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Agora exibindo 1 - 20 de 1794

From DNA to ecosystems: why molecular taxonomy matters in ecology education
(2026) Alves, Kenned Fellype Francisco; Borges, Geovanna Gonçalves; Pinto, Rafael Barbosa; Telles, Mariana Pires de Campos; Nunes, Rhewter
Molecular Ecology has become a key field for understanding biodiversity, evolutionary processes, and ecological interactions. Despite its growing relevance, molecular taxonomy remains largely underrepresented in ecology education. This article argues for the urgent inclusion of molecular approaches in ecology curricula, highlighting how tools such as DNA barcoding, metabarcoding, and bioinformatics can enhance student understanding and professional preparedness. We present didactic strategies, low-cost alternatives, and interdisciplinary project ideas that link molecular methods to real ecological problems. Finally, we propose a research agenda to assess the educational impact of these methods and suggest policy and institutional pathways for broader integration. Including molecular taxonomy in ecology education is not only an academic advancement, but an essential step toward training professionals capable of addressing 21st-century environmental challenges
Mapping scientific production in the Tocantins–Araguaia Basin in Brazil Central: application of automated content analysis in freshwater studies
(2026) Soares, Philip Teles; Bini, Luis Mauricio; Diniz Filho, José Alexandre Felizola; Vieira, Ludgero Cardoso Galli; Telles, Mariana Pires de Campos; Nunes, Rhewter; Nabout, João Carlos
The Tocantins–Araguaia Basin, one of the largest and most ecologically significant watersheds in South America, harbors high biodiversity and provides essential ecosystem services. This study offers a comprehensive assessment of the scientific literature on the Tocantins–Araguaia River Basin using automated content analysis. We compared publication trends and research topics across major Brazilian river basins and applied Structural Topic Modeling (STM) to identify dominant themes, their relationships, and temporal dynamics in studies focused on the Tocantins–Araguaia Basin. Publication trends showed a steady increase in scientific output across all basins, with the Amazon and Paraná accounting for the highest number of papers. Keyword analysis revealed distinct thematic profiles, with research terms for the Tocantins–Araguaia Basin closely resembling those of the São Francisco Basin, both emphasizing aquatic biodiversity, hydropower, and land-use change. For the Tocantins–Araguaia Basin specifically, STM identified ten main research themes, with “Fish Morphology” and “Aquatic Communities” being the most frequent. Topics such as “Biodiversity & Fossils”, “Dams & Fisheries”, and “Agricultural Practices” showed high lexical overlap with other themes, indicating broader thematic integration. Temporal analyses revealed the growing prominence of applied and interdisciplinary themes, such as “Aquatic Communities”, “Agricultural Practices”, and “Land Use & Cerrado”, reflecting global scientific priorities in biodiversity conservation and water management. Despite increased scientific output, topics such as invasive species and eDNA remain underrepresented. The analytical framework applied here provides a transferable approach for identifying research trends and gaps in other understudied regions.
Draft genome assemblies and SSR-Seq dataset for Simarouba amara and S. versicolor , native species to Latin America
(2026) Silva, Marla Arianne Almeida; Corvalán, Leonardo Carlos Jeronimo; Ferreira, Ramilla dos Santos Braga; Brito, Cíntia Pelegrineti Targueta de Azevedo; Franceschinelli, Edivani Villaron; Silva Neto, Carlos de Melo e; Soares, Thannya Nascimento; Telles, Mariana Pires de Campos; Nunes, Rhewter
Simarouba amara (known in Brazilian Portuguese as “marupá”) and S. versicolor (known in Brazilian Portuguese as “pé-de-perdiz”) are Neotropical species belonging to the family Simaroubaceae. These species have historically been used in folk medicine to treat conditions such as malaria, cancer, helminthiasis, viral infections, gastritis, ulcers, di- arrhea, and diabetes. Recent advances in high-throughput sequencing (HTS) technologies have improved the acquisi- tion of genomic datasets for economically wild species. This genomics data enables the development of microsatellite markers (SSR), which are valuable tools in genetic analy- sis, mainly in species with absence of genomic resources, as S. amara and S. versicolor . In this study, we generated high-quality draft assemblies and developed SSR-Seq primers from these assemblies, for both species. We sequenced a total of 20,273,467 and 16,800,708 reads from S. amara and S. versicolor , respectively, with an estimated genome sizes of 372.16 Mb and 249.78 Mb. The genome assemblies by SPAdes resulted in 23,601 and 23,722 total contigs and an N50 value of 28,440 bp and 22,312 bp. Using the QDD pipeline, we identified 11,348 and 12,084 microsatellite regions that are putative for primers design. Using the openPrimeR tool, this dataset was filtered and 87 and 77 sets of SSR-Seq primers survived. Using physicochemical properties, 55 and 56 SSR-seq primer pairs for S. amara and S. versicolor were organized into five and four multiplex sets. The SSR-Seq dataset developed in this study enables the acquisition of genetic information and performs genetic and evolutionary analyses in these wild populations.
