL2-associated X protein (Bax) and the down-regulation of B cell leukemia/lymphoma 2 (Bcl-2) demonstrate apoptosis in hepatopancreas cells. Meanwhile, the activities of both caspase-3 and caspase-9 were increased, indicating caspase-mediated apoptosis. In addition, qRT-PCR results showed the up-regulation of antioxidant genes superoxide dismutase (SOD) and catalase (CAT). The mRNA expression of Cap 'n' Collar isoform-C (CncC) and c-Jun NH2-terminal kinases (JNK) was also significantly increased, implying the involvement of the Nrf2/MAPK pathway in the antioxidative response. The alteration of innate immune-associated genes Toll-like receptor (TLR) and myeloid differentiation primary response gene 88 (Myd88) also indicates the influence of abamectin on immune status. In summary, the present study reveals the cytotoxicity of abamectin on hepatopancreas cells of E. sinensis and this in vitro cell culture model could be used for further assessment of pesticide toxicity.

Roundup and immune challenge have different effects on a native field cricket and its introduced competitor

Animals face many natural challenges, and humans have added to this burden by applying potentially harmful herbicides and unintentionally introducing competitors. We examine the recently introduced Velarifictorus micado Japanese burrowing cricket which shares the same microhabitat and mating season as the native Gryllus pennsylvanicus field cricket. In this study, we assess the combined effects of Roundup (glyphosate-based herbicide) and a lipopolysaccharide (LPS) immune challenge on both crickets. In both species, an immune challenge reduced the numbers of eggs that the female laid; however, this effect was much larger in G. pennsylvanicus. Conversely, Roundup caused both species to increase egg production, potentially representing a terminal investment strategy. When exposed to both an immune challenge and herbicide, G. pennsylvanicus fecundity was harmed more than V. micado fecundity. Furthermore, V. micado females laid significantly more eggs than G. pennsylvanicus, suggesting that introduced V. micado may have a competitive edge in fecundity over native G. pennsylvanicus. LPS and Roundup each had differing effects on male G. pennsylvanicus and V. micado calling effort. Overall, introduced male V. micado spent significantly more time calling than native G. pennsylvanicus, which could potentially facilitate the spread of this introduced species. Despite the population-level spread of introduced V. micado, in our study, this species did not outperform native G. pennsylvanicus in tolerating immune and chemical challenge. Although V. micado appears to possess traits that make this introduced species successful in colonizing new habitats, it may be less successful in traits that would allow it to outcompete a native species.

IMMUNOTOXICITY OF RELEVANT MIXTURES OF PESTICIDES AND METABOLITES ON THP-1 CELLS

Pesticides are used to combat agricultural pests but also trigger side effects on non-target organisms. Particularly, immune system dysregulation is a major concern due to the organism's increased vulnerability to diseases, including cancer development. Macrophages play essential roles in innate and adaptive immunity and can undergo classical (M1) or alternative (M2) activation. The M1 pro-inflammatory phenotype has an antitumor role, while M2 favors tumor promotion. Although previous studies have linked pesticide exposure to immune compromise, macrophage polarization is still poorly studied. Here, we investigated the effects of 72 h-long exposure to the mixture of four pesticides widely used in Brazil (glyphosate, 2,4-D, mancozeb, and atrazine), and their main metabolites (aminomethylphosphonic acid, 2,4-diclorophenol, ethylenethiourea, and desethylatrazine) on human leukemia monocytic THP-1 cell line at concentrations based on the Acceptable Daily Intake (ADI) value established in the country. The data revealed immunotoxicity related to impaired cell metabolism in all exposed groups, decreased cell attachment (Pes: 10^-1; Met: 10^-1; Mix: all concentrations), and disturbance in nitric oxide (NO) levels (Met: 10^-1, 10¹; Mix: all concentrations). The polarization of macrophages towards a more pro-tumor M2-like phenotype was also supported by decreased secretion of the pro-inflammatory cytokine TNF-α (Pes 10⁰, 10¹) and increased IL-8 (Pes 10¹). These outcomes alert about the risk of pesticide exposure in the Brazilian population.

Emamectin benzoate exposure impaired porcine oocyte maturation

Emamectin benzoate (EB) is a widely used insecticide that can damage the central nervous and immune systems. EB exposure significantly reduced the number of eggs laid, hatching rate, and developmental rate of lower organisms such as nematodes. However, effects of EB exposure on the maturation of higher animals such as porcine oocytes remains unknown. Here we reported that EB exposure severely impaired porcine oocyte maturation. EB exposure with 200 μM prevented cumulus expansion and reduced the rates of first polar body (pb1) extrusion, cleavage and blastocyst after parthenogenetic activation. Moreover, EB exposure disrupted spindle organization, chromosome alignment, and polymerization of microfilaments, but also apparently decreased the levels of acetylated α-tubulin (Ac-Tub) in oocytes. In addition, EB exposure perturbed mitochondria distribution and increased levels of reactive oxygen species (ROS), but did not affect the distribution of cortical granules (CGs) in oocytes. Excessive ROS caused DNA damage accumulation and induced early apoptosis of oocytes. EB exposure led to the abnormal expression of cumulus expansion and apoptosis-associated genes. Altogether, these results demonstrate that EB exposure impaired nuclear and cytoplasmic maturation of porcine oocytes probably through oxidative stress and early apoptosis.

Towards Protection of Nucleic Acids from Herbicide Attack: Self-Assembly of Betaines Based on Pillar[5]arene with Glyphosate and DNA

Herbicides are one of the main parts of pesticides used today. Due to the high efficiency and widespread use of glyphosate-based herbicides, the search for substances reducing their genotoxicity is an important interdisciplinary task. One possible approach for solving the problem of herbicide toxicity is to use compounds that can protect DNA from damage by glyphosate derivatives. For the first time, a method for developing DNA-protecting measures against glyphosate isopropylamine salt (GIS) damage was presented and realized, based on low-toxicity water-soluble pillar[5]arene derivatives. Two- and three-component systems based on pillar[5]arene derivatives, GIS, and model DNA from salmon sperm, as well as their cytotoxicity, were studied. The synthesized pillar[5]arene derivatives do not interact with GIS, while GIS is able to bind DNA from salmon sperm with lgKa = 4.92. The pillar[5]arene betaine derivative containing fragments of L-phenylalanine and the ester derivative with diglycine fragments bind DNA with lgKa = 5.24 and lgKa = 4.88, respectively. The study of the associates (pillar[5]arene-DNA) with GIS showed that the interaction of GIS with DNA is inhibited only by the betaine pillar[5]arene containing fragments of L-Phe (lgKa = 3.60). This study has shown a possible application of betaine pillar[5]arene derivatives for nucleic acid protection according to its competitive binding with biomacromolecules.

