Toxicity Values Research Articles

Essential oils of the Lamiaceae family, their blends and their major compounds in the management of the spider mite, Tetranychus urticae Koch

ABSTRACT This research study focused on determining the lethal concentrations of essential oils extracted from O. basilicum L. Mentha piperita L. Origanum vulgare L. and Thymus vulgaris L. against the two-spotted spider mite (Tetranychus urticae). This notorious agricultural pest wreaks havoc on various plants, causing widespread damage worldwide, as well as their blends and major compounds, using the fumigation method. GC-MS identified the essential oils and major compounds. The essential oils of O. basilicum, M. piperita, O. vulgare, and T. vulgaris had estragole (91.8%), menthol (39.11%), carvacrol (76,8%), and thymol (45,76%) as major compounds, respectively. The most toxic LC50 value was observed with O. basilicum essential oil (8.02 μL.L−1). Blends 7, 8, and 11 showed better results in terms of mite toxicity. The major compounds also displayed promising results. Thus, this study individual presents promising alternatives with potential for managing the two-spotted spider mite.

Unveiling the interspecies correlation and sensitivity factor analysis of rat and mouse acute oral toxicity of antimicrobial agents: first QSTR and QTTR Modeling report

Abstract This study aims to identify toxic potential and environmental hazardousness of antimicrobials. In this regard, the available experimental toxicity data with rat and mouse acute oral toxicity have been gathered from ChemID Plus database (n = 202) and subjected to data curation. Upon the data curation 51 and 68 compounds were left for the rat and mouse respectively for the modeling. The quantitative structure toxicity relationship (QSTR) and interspecies correlation analysis by quantitative toxicity-toxicity relationship (QTTR) modeling was approached in this study. The models were developed from 2D descriptors under OECD guidelines by using multiple linear regressions (MLR) with genetic algorithm (GA) for feature selection as a chemometric tool. The developed models were robust (Q2LOO = 0.600–0.679) and predictive enough (Q2Fn = 0.626–0.958, CCCExt = 0.840–0.893). The leverage approach of applicability domain (ad) analysis assures the model’s reliability. The antimicrobials without experimental toxicity values were classified as high, moderate and low toxic based on prediction and ad. The occurrence of the same classification from QSTR and QTTR models revealed the reliability of QTTR models.Finally, the applied “sensitivity factor analysis” typifies the sensitivity of chemicals toward each species. Overall, the first report will be helpful in the toxicity assessment of upcoming antimicrobials in rodents.

Benchmark dose modeling for epidemiological dose-response assessment using case-control studies.

Following a previous article that focused on integrating epidemiological data from prospective cohort studies into toxicological risk assessment, this paper shifts the focus to case-control studies. Specifically, it utilizes the odds ratio (OR) as the main epidemiological measure, aligning it with the benchmark dose (BMD) methodology as the standard dose-response modeling approach to determine chemical toxicity values for regulatory risk assessment. A standardized BMD analysis framework has been established for toxicological data, including input data requirements, dose-response models, definitions of benchmark response, and consideration of model uncertainty. This framework has been enhanced by recent methods capable of handling both cohort and case-control studies using summary data that have been adjusted for confounders. The present study aims to investigate and compare the "effective count" based BMD modeling approach, merged with an algorithm used for converting odds ratio to relative risk in cohort studies with partial data information (i.e., the Wang algorithm), with the adjusted OR-based BMD analysis approach. The goal is to develop an adequate BMD modeling framework that can be generalized for analyzing published case-control study data. As in the previous study, these methods were applied to a database examining the association between bladder and lung cancer and inorganic arsenic exposure. The results indicate that estimated BMDs and BMDLs are relatively consistent across both methods. However, modeling adjusted OR values as continuous data for BMD estimation aligns better with established practices in toxicological BMD analysis, making it a more generalizable approach.

