Assessing the fate, toxicity, and ecological risk of mixtures of di(2-ethylhexyl)phthalate and di-n-butylphthalate using aquatic and terrestrial microcosms.

Di(2-ethylhexyl)phthalate (DEHP) and di-n-butylphthalate (DBP) frequently coexist in different environmental compartments. Thus, in this study, model aquatic and terrestrial microcosms were prepared to analyze the combined effect of DEHP and DBP on their fate, toxicity, and ecological risk. In the aquatic microcosms, with the addition of the same amount of DEHP and DBP, a higher total amount of DEHP was detected in water, suspended particles, and sediment than DBP due to the higher Kow and half-life of DEHP than DBP. Sediment was the major sink of both phthalates, as the highest percentages of DEHP (90.0 % ~ 95.6 %) and DBP (68.7 % ~ 78.1 %) were found in the sediment. The results of the whole sediment toxicity test showed that DBP (LC50/LC10: 6.75/1.171 µg/g dw) was more toxic than DEHP (LC50/LC10: 158.75/27.25 µg/g dw) to the tubificid oligochaete Monopylephorus limosus, with a synergistic toxic effect of the mixture of DEHP and DBP (LC50/LC10: 100.3/4.6 µg/g dw). The mobility of DEHP and DBP in soil was low during irrigation, with the release of 0.054 % ~ 2.29 % DEHP and 0.097 % ~ 1.86 % DBP. The bioconcentration factors/biota-sediment accumulation factors for DEHP (70.8-145 L/kg/0.093-0.359) in the muscle of the fish Carassius auratus were lower than those for DBP (82.2-300 L/kg/0.514-1.625). The bioaccumulation factors of DEHP and DBP for earthworms were 0.373 and 0.682, respectively. The levels of DEHP and DBP in the water and sediment of aquatic systems and in the soil of terrestrial systems might pose high ecological risks to some fish species, M. limosus and earthworms, according to the risk quotient values. These data provide valuable insights for the development of government control strategies to minimize the ecological risks of DEHP and DBP.

In silico and in vivo evaluations of multistage antiplasmodial potency and toxicity profiling of n-Hexadecanoic acid derived from Vernonia amygdalina.

Background: Despite the widely reported potentials of n-Hexadecanoic acid (HA) as a bioactive, its multi-stage antiplasmodial activity and toxicity profiles remain largely unknown. Methodology: Thus, this study uses a combination of in silico approaches and in vivo studies to assess the inhibitory activities of HA at different stages of the Plasmodium lifecycle, antiplasmodial performance, and toxicity profiles. The HA was retrieved from the PubChem database, while antiplasmodial target proteins from different stages of the Plasmodium falciparum life cycle were collated from the Protein Databank (PDB). Molecular Docking and Visualization were conducted between the compound and target proteins using AutoVina PyRx software and Biovia Discovery Studio, respectively. Also, the AdmetLab 3.0 algorithm was used to predict the absorption, Distribution, Metabolism, Excretion, and Toxicity (ADMET) profiles of HA. Based on a 4-day suppressive test, the antiplasmodial activity against the Plasmodium berghei ANKA strain in mice was evaluated. Furthermore, subacute toxicity and micronucleus assays were used for further toxicity assessment. Results: The molecular docking analysis indicates multi-stage, multi-target potentials of HA with favourable ligand-receptor complexes across the four Plasmodium falciparum stages. Meanwhile, the mice administered with 100 mg/kg, 50 mg/kg, and 10 mg/kg of HA demonstrated considerable chemosuppression in a dose-dependent manner of 89.74%, 83.80%, and 71.58% percentage chemosuppression, respectively, at p < 0.05. The ADMET prediction, histopathological tests, and micronucleus assays show that HA is safer at a lower dose. Conclusion: This study showed that n-Hexadecanoic acid is a potential drug candidate for malaria. Hence, it is recommended for further molecular and biochemical investigations.

Flusilazole induced developmental toxicity, neurotoxicity, and cardiovascular toxicity via apoptosis and oxidative stress in zebrafish.