Oxidative stress and immune response of hepatopancreas in Chinese mitten crab Eriocheir sinensis under lipopolysaccharide challenge

Chinese mitten crab (Eriocheir sinensis; H. Milne Edwards, 1853) is one of the important farmed crustaceans in China. Lipopolysaccharide (LPS), as a harmful factor, is prone to occur during the farming process of crabs. Aiming to test the hypothesis that damage degrees of the hepatopancreas in E. sinensis is correlated to LPS concentrations, in this study, E. sinensis were injected with LPS (50 μg/kg, and 500 μg/kg) and analyzed for the activity of antioxidant and immune-related enzymes, immune-related gene expression, and histopathological of hepatopancreas. As result, the hepatopancreas of E. sinensis immune-related genes, i.e., Dorsal, HSP90, Toll2, TLRs, Tube, and proPO, were significantly affected by LPS challenge. Among immune-related genes, Dorsal and proPO might play key roles in combating the LPS challenge. The activity of CAT gradually decreased with the increase of time, and the total antioxidant capacity was decreased after LPS challenge, indicating the inhibition of LPS on the antioxidant system. Interestingly, the decreasing trend of AKP and ACP activity suggested the immune system of crabs was affected by LPS challenge. The hepatopancreas section showed that the damage degree of hepatopancreas was different under the challenge of LPS with different concentrations, and the damage degree was proportional to the concentration. Our findings provide useful information for understanding the mechanism of hepatopancreas injury of E. sinensis induced by LPS infection.

Hemocytes: A Useful Tool for Assessing the Toxicity of Microplastics, Heavy Metals, and Pesticides on Aquatic Invertebrates

Invertebrates have long been an important tool for assessing water pollution due to their characteristics as intermediate consumers in aquatic ecosystem food chains. Most of the time, the effects of contaminants are measured by their effect on oxidative status or by mortality, although there already exists an easier tool-hemocytes. Hemocytes are circulating cells with a very important role in the immune system of invertebrates, which can be found within the hemolymph, analogous to the blood in vertebrates. The collection of hemolymph samples is easy, fast, minimally invasive, and poses no danger to the life of invertebrates. The purpose of this review was to highlight the advantages of using hemolymph for toxicity assays of various substances, including heavy metals, micro- and nano-plastics, pesticides, hydrocarbons, and oil spills. A literature search was conducted for this purpose using the most common and most often used databases, with a focus on the most recent and relevant studies. Bivalve mollusks, crustaceans, and gastropods were chosen for this investigation. This review found a growing number of studies choosing to use hemolymph as the standard methodology for toxicology assays, confirming their qualities as reliable tools.

Acute toxic effects of thiamethoxam on Chinese mitten crab Eriocheir sinensis

The information about toxic effects of thiamethoxam on non-target aquatic organisms is still incomplete. The semi-static toxicity test method was used to investigate the acute toxic effects of thiamethoxam on Eriocheir sinensis. The results showed that the median lethal concentration (LC50) of thiamethoxam to E. sinensis at 96 h was 510 μg/L, and the safety concentration (SC) was 51 μg/L. After 96 h exposure to thiamethoxam, the survival rates of crabs at concentrations of 0, 151.11, 226.67, 340, and 510 μg/L were 100%, 76.19%, 64.29%, 61.91%, and 46.43%, respectively. A significant (P < 0.05) decrease of the number of hemocytes was observed in thiamethoxam groups. With the increase of thiamethoxam concentration, the phagocytic activity of hemocytes, the activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), total antioxidant capacity (T-AOC), and the activities of protease, amylase, and lipase of crabs increased firstly and then decreased, and the above indexes reached the maximum in 151.11 μg/L thiamethoxam group. Collectively, a high concentration of thiamethoxam (510 μg/L) had a great effect on the gene expression of immune metabolism-related factors in hepatopancreas and gill of crabs. These findings indicated that thiamethoxam exposure had the ability to impair immune and metabolic systems and resulted in the reduction of survival rate of crabs.

Glyphosate-based herbicide causes spermatogenesis disorder and spermatozoa damage of the Chinese mitten crab (Eriocheir sinensis) by affecting testes characteristic enzymes, antioxidant capacities and inducing apoptosis

Glyphosate-based herbicide (GBH) is a popular herbicide, which may contaminate the water environment and affect aquatic animals. In this study, testes morphology, physiology function, apoptosis pathway, and spermatozoa quality of Chinese mitten crab (Eriocheir sinensis) were evaluated after 7 days of GBH exposure (48.945 mg/l,1/2 of the 96 h LC50 value of GBH). Results showed that GBH induced spermatogenesis disorder by H.E. staining. The obvious vacuolar degenerations and fewer spermatids of the testes accompanied by decreased primary spermatocytes-type seminiferous tubules (PSc-STs) were observed. The extensive apoptosis of spermatids by TUNEL staining was visible. Meanwhile, testes'' characteristic enzyme activities associated with spermatogenesis, including lactate dehydrogenase (LDH) and acid phosphatase (ACP) were significantly decreased. Testes suffered oxidative damage as reflected by the significant decrease in superoxide dismutase (SOD) activities, the significant increase in malondialdehyde (MDA) contents, and heat shock proteins (HSP-70) mRNA expression. Further studies demonstrated that GBH induced apoptosis of testes through the mitochondrial apoptotic pathway by upregulating the relative mRNA expression of cysteinyl aspartate specific proteinase 3 (Caspase-3), Bcl-2-associated X protein (Bax), and downregulating B-cell lymphoma 2 (Bcl-2). Oxidative damage may be one of the causes of GBH-induced apoptosis in testes. After GBH exposure, the morphology of spermatophores was changed. The survival and the acrosome reaction (AR) ratio of spermatozoa was significantly decreased. Altogether, these results demonstrated that GBH affects spermatogenesis, spermatophore and spermatozoa quality of E.sinensis, which provides novel knowledge about the toxic effects of GBH on the reproductive system of crustaceans.

Comparative proteomic profiling in Chinese shrimp Fenneropenaeus chinensis under low pH stress

Lower pH gives rise to a harmful stress to crustacean. Here, we analyzed the proteomic response of Fenneropenaeus chinensis from control pH (pH value 8.2) and low pH (pH value 6.5) - treated groups by employing absolute quantitation-based quantitative proteomic (iTRAQ) analysis. Among the identified proteins, a total of 76 proteins differed in their abundance levels, including 45 upregulated and 31 downregulated proteins. The up-regulation of proteins like citrate synthase, cytochrome c oxidase, V-type proton ATPase, glyceraldehyde-3-phosphate dehydrogenase and fructose 1,6-bisphosphate-aldolase as well as the enrichment of the DEPs in multiple metabolic processes and pathways illustrated that increased energy and substrates metabolism was essential for F. chinensis to counteract low pH stress. Ion transporting related proteins, such as Na⁺/K⁺/2Cl^- cotransporter and calmodulin, participated in the homeostatic maintenance of pH in F. chinensis. There were significant downregulation expressions of lectin, lipopolysaccharide- and beta-1,3-glucan binding protein, chitinase, cathepsin L and beta-glucuronidase, which indicating the immune dysfunction of F. chinensis when exposure to low pH condition. These findings can extend our understanding on the defensive mechanisms of the low pH stress and accelerate the breeding process of low pH tolerance in F. chinensis.