A Detailed Review on the Green Synthesis of Selenium Nanoparticles Using Plant Extracts and Their Anticancer Applications

AbstractNanobiotechnology is a field of science with tremendous promising applications in cancer chemotherapy, targeted drug delivery, molecular diagnosis, and molecular imaging. Selenium, one of the critical trace elements, participates in the structure of selenocysteine protein, which plays an important role in maintaining redox balance due to its oxidoreductase activity. Elemental selenium (Se0) has significantly lower toxicity values than its oxyanions, selenite, and selenate forms. For this reason, it is important to convert elemental selenium into atomic form in biological studies. In particular, their role in regulating the immune system makes selenium nanoparticles (SeNPs) superior to others. SeNPs have been discussed effectively in the literature in anticancer activity applications. SeNPs green synthesis is focused on a more economical, biocompatible, and environmentally friendly application by using, reducing, and stabilizing agents in plants. The aim of this review is to highlight the anticancer activity applications of SeNPs synthesized with plant extracts in the last 6 years (i.e., between 2019 and 2024). In addition, it aims to shed light on the green synthesis mechanism of NPs by using plant extracts and to highlight the factors affecting green synthesis and its advantages and disadvantages.

Toxicodynamics of cadmium in the green mussel Perna viridis (Linnaeus, 1758) using bioenergetic and physiological biomarkers.

This study evaluated the toxicity of cadmium (Cd) on the green mussel Perna viridis, aiming to identify toxicological endpoints and investigate its responses across physiological, bioenergetic, and biochemical parameters. The 96-hour LC50 value for Cd in P. viridis was 3.03 ± 0.12 mg L-1, with a 95% confidence interval of 2.35-3.91 mg L-1. Chronic toxicity tests revealed a No Observable Effect Concentration (NOEC), Lowest Observable Effect Concentration (LOEC), and chronic toxicity values of 0.20, 0.37, and 0.29 mg L-1, respectively. Cadmium accumulation in treated mussels increased 46- to 215-fold compared to the control group. Superoxide dismutase, catalase, glutathione S-transferase, and glutathione peroxidase levels in exposed mussels exhibited a significant increase compared to the control group. The redox index ratio, acetylcholinesterase activity, and lysosomal membrane stability decreased with increasing exposure concentrations. Levels of reduced and oxidized glutathione, glutathione reductase, lipid peroxidation, and metallothionein-like proteins increased in exposed mussels. Clearance rate, respiration rate, and excretion rate decreased in a dose-dependent manner. Protein, carbohydrate, and lipid levels decreased with increasing exposure concentration (p < 0.001). Mitochondrial electron transport system activity increased, while cellular energy allocation (p < 0.001) and scope for growth decreased in a dose-dependent manner (p < 0.01). The significant increase in antioxidants suggests heightened oxidative stress in mussels under Cd exposure. The physiological activities of the mussels were severely affected, ultimately leading to a reduced scope for growth. The toxicological data generated in this study contribute to the development of seawater quality criteria for the metal Cd.

A-015 Changes of sST2 and NT-proBNP levels predict early cardiovascular toxicity in breast cancer patients treated with anthracycline-containing chemotherapy

Abstract Background Cardiovascular biomarkers play a crucial role in monitoring the risk for cancer therapy-related cardiovascular toxicity, but their changes and values at the early stage of chemotherapy are still inadequate, especially for some new biomarkers.The purpose of this study was to examine changes in cardiovascular biomarkers and evaluate the prognostic values for cardiovascular toxicity in patients with breast cancer treated with anthracycline-containing chemotherapy. Methods In a prospective cohort of 73 patients treated with anthracycline-containing chemotherapy, soluble ST2 (sST2), high-sensitivity cardiac troponin T (hs-cTnT), N-terminal pro-B-type natriuretic peptide (NT-proBNP), Myoglobin (Myo), Creatine kinase isoenzyme MB (CK-MB) and heart-fatty acid binding protein (H-FABP) were measured at baseline, during every chemotherapy cycle (C1-C6, about every month).Cardiovascular toxicity was defined as cancer therapy-related arrhythmias, which was differentiated into bradycardia,tachycardia or atrial fibrillation. According to whether arrhythmia occurred, patients were divided into two groups (healthy group and arrhythmias group), and the basic clinical characteristics were collected and compared among the two groups. Logistic regression analyses and receiver operating characteristic (ROC) curves were conducted to investigate the relationship between the changes in biomarkers and anthracycline-induced cardiotoxicity. Results sST2 levels increased significantly from baseline to C1 (P&amp;lt;0.01). NT-proBNP decreased from baseline to C1, C5 (P&amp;lt; 0.01). Logistic regression analysis showed a greater risk of cardiovascular toxicity was associated with greater interval increase in sST2 from baseline to C1(ΔsST2) (OR:1.27; 95% CI:1.03 to1.56; P= 0.024) and interval decline in NT-proBNP from baseline to C1(ΔNT-proBNP) was associated with cardiovascular toxicity (OR: 0.83; 95% CI: 0.70 to 0.98; P= 0.029). ROC curves showed that ΔsST2, ΔNT-proBNP and ΔsST2+ΔNT-proBNP had good predictive value for cardiovascular toxicity (areas under the curves were 0.631, 0.633, and 0.735, respectively, P&amp;lt;0.05). Conclusions Early changes in sST2 and NT-proBNP levels offer additive information in early cardiovascular toxicity risk prediction in patients with breast cancer who receive anthracycline-containing chemotherapy.

