Acute and chronic toxicity assessment and the gene expression of Dhb, Vtg, Arnt, CYP4, and CYP314 in Daphnia magna exposed to pharmaceuticals

Ecotoxicological impact of succinate dehydrogenase inhibitor (SDHI) fungicides on non-targeted organisms: a review

As the global population continues to grow, the use of pesticides to increase food production is projected to escalate. Pesticides are critical in plant protection, offering a powerful defense against fungal diseases such as apple scab, leaf spot, sclerotinia rot, damping off, sheath blight, and root rot, which threaten crops like cereals, corn, cotton, soybean, sugarcane, tuberous vegetables, and ornamentals. Succinate Dehydrogenase Inhibitor (SDHI) fungicides represent a novel class essential for controlling fungal pathogens and bolstering food security. However, the impact of SDHIs on non-target organisms, including freshwater and terrestrial invertebrates, crustaceans, and oligochaetes, remains insufficiently understood. Empirical studies indicate that SDHIs can induce mortality, mitochondrial dysfunction, oxidative stress, and developmental delays in non-target organims. Additionally, the environmental persistence of these compounds raises concerns about their potential for ecological disruption. The effects of SDHIs on pollinating species and the possible transgenerational transmission of harmful effects warrant further investigation. Comprehensive transcriptomic analyses are necessary to elucidate the molecular disturbances and adverse outcome pathways triggered by SDHIs. Furthermore, there are emerging concerns about the endocrine-disrupting potential of SDHIs in aquatic organisms. For the first time, this review aims to synthesize existing knowledge on the ecotoxicological impacts of SDHIs on non-target organisms and identify critical research directions to address the ecological challenges posed by their use.

Chronic toxicity of tetraconazole and penconazole to Daphnia magna: Insights of growth, reproduction and gene expression changes

Tetraconazole and penconazole are widely used fungicides belonging to the conazole family. Due to the increasing use of these fungicides, their concentrations in aquatic environments are increasing and imply a serious threat to aquatic organisms. However, no studies have investigated the effects of tetraconazole and penconazole on aquatic invertebrates. This study examined for the first time, changes in growth, reproduction, and survival rate as well as changes in the expression of genes related to detoxification (HR96, P-GP, CYP360A8, GST) and reproduction (CUT, CYP314, DMRT, VTG) in D. magna after exposed to different tetraconazole and penconazole concentrations for 21 days. The 48-h EC50 value was 12.35 μg/L for tetraconazole and 326.8 μg/L for penconazole. Chronic toxicity results showed that exposure to varying concentrations of tetraconazole and penconazole decreased body length, total offspring per female, molting frequency, heartbeat rate per minute, and survival rate, and increased day to the first brood in D. magna. The expression of genes related to detoxification and reproduction changed depending on the fungicide type and concentration. In general, transcription of genes related to detoxification was more affected by fungicides. The results revealed that tetraconazole and penconazole caused toxicity in D. magna by inhibiting growth and reproduction and affecting detoxification pathways similarly.

Assessing the chronic toxicity of climbazole to Daphnia magna: Physiological, biochemical, molecular, and reproductive perspectives

The widespread use of climbazole (CBZ) has led to its increased presence in aquatic environments, potentially threatening freshwater ecosystems. However, evidence regarding the harmful effects of CBZ on aquatic organisms remains limited. In this study, Daphnia magna was exposed to CBZ at concentrations of 0, 0.2, 20, and 200 μg/L for 21 days to evaluate its chronic toxicity through assessment of life-history traits, physiological parameters, biochemical analyses, and gene expression. The results indicated that CBZ exposure delayed the days to the first brood, reduced the frequency of molting per adult, decreased the offspring number at first brood, diminished the body length, and decreased both the total number of broods per female and the total number of offspring per female. Additionally, CBZ inhibited the swimming speed, filtration rate, and ingestion rate. Moreover, CBZ altered the levels of superoxide dismutase (SOD), catalase (CAT), and glutathione (GSH), while increasing malondialdehyde (MDA) levels. Gene expression analysis revealed varied responses in mRNA levels related to metabolic detoxification (cyp360a8, gst, and p-gp), digestive enzymes (α-amylase, α-esterase, and trypsin), energy (ak), oxygen transport (dhb), and reproduction (nvd, cyp314, ecr, vtg, and jhe) following CBZ exposure. These results indicate that the presence of CBZ in aquatic environments can induce toxicity by altering energy acquisition, supply, and metabolism; impairing metabolic detoxification pathways; eliciting oxidative stress; and causing reproductive toxicity in D. magna.

