Toxicity Tests Research Articles

Comparative Efficacy of Ocimum basilicum and Ocimum gratissimum Essential Oils Against Cyclas puncticollis Infesting Sweet Potatoes in Burkina Faso

Aims: The aim of the present study was to compare the insecticidal effect of the essential oils Ocimum basilicum and Ocimum gratisiimum on the sweet potato weevil Cyclas punticollis. Study Design: The aim of this approach was to contribute to the management of the sweet potato weevil in Burkina Faso. Place and Duration of Study: The experiments were carried out at the INERA Entomology laboratory in Bobo-Dioulasso during the cropping season 2022-2023. Methodology: Five essential oil concentrations (25; 50; 75; 100 and 125 μL/L) were used. Toxicity tests were carried out by fumigation in jars by depositing a charge of essential oil on a 6 cm disc of filter paper. Batches of ten C. puncticollis adults were introduced into the jars containing a fresh, healthy tuberous root of the sweet potato and immediately closed. Each test was repeated five times. The number of dead insects in each batch (treated and untreated jars) was counted every 30 min up to 5 h of exposure and for 4 days (24 h, 48 h ,72 h and 96h) per observation. Results: The results showed that the different oils had an insecticidal effect on C. puncticollis and that these oils contained chemical substances responsible for the mortality observed. Indeed, mortality rates of 100% were observed after 2 hours of exposure of the weevils with the 125µL/L concentration of O. gratissimum, followed by concentrations of 100µL/L, 75µL/L, 50µL/L after 24 hours and 48 hours with 25µL/L. With O. basilicum essential oil, 100% mortality was observed after 24 hours of weevil exposure with O. basilicum concentrations of 125µL/L and 100µL/L, followed by 98% mortality with concentrations of 75µL/L, 50µL/L and 25µL/L after 96 hours. Conclusion: These results suggest that the essential oils of Ocimun gratissimun and Ocimun basilicum can be used in the management of C. puncticollis. However, it would be necessary to carry out a concrete application of these oil extracts on large potato stocks in order to confirm or not their efficacy.

Study of the Acute Toxicity of an Aqueous Extract of the Leaves of Senna alata (L.) ROXB (Caesalpiniaceae) to Mammals

Senna alata (L.) ROXB (Caesalpiniaceae) is a plant known and appreciated by the Ivorian population. It is commonly used to treat high blood pressure and constipation. The aim of this study was to investigate the acute toxicity of the aqueous extract of leaves of Senna alata leaves (EAqSa) in mammals. To do this, a phytochemical study of this extract was carried out. Acute toxicity was assessed by the intraperitoneal and oral routes. The oral toxicity tests were carried out in accordance with directive 423 of the Organisation for Economic Co-operation and Development (OECD) using three (3) lots of three (3) rats, one control lot and two (2) test lots. The control lot received 2 ml of distilled water, one test lot received 2000 mg/ kg bw of EAqSa and the second test lot received 5000 mg/ kg bw of the extract in a single dose. Toxicity tests by intraperitoneal administration are carried out using six (6) lots of six (6) mices including a control lot receiving 0.5 ml of EAqSa. The five (5) test lots received 0.5 ml of doses ranging from 750 to 2000 mg/kg bw of the extract. The animals from the different test lots were observed for twenty-four (24) hours. Qualitative phytochemical analysis revealed the presence of polyphenols, sterols and polyterpenes, flavonoids, catechic tannins, saponosides, quinonic compounds and alkaloids. Acute toxicity tests show that this extract is only slightly toxic by the intraperitoneal route and non-toxic by the oral route. The oral route of administration would be the most recommended for the pharmacological use of this extract, but should be used in moderation.