A green approach coupled with molecular dynamics simulations and toxicity assays to infer the mode of action for organophosphate esters

Organophosphate esters (OPEs) have attracted extensive attention due to their toxic effects on human health and biological systems as plasticizers and flame retardants. This study focused on exploring a green approach to get toxicity mechanisms that used less solvents or organisms. The toxicity values of selected organophosphate esters including tri (2-chloroethyl) phosphate (TCEP), tri (1, 3-dichloro-2-propyl) phosphate (TDCP), tripropyl phosphate (TPrP), tri-n-butyl phosphate (TnBP), and tritolyl Phosphate (TCrP) to Photobacterium phosphoreum were determined. Their EC50 range was between 7.27 × 10−8–5.12 × 10−6 mol/L. Based on molecular dynamics simulation the data of binding affinity between OPEs and n-octanol / phospholipid bilayer were calculated respectively. Coupling with binding affinity energies and toxicity values, the mode of action (MOA) of OPEs including types of reactive or anesthetic mechanism could be fast deduced. The proposed hypothesis of n-octanol (C8H18O) as a virtual biofilm to replace phospholipid bilayer was verified. The alternative green approach could simplify toxicity assay and realize fast predicting MOA for different chemicals and model organisms.

Workflow for predictive risk assessments of UVCBs: cheminformatics library design, QSAR, and read-across approaches applied to complex mixtures of metal naphthenates.

Substances of unknown or variable composition, complex reaction products, and biological materials (UVCBs) are commonly found in the environment. However, assessing their human toxicological risk is challenging due to their variable composition and many constituents. Metal naphthenate salts are one such category of UVCBs that are the reaction products of naphthenic acids with metals to form complex mixtures. Metal naphthenates are often found or used in household and industrial materials with potential for human exposure, but very few of these materials have been evaluated for causing human health hazards. Herein, we evaluate metal naphthenates using predictions derived from read-across and quantitative structure-activity/property relationship (QSAR/QSPR) models. Accordingly, we first built a computational chemistry library by enumerating the structures of naphthenic acids and derived 11,850 QSAR-acceptable structures; then, we used open and commercial in silico tools on these structures to predict a set of physicochemical properties and toxicity endpoints. We then compared the QSAR/QSPR predictions with available experimental data on naphthenic acids to provide a more complete picture of the contributions of the components to the toxicity profiles of metal naphthenate mixtures. The available systematic acute oral toxicity values (LD50) and QSAR LD50 predictions of all the naphthenic acid components indicated low concern for toxicity. The point of departure predictions for chronic repeated dose toxicity for the naphthenic acid components using QSAR models developed from studies on rats ranged from 25 to 50mg/kg/day. These values are in good agreement with findings from studies on copper and zinc naphthenates, which had no observed adverse effect levels of 30 and 118mg/kg/day, respectively. Hence, this study demonstrates how published in silico approaches can be used to identify the potential components of metal naphthenates for further testing, inform groupings of UVCBs such as naphthenates, as well as fill the data gaps using read-across and QSAR models to inform risk assessment.

