Multi-Biomarker Assessment in Common Carp (Cyprinus carpio, Linnaeus 1758) Liver after Acute Chlorpyrifos Exposure

Effects of sub-lethal concentrations of lindane on histo-morphometric and physio-biochemical parameters of Labeo rohita

Lindane is a broad-spectrum insecticide widely used on fruits, vegetables, crops, livestock and on animal premises to control the insects and pests. The extensive use of pesticides and their residues in the soil and water typically join the food chain and thus accumulate in the body tissues of human and animals causing severe health effects. The study was designed to determine the toxicity effects of sub-lethal concentrations of lindane on hemato-biochemical profile and histo-pathological changes in Rohu (Labeo rohita). A significant increase in the absolute (p<0.05) and relative (p<0.05) weights was observed along with severe histo-pathological alterations in liver, kidneys, gills, heart and brain at 30μg/L and 45μg/L concentration of lindane. A significant (p<0.05) decrease in RBCs count, PCV and Hb concentration while a significant (p<0.05) increased leukocytes were observed by 30μg/L and 45μg/L concentrations of lindane at 45 and 60 days of the experiment. Serum total protein and albumin were significantly (p<0.05) decreased while hepatic and renal enzymes were significantly (p<0.05) increased due to 30μg/L and 45μg/L concentrations of lindane at days-45 and 60 of experiment compared to control group. The observations of thin blood smear indicated significantly increased number of erythrocytes having nuclear abnormalities in the fish exposed at 30μg/L and 45μg/L concentrations of lindane. ROS and TBARS were found to be significantly increased while CAT, SOD, POD and GSH were significantly decreased with an increase in the concentration and exposure time of lindane. The results showed that lindane causes oxidative stress and severe hematological, serum biochemical and histo-pathological alterations in the fish even at sub-lethal concentrations.

Ecotoxicity of commonly used oilfield-based emulsifiers on Guinean Tilapia (Tilapia guineensis) using histopathology and behavioral alterations as protocol

This study examined the histological aberrations in the gill and liver tissues and behavioural changes of Tilapia guineensis fingerlings exposed to lethal concentrations of used Oilfield-based emulsifiers for 96 h. Various concentrations of the surfactants were tested, ranging from 0.0 to 15.0 ml/L. The behaviour of the fish was observed throughout the experiment, and the results showed that increasing concentrations of the surfactants led to progressively abnormal behaviour, including hyperventilation and altered opercular beat frequency. These behavioural changes indicated respiratory distress and neurotoxic effects. Histological analysis revealed structural aberrations in the gill and liver tissues, with higher concentrations causing more severe damage, such as lesions, necrosis, inflammation, and cellular degeneration. This implies that surfactants released even at low concentrations are capable of inducing changes in the tissues of aquatic organisms. These findings highlight the toxic effects of the surfactants on fish health and provide biomarkers of toxicity. Future research should focus on understanding the specific mechanisms and long-term consequences of surfactant toxicity on fish genetic composition, populations, and ecosystems to implement effective conservation measures.

The benefit of using in vitro bioassays to screen agricultural samples for oxidative stress: South Africa's case

Applied pesticides end up in non-target environments as complex mixtures. When bioavailable, these chemicals pose a threat to living organisms and can induce oxidative stress (OS). In this article, attention is paid to OS and the physiological role of the antioxidant defense system. South African and international literature was reviewed to provide extensive evidence of pesticide-induced OS in non-target organisms, in vivo and in vitro. Although in vitro approaches are used internationally, South African studies have only used in vivo methods. Considering ethical implications, the authors support the use of in vitro bioassays to screen environmental matrices for their OS potential. Since OS responses are initiated and measurable at lower cellular concentrations compared to other toxicity endpoints, in vitro OS bioassays could be used as an early warning sign for the presence of chemical mixtures in non-target environments. Areas of concern in the country could be identified and prioritized without using animal models. The authors conclude that it will be worthwhile for South Africa to include in vitro OS bioassays as part of a battery of tests to screen environmental matrices for biological effects. This will facilitate the development and implementation of biomonitoring programs to safeguard the South African environment.