Flusilazole is a well-known triazole fungicide applied to various crops and fruits worldwide. Flusilazole residues are frequently detected in the environment, and many researchers have reported the hazardous effects of flusilazole on non-target organisms; however, the developmental toxicity of flusilazole has not been fully elucidated. In this study, we investigated flusilazole-induced developmental defects in zebrafish, which are used in toxicology studies to assess the toxic effects of chemicals on aquatic species or vertebrates. We confirmed that flusilazole exposure affected the viability and hatching rate of zebrafish larvae, and resulted in morphological defects, reduced body length, diminished eye and head sizes, and inflated pericardial edema. Apoptosis, oxidative stress, and inflammation were also observed. These factors interrupted the normal organ formation during early developmental stages, and transgenic models were used to identify organ defects. We confirmed the effects of flusilazole on the nervous system using olig2:dsRed transgenic zebrafish, and on the cardiovascular system using cmlc2:dsRed and fli1:eGFP transgenic zebrafish. Our results demonstrate the developmental toxicity of flusilazole and its mechanisms in zebrafish as well as the detrimental effects of flusilazole.

Sulfate sensitivity of early life stages of freshwater mussels Unio crassus and Margaritifera margaritifera.

Sulfate is increasingly found in elevated concentrations in freshwater ecosystems due to anthropogenic activities. Chronic exposure to sulfate has been reported to cause sublethal effects on freshwater invertebrates. Previous sulfate toxicity tests have mostly been conducted in hard or moderately hard waters, and research on species inhabiting soft water is needed, given that freshwater organisms face heightened sensitivity to toxicants in water of lower hardness. In the present study, we examined sulfate sensitivity of two endangered freshwater mussel species, Unio crassus, and Margaritifera margaritifera. Glochidia and juveniles of both species were subjected to acute and/or chronic sulfate exposures in soft water to compare sulfate sensitivity across age groups, and effective concentrations (EC)/lethal concentrations (LC) values were estimated. Mussels were individually exposed to allow relatively larger numbers of replicates per treatment. Chronic sulfate exposure significantly reduced growth, foot movement, and relative water content (RWC) in juvenile mussels of M. margaritifera. Mussels at younger stages were not necessarily more sensitive to sulfate. In the acute tests, LC50 of glochidia of M. margaritifera and U. crassus was 1301 and 857 mg/L, respectively. Chronic LC10 was 843 mg/L for 3-week-old U. crassus juveniles, 1051 mg/L for 7-week-old M. margaritifera juveniles, and 683 mg/L for 2-year-old M. margaritifera juveniles. True chronic Lowest Effective Concentration for 7-week-old M. margaritifera may be within the 95% interval of EC10 based on RWC (EC10 = 446 mg/L, 95%CI = 265-626 mg/L). Our study contributed to the understanding of sulfate toxicity to endangered freshwater mussel species in soft water.

Neonicotinoid Residues on Filter Paper Lack Insecticidal Activity.

Neonicotinoid insecticides are used against agricultural, forest, and urban insect pests. Evaluation of dry neonicotinoid residues on treated filter paper is a commonly used method to determine the toxicity of active ingredients towards target and non-target organisms. Dry residues of four neonicotinoids, acetamiprid, dinotefuran, imidacloprid, and thiamethoxam, on filter paper did not cause significant levels of mortality in Hippodamia convergens (Guérin-Méneville) (Coleoptera: Coccinellidae) and Nezara viridula (L.) (Hemiptera: Pentatomidae) when compared to paired untreated groups. Conversely, nearly 100% mortality was observed when test insects were exposed to dry neonicotinoid residues on leaf discs and glass plate surfaces. On the other hand, dry residues of the pyrethroid bifenthrin on filter paper, leaf disks, and glass plates killed significantly more test insects when compared to untreated groups. Additional bioassays tested the toxicity of acetamiprid and thiamethoxam by evaluating the toxicity of dry residues on (1) the upper and (2) lower surfaces of treated filter paper, (3) on a glass plate underneath treated filter paper, (4) on the upper surface of treated filter paper treated with insecticide and adjuvant, and (5) dried residues on a glass plate after dipping treated filter paper in water and letting the solvent dry on the inert test surface. The results indicated that neonicotinoid insecticides applied to filter paper were adsorbed. Toxic compounds possibly move in between and binding to paper fibers so that no toxic residues were left on treated surfaces. However, adsorbed insecticides were still biologically active when washed out of filter paper and dried on an inert glass surface. The results reported here clearly demonstrate that the toxicity of neonicotinoid insecticides should not be evaluated using filter paper as a test surface.

Species sensitivity distribution for nonylphenol: Acute toxicity and ecological risk in Bohai Region.