A Step Towards Optimization of Amide-Linked Coumarin Pharmacophore: As an Anti-HIV Agent.

The aim of the present investigation is to identify effective anti-HIV drugs through the in-silico virtual screening of the coumarin pharmacophore with or without substituents. Virtual screening started with target identification through computation docking and interactions, binding affinity through molecular dynamics, and the ADMET profile through the use of various enzymes. The target study suggests that the target is involved in various stages of HIV replication and in determining the ways in which non-nucleoside reverse transcriptase inhibitors (RTIs) influence it. The interaction pattern and simulation study conclude the specific affinity of coumarin pharmacophore to the HIV's reverse transcriptase enzyme, especially 3HVT. Moreover, the amide linkage worked as a synergistic bridge to provide more interaction to the pharmacophore. The initial results led to the determination of 83 virtual amide-like molecules, which were screened through docking and MD studies (100 ns) on the best-suited enzyme HIV's reverse transcriptase enzyme, such as PDB ID "3HVT". The virtual screening study revealed the high affinity of compounds 7d and 7e with the lowest IC50 values of 0.729 and 0.658 μM; moreover, their metabolism pattern study, toxicity, and QED values in a range of 0.31-0.40 support a good drug candidate. The two compounds were also synthesized and characterized for future in vitro and in vivo studies. The in silico-based descriptor of compounds 7d and 7e indicates the potential future and provides the best two molecules and their synthetic route for the development of a more effective drug to combat HIV/AIDS epidemics.

Influence of Pesticide Application Method, Timing, and Rate on Contamination of Nectar with Systemic and Nonsystemic Pesticides.

Exposure to pesticides is one potential factor contributing to the recent loss of pollinators and pollinator diversity. Few studies have specifically focused on the relationship between pesticide management during ornamental plant production and contamination of nectar. We evaluated contamination of nectar in Salvia 'Indigo Spires' (Salvia longispicata M. Martens & Galeotti × S. farinacea Benth.) associated with applications of the systemic insecticide thiamethoxam, and the nonsystemic fungicides boscalid and pyraclostrobin. Applications were made at the labeled rates for the commercially available products, and we compared the influence of application method (drench vs. spray), timing (relative to flowering), and rate (low vs. high) for each pesticide. Nectar was sampled using 50-µL microcapillary tubes and analyzed by liquid chromatography-tandem mass spectrometry. The results indicate that concentrations from the spray application resulted in the least contamination of nectar with the systemic thiamethoxam, with lower concentrations occurring when thiamethoxam was applied before blooming at the lowest rate. Concentrations of thiamethoxam and its metabolite clothianidin were detected in nectar in all treatments (regardless of the method, timing, or rate of application), and ranged from 3.6 ± 0.5 ng/mL (spray-applied before blooming, low rate) to 1720.0 ± 80.9 ng/mL (drench-applied after blooming, high rate). Residues of clothianidin in nectar ranged from below quantification limits (spray-applied before blooming, low rate) to 81.2 ± 4.6 ng/mL (drench-applied after blooming, high rate). Drench applications resulted in the highest levels of nectar contamination with thiamethoxam, and exceeded published median lethal concentrations (LC50s/median lethal doses for native bees and/or honeybees in all cases). Spray treatments resulted in nectar concentrations exceeding published LC50s for some bee species. In comparison, all nonsystemic treatments resulted in concentrations much lower than the published no-observable-effect doses and sublethal toxicity values, indicating low risks of toxicity. Environ Toxicol Chem 2024;001:1-12. © 2024 SETAC.