Revisão sistemática e análise cienciométrica sobre a aplicação de metodologias ativas no ensino de educação ambiental para crianças em idade escolar
(2025) Silva, Leidyane Alves da; Barreto, Alyne Anne Silva; Pires, Débora de Jesus; Nunes, Rhewter
Objetivo – Este estudio tiene como objetivo realizar una revisión sistemática y un análisis cienciométrico sobre el uso de metodologías activas en la educación ambiental para niños, investigando el panorama científico actual e identificando brechas en la literatura. Metodología – La investigación se basa en el análisis de artículos publicados en la Web of Science entre 1994 y 2024, combinando una revisión sistemática y un análisis cienciométrico para mapear tendencias y patrones en la producción académica sobre el tema. Originalidad/relevancia – El estudio destaca la educación ambiental como un agente transformador esencial para la formación de ciudadanos conscientes y comprometidos con la sostenibilidad. Aunque las metodologías activas, como el Aprendizaje Basado en Proyectos (ABP), el Aprendizaje Basado en Problemas (ABP) y la Clase Invertida, son ampliamente reconocidas, no se encontraron artículos que abordaran específicamente su aplicación en la educación ambiental para niños en edad escolar. Resultados – Los hallazgos indican un crecimiento gradual en la producción académica sobre el tema a partir de 2011, alcanzando su punto máximo en 2021. Sin embargo, aún existe una brecha en la literatura con respecto a la aplicación de metodologías activas en la enseñanza de la educación ambiental para niños. El estudio demuestra que estos enfoques favorecen el protagonismo estudiantil, la ciudadanía activa y la construcción de hábitos sostenibles desde la infancia, contribuyendo a una cultura escolar más consciente y alineada con los Objetivos de Desarrollo Sostenible (ODS). Contribuciones teóricas/metodológicas – El estudio refuerza la necesidad de investigaciones adicionales sobre el uso de metodologías activas en la educación infantil, especialmente en lo que se refiere al impacto de estas estrategias en la formación de comportamientos pro-sostenibilidad. Contribuciones sociales y ambientales – La investigación evidencia que la implementación de metodologías activas en la educación ambiental puede fortalecer la inclusión, la colaboración y la formación de prácticas sostenibles desde la infancia, contribuyendo al desarrollo de ciudadanos más comprometidos con la sostenibilidad.
Cladophialophora carrionii
(2025) Moraes, Dayane; Bailão, Alexandre Melo; Bailão, Mirelle Garcia Silva
A victorivirus infecting Colletotrichum falcatum: genomic characterization and evolutionary analysis
(2026) Henrique, Maressa de Oliveira; Gallan, Diego Zanardo; Schrank, Augusto; Dias, Renata de Oliveira; Coutts, Robert Henry Arnold; Kotta-Loizou, Ioly; Silva Filho, Márcio de Castro
Colletotrichum falcatum is a major fungal pathogen responsible for severe disease in sugarcane. Here, we report the complete genomic characterization of a novel mycovirus infecting C. falcatum, designated Colletotrichum falcatum victorivirus 1 (CfVV1). The CfVV1 genome is 4,906 base pairs (bp) long and comprises two open reading frames encoding a capsid protein (CP) and an RNA-dependent RNA polymerase (RdRP), overlapping at an AUGA motif. The predicted proteins share ca. 70% and 68% identity with those of Colletotrichum cliviicola victorivirus 1 and Colletotrichum nativitas totivirus 1, respectively. Phylogenetic analysis based on concatenated RdRP and CP amino acid sequences places CfVV1 within the genus Victorivirus of the recently established family Pseudototiviridae. Transmission electron microscopy confirmed the presence of isometric virus-like particles ca. 40 nm in diameter, consistent with the typical morphology of victoriviruses. To our knowledge, this is the first report of a complete victorivirus genome infecting C. falcatum.