Nonylphenol (NP), a main byproduct of nonylphenol polyethoxylates (NPEs) degradation, is prevalent across diverse environmental settings. Given its widespread presence, evaluating the ecological risks associated with NP in coastal waters and sediments is essential for the protection of the marine environment. This study evaluates the acute toxicity of NP on ten representative aquatic species from the Bohai Sea, determining the Aquatic Life Criteria (ALC) through two distinct methods. The Criteria Maximum Concentration (CMC) for NP in seawater was established at 12.0 µg/L, with a Predicted No-Effect Concentration (PNEC) for water at 15.2 µg/L and for sediment at 33.3 µg/kg. Additionally, a tiered ecological risk assessment (ERA) of both surface seawater and sediment in the Bohai Sea revealed significant ecological risks at various sediment sites. These results offer crucial insights for assessing the ecological risks to coastal ecosystem and provide foundational data necessary for informed environmental protection and management strategies.

Evaluation of Ointments with Daldinia eschscholtzii in Wound Healing in an In Vivo Model.

Fungi are a source of a variety of secondary metabolites of importance in different areas of biotechnology. Several compounds have been characterized with antioxidant, antimicrobial, and anti-inflammatory activity from fungi of the division of the Ascomycota, among which is the species Daldinia eschscholtzii, an endophyte fungus of pantropical distribution. In this study, we evaluated the effect of an ointment made with D. eschscholtzii on the wound healing of BALB/c mice. The species was corroborated using a molecular marker Internal Transcribed Spacer (ITS1 and ITS4). The extracts and dust of the fungus were considered nontoxic as they caused a mortality of <15% in the nematode Panagrellus redivivus, and experimental ointments had no adverse effects on the skin of BALB/c mice. Wounds treated with the D. eschscholtzii ointments had 99.9-100% wound contraction after 17 days, which was similar to commercial healing (positive control). As such, the ointment of D. eschscholtzii is a natural alternative to improve wound healing.

Validating Well-Functioning Hepatic Organoids for Toxicity Evaluation.

"Organoids", three-dimensional self-organized organ-like miniature tissues, are proposed as intermediary models that bridge the gap between animal and human studies in drug development. Despite recent advancements in organoid model development, studies on toxicity using these models are limited. Therefore, in this study, we aimed to analyze the functionality and gene expression of pre- and post-differentiated human hepatic organoids derived from induced pluripotent stem cells and utilize them for toxicity assessment. First, we confirmed the functional similarity of this hepatic organoid model to the human liver through various functional assessments, such as glycogen storage, albumin and bile acid secretion, and cytochrome P450 (CYP) activity. Subsequently, utilizing these functionally validated hepatic organoids, we conducted toxicity evaluations with three hepatotoxic substances (ketoconazole, troglitazone, and tolcapone), which are well known for causing drug-induced liver injury, and three non-hepatotoxic substances (sucrose, ascorbic acid, and biotin). The organoids effectively distinguished between the toxicity levels of substances with and without hepatic toxicity. We demonstrated the potential of hepatic organoids with validated functionalities and genetic characteristics as promising models for toxicity evaluation by analyzing toxicological changes occurring in hepatoxic drug-treated organoids.

Green Synthesis of Selenium Nanoparticles From Clove and Their Toxicity Effect and Anti-angiogenic, Antibacterial and Antioxidant Potential.

Introduction  Nanoparticles, owing to their minuscule size, have become pivotal in diverse scientific endeavors, presenting unique characteristics with applications spanning medicine to environmental science. Selenium nanoparticles (SeNPs) exhibit potential in diverse biomedical uses. Aim This research investigates the potential anti-inflammatory and anticancer properties of SeNPs, which are synthesized using the green synthesis method. This eco-friendly approach aligns with sustainable practices and utilizes clove extract (Syzygium aromaticum). Materials and methods Clove extract facilitates SeNP synthesis via sodium selenite reduction. The characterization methods comprised Fourier-transform infrared (FTIR) spectroscopy, UV-VIS spectroscopy, and scanning electron microscopy (SEM). Assessments covered antioxidant properties, chorioallantoic membrane assay (CAM) assay for antiangiogenic effects, toxicity evaluation, and antibacterial assays. Results Successful synthesis of SeNPs was verified by a UV-visible absorption peak at 256 nm and FTIR peaks around 3500-500 cm -1, and the spherical morphology was confirmed by SEM analysis with EDAX, which indicated the presence of SeNPs and their unique properties. Phytochemical substances are active chemicals that contribute to the properties of SeNPs. The SeNPs exhibited antioxidant activity with an IC50 value of 0.437 µg/mL and antibacterial properties against bacterial pathogen Salmonella species, with a zone of inhibition measuring 19 mm. The CAM assay demonstrated possible antiangiogenic actions, and toxicity testing on Artemia nauplii showed biocompatibility. Conclusion This study underscores the efficient synthesis of SeNPs using clove extract, emphasizing their potential applications. The notable properties of SeNPs emphasize their promise for diverse biomedical and environmental uses.