The synergetic effects of 4-nonylphenol and polyethylene microplastics in Cyprinus carpio juveniles using blood biomarkers

Microplastics are widely distributed in aquatic ecosystems along with other chemical pollutants. Therefore, it is vital to study the health-hazardous effects of MPs in combination with 4-nonylphenol (4-NP), which is a highly abundant industrial waste and a critical alkylphenol endocrine disruptor. We investigated the effects of the exposure to polyethylene microplastics (PE-MPs), 4-NP, and their combination on blood biomarkers in Cyprinus carpio juveniles. Four study groups were treated for 15 consecutive days: (1) control group, (2) 10 mg/L PE-MP group, (3) 10 mg/L PE-MPs + 200 µg/L 4-NP group, and (4) 200 µg/L 4-NP group, followed by 15 days of recovery. Biochemical analyses showed that creatine kinase, lactate dehydrogenase, glucose, liver enzymes, total protein, and A/G ratios were significantly increased after exposure to PE-MPs, 4-NP, and the combination. Hematological parameters (RBC's, Hb, Ht, neutrophil percentage, and WBC's) were significantly decreased in the three exposure groups, whereas mean corpuscular volume and lymphocyte percentages were significantly increased. The 15-day recovery period improved most hematobiochemical parameters and PE-MP accumulation indices. Taken together, we demonstrated the hazardous effects of PE-MP and 4-NP combinations on C. carpio blood parameters and highlighted their potential risk to human health.

Protective effect of total saponins of ginseng stems and leaves (GSLS) on chlorpyrifos-induced brain toxicity in mice through the PTEN/PI3K/AKT axis

Chlorpyrifos (CPF) is a class of toxic compounds which has been widely used in agriculture that can cause multi-organ damage to the liver, kidneys, testes, and nervous system. Currently, most studies on ginseng have concentrated on the roots and rhizomes, and less research has been conducted on the above-ground parts. Our laboratory found that ginseng stem and leaf total saponin (GSLS) features strong antioxidant activity. In this experiment, we selected different concentrations of CPF to induce hippocampal neuronal cell injury model in mice, conducted a cell survival screening test, and also selected appropriate concentrations of CPF to induce brain injury model in mice. CCK-8, flow cytometry, Elisa, Hoechst 33258 staining, Annexin V-FITC/PI staining, HE staining, Morris water maze, and qRT-PCR were adopted for detecting the effects of GSLS treatment on CPF-induced cell viability, mitochondrial membrane potential, reactive oxygen species (ROS) levels, Ca2+ concentration and GSLS treatment on CPF-induced brain injury and related signaling in mice, respectively. The effects of GSLS treatment on CPF-induced brain injury and the related signaling pathways in mice were examined. The results showed that GSLS at 60 μg/ml and 125 μg/ml concentrations elevated the viability of CPF-induced HT22 cells, increased mitochondrial membrane potential, depleted ROS, decreased Ca2+ concentration, and decreased apoptosis rate. Meanwhile, GSLS treatment significantly reduced CPF-induced escape latency in mice, elevated the number of entries into the plateau and effective area, increased the effective area and target quadrant residence time, as well as improved the pathological damage of mouse hippocampal neurons. The results of mouse brain sections demonstrated that GSLS treatment significantly increased SOD and CAT activities and lowered MDA accumulation in CPF-induced mice. qRT-PCR revealed that PTEN mRNA expression was significantly decreased with PI3K and AKT expression being significantly increased in GSLS-treated CPF-induced mice. Thus, the obtained results indicate that GSLS can effectively antagonize CPF-induced brain toxicity in mice through regulating PTEN/PI3K/AKT pathway.