Influence of Coated Phycocyanin on Shelf Life of Infected Penaeus semisulcatus

ABSTRACTThe present study was undertaken to evaluate the antioxidant and antimicrobial activity of chitosan‐alginate‐coated phycocyanin (PC) extract from Spirulina sp. on Penaeus semisulcatus infected with Salmonella typhimurium stored at 4°C and 8°C for 21 days. Four groups of shrimp treatments—a control sample (without infection and PC), an infected sample without PC, a non‐infected sample + PC and an infected sample + PC—were used. The toxicity test revealed no toxicity of PC against Caenorhabditis elegans. The results of the pH, thiobarbituric acid, peroxide value (PV) and total volatile basic nitrogen showed that the lowest amounts of these factors were observed in the samples immersed in PC, whereas the highest values belonged to the samples infected with Salmonella. On the basis of the total number of bacteria in food (log 10⁷ CFU/g), the shelf life of shrimps treated with PC increased by 14 and 4 days at 4°C and 8°C, respectively, compared to the control. The diphenyl‐2‐picrylhydrazyl (DPPH) and ABTS results of the antioxidant activity indicated that the highest values were observed in the infected sample + PC after 21 days at 4°C and 8°C (82.65 ± 0.36 and 89.50 ± 0.43), respectively. The results of the colour assessment showed that the highest and lowest values belonged to the control sample (without infection and PC) and the non‐infected sample with PC, respectively. The results of sensory analysis showed that the samples enriched with PC had a higher overall acceptability than samples without PC. In conclusion, PC increased the shelf life of shrimp infected with Salmonella sp.

Closed-perfusion transretinal ERG setup for preclinical drug and nanostructure testing.

The isolated mammalian retina may serve as a sensitive biosensor for preclinical drug testing, including eye drugs and a broader range of pharmaceuticals. To facilitate testing with minimal amounts of drug molecules or nanostructures, we developed a closed-perfusion transretinal electroretinography (tERG) setup. The major challenge with small amounts of circulating perfusate was maintaining retinal viability and stability during long experiments. We conducted ex vivo tERG using WT C57BL/6J and Gnat1-/- mice to assess rod- and cone-mediated light signals. The dark-adapted retina was stimulated with full-field light flashes while perfused at 5-6 ml/min. The minimum perfusate needed in our closed-circulation was around 50 ml. Penicillin-Streptomycin (Pen-Strep) was indispensable for long recordings. Rod responses remained stable for at least 42 hours, the longest recording we conducted, with the retina still responsive, and rod and cone bipolar cell responses for up to 12 hours. IBMX (3-isobutyl-1-methylxanthine), a non-specific phosphodiesterase (PDE) inhibitor with reversible effects, validated our setup. We used our setup to test the zwitterionic polymer poly(sulfobetaine methacrylate) (PSMBA), serving as a promising material for thermoresponsive nanostructures, and the corresponding monomer SBMA for possible harmful effects on mouse rod and bipolar cell functioning. Our closed-perfusion tERG setup enables long experiments with small amounts of perfusate. PSMBA or SBMA had no effect on rod and bipolar cell responses. This method is applicable for assessing drug functionality, as well as conducting preliminary biocompatibility and toxicity testing using small amounts of molecules or nanostructures that could impact neuronal or synaptic function.

Effect of supramolecular peptide hydrogel scaffold charge on HepG2 viability and spheroid formation.

Supramolecular bioinspired self-assembling peptide hydrogel (SAPH) scaffolds represent a class of fully defined synthetic materials whose chemical and mechanical properties can be finely engineered. In this study, the relationship between SAPHs physicochemical properties and HepG2 cells viability, spheroid formation and function are discussed. We first report that negatively charged SAPHs promote hepatocyte proliferation and spheroids formation in vitro 3D culture while positively charged SAPHs lead to hepatocyte death irrespective of the hydrogel mechanical properties. More specifically HepG2 cultured in 3D in E(FKFE)2 negatively charged SAPH maintained a differentiated phenotype and assembled into well-defined spheroids with strong cell-cell interactions. Furthermore, HepG2 spheroids responded to acetaminophen exposure with upregulation of key CYP450 enzymes expression clearly showing their potential for drug toxicity testing. These findings demonstrate how fine-tuned functional SAPH scaffolds can be used to identify key scaffolds parameters affecting cells. In this case we demonstrated the potential of negatively charged SAPHs for the 3D culture of HepG2 with potential applications in drug screening.