Assessment of toxic effects of imidacloprid on freshwater zooplankton: An experimental test for 27 species.

The neonicotinoid pesticide imidacloprid has been used worldwide since 1992. As one of the most important chemicals used in pest control, there have been concerns that its run-off into rivers and lakes could adversely affect aquatic ecosystems, where zooplankton play a central role in the energy flow from primary to higher trophic levels. However, studies assessing the effects of pesticides at the species level have relied on a Daphnia-centric approach, and no studies have been conducted using species-level assessments on a broad range of zooplankton taxa. In the present study, we therefore investigated the acute toxicity of imidacloprid on 27 freshwater crustacean zooplankton (18 cladocerans, 3 calanoid copepods and 6 cyclopoid copepods). The experiment showed that a majority of calanoid copepods and cladocerans were not affected at all by imidacloprid, with the exception of one species each of Ceriodaphnia and Diaphasoma, while all six cyclopoid copepods showed high mortality rates, even at concentrations of imidacloprid typically found in nature. In addition, we found a remarkable intra-taxonomic variation in susceptibility to this chemical. As many cyclopoid copepods are omnivorous, they act as predators as well as competitors with other zooplankton. Accordingly, their susceptibility to imidacloprid is likely to cause different responses at the community level through changes in predation pressure as well as changes in competitive interactions. The present results demonstrate the need for species-level assessments of various zooplankton taxa to understand the complex responses of aquatic communities to pesticide disturbance.

Assessment of the Artemia salina toxicity assay as a substitute of the mouse lethality assay in the determination of venom-induced toxicity and preclinical efficacy of antivenom.

Mice are routinely used in snake venom research but are costly and subject to pain and suffering. The crustacean Artemia salina could be an alternative to mice, but data to support its adoption in snake venom research is limited. The aim of the present study was to evaluate the suitability of A. salina as a surrogate of mice in assessing the toxicity of venoms and the preclinical efficacy of antivenoms. The toxicity of venoms from 22 snakes of medical importance in sub-Saharan Africa was evaluated in mice (intraperitoneally; i.p. and intravenously; i.v.) and in A. salina. Subsequently, the capacity of a commercial antivenom to neutralize the toxicity of these venoms in mice and A. salina was investigated. There was a positive correlation between the i.v. median lethal doses (LD50s) and the i.p. LD50s in mice (r = 0.804; p < 0.0001), a moderate correlation between the i.v. LD50s in mice and the median lethal concentrations (LC50s) in A. salina (r = 0.606; p = 0.003), and a moderate correlation between the i.p. LD50s in mice and the LC50s in A. salina (r = 0.426; p = 0.048). Moreover, there was a strong correlation between the i.p. median effective doses (ED50s) and the i.v. ED50s in mice (r = 0.941, p < 0.0001), between the i.p. ED50s in mice and the ED50s in A. salina (r = 0.818, p < 0.0001), and between the i.v. ED50s in mice and the ED50s in A. salina (r = 0.972, p < 0.0001). These findings present A. salina as a promising candidate for reducing reliance on mice in snake venom research. Future investigations should build upon these findings, addressing potential limitations and expanding the scope of A. salina in venom research and antivenom development.

False positive findings associated with adenoviral vector-based vaccine underscore the regulatory necessity to eliminate abnormal toxicity test.

Accumulating evidence has shown that the abnormal toxicity test (ATT) is not suitable as a quality control batch release test for biologics and vaccines. The purpose of the current study was to explore the optimal ATT experimental design for an adenoviral vector-based vaccine product to avoid false positive results following the standard test conditions stipulated in the Pharmacopoeias. ATT were conducted in both mice and guinea pigs based on methods in Pharmacopeias, with modifications to assess effects of dose volume and amount of virus particles (VPs). The results showed intraperitoneal (IP) dosing at human relevant dose and volume (i.e., VPs), as required by pharmacopeia study design, resulted in false positive findings not associated with extraneous contaminants of a product. Considering many gene therapy products use adeno associated virus as the platform for transgene delivery, data from this study are highly relevant in providing convincing evidence to show the ATT is inappropriate as batch release test for biologics, vaccine and gene therapy products. In conclusion, ATT, which requires unnecessary animal usage and competes for resources which otherwise can be spent on innovative medicine research, should be deleted permanently as batch release test by regulatory authorities around the world.