Potansiyel bisphenol-A ikameleri sucul yaşam için gerçekten güvenli mi? Birincil üreticiler üzerindeki etkisi

Bisphenol A threat to environmental health and human health and has been added to the Candidate List as Very High Concern Substances by the European Chemicals Agency. This led to the replacement of bisphenol A (BPA) with bisphenol analogues, which were considered "safer". However, there are very few scientific studies on the impact of BPA analogues on the environment. In this study, three analogues bisphenol B (BPB), bisphenol A diglycidyl ether (BADGE) and bisphenol F diglycidyl ether (BFDGE) were selected to investigate their ecotoxicological effects on the marine phytoplankton species Phaeodactylum tricornutum, which is representative of primary producers. Phaeodactylum tricornutum was exposed to different concentrations (0.5, 0.8, 1.0, 1.5, 2.0 mg/L) of BPB, BADGE and BFDGE analogues for 72 hours and the toxicity values of three BPA analogues were calculated by OECD 201 algal growth inhibition assay (IC50/EC50). In the light of the data obtained, algal growth inhibition (IC50/EC50) values for marine phytoplankton Phaeodactylum tricornutum were determined as 3.91 mg-BPA/L, 7.83 mg-BPB/L, 5.69 mg-BFDGE/L, 11.71 mg-BADGE/L. The results revealed that BPB, BFDGE and BADGE showed lower toxicity to Phaeodactylum tricornutum compared to BPA algal growth inhibition (3.91 mg-BPA/L). Therefore, it is necessary to share the results of the adverse effects of BPA analogues on aquatic organisms and to conduct ecotoxicological risk assessments.

PSLBI-15 Effects of heat shock protein 70 on cell viability and protective capacity of serum against histone cytotoxicity

Abstract Bovine respiratory disease (BRD) is the most significant health problem associated with newly received cattle in the beef industry. Serum concentrations of extracellular histones increase in a variety of diseases and histones are known to be cytotoxic to mammalian cells. Work in our lab indicated that failure to protect against cytotoxic effects of extracellular histones may be a component of severe cases of respiratory disease in cattle. The mechanisms or proteins that neutralize cytotoxic effects of extracellular histones are not fully elucidated, but C-reactive protein and complement activity have been associated with a reduced cytotoxic effect of extracellular histones. Work in the literature suggests that heat shock protein 70 (HSP70) concentrations in the serum is increased in disease and may directly activate complement. Unpublished observations in our lab indicated that HSP70 potentially interacts with histones to exacerbate cytotoxicity leading to our hypothesis that increased concentrations of HSP70 will decrease the protective capacity against histone cytotoxicity. Therefore, the objectives of the current study were to evaluate serum concentrations of HSP70 in weaned bulls entering the feedlot and the effects of increasing HSP70 concentrations on histone cytotoxicity in vitro. Weaned seedstock bulls (n = 130) composed of various breeds were fed using the GrowSafe System at the Tucumcari Bull Test for 122 d. At receiving, blood samples were obtained via coccygeal venipuncture, centrifuged, and serum immediately frozen on dry ice. Serum was analyzed for complement activity (CH50 assay) and protective capacity against extracellular histones using our novel histone toxicity assay. The ratio value of histone toxicity to CH50 was used to separate a subset of bulls as protective (n = 10) and non-protective (n = 10). Concentrations of HSP70 were quantified utilizing a commercially available ELISA kit. Data were analyzed using the GLM procedure of SAS. Serum concentrations of HSP70 were similar (P &amp;gt; 0.10) for protective and non-protective bulls. To test the responses to increased concentrations of HSP70 to mimic disease, protective and non-protective serum was tested against histones alone and in combination with 0.5 or 40 ng/mL recombinant bovine HSP70. Complement activity from protective and non-protective bulls was not influenced (P &amp;gt; 0.10) in the presence and absence of recombinant bovine HSP70. Exogenous HSP70 at 0.5 or 40 ng/mL did not influence protective capacity in non-protective animals (P = 0.95). However, HSP70 at 0.5 ng/mL did not (P = 0.18) reduce protective capacity and reduced protective capacity (P &amp;lt; 0.01) at 40 ng/mL in serum from bulls that were assigned to the protective group. Results indicate that weaned bulls entering the feedlot display varied capacity to protect against histone toxicity and increased concentrations of HSP70 can reduce the protective capacity indicating that circulating HSP70 may play a role in bovine respiratory disease pathogenesis.