Toxic effects of glyphosate on the intestine, liver, brain of carp and on epithelioma papulosum cyprinid cells: Evidence from in vivo and in vitro research

Glyphosate (GLY) is the most widely used organophosphorus herbicide in agriculture. The present study aimed to analyze the comprehensive toxicological effects of GLY on juvenile common carp and an epithelioma papulosum cyprinid (EPC) cell line. In the in vivo experiments, exposure to GLY (5 and 15 mg/L) for 30 days induced liver inflammation and oxidative damage in common carp and changed the physical barrier of the intestine. Histopathological analysis of the intestine, liver, brain, and changes in oxidative stress biomarkers provided evidence of damage and immune system responses to GLY. Moreover, an inhibitory effect of 15 mg/L GLY on acetylcholinesterase (AChE) activity was found in the brain, which may be an important reason for the significant decrease in both swimming distance and average acceleration of common carp. Cell experiments showed that 0.65 and 3.25 mg/L GLY inhibited the viability of EPCs. Furthermore, oxidative DNA damage, mitochondrial dysfunction, and reactive oxygen species (ROS) production were observed in EPC cells following GLY exposure. Taken together, this study not only highlights the negative effects of GLY on common carp but also enriches the knowledge of the cytotoxicity mechanism to further clarify the comprehensive toxicity of GLY in common carp.

Investigation of the impact caused by different sizes of polyethylene plastics (nano, micro, and macro) in common carp juveniles, Cyprinus carpio L., using multi-biomarkers

Plastic pollution poses a global threat to aquatic organisms, yet its effect on many species remains poorly documented and understood. This study addresses the impact caused by different sizes of polyethylene (PE) plastics on the common carp and evaluates their multi-biomarkers response. We investigated the histological structure and measurement of biochemical alterations, antioxidant enzymes, immunological responses, and fluctuations in blood profiles of the organisms after 15 days of exposure to a concentration of 100 mg/L of nano- (NPs), micro- (MPs) and macroplastics (MaPs). The fish health status was altered in the sole presence of PE particles. All biomarkers changed after exposure compared to the control group, with larger changes being observed with the decreasing size of particles (NPs > MPs > MaPs) compared to their absence. A synergistic effect resulting from the individual impact of plastics penetration in the circulatory system, bursting biochemical responses, and lesions in tissues, might explain the more considerable impact of NPs compared to MPs and/or MaPs.

Ecotoxicity of chlorpyrifos on earthworm Eisenia fetida (Savigny, 1826): Modifications in oxidative biomarkers

Chlorpyrifos (CPF; O, O'-diethyl-3, 5, 6-trichloro-2-pyridyl phosphorothionate) as an organophosphate compound with moderate toxicity that entered the soil in 1965, is widely used as an active substance of many insecticides. CPF may affect some biochemical mechanisms, particularly through disrupting pro- and anti-oxidant balance and inducing free radical-induced oxidative stress. Expired pesticides, if present in ecosystem, may pose new issues of toxicological concern. In the current study, modifications in the oxidative stress (OS) hallmarks including the content of lipid peroxidation (LPO/MDA) and the activities of antioxidant enzymes catalase (CAT) and glutathione S-transferase (GST) in the whole body extract and total antioxidant capacity (TAC), in the coelomic fluid (CF) of earthworm Eisenia fetida were evaluated spectrophotometrically after exposure to different concentrations (1/20th, 1/10th, and 1/5th of LC₅₀) of fresh and expired CPF for 4 and 8 days. First, LC₅₀ for both fresh and expired CPF were determined by using probit method as ≤192 and ≤ 209 mg/kg dry soil, respectively. Our results also revealed that both fresh and expired CPF could be toxic to earthworms via inducing OS at higher concentrations. Here, CPF-induced OS was determined by a significant elevation (p < 0.05) in LPO content, CAT and GST activities and also a meaningful decrease (p < 0.05) in TAC value. Briefly, CPF may exhibit toxic effects in earthworms in the fresh and expired forms via changing oxidative balance and modifying some biochemical markers in the whole body. Further unraveling is needed to elucidate CPF-related impairments in soil organisms.