Herbicide atrazine exposure induce oxidative stress, immune dysfunction and WSSV proliferation in red swamp crayfish Procambarus clarkii

Atrazine is considered as a potential environmental endocrine disruptors and exhibits various toxic effects on animals. It has a great impact in the aquatic ecosystems, but there are few studies on its immunotoxicity in crustaceans. In the present study, the Procambarus clarkii were utilized to assess the immune toxicity after 0.5 mg/L and 5 mg/L atrazine exposure. A significant decrease in total hemocytes count (THC) was observed at 5 mg/L atrazine exposure throughout the experiment. The activities of antioxidant enzymes including superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) were significantly inhibited, but the content of reactive oxygen species (ROS) and malondialdehyde (MDA) were up-regulated, indicating the potential oxidative stress. The analysis of the integrated biomarker response (IBR) showed the induction of oxidative stress biomarkers and the inhibition of antioxidants. After 5 mg/L atrazine exposure for 144 h, the integrity of crayfish hepatopancreas was destroyed with disappeared connections between tubules and increased liver tubules vacuoles. The relative expression levels of different immune genes in hepatopancreas after atrazine exposure were measured. Most of these genes were suppressed and exhibited a certain dose-dependent effect. The results of crayfish white spot syndrome virus (WSSV) replication shown the amount of virus in muscle was significantly higher and exhibited a higher mortality rate at 5 mg/L group than other groups. The present study determined the impact of atrazine exposure on WSSV outbreaks, and also provide an important basis for further assessing the occurrence of pesticides on diseases of P. clarkii.

Glyphosate disrupts sperm quality and induced DNA damage of rainbow trout (Oncorhynchus mykiss) sperm

As a widespread pollutant, glyphosate (GLY) adversely affects the aquatic environment and can impair the reproductive ability and functions of fish. The purpose of the current study was to assess in vitro effect of GLY on rainbow trout (Oncorhynchus mykiss) sperm cells. The sperm cells were exposed to different GLY concentrations (2.5, 5, 10 mg/L). Sperm motility parameters were analyzed with computer assisted sperm analysis. DNA fragmentation (%) was measured by the comet assay using fluorescence microscopy. With increased GLY concentration, sperm motility and duration decreased after exposure. DNA fragmentation (% DNA in tail) in sperm cells was higher in treatments containing GLY than control (p < 0.05). Consequently, sperm cells are sensitive to low doses of GLY, and this can negatively affect natural populations.

Effects of cadmium on antioxidant and non-specific immunity of Macrobrachium nipponense

As a non-essential and toxic element, cadmium poses an important threat to aquatic organisms and human food safety. In this study, the effects of cadmium on antioxidant and non-specific immunity of Macrobrachium nipponense were studied from the physiological and biochemical indexes, histology and expression of related genes. These results showed that low concentrations (0.01, 0.02 mg/L) of cadmium have a positive effect on the non-specific immunity of M. nipponense, but high concentration (0.04 mg/L) of cadmium could inhibit or even damage the non-specific immunity of M. nipponense. The cadmium could induce oxidative stress in M. nipponense, and M. nipponense actived the antioxidant defense system to deal with oxidative stress, but high concentration (0.04 mg/L) of cadmium could inhibit the antioxidant defense system of M. nipponense, leading to oxidative damage, and may induce apoptosis in severe case. At the same time, the results of histology showed that cadmium can damage the structure of gill and hepatopancreas tissues of M. nipponense. This study provides theoretical data for evaluating the influences of heavy metal cadmium on M. nipponense and the toxic mechanism of heavy metal cadmium.

Glyphosate-based herbicides: Evidence of immune-endocrine alteration

Glyphosate (G) is the active ingredient of the most widely used herbicide products. It targets the enzyme 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS), which lacks in humans, suggesting to confer a low mammalian toxicity to G-based herbicides (GBHs). Despite this, the use of G is currently under intense debate. Many studies indicating its hazard and toxicity on non-target organisms are emerging, and associations between GBHs and immune-endocrine disturbances have been described. This review aims to investigate, based on recent epidemiological studies and studies performed in vitro and in vivo in animals, the possible association between GBHs and immune-endocrine alterations. Published data suggest that GBHs have endocrine disrupting potentiality targeting sex and thyroid hormones, although its relevance for humans will require further investigations. Evidence of immunotoxicity are limited compared to those on endocrine effects, but overall highlight possible noxious effects, including lung inflammation and rhinitis. An attractive hypothesis could be the one that connects microbiota dysbiosis with possible immune-endocrine outcomes. Indeed, several intestinal microorganisms express the enzyme EPSPS and, studies are emerging that highlight a possible G-induced dysbiosis. Considering the wide use of GBHs in agriculture, further studies investigating their noxious effects at levels relevant for human exposure should be performed. A critical analysis of emerging evidence of G toxicity is required to better characterize its safety profile. In addition, attention should be paid to the differences between G alone and its formulations, which, containing substances able to increase G absorption, may present a different toxicity profile.

Effects of Temperature and Glyphosate on Fatty Acid Composition, Antioxidant Capacity, and Lipid Peroxidation in the Gastropod Lymneae sp

Little is known about the potential effects of glyphosate on freshwater gastropods and possible interactions between glyphosate and other stressors. A two-way factorial experiment was conducted to investigate the effects of temperature (20 °C/25 °C) and glyphosate (0 µg/L/200 µg/L) on Lymnaea sp. After 21 days, antioxidant capacity (superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione-S-transferase (GST)), malondialdehyde content (MDA), and fatty acid (FA) composition of Lymnaea sp. tissue were measured. Temperature had an effect on SOD activity and GPx activity. In contrast, an increase in GST activity was observed in glyphosate-exposed snails, highlighting the role of GST in the glyphosate detoxification process. Differences in temperature and glyphosate did not affect lipid peroxidation (MDA); however, we observed a trend suggesting the presence of higher MDA content in glyphosate-exposed snails at 20 °C. The FA groups were generally not strongly affected by the treatments, except for omega−9 (n-9) that was markedly lower at the higher temperature. Changes were also observed in individual FA as a response to glyphosate and/or temperature. For example, a significant decrease in 18:1n9 was observed at 25 °C. Our results showed that antioxidant capacity and FA profiles were mainly affected by temperature, while glyphosate seemed to have a lesser impact.

Effects of a mixture of glyphosate, 17α-ethynylestradiol and amyl salicylate on cellular and biochemical parameters of the mussel Mytilus galloprovincialis

In this study the effects of a mixture of glyphosate (herbicide), 17a-ethinylestradiol (synthetic estrogen) and amyl salicylate (fragrance) to the mussel Mytilus galloprovincialis were evaluated. Mussels were exposed for 7 days to two realistic concentrations of the mixture (10 and 100 ng/L) and the effects on total haemocyte counts, haemocyte diameter and volume, haemocyte proliferation, haemolymph lactate dehydrogenase activity and haemocyte lysate lysozyme activity were measured. In addition, superoxide dismutase, catalase, acetylcholinesterase, glutathione-S-transferase and glutathione reductase activities were measured in gills and digestive gland. The survival-in-air test was also performed. Results demonstrated that the mixture affected both cellular and biochemical biomarkers, but not tolerance to aerial exposure of M. galloprovincialis. The negative effects recorded in this study suggested that more efforts should be done to assess the ecotoxicological risks posed by contaminant mixture to aquatic invertebrates.