Predicting the ecological risk thresholds of soil metals in Europe using the quantitative ion character-activity relationships (QICAR) model

Metal pollutants have become increasingly diverse. Therefore, managing the ecological risks associated with these elements in soil is urgently required. However, determining the soil ecological risk thresholds of elements through routine toxicological tests is time-consuming and laborious, establishing prediction models is vital to risk management. Accordingly, this study aimed to predict the element toxicity to soil organisms by collecting the toxicological data of eight elements to soil organisms at 18 European and 17 Chinese sites through literature and toxicology databases, using the quantitative ion character-activity relationship (s-QICAR) model. Firstly, the toxicity values (logEC10) of eight elements to five biological species and three microbial processes were obtained through clustering and soil normalization methods in three typical soil scenarios. Correlation analysis revealed that for different species and microbial processes, there are three to six physicochemical properties of elements related to their toxicity, among which, the covalent radius of the element was the best significantly correlated with logEC10 of all organisms (R2 = 0.77–0.95). Based on this, the s-QICAR model was established and used to predict the logEC10 of Sc, Ti, V, Cr, Co, Ni, Cu, and Zn to eight organisms. Furthermore, along with the species sensitivity distribution curve, the HC5 values (i.e., 95% species protection level) for the above eight elements were calculated. Following correction, the predicted no-effect concentrations of these elements ranging from 9 to 189 mg/kg, and the ecological risk threshold map has been produced. In summary, we present a new method to quantify the ecological risk of metal-induced pollution in European soils without routine toxic measurements, and provide important insights into soil pollution risk assessment and management.

Community-Engaged Research and the Use of Open Access ToxVal/ToxRef In Vivo Databases and New Approach Methodologies (NAM) to Address Human Health Risks From Environmental Contaminants.

The paper analyzes opportunities for integrating Open access resources (Abstract Sifter, US EPA and NTP Toxicity Value and Toxicity Reference [ToxVal/ToxRefDB]) and New Approach Methodologies (NAM) integration into Community Engaged Research (CEnR). CompTox Chemicals Dashboard and Integrated Chemical Environment with in vivo ToxVal/ToxRef and NAMs (in vitro) databases are presented in three case studies to show how these resources could be used in Pilot Projects involving Community Engaged Research (CEnR) from the University of California, Davis, Environmental Health Sciences Center. Case #1 developed a novel assay methodology for testing pesticide toxicity. Case #2 involved detection of water contaminants from wildfire ash and Case #3 involved contaminants on Tribal Lands. Abstract Sifter/ToxVal/ToxRefDB regulatory data and NAMs could be used to screen/prioritize risks from exposure to metals, PAHs and PFAS from wildfire ash leached into water and to investigate activities of environmental toxins (e.g., pesticides) on Tribal lands. Open access NAMs and computational tools can apply to detection of sensitive biological activities in potential or known adverse outcome pathways to predict points of departure (POD) for comparison with regulatory values for hazard identification. Open access Systematic Empirical Evaluation of Models or biomonitoring exposures are available for human subpopulations and can be used to determine bioactivity (POD) to exposure ratio to facilitate mitigation. These resources help prioritize chemical toxicity and facilitate regulatory decisions and health protective policies that can aid stakeholders in deciding on needed research. Insights into exposure risks can aid environmental justice and health equity advocates.

Dissolved Barium Causes Toxicity to Groundwater Cyclopoida.