Reproductive toxicity assessment of cellulose nanofibers, citric acid, and branched polyethylenimine in sea urchins: Eco-design of nanostructured cellulose sponge framework (Part B).

In the framework of a safe-by-design approach, we previously assessed the eco-safety of nanostructured cellulose sponge (CNS) leachate on sea urchin reproduction. It impaired gamete quality, gamete fertilization competence, and embryo development possibly due to the leaching of chemical additives used during the CNS synthesis process. To extend this observation and identify the component(s) that contribute to CNS ecotoxicity, in the present study, we individually screened the cytotoxic effects on sea urchin Arbacia lixula and Paracentrotus lividus gametes and embryos of the three main constituents of CNS, namely cellulose nanofibers, citric acid, and branched polyethylenimine. The study aimed to minimize any potential safety risk of these components and to obtain an eco-safe CNS. Among the three CNS constituents, branched polyethylenimine resulted in the most toxic agent. Indeed, it affected the physiology and fertilization competence of male and female gametes as well as embryo development in both sea urchin species. These results are consistent with those previously reported for CNS leachate. Moreover, the characterisation of CNS leachate confirmed the presence of detectable branched polyethylenimine in the conditioned seawater even though in a very limited amount. Altogether, these data indicate that the presence of branched polyethylenimine is a cause-effect associated with a significant risk in CNS formulations due to its leaching upon contact with seawater. Nevertheless, the suggested safety protocol consisting of consecutive leaching treatments and conditioning of CNS in seawater can successfully ameliorate the CNS ecotoxicity while maintaining the efficacy of its sorbent properties supporting potential environmental applications.

Exploring Alternatives for Marine Toxicity Testing: Initial Evaluation of Fish Embryo and Mysid Tests.

Current regulations require that toxicity assessments be performed using standardized toxicity testing methods, often using fish. Recent legislation in both the European Union and United States has mandated that toxicity testing alternatives implement the 3Rs of animal research (replacement, reduction, and refinement) whenever possible. There have been advances in the development of alternatives for freshwater assessments, but there is a lack of analogous developments for marine assessments. One potential alternative testing method is the fish embryo toxicity (FET) test, which uses fish embryos rather than older fish. In the present study, FET methods were applied to two marine model organisms, the sheepshead minnow and the inland silverside. Another potential alternative is the mysid shrimp survival and growth test, which uses an invertebrate model. The primary objective of the present study was to compare the sensitivity of these three potential alternative testing methods to two standardized fish-based tests using 3,4-dichloroaniline (DCA), a common reference toxicant. A secondary objective was to characterize the ontogeny of sheepshead minnows and inland silversides. This provided a temporal and visual guide that can be used to identify appropriately staged embryos for inclusion in FET tests and delineate key developmental events (e.g., somite development, eyespot formation, etc.). Comparison of the testing strategies for assessing DCA indicated that: (1) the standardized fish tests possessed comparable sensitivity to each other; (2) the mysid shrimp tests possessed comparable sensitivity to the standardized fish tests; (3) the sheepshead minnow and inland silverside FET tests were the least sensitive testing strategies employed; and (4) inclusion of sublethal endpoints (i.e., hatchability and pericardial edema) in the marine FETs increased their sensitivity. Environ Toxicol Chem 2024;43:1285-1299. © 2024 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Toxicity Assessment of New Ag-ZnO/AgO Nanocomposites: An In Vitro and In Vivo Approach.