A nationwide Swedish retrospective study on poisoning deaths between the years 2000 and 2022.

Approximately 1% of Sweden's 90 000 annual deaths were reported caused by poisoning. In this study, we aim to describe this poisoning population's characteristics, autopsy frequency and results of toxicology testing. A national cohort study based on Swedish national registers. All deceased subjects older than 18 years with poisoning as the cause of death registered between 1 January 2000 and 31 December 2021 were included. Causes of death according to primary ICD-10 code were analysed along with the substances found in forensic chemistry testing. There were 27 057 poisonous deaths during the study periods 2 018 495 adult deaths. Subjects deceased due to poisoning had a median age of 53 years, and 18 838 (70%) were men. A private home was the most reported location of death (52%). In total, 23 260 (87%) did undergo some sort post-mortem examination. Drugs (synthetic narcotics, opioids, heroin) caused 12 448 (46%) deaths, and alcohols explained 9056 cases (33%). Positive toxicological tests were found in 22 550 (83%) of the subjects. The most common separate substances were ethanol, zopiclone and nordazepam. Poisoning caused 1.3% of Swedish deaths. Men in their 50s were the most common victims, and their deaths were often cause by synthetic narcotics, other opioids or alcohol. The autopsy frequency was lower than expected for poisonous deaths.

Is environmental risk assessment possible with the alternatives to acute fish toxicity test? Case study with pharmaceuticals

BackgroundAcute fish toxicity test (AFT) is one of the cornerstones of environmental risk assessment (ERA) of chemicals for the aquatic environment. Despite many efforts to find an alternative able to fully replace the test, there is still lasting pressure from stakeholders for AFT results. ResultsHere, we present the results of a case study with eight pharmaceuticals from various pharmaceutical groups with different levels of expected toxicity to fish. Selected compounds were tested in two validated alternative tests—fish embryo toxicity test with zebrafish (Danio rerio) (zFET) and in vitro RTgill-W1 assay according to their corresponding OECD guidelines TG 236 and TG 249, respectively. Data for AFT were collected from PubMed and ECOTOX knowledgebase databases, and acute toxicity to fish was further predicted in silico by the ECOSAR program. Predicted environmental risks (risk quotients, RQ, calculated using the exposure data from NORMAN) from both zFET and RTgill-W1 well correlated with the average RQs based on AFT LC50s. The strongest and most significant correlation was observed while comparing the AFT results with the median of combined alternative methods (zFET, RTgill-W1, ECOSAR).ConclusionsThis proposed approach combining experimental data with modeling could serve as a reliable tool for predictions of environmental risks promoting the 3R alternatives to acute fish toxicity testing.

Nanoenabled Self-Assembled Metal-Organic Algaecides Generated Photosynthetic Inhibition and Oxidative Stress for Sustainable Food Security.

Achieving food sustainability is one of the biggest challenges in the new millennium. Plant factory cultivation systems provide an alternative for food sustainability, while they often suffer from algal blooms. The overuse of conventional algaecides has caused significant environmental pollution and concerns about food security. Here, we design a nanoenabled metal-organic algaecide that is self-assembled from natural polyphenols and two functional metal ions for providing shading effects and delivering active ingredients synergistically to suppress algal blooms. Black wattle tannin (BWT) and Fe3+ ions are utilized to develop self-assembled FeBWT nanoalgaecides with significant shading effects for decreasing light transmission (up to 97 %) and effectively inhibiting algal photosynthesis. Further, the FeBWT is functionalized with Cu2+ ions (bimetallic Cu/FeBWT) to target the algal cells and release Cu2+ ions via phenolic-mediated cell surface interactions, thus enhancing the inhibition efficiency. Importantly, the biosafety of Cu/FeBWT is demonstrated through toxicity tests on zebrafish and NIH3T3 cells. In our real-world field test, the Cu/FeBWT demonstrates high algal inhibition performance (>95 %, over 30 days), and enhances the accumulation of food nutrients in model plant lettuces. Collectively, the supramolecular metal-organic nanoalgaecide provides a promise for nanoagrochemical application and promotes food sustainability and security.