Barium (Ba) dissolution and mobilization in groundwater are predominantly controlled by sulfate because of the low solubility of barium sulfate (BaSO4) minerals. Naturally present at low concentrations in groundwater, elevated concentrations of Ba can occur as a result of anthropogenic activities, including use of barite in drill operations, and geogenic sources such as leaching from geological formations. No toxicity data exist for Ba with groundwater organisms (stygofauna) to assess the risk of elevated Ba concentrations. The present study measured Ba toxicity to two stygobiont Cyclopoida species: one collected from Wellington and the other from Somersby, New South Wales, Australia. Toxicity was measured as cyclopoid survival over 2, 4, 7, 14, 21, and 28 days in waters of varying sulfate concentration (<1-100 mg SO4/L). When sulfate was present, dissolved Ba concentrations decreased rapidly in toxicity test solutions forming a BaSO4 precipitate until dissolved sulfate was depleted. Barium in excess of sulfate remained in the dissolved form. The toxicity of Ba to cyclopoids was clearly attributed to dissolved Ba. Precipitated Ba was not toxic to the Wellington cyclopoid species. Toxicity values for dissolved Ba for the Wellington and Somersby cyclopoid species included a (21-day) no-effect concentration of 3.3 mg/L and an effective concentration to cause 5% mortality of 4.8 mg/L (at 21 days). Elevated dissolved Ba concentrations due to anthropogenic and/or biogeochemical processes may pose a risk to groundwater organisms. Further toxicity testing with other stygobiont species is recommended to increase the data available to derive a guideline value for Ba that can be used in contaminant risk assessments for groundwaters. Environ Toxicol Chem 2024;00:1-14. © 2024 The Author(s). Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Honey bee larval toxicity study designs: Applicability of the current study protocols and endpoints asa predictor of pesticide hazard for pollinators.

The assessment of pesticide risks to bees in North America currently relies in part on Tier 1 honey bee laboratory toxicity studies to support the registration and registration review processes for crop protection chemicals. For immature stages, the studies follow two standardized test designs recommended by the Organization for Economic Cooperation (OECD), evaluating acute (seven-day single-dose, TG OECD 237) and chronic (22-day repeated-dose, GD OECD 239) toxicity in bee larvae. In this article, we aim to evaluate the current approach for generating and interpreting honey bee larval toxicity data, enhancing pesticide risk assessment for pollinators. First, by considering that the repeated-dose larval study covers all stages of honey bee brood development up to adult emergence, we compared endpoints (larval LD/ED50 and LC/EC50 values) from seven-day acute exposure studies with the 22-day chronic exposure studies. Our goal was to identify the study design offering greater sensitivity in assessing pesticide toxicity to immature bees. Our second objective involved analyzing available weight data from emerged adults and comparing it to survival endpoints (e.g., NOEL and LD50) to determine if the weight after adult emergence would accurately represent a sensitive indicator of pesticide effects on developing honey bees. Our analysis determined that the use of a single 22-day chronic exposure study adequately covers all immature stages and that the toxicity values based on cumulative dose are more accurate and representative measures of exposure for immature bees than using endpoints based on estimated daily doses. Furthermore, our analysis suggests that measuring the weight of emerged adults was a more sensitive indicator than mortality of treatment-related effects in 22% of the compounds included in our analysis. Here we also discuss the importance of standardized protocols for proper collection of weight after emergence and the need for further discussion on the relevance of this parameter at risk assessment scheme. Integr Environ Assess Manag 2024;20:2283-2293. © 2024 Pollinator Research Task Force. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

Molecular docking of sterol derivatives in Tagetes erecta Linn. as an antiatherosclerotic agents through activation of PPARγ and LXRα receptors

Atherosclerosis is a condition characterized by inflammation in the arteries, which is linked with the accumulation of lipids and alterations in metabolism. Considering that atherosclerosis is the main factor causing death in the world, it is necessary to carry out immediate prevention and treatment to reduce the risk of developing clinical severity. The creation of foam cells, which originate from macrophages, is considered a key element in cardiovascular ailments, particularly in the advancement of atherosclerosis. Two types of the nuclear receptors known as Peroxisome proliferator-activated receptor γ (PPARγ) and liver X receptor α (LXRα), which serve as a primary regulator of cholesterol, intracellular lipid homeostasis and they are instrumental in the process of reverse cholesterol transport (RCT). Activation of these receptors could potentially decrease foam cell formation, consequently lowering the risk of atherogenesis and reducing cardiovascular disease risk. This research aims to determine sterol derivative compounds in Tagetes erecta Linn. which have the best interaction and potential as anti-atherosclerosis through peroxisome proliferator-activated receptor γ (PPARγ) and liver X receptor α (LXRα) activation. The analysis of this study is using docking molecular analysis. The parameters observed in this study were docking score, visualization results, absorption, distribution, metabolism, excretion profile, and toxicity value. The molecular docking outcomes indicate that β-sitosterol and 7β-hydroxysitosterol possess the most favorable binding energy values. They exhibit a positive pharmacokinetic profile, with the exception of gastrointestinal absorption and respiratory toxicity.