Zinc oxide nanoparticles (ZnO NPs) are metal oxide nanomaterials, which are important for several applications: antibacterial, anthelmintic, antiprotozoal and antitumoral, among others. These applications are mainly related to the ability to spontaneously produce and induce the production of reactive oxygen species that are important components for the destruction of pathogens and tumor cells. While trying to potentiate ZnO NPs, studies have associated these NPs with silver oxide (AgO) or silver (Ag) NPs. It has already been reported that this combination (Ag-ZnO/AgO NPs) is able to enhance the microbicidal potential. Although possessing much potential for several purposes, it is important to evaluate whether this association also poses the risk of toxicity to cells and experimental models. Therefore, this work aimed to evaluate the toxicity of various Ag-ZnO/AgO NP nanocomposites, in vitro and in vivo. Accordingly, ZnO nanocrystals and nanocomposites with various concentrations of AgO (ZnO:5Ag, ZnO:9Ag or ZnO:11Ag) were used in different cytotoxicity models: Galleria mellonella (G. mellonella), cell lines (VERO and RAW 264.7) and C57BL/6 mice. In the G. mellonella model, four concentrations were used in a single dose, with subsequent evaluation of mortality. In the case of cells, serial concentrations starting at 125 µg/mL were used, with subsequent cytotoxicity assessment. Based on the safe doses obtained in G. mellonella and cell models, the best doses were used in mice, with subsequent evaluations of weight, biochemistry as also renal and liver histopathology. It was observed that the toxicity, although low, of the nanocomposites was dependent upon the concentration of AgO used in association with ZnO NPs, both in vitro and in vivo.

Toxicity of urban stormwater on Chlorella pyrenoidosa: Implications for reuse safety.

Urban stormwater is an alternative water source used to mitigate water resource shortages, and ensuring the safety of stormwater reuse is essential. An in-depth understanding of both individual pollutant concentrations/loads in stormwater and holistic stormwater quality can be used to comprehensively evaluate how safely stormwater can be reused. The toxicity test takes all pollutants present in water samples into account, and the results reflect the integrated effect of these pollutants. In this study, the influence of urban stormwater sourced from different land uses on microalgae (Chlorella pyrenoidosa) and the possible toxicity mechanisms were investigated. The results showed that urban stormwater, particularly residential road stormwater, significantly inhibited microalgal growth. The chlorophyll contents of microalgae exposed to residential road stormwater were relatively lower, while the corresponding values were relatively higher for microalgae exposed to grassland road stormwater. Additionally, the antioxidant-related metabolism of microalgae could be dysregulated due to exposure to urban stormwater. A possible toxicity mechanism is that urban stormwater influences metabolic pathways related to chlorophyll synthesis and further hinders photosynthesis and hence microalgal growth. To resist oxidative stress and maintain regular microalgal cell activities, the ribosome metabolism pathway was upregulated. The research results contribute to elucidating the toxicity effects of urban stormwater and hence provide useful insight for ensuring the safety of stormwater reuse. It is also worth noting that the study outcomes can only represent the influence of land use on stormwater toxicity, while the impacts of other factors (particularly rainfall-runoff characteristics) have not been considered. Therefore, the consideration of all influential factors of stormwater is strongly recommended to generate more robust results in the future and provide more effective guidance for real practices related to stormwater reuse safety.

Evaluation of short-term copper toxicity in a co-culture of Synechococcus sp., Chaetoceros gracilis and Pleurochrisys cf. roscoffensis exposed to changes in temperature and salinity levels.

Metals such as copper (Cu) enter marine environments from natural and anthropogenic sources, causing changes in the biodiversity of marine microalgae and cyanobacteria. Cu plays a dual role as either a micronutrient or toxicant depending on the environmental concentration. Many studies have summarized the potential of Cu to become more toxic to microalgae under environmental stress (for instance climate change). Most of the data available on Cu toxicity concerning microalgae and cyanobacteria have been produced using single-species laboratory tests, and there is still a significant gap in the information concerning the behavior of a group of algae exposed to environmental stressors. Thus, the objective of this study was to evaluate the toxicity of Cu at two concentrations (C1 = 2 µg L-1 and C2 = 5 µg L-1) in multispecies bioassays using three phytoplankton species (one cyanobacteria, Synechococcus sp., and two microalgae, Chaetoceros gracilis and Pleurochrisys cf. roscoffensis). Combinations of two temperatures (20 and 23 °C) and two salinities (33 and 36 PSU), were applied in a 96 h study using flow cytometry analysis (FCM). Algal growth and reactive oxygen species (ROS) production by 2'7'-dichlorofluorescein (DCFH) were monitored by FCM. The results indicated that Synechococcus sp. was more sensitive than C. gracilis and P. roscoffensis to Cu stress at a temperature 23 °C and salinity of 36 PSU under both concentrations of Cu. Chlorophyll a fluorescence showed a significant decrease (p < 0.05) in Synechococcus sp. under 5 µg L-1 of Cu in the combined treatment of 20 °C and 33 PSU; however, there was a significant increase in P. roscoffensis in all combinations at C2 = 5 µg L-1 compared to the control with no Cu, indicating a potential hormetic response to Cu for P. roscoffensis. ROS levels were triggered in a combination of 23 °C and 33 PSU and 5 µg L-1 of Cu, which was higher than all the other combinations studied. Our study resulted in data concerning the potential impacts caused by possible future climate change scenarios in aquatic habitats chronically exposed to metals.