Mercury Accumulation and Elimination in Different Tissues of Zebrafish (Danio rerio) Exposed to a Mercury-Supplemented Diet

In this study, we evaluated the bioaccumulation of mercury in zebrafish (Danio rerio) exposed to mercury-contaminated food for 21 days and the depuration of mercury for a subsequent post-exposure period of 28 days. Four tissues (muscle, liver, gills, and skin) were analyzed for mercury content. Overall, data indicated that Hg accumulation in the liver is faster than in other tissues. Furthermore, the liver is the tissue with the highest accumulation rate per day (0.021 µg Hg g−1 day−1), followed by muscle, skin, and gills. Conversely, the Hg depuration rates in different tissues showed the following order: gills > skin > muscle > liver. The bioaccumulation factor values of liver and muscle increased linearly during the uptake period. The ratios between mercury concentration in liver and muscle during the experiment also increased during the uptake period and remained higher than 1 during the elimination period, suggesting that Danio rerio needed more than 4 weeks of depuration. Finally, the distribution of Hg in the water column during the accumulation period is Hg particulate > Hg dissolved, and during the depuration period it is the opposite, mercury particulate < mercury dissolved. In conclusion, this study contributes to a better understanding of the differences in Hg dynamics during the accumulation and depuration stages in a model fish, also emphasizing the alterations on Hg available in the water column.

Chronological Trends and Mercury Bioaccumulation in an Aquatic Semiarid Ecosystem under a Global Climate Change Scenario in the Northeastern Coast of Brazil

Simple Summary

Managing aquatic systems is becoming increasingly complex due to human impacts, multiple and competing water needs and climate variability. Considering the Hg concentration present in the top layers of sediment (~20 cm around 30 to 40 years) with the outer layers in the tree cores tree rings cores and in the sediment’s cores from Pacoti estuary and the Ceará estuary, overall data indicate an increase in mercury in recent years. A positive and significant correlation (p < 0.05) was revealed between Hg trends in sediments and Hg trends in annular tree rings. This shared Hg pattern reflects local environmental conditions. The results of this work reinforce the indicators previously described in the semiarid NE region of Brazil, showing that global climate change and some anthropogenic factors are key drivers to Hg exposure and biomagnification for wildlife and humans. Possible climate-induced shifts in these aquatic systems highlight the need for accurate and regionally specific metrics of change in the past in response to climate and for improved understanding of response to climate factors. These processes are inducing a greater mobilization of bioavailable Hg, which could allow an acceleration of the biogeochemical transformation of Hg.