Seasonal hot spots of pollution and risks in Western Kenya: A spatial-temporal analysis of almost 800 organic micropollutants

The release of chemicals into the environment presents a significant threat to aquatic ecosystems dependent on the proximity to emission sources and seasonal dynamics of emission and mobilization. While spatial-temporal information on water pollution in Europe is increasing, there are substantial knowledge gaps on seasonal pollution dynamics in tropical countries. Thus, we took Lake Victoria South Basin in western Kenya as a case study to identify spatial and seasonal hot spots of contamination, quantified toxic risks to different groups of organisms, and identified seasonal risk drivers. For this purpose, we analyzed grab water samples from five rivers with agricultural and wastewater treatment plants in their catchment in four different seasons. We used liquid chromatography coupled to high resolution mass spectrometry (LC-HRMS) with a target list of 785 organic micropollutants. A total of 307 compounds were detected with concentrations ranging from 0.3 ng/L to 6.6 μg/L. Using a Toxic Unit (TU) approach based on mixture toxicity to standard test organisms, crustaceans were identified as the most affected group followed by algae and fish. For crustaceans, chronic risk thresholds were exceeded in 96 % of all the samples, while 56 % of all samples are expected to be acutely toxic, with the highest risk in February during the dry season. High toxic unit values for algae and fish were recorded in July dry season and May wet season. Diazinon, imidacloprid, clothianidin and pirimiphos-methyl were the major drivers for crustacean toxicity while triclosan and different herbicide mixtures drive risks to algae in dry and wet seasons, respectively. A total of 18 chemicals were found to exceed acute and chronic environmental risk thresholds. With this study, strong spatial-temporal patterns of pollution, risks and risk drivers could be confirmed informing prioritization of monitoring and abatement to enhance water quality and reduce toxic risks.

Species-specific bioassays reveal spatial variation in chemical contamination of green sea turtles

The rapid increase of anthropogenic activity at shipping ports and surrounding coastal areas has been correlated with higher chemical contamination entering the surrounding marine environment. Chemical contaminants in marine environments can lead to significant health problems for green turtles (Chelonia mydas), especially when these contaminants accumulate in their foraging grounds. This study examined the exposure and toxicological effects of chemical contaminants on green turtle cells using a species-specific cell viability assay. Using the QuEChERs extraction, organic contaminants were extracted from 60 blood samples collected from green turtles in three foraging locations: Port Curtis, and two reefs (Heron Reef and Hoskyn-Fairfax Reefs) within the Capricorn Bunker Group of the outer Great Barrier Reef. Blood extracts were tested for cytotoxicity against primary green turtle fibroblast cells using an in vitro resazurin bioassay to assess cell viability. Extracts from Gladstone and Heron Reef indicated significant chemical contamination, at levels high enough to cause adverse health effects of green turtles. Very low toxicity values at the Hoskyn-Fairfax Reefs location indicate its potential to be established as a reference site for the southern Great Barrier Reef.

Seawater quality criteria derivation and ecological risk assessment for dichlorvos in China

Dichlorvos (DDVP) is a widely used organophosphorus pesticide (OPP) that has been frequently detected in the marine environment of China. Water quality criteria (WQC) is however not available for this emergent pollutant in the marine environment, which hinders its ecological risk assessment. This study, therefore, screened toxicity values of DDVP and conducted toxicity tests on six marine species to supplement toxicity data. The WQC for DDVP was derived with the species sensitivity distribution (SSD) methodology, based on which the ecological risk of DDVP in the seawater of China was assessed. The results showed that the recommended short-term (SWQC) and long-term water quality criteria (LWQC) for DDVP were 1.47 and 0.0521 μg/L, respectively. Most marine waters of China showed low or negligible risk (HQ < 1, ORP < 2 %), whereas some estuarine waters warrant further concern due to higher risk. This study provides the scientific basis for seawater quality standard formulation and ecological risk management for DDVP.