Design, synthesis, biological evaluation and computational studies of 4-Aminopiperidine-3, 4-dihyroquinazoline-2-uracil derivatives as promising antidiabetic agents

A novel series of 4-aminopiperidin-3,4-dihyroquinazoline-2-uracil derivatives (9a-9 L) were logically designed and synthesized as potent DPP4 inhibitors as antidiabetic agents. Chemical structure of all new compounds were confirmed by different spectroscopic methods. The designed compounds were evaluated using a MAK 203 kit as DPP4 inhibitors in comparison with Sitagliptin. The biological evaluation revealed that compound 9i bearing chloro substitution on phenyl moiety of 6-bromo quinazoline ring had promising inhibitory activity with IC50 = 9.25 ± 0.57 µM. The toxicity test of all compounds confirmed safety profile of them. Kinetic studies showed that compound 9i exhibited a competitive-type inhibition with a Ki value of 12.01 µM. Computational approach supported the rationality of our design strategy, as 9i represented appropriate binding interactions with the active sites of DPP4 target. MD simulation outputs validated the stability of ligand 9i at DPP4 active site. Also, Density functional theory (DFT) including HOMO-LUMO energies, ESP map, thermochemical parameters, and theoretical IR spectrum was employed to study the reactivity descriptors of 9i and 9a as the most and least potent compounds respectively. Based on the DFT study, compound 9i was softer and, as a result, more reactive than 9a. Taken together, our results showed the potential of 4-aminopiperidin-3,4-dihyroquinazoline-2-uracil derivatives as promising candidates for developing some novel DPP4 inhibitors for managing of type 2 diabetes.

Bioaccumulation and biochemical impact of polyethylene terephthalate microplastics in Cipangopaludina chinensis: Tissue-specific analysis and homeostasis disruption

Microplastics are a novel pollutant that adversely affect freshwater benthic organisms. However, few studies have investigated the mechanism underlying the bioaccumulation and the toxicity of microplastics. In this study, microplastics bioaccumulation of wild Cipangopaludina chinensis in the Songhua River were utilized, and a 28-day aquatic toxicity test was performed to determine the effects of exposure to polyethylene terephthalate (PET), the bioaccumulation of PET, and changes in multiple biomarkers in the muscle, gill, and kidney tissues. The concentration pattern of microplastics was as follows: kidney tissue > muscle tissue > gill tissue. Microplastic ingestion caused AChE inhibition led to significant increases in redox and energy metabolism indicators. Furthermore, the IBR analysis presented a "response-resistance-breakdown" process, indicating that Cipangopaludina chinensis possessed resistance with time (D14 and D21) and concentration (0.10 mg/L and 1.00 mg/L) thresholds. Tissue sensitivity to microplastics was ranked as gill > muscle > kidney, which was the opposite order of microplastic accumulation. These findings implied that less sensitive tissues stored a larger amount of pollutants, suggesting a reduction in tissue sensitivity to microplastics with higher microplastic occurrence rates. This study provides new insights into biological resistance to pollutant stress, warranting further investigation into the underlying mechanisms.

Joint Toxicity and Interaction of Carbon-Based Nanomaterials with Co-Existing Pollutants in Aquatic Environments: A Review

This review paper focuses on the joint toxicity and interaction of carbon-based nanomaterials (CNMs) with co-existing pollutants in aquatic environments. It explores the potential harmful effects of chemical mixtures with CNMs on aquatic organisms, emphasizing the importance of scientific modeling to predict mixed toxic effects. The study involved a systematic literature review to gather information on the joint toxicity and interaction between CNMs and various co-contaminants in aquatic settings. A total of 53 publications were chosen and analyzed, categorizing the studies based on the tested CNMs, types of co-contaminants, and the used species. Common test models included fish and microalgae, with zebrafish being the most studied species. The review underscores the necessity of conducting mixture toxicity testing to assess whether the combined effects of CNMs and co-existing pollutants are additive, synergistic, or antagonistic. The development of in silico models based on the solid foundation of research data represents the best opportunity for joint toxicity prediction, eliminating the need for a great quantity of experimental studies.