Low-dose exposure of glyphosate-based herbicides disrupt the urine metabolome and its interaction with gut microbiota

Glyphosate-based herbicides (GBHs) can disrupt the host microbiota and influence human health. In this study, we explored the potential effects of GBHs on urinary metabolites and their interactions with gut microbiome using a rodent model. Glyphosate and Roundup (equal molar for glyphosate) were administered at the USA glyphosate ADI guideline (1.75 mg/kg bw/day) to the dams and their pups. The urine metabolites were profiled using non-targeted liquid chromatography-high resolution mass spectrometry (LC-HRMS). Our results found that overall urine metabolite profiles significantly differed between dams and pups and between female and male pups. Specifically, we identified a significant increase of homocysteine, a known risk factor of cardiovascular disease in both Roundup and glyphosate exposed pups, but in males only. Correlation network analysis between gut microbiome and urine metabolome pointed to Prevotella to be negatively correlated with the level of homocysteine. Our study provides initial evidence that exposures to commonly used GBH, at a currently acceptable human exposure dose, is capable of modifying urine metabolites in both rat adults and pups. The link between Prevotella-homocysteine suggests the potential role of GBHs in modifying the susceptibility of homocysteine, which is a metabolite that has been dysregulated in related diseases like cardiovascular disease or inflammation, through commensal microbiome.

Protective effects of black seed (Nigella sativa) diet supplementation in common carp (Cyprinus carpio) against immune depression, oxidative stress and metabolism dysfunction induced by glyphosate

Sustainable aquaculture arises as key to increase food production in the coming years. However, the sector still faces many challenges such as the exposure of the cultured animals to pesticide-contaminated water. Pesticides used in agriculture can reach aquaculture systems either directly (integrated-agriculture aquaculture practices) or indirectly (soil leakage) and cause a broad range of ecotoxicological effects on cultured fish and shellfish. Here, we studied how glyphosate affects several haematological, biochemical, and immune parameters in common carp (Cyprinus carpio) fingerlings, the fourth most important cultured fish species worldwide. We also evaluated the potential of dietary supplementation with black seed (Nigella sativa, 0.25, 0.5 and 1%) to lower glyphosate-associated toxicity. Our results showed that 14-day sub-lethal exposure of common carp fingerlings to glyphosate increases oxidative stress, decreases antioxidant defences, affects several metabolic pathways, and induced immune depression. Furthermore, we showed that fish fed with N. sativa-enriched diets at 0.25, 0.5 and 1% for 60 days coped better with glyphosate exposure than control fish and displayed more stable levels of biochemical serum parameters (total protein, albumin, triglycerides, low-density lipoprotein LDL), cholesterol and high-density lipoprotein HDL), higher levels of immune defences (lysozyme and immunoglobulin) and higher antioxidant enzymes (superoxide dismutase SOD, glutathione peroxidase GPx) than control fish. Fish fed with all enriched diets also displayed lower lipid peroxidation (malondialdehyde MDA), lower metabolic enzymes (alanine aminotransferase ALT, aspartate aminotransferase AST and alkaline phosphatase ALP) levels in blood serum and lower cortisol levels than control fish. Altogether, our results show that dietary inclusion of black seed can be used as a sustainable bio-remediation strategy, mitigating many of the negative effects of glyphosate exposure in fish.

DNA damage, immunotoxicity, and neurotoxicity induced by deltamethrin on the freshwater crayfish, Procambarus clarkii

Pyrethroid pesticides are applied to both agricultural and aquacultural industries for pest control. However, information of their impact on the commercial important freshwater crayfish, Procambarus clarkii is scarce. Therefore, the present study aimed to characterize to effects of a commonly used pyrethroid pesticide, deltamethrin on DNA damage, immune response, and neurotoxicity in P. clarkii. Animals were exposed to 7, 14, and 28 ng/L of deltamethrin, which correspond to 1/8, 1/4, and 1/2 of the LC50 (96 hours) of this pyrethroid to P. clarkii. Significant increase of olive tail moment (OTM) and 8-hydroxy-2'-deoxyguanosine (8-OHdG) was found after deltamethrin exposure in a dose-dependent way. Total hemocyte counts (THC) and activities of immune-related enzymes including acid phosphatase (ACP), lysozyme (LZM), and phenoloxidase (PO) were all decreased and significantly lower than control at concentration of 28 ng/L after 96 hours exposure. Acetylcholinesterase (AChE) activity, an indicator of neurotoxic effect was investigated and it was decreased significantly in muscles at 14 and 28 ng/L after 24 hours exposure. The level of intracellular reactive oxygen species (ROS) in hemocytes was also measured and the significant increase of ROS was found at 14 and 28 ng/L concentrations. The results revealed that deltamethrin induced DNA damage, immunotoxicity, and neurotoxicity in P. clarkii by excessive generation of ROS. Because of the dose-dependent responses of all parameters under exposure of deltamethrin at environmentally realistic concentrations, these parameters could be used as sensitive biomarkers for risk assessment of deltamethrin in aquaculture area.

Protective effects of dietary arginine against oxidative damage and hepatopancreas immune responses induced by T-2 toxin in Chinese mitten crab (Eriocheir sinensis)

T-2 toxin is a secondary metabolite produced by Fusarium spp. that is a major cereal and animal feed contaminant. T-2 toxin has numerous adverse effects on animals, including hepatotoxicity. Arginine (Arg) is closely associated with the regulation of immune responses and antioxidant activity in tissues. The objective of the present study was to evaluate the protective effects of dietary Arg against oxidative damage and immune responses of the hepatopancreas induced by T-2 toxin in Chinese mitten crab. According to the results, 3.17% Arg in the diet decreased alanine aminotransferase, aspartate aminotransferase, and alkaline phosphatase activity in the haemolymph significantly, when compared with the levels of activity in the T-2 toxin group. Arg supplementation also increased superoxide dismutase and glutathione peroxidase activity, while decreasing malondialdehyde concentrations in the hepatopancreas, when compared with the levels in the T-2 toxin group. In addition, 3.17% Arg in the diet increased acid phosphatase and alkaline phosphatase activity in the hepatopancreas, as well as albumin concentrations in the haemolymph, when compared with the T-2 toxin group. Dietary Arg also regulated the expression of antioxidant enzyme-related genes (mitochondrial manganese superoxide dismutase, cytosolic manganese superoxide dismutase, and catalase) and immune related genes (prophenoloxidase, NF-κB-like transcription factor Relish, and lipopolysaccharide-induced TNF-α factor) to alleviate the damage associated with the T-2 toxin. Furthermore, Arg ameliorated damage to the hepatopancreas microstructure in the crabs. The results of the present study indicate that dietary Arg could enhance the antioxidant and immune capacity of Chinese mitten crab against oxidative damage and immune injury to the hepatopancreas induced by T-2 toxin.

Abamectin at environmentally-realistic concentrations cause oxidative stress and genotoxic damage in juvenile fish (Schizothorax prenanti)

Abamectin (ABM) has been extensively used in Chinese aquaculture systems for parasite control, but no information is available regarding its effects on the important freshwater commercial fish species Schizothorax prenanti. We performed an acute toxicity test to determine the effects of ABM on S. prenanti, and the 48- and 96-h median lethal concentration values were 33.32 and 15.98 μg/L, respectively. In a second test, animals were exposed to sublethal concentrations of ABM (0.5, 2 or 8 μg/L) for 8 days, and various cytological and biochemical parameters were measured. ABM caused DNA damage in hepatocytes, with significant increases in Olive Tail Moment values and 8-hydroxy-2'-deoxyguanosine levels. Hepatocytic apoptosis occurred following all treatments, and was accompanied by an increase in reactive oxygen species (ROS) generation and caspase activity in a dose- and time-dependent manner. In addition, there were significant decreases in glutathione peroxidase levels and superoxide dismutase and catalase activity and increases in malonaldehyde levels. ABM-induced hepatocytic apoptosis in S. prenanti was probably triggered by ROS generation following a cascade reaction of caspases in mitochondrial or death receptor pathways, which caused antioxidant inhibition, oxidative product accumulation, and DNA damage in the liver.