Abstract

Due to global warming, in the northeastern semiarid coastal regions of Brazil, regional and global drivers are responsible for decreasing continental runoff and increasing estuarine water residence time, which promotes a greater mobilization of bioavailable mercury (Hg) and allows increasing fluxes and/or bioavailability of this toxic trace element and an acceleration of biogeochemical transformation of Hg. In this work, an application of dendrochemistry analysis (annular tree rings analysis) was developed for the reconstruction of the historical pattern of mercury contamination in a contaminated area, quantifying chronological Hg contamination trends in a tropical semiarid ecosystem (Ceará River Estuary, northeastern coast of Brazil) through registration of mercury concentration on growth rings in specimens of Rhizophora mangle L. and using the assessment in sediments as a support for the comparison of profiles of contamination. The comparison with sediments from the same place lends credibility to this type of analysis, as well as the relationship to the historical profile of contamination in the region, when compared with local data about industries and ecological situation of sampling sites. In order to evaluate the consequences of the described increase in Hg bioavailability and bioaccumulation in aquatic biota, and to assess the biological significance of Hg concentrations in sediments to fish and wildlife, muscle and liver from a bioindicator fish species, S. testudineus, were also analyzed. The results of this work reinforce the indicators previously described in the semiarid NE region of Brazil, which showed that global climate change and some anthropogenic factors are key drivers of Hg exposure and biomagnification for wildlife and humans. Considering the Hg concentration present in the top layers of sediment (~20 cm around 15 to 20 years) with the outer layers in the tree ring cores and in the sediment’s cores from Pacoti estuary and the Ceará estuary, overall the data indicate an increase in mercury in recent years in the Hg surface sediments, especially associated with the fine sediment fraction, mainly due to the increased capacity of small particles to adsorb Hg. There was revealed a positive and significant correlation (p < 0.05) between Hg trends in sediments and Hg trends in annular tree rings. This shared Hg pattern reflects local environmental conditions. The Hg concentration values in S. testudineus from both study areas are not restrictive to human consumption, being below the legislated European limit for Hg in foodstuffs. The results from S. testudineus muscles analysis suggest a significant and linear increase in Hg burden with increasing fish length, indicating that the specimens are accumulating Hg as they grow. The results from both rivers show an increase in BSAF with fish growth. The [Hg] liver/[Hg] muscles ratio >1, which indicates that the S. testudineus from both study areas are experiencing an increase in Hg bioavailability. Possible climate-induced shifts in these aquatic systems processes are inducing a greater mobilization of bioavailable Hg, which could allow an acceleration of the biogeochemical transformation of Hg.

Which Is More Toxic? Evaluation of the Short-Term Toxic Effects of Chlorpyrifos and Cypermethrin on Selected Biomarkers in Common Carp (Cyprinus carpio, Linnaeus 1758)

The general aim of this study was to investigate the negative short-term effects of different concentrations of chlorpyrifos (CPF) and cypermethrin (CYP), based on the EU legislation (MAC-EQS) in common carp (Cyprinus carpio Linnaeus, 1758) under laboratory conditions and to compare their toxicity. The fish were exposed to the pesticides for 96 h and then different histological and biochemical biomarkers were investigated in the gills and liver, and bioaccumulation analyses were conducted. The chemical studies showed increased pesticide concentrations in the gills as the first site for pollutants compared to the liver at the 96th hour. In addition, the histological analyses showed severe alterations in the gills and liver after exposure to both tested pesticides. In the gills, we found mainly intense proliferative and, to a lesser extent, degenerative changes and alterations in the circulatory system, such as necrosis and vasodilation. In the liver, regressive and progressive lesions, as well as circulatory disturbances and inflammation, were observed. The regressive lesions showed a higher degree of expression compared to the other changes. Furthermore, we found altered enzymatic activities—catalase, glutathione reductase, and glutathione peroxidase—in the liver, compared to the control. Overall, both tested pesticides impacted the studied biomarkers in common carp, even at concentrations lower than those permitted by law. However, the results of the comparative analysis showed a relatively higher toxicity of CYP compared to CPF in the fish. Still, questions persist as to whether the observed changes are adaptive or entirely destructive. To avoid any danger or risk, these pesticides must be applied cautiously, especially near water bodies.

Effects of Essential Oil Derived from the Bitter Orange (Citrus aurantium) on Growth Performance, Histology and Gene Expression Levels in Common Carp Juveniles (Cyprinus carpio)

The aim of this study was to detect effects of bitter orange (Citrus aurantium) essential oil, commonly called neroli oil (NO) (0, 0.25, 0.50, 1, and 1.5% referred to as NO0 NO0.25, NO0. 05, NO1 and NO1.5, respectively) on growth performance output and expression levels of some growth-related genes in the muscle tissue and some immune-related genes in the head kidney and pathological differences in digestive system organs of common carp Cyprinus carpio. The NO0.25 group had a large improvement in growth efficiency at the end of the 60-day feeding cycle. Real-time PCR (Bio RAD, USA) system was used to detect variations in gene expression levels. Furthermore, NO supplementation of up to 0.25% in muscle tissue controlled the release of growth hormone (GH) and insulin-like growth factor I (IGF-I). Furthermore, in the NO0.25 treatment category, immune response gene levels TNF-α, IL-8 and IL-1ß increased in head kidney tissue. In the histological examination of the liver and intestine, there were significant differences between fish fed with N1 and N1.5 diets. This study confirms that dietary supplementation of NO up to 0.25% can improve common carp growth efficiency and increase the expression of genes (GH and IGF-I) related to muscle growth, TNF-α, IL-8 and IL-1ß genes related to immune status, and liver and intestine histological status of common carp.