Cannabis Use During Early Pregnancy Following Recreational Cannabis Legalization

It is unknown whether state recreational cannabis legalization (RCL) is related to increased rates of prenatal cannabis use or whether RCL-related changes vary with cannabis screening methods or the local policy environment. To test whether RCL in California was associated with changes in prenatal cannabis use rates, whether changes were evident in both self-report and urine toxicology testing, and whether rates varied by local policies banning vs allowing adult-use retailers post-RCL. This population-based time-series study used data from pregnancies in Kaiser Permanente Northern California universally screened for cannabis use during early pregnancy by self-report and toxicology testing from January 1, 2012, to December 31, 2019. Analyses were conducted from September 2022 to August 2024. California state RCL passage (November 9, 2016) and implementation of legal sales (January 1, 2018) were examined with a 1-month lag. Local policies allowing vs banning medical retailers pre-RCL and adult-use retailers post-RCL were also examined. Any prenatal cannabis use was based on screening at entrance to prenatal care (typically at 8-10 weeks' gestation) and defined as (1) a positive urine toxicology test result or self-report, (2) a positive urine toxicology test result, or (3) self-report. Interrupted time series models were fit using Poisson regression, adjusting for age, race and ethnicity, and neighborhood deprivation index. The sample of 300 993 pregnancies (236 327 unique individuals) comprised 25.9% Asian individuals, 6.4% Black individuals, 26.0% Hispanic individuals, 37.7% White individuals, and 4.1% individuals of other, multiple, or unknown race, with a mean (SD) age of 30.3 (5.4) years. Before RCL implementation, rates of prenatal cannabis use rose steadily from 4.5% in January 2012 to 7.1% in January 2018. There was no change in use rates at the time of RCL passage (level change rate ratio [RR], 1.03; 95% CI, 0.96-1.11) and a statistically significant increase in rates in the first month after RCL implementation, increasing to 8.6% in February 2018 (level change RR, 1.10; 95% CI, 1.04-1.16). Results were similar when defining prenatal cannabis use by (1) a toxicology test or (2) self-report. In local policy analyses, the post-RCL implementation increase in use was only found among those in jurisdictions allowing adult-use cannabis retailers (allowed RR, 1.21; 95% CI, 1.10-1.33; banned RR, 1.01; 95% CI, 0.93-1.10). In this time-series study, RCL implementation in California was associated with an increase in rates of cannabis use during early pregnancy, defined by both self-report and toxicology testing, driven by individuals living in jurisdictions that allowed adult-use retailers.

Clinician perspectives on barriers and facilitators to the treatment of adolescent cannabis use: A qualitative study

IntroductionCannabis use among adolescents is prevalent, and clinicians who work with adolescents have unique insights about how to treat cannabis use in this population. MethodsThis qualitative study interviewed 32 clinicians from addiction medicine recovery services (AMRS), the emergency department (ED), mental health (MH), and pediatrics in an integrated healthcare system to understand their perspectives and experiences regarding barriers and facilitators to treating adolescent cannabis use. The analysis was developed using thematic analysis of interviews. ResultsThirty-two clinicians (Mean age = 45.9, SD =7.6; 56.3 % Female; 56.3 % White) were recruited from AMRS (n = 13; 41.9 %), the ED (n = 7; 22.5 %), MH (n = 7; 22.5 %) and pediatrics (n = 5; 16.1 %). Clinicians discussed several key barriers and facilitators of treating adolescent cannabis use. Facilitators include the use of multiple screening tools for adolescent cannabis use (i.e., self-report and toxicology testing) which provide more comprehensive information; patient-centered treatment approaches; and discussing cannabis use in the context of adolescents' mental health. Barriers discussed included adolescents' and parents' minimization of adolescent cannabis use risks. Several factors were discussed as potential facilitators or barriers, depending on context, including the influence of peers, virtual treatment, and parental involvement or lack thereof in treatment. ConclusionsInterviews with clinicians who work with adolescents across settings highlighted factors that serve as barriers and facilitators to treating adolescent cannabis use. These findings have important implications for guiding future research and intervention efforts, including the inclusion of universal screening practices, addressing stigma, reducing adolescents' and parents' minimization of cannabis use-related harms, and improving adolescent and parent engagement in treatment.