Enhancing the potential of rapeseed cake as protein-source food by γ-irradiation.

Rapeseed cake serves as a by-product in the oil extraction industry, characterized by its elevated protein content. However, the presence of antinutritional factors limits the utilization of rapeseed cake as a viable protein source. In this study, different doses of γ-irradiation were used to irradiate rapeseed cake and rapeseed protein isolate was extracted through a modified alkaline solution and acid precipitation method from rapeseed cake. The chemical composition and in vivo acute toxicity of rapeseed protein isolate were determined. The protein recovery rate of rapeseed protein isolate was 39.08 ± 3.01% after irradiation, while the content of antinutritional factors was significantly reduced. Moreover, γ-irradiation did not have any experimentally related effects on clinical observations or clinicopathology in mice. Overall, the reduced antinutrients and increased functional properties suggest that the irradiation of rapeseed cake (<9 kGy) could be utilized as a pre-treatment in the development of rapeseed cake-based value-added protein products.

Features of the rare pathogen Meyerozyma guilliermondii strain SO and comprehensive in silico analyses of its adherence-contributing virulence factor agglutinin-like sequences.

Meyerozyma guilliermondii is a rare yeast pathogen contributing to the deadly invasive candidiasis. M. guilliermondii strain SO, as a promising protein expression host, showed 99% proteome similarity with the clinically isolated ATCC 6260 (type strain) in a recent comparative genomic analysis. However, their in vitro virulence features and in vivo pathogenicity were uncharacterized. This study aimed to characterize the in vitro and in vivo pathogenicity of M. guilliermondii strain SO and analyze its Als proteins (MgAls) via comprehensive bioinformatics approaches. M. guilliermondii strain SO showed lower and higher sensitivity towards ß-mercaptoethanol and lithium, respectively than the avirulent S. cerevisiae but exhibited the same tolerance towards cell wall-perturbing Congo Red with C. albicans. With 7.5× higher biofilm mass, M. guilliermondii strain SO also demonstrated 75% higher mortality rate in the zebrafish embryos with a thicker biofilm layer on the chorion compared to the avirulent S. cerevisiae. Being one of the most important Candida adhesins, sequence and structural analyses of four statistically identified MgAls showed that MgAls1056 was predicted to exhibit the most conserved amyloid-forming regions, tandem repeat domain and peptide binding cavity (PBC) compared to C. albicans Als3. Favoured from the predicted largest ligand binding site and druggable pockets, it showed the highest affinity towards hepta-threonine. Non-PBC druggable pockets in the most potent virulence contributing MgAls1056 provide new insights into developing antifungal drugs targeting non-albicans Candida spp. Virtual screening of available synthetic or natural bioactive compounds and MgAls1056 deletion from the fungal genome should be further performed and validated experimentally.Communicated by Ramaswamy H. Sarma.

Amitriptyline ecotoxicity in Danio rerio (Hamilton, 1822) embryos - similar toxicity profile in the presence of nanoplastics.

Interaction of nanoplastics (NPls) with other environmental contaminants could affect their uptake by the organisms and their toxicity. Thus, the present study aims to investigate the polystyrene NPls (44 nm) interaction with the antidepressant amitriptyline (AMI) and its toxicity to Danio rerio embryos. A similar toxicological profile for NPls + AMI exposure was found for most of the evaluated endpoints, comparing with AMI single exposure, showing that the presence of NPls did not modulate the AMI toxicity. However, the behavioral assessment showed a different pattern with hypoactivity for the NPls + AMI exposure (NPls - hyperactivity; AMI - no effect). Interaction effects between NPls and AMI were also found in the protein contents (antagonism) and in the total glutathione content (synergism). This study highlights the complexity and unpredictability of NPls interaction with pharmaceuticals, important for an accurate environmental risk assessment and for the developing of effective strategies and interventions against plastic pollution.