In Vitro Immunotoxicity of Organophosphate Flame Retardants in Human THP-1-Derived Macrophages

Scarce attention has been paid to the immunotoxicity of organophosphate flame retardants (PFRs), which poses a challenge to the systematic assessment of their health risks. In this study, a battery of in vitro immunotoxicity screening assays, including adhesion, phagocytosis, and 48 cytokine/chemokine production, was measured after exposing THP-1-derived macrophages to six selected common PFRs (TPHP, TDCPP, TNBP, TOCP, TCEP, and TBOEP) at a noncytotoxic concentration (≤50 μM). Our results showed that TPHP and TBOEP partially attenuated the adhesion and phagocytosis of the THP-1 mφs and that TDCPP caused a functional loss of phagocytosis, implying the potential immunosuppression. In contrast, TNBP and TOCP may cause an immunostimulation by significantly promoting cell adhesion and enhancing phagocytic efficiency. Additionally, the results from a cytokine/chemokine secretion analysis revealed the proinflammatory properties of TDCPP, TPHP, and TBOEP. TOCP was thought to disrupt the inflammatory balance by inhibiting both proinflammatory and antiinflammatory cytokines. TCEP showed no effect on adhesion or phagocytosis and little modulation of cytokine release at this experimental concentration. Overall, this study supports that PFRs can be immunotoxic to macrophages in different ways and provides evidence for developing more sensitive in vitro immunotoxicity bioassay methods.

Cytotoxicity induced by abamectin exposure in haemocytes of Chinese mitten crab, Eriocheir sinensis

Abamectin is widely utilized in both agricultural and aquaculture areas in China for pest control. However, information about toxic effects of abamectin on non-target aquatic organisms is still incomplete. The Chinese mitten crab, Erocheir sinensis has been extensively bred in the rice-crab co-culture system for years, resulting in the frequent exposure to pesticides including abamectin. In the present study, a primary haemocyte culture model was established to investigate the immune response under exposure of abamectin. The results showed that medium osmolarity ranging from 360 to 480 mOsM/Kg was optimal for primary haemocyte culture from E. sinensis. Abamectin could induce significant decrease of cell viability, inhibition of phagocytic activity, as well as decline of acid phosphatase (ACP) and alkaline phosphatase (AKP) activities. All parameters decreased in time- and dose- dependent manners throughout the experiment, indicating the remarkable immunosuppression of abamectin on E. sinensis and also the sensitivity of the cytotoxicology model of haemocytes in vitro under abamectin exposure. In addition, a dose dependent increase of intracellular reactive oxygen species (ROS) was found after 6 h exposure. It revealed that excessive generation of ROS may a main reason to the degradation of cell viability, and moreover, the decrease in immune function.

Impact of field-realistic doses of glyphosate and nutritional stress on mosquito life history traits and susceptibility to malaria parasite infection

Glyphosate is the world's most widely used herbicide. The commercial success of this molecule is due to its nonselectivity and its action, which would supposedly target specific biosynthetic pathways found mainly in plants. Multiple studies have however provided evidence for high sensitivity of many nontarget species to glyphosate and/or to formulations (glyphosate mixed with surfactants). This herbicide, found at significant levels in aquatic systems through surface runoffs, impacts life history traits and immune parameters of several aquatic invertebrates' species, including disease-vector mosquitoes. Mosquitoes, from hatching to emergence, are exposed to aquatic chemical contaminants. In this study, we first compared the toxicity of pure glyphosate to the toxicity of glyphosate-based formulations for the main vector of avian malaria in Europe, Culex pipiens mosquito. Then we evaluated, for the first time, how field-realistic dose of glyphosate interacts with larval nutritional stress to alter mosquito life history traits and susceptibility to avian malaria parasite infection. Our results show that exposure of larvae to field-realistic doses of glyphosate, pure or in formulation, did not affect larval survival rate, adult size, and female fecundity. One of our two experimental blocks showed, however, that exposure to glyphosate decreased development time and reduced mosquito infection probability by malaria parasite. Interestingly, the effect on malaria infection was lost when the larvae were also subjected to a nutritional stress, probably due to a lower ingestion of glyphosate.

In vitro effects of glyphosate-based herbicides and related adjuvants on primary culture of hemocytes from Haliotis tuberculata

Glyphosate-based herbicides are among the most produced and widely-used herbicides. Studies have shown that commercial formulations and adjuvants may be more toxic to non-target organisms than the active ingredients alone, but the mechanisms of action of these chemicals remain unclear. The aim of this study was to investigate the in vitro effects of glyphosate, a commercial formulation and adjuvant alone using primary culture of hemocytes from the European abalone Haliotis tuberculata, a commonly farmed shellfish. Glyphosate was found to have negligible effects on viability, phagocytic activities and lysosome stability even with very high doses (i.e. 100 mg L-1). By contrast, greater effects on viability were observed for the commercial formulation and adjuvant alone, with EC50 values of 41.42 mg L-1 and 1.85 mg L-1, respectively. These results demonstrate that the toxic sublethal effects (i.e. phagocytic activity and destabilization of lysosomal membranes) of formulated glyphosate came from adjuvants and suggest they may be related to cell and organelle membrane destabilization.

Oxidative stress, immunological response, and heat shock proteins induction in the Chinese Mitten Crab, Eriocheir sinensis following avermectin exposure

In this study, the Chinese mitten crabs, Eriocheir sinensis were exposed to avermectin at 0.03, 0.06, 0.12, 0.24, and 0.48 mg/L respectively for 96 hours. The results showed that levels of superoxide dismutase, catalase, and glutathione peroxidase in hepatopancreas were slightly induced at concentration of 0.03 and 0.06 mg/L, but significantly (P < .05) decreased at higher concentrations, meanwhile similar trend of the activities of acid phosphatase, alkaline phosphatase and lysozyme were observed. Significant induction of HSP70 and HSP90 mRNA expression was detected at 24 hours whereas no significant change was found in HSP60. In addition, levels of reactive oxygen species in hepatocytes increased in dose- and time- dependent manners, and cell viabilities of hepatocytes and haemocytes decreased. These results indicated that sublethal concentration exposure of avermectin had a prominent oxidative stress effect on E. sinensis based on the antioxidative and immunological activity inhibition, and HSP60, 70, and 90 perform a protective response during the exposure.

Fermented Animal Source Protein as Substitution of Fishmeal on Intestinal Microbiota, Immune-Related Cytokines and Resistance to Vibrio mimicus in Freshwater Crayfish (Cherax cainii)

A feeding trial was carried out to evaluate the effects of substitution of fishmeal (FM) by dietary poultry by-product meal, fermented by Lactobacillus casei and Saccharomyces cerevisiae on growth, intestinal health, microbial composition, immune related cytokines and disease resistance of freshwater crayfish, marron (Cherax cainii) against Vibrio mimicus. Two isonitrogenous and isocaloric diets were formulated by replacing FM protein with fermented poultry by-product meal (FPBM) protein at 0% (Control) and 75% (FPBM), and fed marron for 70 days. The results indicated no significant difference (P > 0.05) in final body weights between two groups of marron, whilst intestinal microvilli number per fold was increased in marron fed FPBM than the control. The 16S rRNA sequences revealed an increased number of Lactobacillus and Streptococcus, and decreased number of Aeromonas at genus level in the distal intestine of marron fed FPBM. Marron fed FPBM showed up-regulated expression of IL-8, IL-10, and IL-17F genes in the distal intestine. Significantly (P < 0.05) increased lysozyme and phagocytic activity, and higher survival was found in marron fed FPBM following a bacterial challenge with Vibrio mimicus. Therefore, it is concluded that FPBM is beneficial to marron in terms of microbial community, immune-related cytokines and disease resistance against V. mimicus.