Electrochemical activation of periodate with graphite electrodes for degradation of high concentrations of thiocyanogen (SCN−) in mineral processing tail liquid

Cyanide has been widely used in gold extraction due to its cost-effectiveness, high selectivity and recovery. Regrettably, its wide application also leads to the presence of a large amount of thiocyanogen (SCN−) in the tail liquid of mineral processing plants, which affects the quality of the effluent water, and thus poses a threat to the ecological environment and human health. This paper investigates the degradation of high concentration of SCN− in water using electrochemical oxidation/periodate (E-GP/PI) system. A degradation rate of 90.25 % of SCN− was achieved by optimising various operating parameters. The effects of organic matter and typical heavy metal ion concentrations on the degradation of SCN− were investigated, and it was found that Cu2+ was able to promote the degradation of SCN− through the formation of stable complexes with SCN−, which enhanced the degradation rate to 96.48 %. However, the presence of Octadecyltrimethylammonium bromide (OTAB) and butylxanthin hindered the degradation process, where 500 mg/L of OTAB reduced the degradation rate of SCN− to 80.88 %, while 100 mg/L of butylxanthin reduced the degradation rate to 78.66 %. On this basis, experiments were carried out using real wastewater samples and SCN− degradation efficiencies of about 90 % were obtained. Afterwards, through electron paramagnetic resonance analysis, free radical burst, ion chromatograph and other research techniques, IO3 and O2– were obtained as the main drivers of SCN− degradation and SCN− degradation pathways were elucidated. Finally, the E-GP/PI system was shown to be effective in reducing the ecotoxicity of SCN− by increasing the 24-h LC50 from 12.5 % to 48.5 % in a toxicity test with daphnia. This study provides a new idea for the green and efficient treatment of SCN− rich beneficiation tail liquid.

Identifying in vitro toxicity testing approaches for (novel) proteins in the context of food and feed risk assessment

Abstract This report documents the outcomes of the EFSA procurement (OC/EFSA/NIF/2022/01) aimed at identifying in vitro toxicity testing approaches for (novel) proteins in the context of food and feed safety assessment. In the present report, we present an integrated testing strategy for the evaluation of toxicity of novel/toxic proteins. A text‐mining approach was used to create a literature database of toxic outcomes associated with toxic proteins retrieved from the UniProt KB database using the search term “Toxin activity”. It was shown that toxic proteins are produced by a relatively limited phylogenetic subset, including, among others, bacteria, insects, serpents, molluscs, and fungi. Toxicological effects of these proteins are generally conserved within phylogenetic groups. Analysis of toxic effects from these proteins was performed using GO term analysis as well as a text‐mining based approach. Relevant tests to address and quantify these toxicity effects were identified and evaluated for their applicability in an in vitro based toxicity testing strategy. A stepwise approach was developed. As a first step, an initial in silico prediction of toxicity is carried out (Step 1). This is followed by a battery of in vitro assays to address the primary mechanisms of toxicity associated with toxic proteins (Step 2). If concern arises in the Step 2 battery of tests, the use of relevant in vitro model systems to explore potential target organ toxicity are required (Step 3). Knowledge gaps have been identified and recommendations are provided in in vitro toxicity testing strategies, in particular for (novel) proteins. Some of these gaps involve the selection and integration of a standardized, relevant in vitro digestion step, reflective of passage through the digestive tract, within the testing strategy, as well as a thorough assessment of the suitability and applicability of in vitro tests and new approach methodologies for regulatory toxicity assessment of (novel) proteins. To accelerate the incorporation of NAMs in the assessment of protein safety, case studies and proof of concept projects are needed to demonstrate the utility and effectiveness of in vitro toxicity testing strategies in the safety assessment of (novel) proteins.