Adverse effects of the 5-alpha-reductase inhibitor finasteride on Daphnia magna: Endocrine system and lipid metabolism disruption

Finasteride, a steroid 5-alpha reductase inhibitor, is commonly used for the treatment of benign prostatic hyperplasia and hair loss. However, despite continued use, its environmental implications have not been thoroughly investigated. Thus, we investigated the acute and chronic adverse impacts of finasteride on Daphnia magna, a crucial planktonic crustacean in freshwater ecosystems selected as bioindicator organism for understanding the ecotoxicological effects. Chronic exposure (for 23 days) to finasteride negatively affected development and reproduction, leading to reduced fecundity, delayed first brood, reduced growth, and reduced neonate size. Additionally, acute exposure (< 24 h) caused decreased expression levels of genes crucial for reproduction and development, especially EcR-A/B (ecdysone receptors), Jhe (juvenile hormone esterase), and Vtg2 (vitellogenin), with oxidative stress-related genes. Untargeted lipidomics/metabolomic analyses revealed lipidomic alteration, including 19 upregulated and 4 downregulated enriched lipid ontology categories, and confirmed downregulation of metabolites. Pathway analysis implicated significant effects on metabolic pathways, including the pentose phosphate pathway, histidine metabolism, beta-alanine metabolism, as well as alanine, aspartate, and glutamate metabolism. This comprehensive study unravels the intricate molecular and metabolic responses of D. magna to finasteride exposure, underscoring the multifaceted impacts of this anti-androgenic compound on a keystone species of freshwater ecosystems. The findings emphasize the importance of understanding the environmental repercussions of widely used pharmaceuticals to protect biodiversity in aquatic ecosystems.

Proof of Concept for Cell Culture-Based Coffee

The global coffee production is facing serious challenges including land use, climate change, and sustainability while demand is rising. Cellular agriculture is a promising alternative to produce plant-based commodities such as coffee, which are conventionally produced by farming. In this study, the complex process of drying and roasting was adapted for bioreactor-grown coffee cells to generate a coffee-like aroma and flavor. The brews resulting from different roasting regimes were characterized with chemical and sensory evaluation-based approaches and compared to conventional coffee. Roasting clearly influenced the aroma profile. In contrast to conventional coffee, the dominant odor and flavor attributes were burned sugar-like and smoky but less roasted. The intensities of bitterness and sourness were similar to those of conventional coffee. The present results demonstrate a proof of concept for a cellular agriculture approach as an alternative coffee production platform and guide future optimization work.

Fragrance materials affect life history parameters and gene expression in Daphnia magna: An emerging issue for freshwater ecosystems

A chronic toxicity test (21 d exposure) with the model organism Daphnia magna was performed to study the single-compound and combined effects of four fragrance materials (FMs), including musk xylene (MX), Celestolide™ (ADBI), Galaxolide™ (HHCB), and ethylene brassylate (MT). Furthermore, the transcriptional responses of ten target genes related to detoxification, molting and reproduction (DHR96, P-gp, CYP360A8, GST, CYP314, EcRb, Vtg, CAT, GPX, and GCLC) were determined by performing a quantitative real-time polymerase chain reaction (qRT‒PCR) after juvenile D. magna was exposed for 48 h. The results showed that MX, ADBI and HHCB affected development and reproduction after chronic exposure at a concentration of 10 μg L^-1. Conversely, MT did not affect reproduction, growth or molting during the 21 d exposure. In juvenile D. magna, gene expression was significantly altered by ADBI (DHR96, CYP260A8, and GCLC) and MX (DHR96, CYP360A8, EcRb, Vtg, CYP314, and GCLC) but not by HHCB. These results suggest that compared to biochemical measures, conventional biological endpoints provide more informative data regarding the effects of this FM. Compared to single substances in the chronic test, the mixture of the four FMs showed effects at lower concentrations and increased gene expression for EcRb and CYP314 during juvenile exposure, indicating a possible additive or synergistic effect of the four FMs compared to single compound exposure.