The mitochondrial genome of pequi tree (Caryocar brasiliense Cambess.): genome structure, gene transfers, and evolutionary insights within Malpighiales
(2025) Carvalho, Larissa Resende; Corvalán, Leonardo Carlos Jeronimo; Dias, Renata de Oliveira; Ferreira, Ramilla dos Santos Braga; Brito, Cíntia Pelegrineti Targueta de Azevedo; Diniz Filho, José Alexandre Felizola; Telles, Mariana Pires de Campos; Nunes, Rhewter
The complete mitochondrial genome of Caryocar brasiliense (Caryocaraceae), an ecologically and economically important species native to the Brazilian savannas, was assembled and annotated. Using a hybrid assembly approach combining Oxford Nanopore and Illumina sequencing data, we assembled a 533,641 bp bipartite mitogenome organized into two circular chromosomes. A high density of dispersed repeats and simple sequence repeats (SSRs) was detected, along with extensive DNA transfers from the chloroplast and nuclear genomes (MTPTs and NUMTs). The variation of mitogenome size is positively correlated with the number of dispersed repeats (R² = 0.88). Genome annotation revealed 74 protein-coding genes, including sequences derived from both mitochondrial and chloroplast origins, as well as 376 predicted RNA editing sites, particularly concentrated in energy metabolism genes such as ccm and nad gene family. Comparative analysis across ten Malpighiales species identified conserved core mitochondrial genes and revealed topological differences between mitochondrial and plastid phylogenies. These findings offer new insights into the structural and evolutionary dynamics of angiosperm mitochondrial genomes and provide a foundational resource for future genetic, evolutionary, and conservation studies in C. brasiliense and related taxa.
Digestion in the arachnid Mischonyx squalidus as a probable source of lipids to synthesize opiliones defense and communication molecules
(2025) Silva, Jefferson Oliveira; Viala, Vincent Louis; Dias, Renata Oliveira; Ferreira, Clelia; Terra, Walter Ribeiro; Rocha, Ricardo Pinto da; Lopes, Adriana Rios
Opiliones (Arachnida) comprises approximately 7,000 species. Due to their lack of venom glands, their defense is mainly based on the secretion of scent glands, which also play roles in communication and antimicrobial activity. This odoriferous secretion has a diverse composition according to harvestmen species but frequently contains benzoquinones. Studies of benzoquinone synthesis intermediates suggest a pathway based on lipid metabolism from diet. This study provides the first transcriptomic and enzymatic analysis of the midgut of Mischonyx squalidus to understand the acquisition of nutrients. The enzymatic analysis tested 11 digestive enzymes and found high lipase activity and moderate and low activity for peptidases and carbohydrases, respectively. Transcriptome sequencing yielded 19,658 unigenes, predominating enzymes and binding proteins closely associated with Xiphosura and Scorpiones proteins; a third of which are hydrolases. A multigene lipase family is expressed. Cathepsin L peptidases were prominently abundant, indicating their relevance for protein digestion. Additionally, toxin-like proteins and lipid metabolism-related enzymes, such as phospholipase A2 and NPC cholesterol transporters, were represented, indicating a sophisticated digestive and metabolic system for lipids. These findings suggest a link between lipid digestive metabolism and defensive and communicative molecule synthesis, underscoring Opiliones’ unique evolutionary adaptations.