Ethyl alcohol consumption characteristics of deceased individuals in Lithuania

The number of alcohol-related deaths in Lithuania has fallen by almost one-third in the last decade; however, the number of deaths has been on the rise since 2019. Data on the postmortem investigation of victims between 2018 and 2022 were obtained from the Lithuanian State Forensic Medicine Service database. This study analyzed data from 1,200 autopsies. The deceased victims were categorized based on their cause of death and blood alcohol concentration (sober, legally intoxicated, mild, medium, or heavy). The causes of death were diseases (54.17%, n=650), suicides (12.08%, n=145), homicides (2.5%, n=30), and accidents (31.25%, n=375). Toxicological tests for alcohol were performed in all cases. Alcohol levels in the blood and urine were measured using gas chromatography. A significant correlation was observed between blood alcohol concentration and age (r=-0.13, p=0.007). A statistically significant difference was observed in the proportions of men and women who were intoxicated. Among the causes of death, the group of individuals who died because of accidents exhibited the highest average blood alcohol concentration. Alcohol intoxication is undoubtedly a contributing factor to fatalities resulting from accidents and homicides. These findings assist in determining the intoxication level of victims and in assessing any potential links that may contribute to or predispose victims to lethal outcomes in cases of disease, suicide, homicide, or accident.

Nickel toxicology testing in alternative specimen from farm ruminants in a urban polluted environment

The impact of nickel (Ni) metal toxicity, on public health was assessed analyzing forage samples (Acacia nilotica, Zea mays, Pennisetum glaucum, Capparis decidua and Medicago sativa), soils and blood samples of cow, buffalo and sheep (blood plasma, fecal, and hair) collected from three different agro-ecological zones and analyzed through atomic absorption spectrophotometer. Results showed that nickel values differed in soil samples ranging from 4.49 to 9 to 25 mg/kg, in forages from 3.78 to 9.53 mg/kg and in animal samples from 0.65 to 2.42 mg/kg. Nickel concentration, in soil and forage samples, was below the permitted limits. Soil with the minimum nickel level was found under C. decidua while the maximum concentration was reached under the A. nilotica. Among the animals, nickel was maximum in buffaloes that grazed on the Z. mays fodder. Ni was more accumulated in feces than other body tissues. The sheep and buffaloes showed high vulnerability to Ni pollution due to the highest contamination levels at site II and III. Bioconcentration factor, pollution load index and enrichment factor were found to be higher in buffaloes than cows, respectively. The daily intake and health risk index ranged from 0.0056 to 0.0184 mg/kg/day and 0.186–0.614 mg/kg/day respectively. In short, the results of this study evidenced that Nickel-containing fertilizers should never not be used to grow forage species. Government should to lessen the toxic metal accessibility to animals. Although general values were lower than the admitted limit, nickel can be accumulated and the consume of food containing nickel can increase health risks. General monitoring of soil and vegetation pollution load, as well as the use of other non-conventional water like canal water for forage irrigation could be a sustainable solution to decrease the access of nickel in the food chain.