Acute and Transgenerational Effects of Non-Steroidal Anti-Inflammatory Drugs on Daphnia magna

Pharmaceuticals pose a great threat to organisms inhabiting the aquatic environment. Non-steroidal anti-inflammatory drugs (NSAIDs) are major pharmaceutical pollutants with a significant presence in freshwater ecosystems. In this study, the impact of indomethacin and ibuprofen, two of the most commonly prescribed NSAIDs, was assessed on Daphnia magna. Toxicity was assessed as the immobilization of animals and used to determine non-lethal exposure concentrations. Feeding was assessed as a phenotypic endpoint and key enzymes were used as molecular endpoints of physiology. Feeding was decreased in mixture exposures for five-day-old daphnids and neonates. Furthermore, animals were exposed to NSAIDs and their mixture in chronic and transgenerational scenarios revealing changes in key enzyme activities. Alkaline and acid phosphatases, lipase, peptidase, β-galactosidase, and glutathione-S-transferase were shown to have significant changes in the first generation at the first and third week of exposure, and these were enhanced in the second generation. On the other hand, the third recovery generation did not exhibit these changes, and animals were able to recover from the induced changes and revert back to the control levels. Overall, our study points towards transgenerational exposures as more impactful laboratory studies to understand pharmaceutical stressors with a combination of molecular and phenotypic markers of physiology.

Assessment of ecotoxicity effects of aspirin on non-target organism (Daphnia magna) via analysis of the responses of oxidative stress, DNA methylation-related genes expressions and life traits changes

Aspirin (acetylsalicylic acid, ASA), a widely used non-steroidal anti-inflammatory drug, was frequently detected in aquatic environments around the world. However, information on the potential toxic effects of aspirin on non-target aquatic invertebrates is limited. In the present study, we investigated the effects of ASA on the transcriptional expressions of antioxidant genes (Nrf2, Keap1, HO-1, GCLC, GPx, TRX, TrxR and Prx1) and DNA methylation genes (DNMT1, DNMT3 and TET2) in Daphnia magna (D. magna)for 24, 48 and 96 h and the changes of antioxidant enzymatic activity and GSH, MDA content for 48 h. The effects of ASA on the life traits of D. magna were also addressed via a 21-days chronic toxicity test. Results showed that the expressions of Nrf2 and its target genes (HO-1, GPx and TrxR, GCLC, TRX and Prx1) were induced to different degrees at 48 h and/or 96 h. The activity of antioxidant enzymes (SOD, CAT, GST and GPx) and MDA content increased but GSH content decreased, indicating that ASA caused oxidative stress in D. magna. ASA also changed the expression of DNA methylation genes, such as DNMT and TET2, in D. magna. We speculated that ASA may affect the antioxidant system responses through regulation of Nrf2/Keap1 signaling pathway, and/or through indirectly influencing DNA methylation levels by DNMT and TET gene expression, but the detailed mechanism needs further investigations. Chronic exposure to ASA for 21 days caused inhibitions on the growth, reproduction and behavior of D. magna (e.g., delaying days to the first brood and shortening the body length). In summary, ASA significantly affected the antioxidant responses of D. magna, and negatively disturbed its life traits in growth, development and reproduction.