Immune response to abamectin-induced oxidative stress in Chinese mitten crab, Eriocheir sinensis

It is known that abamectin (ABM) inflicts oxidative damage on aquatic animals; however, knowledge about the immune response under pesticide-induced oxidative stress is incomplete. In the present study, several cellular and humoral immune parameters, including total haemocyte counts (THC), lysosomal membrane stability (LMS), activities of acid phosphatase (ACP), alkaline phosphatase (AKP) and lysozyme (LZM) were investigated to reveal the effects of ABM exposure on the immune defence mechanisms of the important freshwater crab, Erocheir sinensis. According to the results, a significant increase of THC was found in low concentration groups (0.03 and 0.06 mg/L), while dramatic decreases occurred in high concentration groups (0.12 and 0.24 mg/L) after 96 h of exposure. We also detected significant increases of reactive oxygen species (ROS) in haemocytes at 0.12 and 0.24 mg/L, and there was a dose- and time-dependent decrease of lysosomal membrane stability. These results suggest that the excessive generation of ROS induced by ABM may be leading the massive collapse of lysosomal membrane, which in turn may be causing the sharp drop of haemocyte counts in E. sinensis. The increase of hydrolytic enzymes ACP and AKP at low concentrations and the decrease at high concentrations also indicate an immune response associated with haemocytes status under stress. However, activities of LZM decreased significantly. After injection of Aeromonas hydrophil, mortalities increased under exposure to ABM and were positively related to ABM concentration. These results confirm that ABM exposure has the ability to impair immune defence and result in the host's susceptibility to pathogens.

The effect of a glyphosate-based herbicide on acetylcholinesterase (AChE) activity, oxidative stress, and antioxidant status in freshwater amphipod: Gammarus pulex (Crustacean)

This study had determined the effect of glyphosate-based herbicide (GBH) on acetylcholinesterase (AChE) enzyme activity, oxidative stress, and antioxidant status in Gammarus pulex. Firstly, the 96-h LC50 value of glyphosate on G. pulex was determined and calculated as 403 μg/L. Subsequently, the organisms were exposed to sub-lethal concentrations (10, 20, and 40 μg/L) of the determined GHB for 24 and 96 h. The samples were taken from control and GBH-treated groups at 24 and 96 h of study and analysed to determine the malondialdehyde (MDA) and reduced glutathione (GSH) levels, the AChE, superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) enzyme activities. In the G. pulex exposed to GBH for 24 and 96 h, the MDA level increased significantly (p < 0.05). The GSH level, the AChE, the CAT, and the GPx activities decreased compared with the control group (p < 0.05). G. pulex exposure to GBH for 24 h showed a temporary reduction in the SOD. GBH exposure led to oxidative stress in the G. pulex as well as affected the cholinergic system of the organism. These results indicated that the parameters measured may be important indicators of herbicide contamination in G. pulex.

Avermectin induces the oxidative stress, genotoxicity, and immunological responses in the Chinese Mitten Crab, Eriocheir sinensis

Avermectin is commonly used in aquaculture systems for pest control in recent decades in China. However, no information is provided for the toxic effect to the important commercial species, Chinese mitten crab, Eriocheir sinensis. To investigate the aquatic toxicity of avermectin, an acute toxic test was performed in this study. The results showed that the 48 h- and 96 h- LC₅₀ were 1.663 and 0.954 mg/L, respectively. For further research, crabs were exposed to sublethal concentrations of 0.03, 0.06, 0.12, 0.24 and 0.48 mg/L. Levels of antioxidants, including superoxide dismutase (SOD), catalase (CAT) and total antioxidant capacity (T-AOC) were significantly (P<0.05) decreased with dose- and time- dependent responses, meanwhile the oxidative products including malondialdehyde (MDA), hydrogen peroxide (H₂O₂) and protein carbonyl in serum increased significantly (P<0.05) at concentrations of 0.24 and 0.48 mg/L throughout the experiment. A significant (P<0.05) increase of intracellular ROS and decrease of phagocytic activity was observed in high concentration groups, with dose- and time- dependent manners during the exposure. In addition, serious genetic damage was detected, for the significant increase (P<0.05) of both comet ratio and %DNA in tail at each concentration, and micronucleus (MN) frequency at concentrations of 0.12, 0.24 and 0.48 mg/L at 96 h. These results indicated that sublethal concentration exposure of avermectin had a prominent toxic effect on E. sinensis based on the oxidative stress induced by generated ROS, immunological activity inhibition and genotoxicity.

Ecotoxicological hazard of a mixture of glyphosate and aminomethylphosphonic acid to the mussel Mytilus galloprovincialis (Lamarck 1819)

Assessment of the effects of chemical mixtures is a very important objective of the ecotoxicological risk assessment. This study was aimed at evaluating for the first time the effects of a mixture of glyphosate and its main breakdown product aminomethylphosphonic acid (AMPA) on various biomarkers in the mussel Mytilus galloprovincialis. Mussels were exposed for 7, 14 and 21 days to either 100 µg/L of glyphosate, 100 µg/L of AMPA or a mixture of both (100 + 100 µg/L). Various haemocyte parameters, such as total haemocyte counts, haemocyte diameter and volume, haemocyte proliferation, haemolymph lactate dehydrogenase activity and haemocyte lysate acid phosphatase activities were measured. In addition, the effects of exposure on the activity of antioxidant enzymes, acetylcholinesterase and glutathione-S-transferase were evaluated in gills and digestive gland from mussels. On the whole, this study demonstrated that the variables considered in the experimental plan, namely treatment, exposure time and their interaction, affect significantly biomarker responses in M. galloprovincialis. The effects of the mixture were comparable to those of the individual compounds, whereas their synergistic effects were occasionally observed, under the experimental conditions tested at least.

Effect of a beta-cypermethrin and emamectin benzoate pesticide mixture on reproductive toxicity in male mice in a greenhouse environment

With the widespread use of pesticides, the resistance to pesticides of pests has gradually increased, caused mixed pesticides to become even more widely used for practical applications. To investigate the effects of mixed pesticides on reproductive health in an occupational greenhouse environment, the greenhouse environment and the characteristics of the actual application were constructed, and then the male mice were comprehensively exposed to a mixture of the beta-cypermethrin and emamectin benzoate environmental. Additionally, the effect of the beta-cypermethrin and emamectin benzoate mixture on the reproductive health of male mice was known. The results showed that with the prolongation of exposure duration, the activities of Glutathione Peroxidase (GSH-Px), Total Superoxide Dismutase (T-SOD), Lactate dehydrogenase (LDH) and Acid phosphatase (ACP) in the testes of mice gradually decreased and the activity of Malondialdehyde (MDA) gradually increased. It was also found that the apoptosis rate of murine testicular cells increased and that DNA damage occurred with prolonged exposure duration. Therefore, it can be inferred that exposure to a mixture of the pesticides beta-cypermethrin and emamectin benzoate in the greenhouse environment may have adverse effects on the reproductive health of male mice.