Polyethylene microplastic modulates the toxicity of pentachlorophenol to the microalgae Isochrysis galbana, clone t-ISO

Pentachlorophenol (PCP) and polyethylene microplastic (PE-MP) have been designated as emerging and persistent pollutants, respectively. The combined effects of those pollutants are still unknown, especially to organisms like phytoplankton that may adsorb to their surface. Therefore, the purpose of this study was to investigate for the first time the effects of PE-MP alone and in combination with PCP on the microalgae Isochrysis galbana, clone t-ISO following 72 h of exposure. Photosynthetic pigments amounts, carotenoid, protein, carbohydrate and fatty acids have been assessed. Acute toxicity test showed that the 72 h median inhibition concentration (72 h-EC50) was 148.2, 0.66 and 087 mg L−1 for PE-MP, PCP and their mixture. The utmost effects in growth inhibition rates were noted with 0.5 and 1.25 mg L−1 PCP (23% and 85%, respectively), and 100 and 300 mg L−1 PE-MP (49% and 64%, respectively). Moreover, it was found that those concentrations had a major impact on the photosynthetic pigments, protein, carbohydrate, and fatty acids amounts in algal cells. Furthermore, levels of H2O2 and Malondialdehyde (MDA), as well as the activities of catalase (CAT), superoxide dismutase (SOD), and ascorbate peroxidase (APX), indicated the induction of an oxidative stress in algal cells. It appears that adding PE-MP at a no-effect concentration (25 mg L−1) reduces the toxicity caused by PCP due to its adsorption to polyethylene microplastics.

Biodiversity-safeguarding threshold for urea-fertilizer application on paddy fields: Protozoa-based toxicity tests

Urea is a widely applied fertilizer to enhance crop yields. Ecological risks associated with the excessive application of urea fertilizer threaten the paddy fields' sustainable agriculture and biodiversity preservation. There are no practical thresholds based on proven data on microbial communities. Protozoa are nitrogen-sensitive organisms. For the first time, this study conducted acute and chronic urea toxicity tests on eight species of organisms. The results indicate that Blepharisma sp. is the most sensitive species to urea exposure and is a suitable indicator for determining the safe threshold of urea. This study estimated the predicted no-effect concentration using species sensitivity distribution curves. Subsequently, it established the threshold for urea application in rice fields based on the fields' area and the surface water's height. The short-term safety threshold for urea in the studied paddy field with black soil is 87.7mg/L, equivalent to 43.85kg of urea per hectare for a single nitrogen fertilizer application. The long-term safety threshold is 5.02mg/L, representing the concentration for re-applicating urea. The biodiversity-safeguarding application threshold provides the basis for developing a urea fertilizer reduction protocol to safeguard the paddy fields' biodiversity.

Preparation, Characterization of Pearl Powder and its In Vivo Detoxification Potential for Heavy Metals in Mice

Rapid industrialization has heightened concerns over heavy metal pollution, its persistence in the environment, and the potential health risks posed to humans and ecosystems. Traditional Chinese Medicine (TCM) has utilized natural compounds for their medicinal properties, including detoxification, for centuries. This study aims to evaluate the detoxifying efficacy of pearl powder, derived from Hong Kong pearl oyster shells, a product with a long history of use in TCM, in chelating heavy metals like mercury, lead, and aluminium, and assess its protective effects against organ damage. Through a combination of in vitro and in vivo methodologies, In vitro experiments assessed pearl powder's chelation capabilities in controlled conditions, while in vivo studies in animal models investigated its impact on kidney and liver health and its overall safety profile. The results demonstrate that pearl powder, at doses up to 500 mg/kg body weight (b.w), effectively chelates heavy metals, facilitating their removal and offering protective effects against renal and liver damage. Safety assessments, including cytotoxicity and acute toxicity tests, confirmed the non-toxic nature of pearl powder, with a median lethal dose (lethal dose 50%, LD50) of 5000 mg/kg body weight. Pearl powder from Hong Kong pearl oyster shells demonstrates significant potential as a natural detoxifying agent against heavy metal accumulation. These findings validate the traditional use of pearl powder in TCM, showcasing its potential as a natural remedy to mitigate heavy metal accumulation and its associated health risks. Integrating traditional knowledge with modern scientific methods, this research highlights the relevance of natural detoxifying agents in combating heavy metal pollution.