Endocrine-disrupting potential and toxicological effect of para-phenylphenol on Daphnia magna

Several phenol derivatives are suspected endocrine disruptors and have received attention in risk assessment studies for several decades owing to the structural similarity between estrogens and phenolic compounds. We assessed the endocrine disrupting effect of the phenolic compound para-phenylphenol (PPP) through acute tests and evaluating chronic endpoints in an invertebrate model, Daphnia magna. Exposure of D. magna to PPP induced substantial adverse effects, namely, reduced fecundity, slowed growth rate, delayed first brood, and a reduction in neonate size. Furthermore, we investigated the mRNA expression of relevant genes to elucidate the mechanism of endocrine disruption by PPP. Exposure of D. magna to PPP induced the substantial downregulation of genes and markers related to reproduction and development, such as EcR-A, EcR-B, Jhe, and Vtg. Consequently, we demonstrated that PPP has an endocrine disrupting effect on reproduction and development in D. magna.

Occurrence of caffeine, fluoxetine, bezafibrate and levothyroxine in surface freshwater of São Paulo State (Brazil) and risk assessment for aquatic life protection

The prioritization of active pharmaceutical ingredients (APIs) for monitoring programmes and/or environmental risk assessment (ERA) purposes is based on several criteria, including environmental occurrence data. However, data on API occurrence in Brazilian surface freshwaters are still scarce. The Brazilian Unified Health System (SUS) provides several medicines free-of-charge, including medications that have bezafibrate, fluoxetine and levothyroxine as the API. Thus, our objective was to investigate the occurrence of bezafibrate, fluoxetine and levothyroxine in samples collected at sampling sites included in the surface freshwater monitoring program of the São Paulo State Environmental Agency (CETESB); caffeine was also included in the analysis because it is commonly used as an anthropogenic marker of aquatic environment contamination. Monitoring results showed that levothyroxine was not found in any of the analysed samples. Caffeine was ubiquitous in the analysed samples, thus indicating anthropic contamination in the studied water bodies. Caffeine and bezafibrate presented risk quotient (RQ) < 1 for all the sampling sites and periods evaluated in this study. For fluoxetine, RQs > 1 were found in all water samples in which this API was found, indicating a potential risk for freshwater pelagic biota. Thus, fluoxetine should be regulated in São Paulo State in order to protect the aquatic biota. Additional occurrence studies in other Brazilian states are still needed to evaluate if fluoxetine is a nationwide pollutant.

Evaluation of boscalid toxicity on Daphnia magna by using antioxidant enzyme activities, the expression of genes related to antioxidant and detoxification systems, and life-history parameters

Boscalid is a succinate dehydrogenase inhibitor fungicide commonly used to control a range of plant pathogens. Although it is one of the most common fungicides in the aquatic environment, the potential adverse effects of boscalid on freshwater invertebrates still remain unclear. This study aimed to evaluate the toxicity of boscalid on Daphnia magna (D. magna) and provide new information to assess the eco-toxicity of the boscalid on aquatic invertebrates. The effects of boscalid on malondialdehyde (MDA) level, activities of antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT) and glutathione S-transferase (GST) and the mRNA level of genes associated with antioxidant system (sod, cat, and gst) and detoxification (cytochrome P450 4 (cyp4) and nuclear respiratory factor 1 (nrf1)) were determined after 48 h treatment. The effect of boscalid on reproduction and development of D. magna was evaluated by a 21-d-chronic toxicity test. Boscalid dose-dependently altered activities of SOD, CAT, and GST and led to lipid peroxidation during acute exposure in D. magna. Exposure to 5 and 10 mg/L boscalid also significantly decreased gene expression of sod, gst, cyp4 and nrf1 but increased cat gene expression. Furthermore, chronic toxicity results showed that exposure to boscalid decreased molting frequency, number of neonates per Daphnia, and the number of broods per female as compared to the control groups. The above results indicated that boscalid had significant negative impacts on D. magna, and information present here helps to evaluate the eco-toxicity caused by boscalid on aquatic invertebrates.