Effects of the glyphosate-based herbicide roundup on the survival, immune response, digestive activities and gut microbiota of the Chinese mitten crab, Eriocheir sinensis

Glyphosate is one of the most widely used pesticides in the world and can be transported easily by surface runoff, air, and rivers, potentially affecting aquaculture. In this study, the survival rate, intestinal and hepatopancreatic immune and digestive functions, and the intestinal microbial diversity of Chinese mitten crab (Eriocheir sinensis) were evaluated after 7 days of exposure to glyphosate (48.945 mg/L from 1/2 96-h LC50 value). The results showed that glyphosate significantly reduced the survival rate of E. sinensis. After exposure to glyphosate, the totoal antioxidant capacity (T-AOC) in the midgut and hindgut of E. sinensis was significantly decreased, and malondialdehyde (MDA) content in the midgut was significantly increased (P < 0.05). After glyphosate exposure, the activities of digestive enzymes (including lipase and amylase) in the intestinal tract were significantly decreased and trypsin was significantly increased, while three enzymes in the hepatopancreas were significantly increased (P < 0.05). Using high-throughput sequencing analysis of the gut microbiota, the results showed that glyphosate significantly decreased the diversity of E. sinensis gut microbiota, while significantly increasing the taxonomic richness of Bacteroidetes and Proteobacteria (P < 0.05). This study suggested that these bacteria may be involved in glyphosate effects on survival by regulation of immune and digestive function.

Glyphosate does not substitute for glycine in proteins of actively dividing mammalian cells

OBJECTIVES

Glyphosate (N-phosphonomethyl glycine) and its commercial herbicide formulations have been shown to exert toxicity via various mechanisms. It has been asserted that glyphosate substitutes for glycine in polypeptide chains leading to protein misfolding and toxicity. However, as no direct evidence exists for glycine to glyphosate substitution in proteins, including in mammalian organisms, we tested this claim by conducting a proteomics analysis of MDA-MB-231 human breast cancer cells grown in the presence of 100 mg/L glyphosate for 6 days. Protein extracts from three treated and three untreated cell cultures were analysed as one TMT-6plex labelled sample, to highlight a specific pattern (+/+/+/-/-/-) of reporter intensities for peptides bearing true glyphosate treatment induced-post translational modifications as well as allowing an investigation of the total proteome.

RESULTS

Comparative statistical analysis of global proteome changes between glyphosate treated and non-treated samples did not show significant differences. Crucially, filtering of data to focus analysis on peptides potentially bearing glycine for glyphosate replacement revealed that the TMT reporter intensity pattern of all candidates showed conclusively that they are all false discoveries, with none displaying the expected TMT pattern for such a substitution. Thus, the assertion that glyphosate substitutes for glycine in protein polypeptide chains is incorrect.

Glyphosate affects haemocyte parameters in the clam Ruditapes philippinarum

This study was aimed at evaluating the effects of glyphosate on haemocyte parameters of the clam Ruditapes philippinarum. Clams were exposed for 7 days to differing glyphosate concentrations (10, 100 and 1000 μg/L) and various haemocyte parameters were measured, such as total haemocyte count (THC), haemocyte diameter and volume, haemocyte proliferation, haemolymph lactate dehydrogenase activity, haemocyte lysate lysozyme and acid phosphatase activities. Glyphosate reduced significantly THC values, while increased both diameter and volume of haemocytes. Exposure to the highest herbicide concentration increased significantly haemocyte proliferation. No significant effects on haemolymph lactate dehydrogenase and haemocyte lysate lysozyme activities were observed, whereas haemocyte lysate acid phosphatase activity resulted significantly increased in clams exposed at 100 and 1000 μg/L. On the whole, this study demonstrated that glyphosate influenced significantly haemocyte parameters in R. philippinarum.

Antioxidative status, immunological responses, and heat shock protein expression in hepatopancreas of Chinese mitten crab, Eriocheir sinensis under the exposure of glyphosate

As a broad-spectrum herbicide, glyphosate was extensively utilised in China for several decades. The contradiction between glyphosate spraying and crab breeding in the rice-crab co-culture system has become more obvious. In this study, the antioxidative status and immunological responses of Chinese mitten crab, Eriocheir sinensis, under sublethal exposure of glyphosate were investigated by detecting the antioxidative and immune-related enzyme activity, acetylcholinesterase (AChE) activity and relative mRNA expression of heat shock proteins (HSPs) in hepatopancreas. The results showed that high concentrations of glyphosate (44 and 98 mg/L) could induce significant alteration of superoxide dismutase (SOD), peroxidase (POD), acid phosphatase (ACP), alkaline phosphatase (AKP), and phenoloxidase (PO) activities by first rising then falling during the exposure. However, AChE activity in all treatments including 4.4 mg/L was inhibited markedly after 6 h of exposure. In addition, the relative mRNA expression of HSP 60, HSP 70, and HSP 90 was significantly upregulated at both 48 h and 96 h. These results revealed that glyphosate has a prominent toxic effect on E. sinensis based on antioxidative and immunological response inhibition and AChE activity reduction even at the lowest concentration of 4.4 mg/L, and a protective response by upregulation of HSPs was carried out by the species to ease the environmental stress.

The protective effects of melatonin on oxidative damage and the immune system of the Chinese mitten crab (Eriocheir sinensis) exposed to deltamethrin

Deltamethrin (Del), an important broad-spectrum insecticide, is widely used in agricultural activities. However, Del is an effective reactive oxygen species (ROS) inducer that induces oxidative stress damage in cells or tissues. Del is significantly more toxic to aquatic organisms, especially crustaceans, than to mammals and birds. This study was designed to evaluate the protective effect of melatonin (MT) on the toxicity-induced damage of Del after 6 h in Eriocheir sinensis. The results showed that Del exposure significantly induced oxidative damage in the hepatopancreas and mitochondria, with malondialdehyde (MDA) and glutathione (GSH) levels being significantly increased and superoxide dismutase (SOD) activity being significantly decreased. Moreover, Del exposure significantly induced functional damage of the hepatopancreas and mitochondria, with a significant increase in alanine aminotransferase (ALT), aspartate aminotransferase (AST), acid phosphatase (ACP) and alkaline phosphatase (AKP) activities in the hepatopancreas and the ratio of albumin/globulin (ALB/GLB) in serum, which indicated the permeability and integrity of the membranes were damaged and had caused cell damage. In addition, ATP content, Na⁺-K⁺-ATPase activity and cytochrome C (Cyt‑C) content in mitochondria decreased significantly, which indicated that Del exposure destroyed the normal respiratory chain of mitochondria. We also evaluated the hematological parameters. Although there were no significant differences in total hemocyte count (THC) levels, hemocyte apoptosis was significantly induced by Del exposure, and the hemocyte phagocytic activity and the hemocyanin levels decreased significantly with Del exposure. However, MT pretreatment not only prevented oxidative damage and functional damage caused by Del exposure to the hepatopancreas and mitochondria, but it also restored the hemocyte apoptotic rate and phagocytic activity to normal levels. In short, Del exposure caused significant oxidative and functional damage to the hepatopancreas, mitochondria and hemocytes of E. sinensis, whereas the use of MT almost completely eliminated the damage caused by Del exposure.