Analysis of the biochemical and histopathological impact of a mild dose of commercial malathion on Channa punctatus (Bloch) fish

The intensive application of pesticides without proper disposal management has led their excess residues to reach the neighbouring aquatic ecosystem and its inhabitants mainly fish. In natural water body pesticides get diluted, and therefore to study the silent toxic effect, a low dose of malathion (0.4 mg/L; 1/20th of 96-h LC50 value) for the different duration (1, 4, 8, 12 days) was evaluated through biochemical and histopathological biomarkers of the blood and hepatorenal tissues of Channa punctatus. With the increase in pesticide exposure periods, the biometric indices: Condition Factor (K), HSI and KSI and hepatorenal tissues weight decreased. Among the biochemical alterations in malathion exposed fish, serum glucose levels reduced by 72.23 % while protein amounts increased by 29.03 % in 12 days malathion exposed fish. Other parameters, viz., cholesterol, albumin, and phosphorous, remained the same as control fish after malathion exposure. Though serum bilirubin (total and direct) followed a biphasic response, it reduced by 60 % after 12 days of malathion exposure compared to control. Biochemical changes are reflecting the induction of compensatory energy mechanism to cope up with the malathion stress. The transaminases and ALP biomarker enzymes used for liver functionality test declined in the order of AST > ALP > ALT in a time-dependent manner in malathion exposed fish serum, indicating liver injuries in fish due to malathion. The elevated levels of urea, BUN, creatinine, and Ca2+ in the serum of 12 days of malathion exposed fish revealed renal dysfunction. In the treated fish, antioxidative (SOD and CAT) and LPO activities were significantly higher in the liver followed by the kidney than their controls. Further, histological examination registered progressive damages in the hepatorenal tissues of malathion exposed fish with the increased exposure periods compared to control. Thus, even a small dose of malathion in water could severely deteriorate the structure and function of tissue on its prolonged exposure, and therefore utmost care should be taken to prevent their seepage into the water bodies.

Determination of the Ecotoxicity of Herbicides Roundup® Classic Pro and Garlon New in Aquatic and Terrestrial Environments

Herbicides help increase agricultural yields significantly, but they may negatively impact the life of non-target organisms. Modifying the life cycle of primary producers can affect other organisms in the food chain, and consequently in the whole ecosystem. We investigated the effect of common herbicides Roundup® Classic Pro (active substance glyphosate) and Garlon New (triclopyr and fluroxypyr) on aquatic organisms duckweed Lemna minor and green algae Desmodesmus subspicatus, and on the enzymatic activity of soil. We also compared the effects of Roundup® Classic Pro to that of a metabolite of its active substance, aminomethylphosphonic acid (AMPA). The results of an algal growth test showed that AMPA has a 1.5× weaker inhibitory effect on the growth of D. subspicatus than the Roundup formula, and the strongest growth inhibition was caused by Garlon New (IC50Roundup = 267.3 µg/L, IC50Garlon = 21.0 µg/L, IC50AMPA = 117.8 mg/L). The results of the duckweed growth inhibition test revealed that Roundup and Garlon New caused 100% growth inhibition of L. minor even at significantly lower concentrations than the ready-to-use concentration. The total chlorophyll content in the fronds was lowest when Garlon New was used. The highest dehydrogenase activity was observed in soil treated with Garlon New, and the lowest in soil treated with Roundup® Classic Pro. The results of this study showed that all three tested substances were ecotoxic to the tested organisms.