Multigenerational Effects of the Antibiotic Tetracycline on Transcriptional Responses of Daphnia magna and Its Relationship to Higher Levels of Biological Organizations

Given the risk of environmental pollution by pharmaceutical compounds and the effects of these compounds on exposed ecosystems, ecologically relevant and realistic assessments are required. However, many studies have been mostly focused on individual responses in a single generation exposed to one-effect concentrations. Here, transcriptional responses of the crustacean Daphnia magna to the antibiotic tetracycline across multiple generations and effect concentrations were investigated. The results demonstrated that tetracycline induced different transcriptional responses of daphnids that were dependent on dose and generation. For example, reproduction-related expressed sequence tags (ESTs), including vitellogenin, were distinctly related to the dose-dependent tetracycline exposure, whereas multigenerational exposure induced significant change of molting-related ESTs such as cuticle protein. A total of 65 ESTs were shared in all contrasts, suggesting a conserved mechanism of tetracycline toxicity regardless of exposure concentration or time. Most of them were associated with general stress responses including translation, protein and carbohydrate metabolism, and oxidative phosphorylation. In addition, effects across the dose-response curve showed higher correlative connections among transcriptional, physiological, and individual responses than multigenerational effects. In the multigenerational exposure, the connectivity between adjacent generations decreased with increasing generation number. The results clearly highlight that exposure concentration and time trigger different mechanisms and functions, providing further evidence that multigenerational and dose-response effects cannot be neglected in environmental risk assessment.

Effects of three diamides (chlorantraniliprole, cyantraniliprole and flubendiamide) on life history, embryonic development and oxidative stress biomarkers of Daphnia magna

The diamides have become one of the most promising new classes of insecticides. In this study, we evaluated the toxicity of three diamides (chlorantraniliprole, cyantraniliprole and flubendiamide) to Daphnia magna. The acute toxicity test showed that the 48-h EC₅₀ of chlorantraniliprole, cyantraniliprole and flubendiamide were 8.5, 23.9 and 63.5 μg/L, respectively. Biochemical measurements revealed a significant increase in reactive oxygen species (ROS) in D. magna after acute exposure to the three diamides. A significant decrease in activities of antioxidant enzymes superoxide dismutase (SOD) and glutathione peroxidase (GPx) was observed, which was consistent with the down-regulated transcription of antioxidant genes sod and gpx. Catalase (CAT) activity exhibited a significant increase while the related gene cat showed no obvious change in daphnids acutely exposed to the three diamides. The chronic test revealed that the three diamides could cause lethal and sub-lethal effects on daphnids within constricted range of concentrations at μg/L level. The 21-d EC₅₀ of chlorantraniliprole, cyantraniliprole and flubendiamide for mobility were 5.0, 13.6 and 36.8 μg/L, respectively. The chronic LOEC of chlorantraniliprole, cyantraniliprole and flubendiamide based on survival, growth and reproduction of D. magna were 4.05, 10.24 and 19.36 μg/L, respectively. Moreover, these three diamides can induce severe developmental abnormalities in D. magna embryos including underdeveloped second antennae, curved tail spine and abnormal body region after acute exposure and the 48-h EC₅₀ were 6.2, 14.1 and 30.8 μg/L for chlorantraniliprole, cyantraniliprole and flubendiamide respectively. Our findings indicate that even low levels of diamides can pose ecological risks to aquatic ecosystems.

Toxicity detection using lysosomal enzymes, glycoamylase and thioredoxin fused with fluorescent protein in Saccharomyces cerevisiae

Saccharomyces cerevisiae is the simplest and a favorite eukaryotic system that contains lysosome and thus, is a suitable organism for monitoring some toxic effects in environmental pollution. In this study, S. cerevisiae was transformed with two recombinant plasmids. Sporulation-specific glycoamylase (SGA1), which was upregulated in response to arsenic, was fused with the blue fluorescent protein (BFP) for the construction of an oxidative stress-causing chemicals sensor. Additionally, thioredoxin (TRX2), a protein overexpressed exclusively under tetracycline's influence, fused with the cyan fluorescent protein (CFP) to create a detector for this kind of chemical. In summary, we developed two recombinant S. cerevisiae that facilitate the detection of both kinds of toxic chemicals, specifically visualized by different color indicators.