Assessment of the oxidative and genotoxic effects of the glyphosate-based herbicide roundup on the freshwater shrimp, Macrobrachium nipponensis

In the present study, an acute toxic test was performed to assess the oxidative stress and genotoxic effects of the herbicide on the freshwater shrimp Macrobrachium nipponensis. The results showed that the 48-h and 96-h LC50 values of Roundup to M. nipponensis were 57.684 mg/L and 11.237 mg/L, respectively. For further investigation, the shrimps were exposed to sublethal concentrations of 0.35, 0.70, 1.40, 2.80 and 5.60 mg/L for 96 h. A significant decrease in total haemocytes count (THC) was observed at concentration of 5.60 mg/L throughout the experiment. The level of superoxide dismutase (SOD), catalase (CAT) and total antioxidant capacity (T-AOC) in all the treatments decreased in a dose- and time-dependent manner except for the concentration group of 0.35 mg/L. The malondialdehyde (MDA), hydrogen peroxide (H2O2) and protein carbonyl in serum increased significantly at concentrations of 2.80 mg/L and 5.60 mg/L. A significant decrease in acetylcholinesterase (AChE) activity was observed at each concentration (P＜0.05). In addition, the micronucleus (MN) frequency of haemocytes significantly increased (P＜0.05) at concentrations of 1.40, 2.80 and 5.60 mg/L, whereas the comet ratio and %DNA in the tails exhibited a clear time- and dose-dependent response during the exposure. The analysis of the integrated biomarker response (IBR) showed the induction of oxidative stress biomarkers and the inhibition of antioxidants, and this dose-dependent relation suggests the sensitivity and availability of all the biomarkers. These results revealed that Roundup had a prominent toxic effect on M. nipponensis based on the antioxidative response inhibition and genotoxicity.

The mechanism of DNA damage induced by Roundup 360 PLUS, glyphosate and AMPA in human peripheral blood mononuclear cells - genotoxic risk assessement

Glyphosate is the most heavily applied among pesticides in the world, and thus human exposure to this substance continues to increase. WHO changed classification of glyphosate to probably cancerogenic to humans, thus there is urgent need to assess in detail genotoxic mechanism of its action. We have assessed the effect of glyphosate, its formulation (Roundup 360 PLUS) and its main metabolite (aminomethylphosphonic acid, AMPA) in the concentration range from 1 to 1000 μM on DNA damage in human peripheral blood mononuclear cells (PBMCs). The cells were incubated for 24 h. The compounds studied and formulation induced DNA single and double strand-breaks and caused purines and pyrimidines oxidation. None of compounds examined was capable of creating adducts with DNA, while those substances increased ROS (including •OH) level in PBMCs. Roundup 360 PLUS caused damage to DNA even at 5 μM, while glyphosate and particularly AMPA induced DNA lesions from the concentration of 250 μM and 500 μM, respectively. DNA damage induced by glyphosate and its derivatives increased in order: AMPA, glyphosate, Roundup 360 PLUS. We may conclude that observed changes were not associated with direct interaction of xenobiotics studied with DNA, but the most probably they occurred through ROS-mediated effects.

Generation of a novel Streptococcus agalactiae ghost vaccine and examination of its immunogenicity against virulent challenge in tilapia

Streptococcus agalactiae (S. agalactiae) is a gram-positive pathogen that causes a wide range of infections in fish and other animals including humans. Bacterial ghosts (BGs) are nonliving, empty cell envelopes and are well represented as novel vaccine candidates. In this study, we examined the immunogenicity and protective efficacy of S. agalactiae ghosts (SAG) against a virulent challenge in tilapia. Nonliving SAG was generated by a culture with Penicillin and Streptolysin, and then treated with the MIC of sodium hydroxide. The formation of a transmembrane lysis tunnel structure in SAG was visualized by electron microscopy. To investigate the SAG as a vaccine candidate, fish were divided into three groups, A (SAG immunized), B [Formalin-inactivated S. agalactiae (FSA) immunized] and C (phosphate-buffered saline, PBS-immunized control). The IgM antibody responses were significantly stronger in the SAG-immunized group than in FSA-immunized group, which was higher than in the non-immunized control group (P < 0.05). Moreover, phagocytic activity (percent phagocytes, PP) was significantly higher (p < 0.05) in the SAG-immunized group than in FSA-immunized group, which was higher than in the non-immunized control group (P < 0.05). In addition, non-specific immune immunity, such as lysozyme and superoxide dismutase activities, in the SAG-immunized fish showed significantly higher activities than FSA-immunized fish and the control group fish (P < 0.05). Also, fish immunized with SAG and FSA showed significantly higher (p < 0.05) gene expression of IL-1β, TNF-α, IFN-γ and TGF-β in the head kidney and spleen than fish treated with PBS during the whole observed period. In addition, fish immunized with SAG showed significantly higher gene expression of L-1β, TNF-α, and TGF-β in the spleen than in the FSA-immunized fish. Although there was no significant (P > 0.05) difference of survival rate (SR) or relative percent survival (RPS) between SAG and FSA immunized groups, they were all significantly more protected against the S. agalactiae challenge (SR: 86.67%, RPS: 76.395) and (SR: 80.00%, RPS: 67.50%) respectively, compared to the PBS-treated group (SR: 33.33%). These results suggest that immunization with SAG induces immune responses and provides protection against a virulent S. agalactiae challenge.

Different concentrations of Edwardsiella tarda ghost vaccine induces immune responses in vivo and protects Sparus macrocephalus against a homologous challenge

Bacterial ghosts (BGs) can be generated by the controlled expression of the PhiX174 lysis gene E in gram-negative bacteria. They are intriguing vaccine candidates since ghosts retain functional antigenic cellular determinants often lost during traditional inactivation procedures. Here we prepared Edwardsiella tarda ghost (ETG) and tested different concentrations in vaccination trials. The results showed that serum IgM antibody titers were significantly higher in three different concentration immunization groups than control group (P < 0.05), However, there was no significant (P > 0.05) difference between the immunized groups. The phagocytic percentage (PP) was significantly higher (P < 0.05) in ETG immunized groups than in the control group from 3 days post-treatment. The PP continued to rise with time until day 21, when the values of three ETG immunized groups were 45.7%,51.2% and 50.7%, respectively. In addition, phagocytic index (PI) was significantly higher (P < 0.05) in ETG immunized groups than in the control group after 7 days post-treatment. However, there was no significant (P > 0.05) difference of PP or PI between immunized groups. In addition, non-specific immune immunity, such as acid phosphatase, alkaline phosphatase, superoxide dismutase and lysozyme activities displayed a similar pattern in all immunized groups, all immunized fish showed significantly higher activities than control group fish (P < 0.05). Most importantly three ETG immunized groups were all significantly more protected against the E. tarda challenge (19/25, 76% survival), (21/25, 84% survival) and (20/25, 80% survival) respectively, compared to (9/25, 36% survival) survival in the control group, but there was no significant (P > 0.05) difference of survival rate (SR) or relative percent survival (RPS) between immunized groups. All these results suggest that an ETG could stimulate cellular and humoral immunity, and could be used as a vaccine candidate in S.m. In summary, ETG can protect fish from Edwardsiellosis, and there is no significant difference in SR and RPS when three different concentrations of ETG are used, so it can easily be developed as a vaccine for mechanical and artificial operations.