Integrating classical and quantum mechanics in melatonin receptors for structure-guided drug design
(2025) Menezes, Gabriela de Lima; Silva, Gabriel Vinicius Rolim; Bezerra, Katyanna Sales; Saivish, Marielena Vogel; Dantas, Clara Sales Gurgel Ribeiro; Galvão, Douglas Soares; Araújo, John Fontenele; Oliveira, Jonas Ivan Nobre; Silva, Roosevelt Alves da; Fulco, Umberto Laino
Although melatonin receptor agonists are acknowledged for their therapeutic potential for managing sleep problems, the structural optimization of these compounds is made challenging by variations in crystallographic data. This study aims to improve the structure of the melatonin receptor type 1 and ramelteon (MT1-RMT) complex and propose a new melatonin receptor agonist with an enhanced binding affinity. Molecular dynamics (MD) simulations have been used to improve the experimental MT1-RMT complex, followed by quantum-mechanical (QM) calculations employing density functional theory (DFT) to assess ligand–receptor interactions. The MD simulations effectively optimized the MT1-RMT complex, resulting in a conformation that was consistent with the experimental binding affinities. The QM calculations validated the improved binding affinity, and additional structural insights facilitated the rational design of a new agonist, N-[2-(5-methoxy-2-phenyl-1H-indol-3-yl)ethyl]propanamide (MPI), which exhibited better affinity for the MT1 and melatonin receptor type 2 (MT2) receptors. These findings suggest that MD-based refinement enhances the precision of protein–ligand complex models and that MPI is a suitable candidate for future pharmaceutical development. Subsequent research should examine the pharmacokinetic characteristics and in vivo effectiveness of MPI.
The loss of the urea cycle and ornithine metabolism in different insect orders: an omics approachThe loss of the urea cycle and ornithine metabolism in different insect orders: an omics approach
(2025) Martins, Jéssica Cristina Silva; Romão, Héctor Antônio Assunção; Canettieri, Carolina Kurotusch; Cercilian, Amanda Caetano; Oliveira, Patrícia Rasteiro Ordiale; Ferreira, Clelia; Terra, Walter Ribeiro; Dias, Renata de Oliveira
Previous studies suggest that some insects require dietary arginine because they cannot synthesize this amino acid through the urea cycle. To determine whether this finding applies to all insects and what its metabolic implications are, we analysed the conservation of 20 genes involved in arginine biosynthesis and metabolism in the genomes of 150 species from 11 taxonomic orders. Our results showed that no insect can synthesize arginine via the urea cycle, as ornithine carbamoyltransferase is absent from all genomes analysed. While we found losses in other genes encoding urea cycle enzymes, nitric oxide synthase (NOS) was conserved across orders. However, the citrulline produced by NOS cannot be converted back to arginine in several insects due to the loss of argininosuccinate synthase and argininosuccinate lyase genes. Despite the inability to synthesize arginine, all insects (except some Hemiptera) can degrade it to ornithine and urea, as the arginase (ARG) gene is conserved across the orders analysed. For some Hemiptera that have lost ARG, we investigated how these insects produce or metabolize ornithine. Our results show that the genes for converting ornithine to glutamate, proline and putrescine are conserved across orders. However, while all insects have enzymes to synthesize putrescine and spermidine, some lack the ability to produce spermine due to the absence of the spermine synthase gene. Taken together, our results show that the loss of the urea cycle has led to significant changes in the pathways by which insects metabolize and recover arginine, which is particularly important for the diversification of hemipterans.
First assembly of a draft genome of the critically endangered northern muriqui (Brachyteles hypoxanthus , Primates, Atelidae) including non-invasive genotyping strategies for the species
(2025) Ximenes, Amanda Alves de Melo; Batista, Romina do Socorro da Silva; Corvalán, Leonardo Carlos Jeronimo; Bone, Tomàs Marquès; Kuderna, Lukas Felix Karl; Farh, Kyle Kai-How; Rogers, Jeffrey; Kaizer, Mariane da Cruz; Philippe, Jean
Genomic resources, such as draft genomes, are vital for biodiversity monitoring and conservation. For endangered species, they enable the development of tools like organellar genomes and molecular markers, which are crucial for population genetics. Advances in sequencing technologies now allow high-throughput genotyping with detailed amplicon sequences, enhancing genetic variation studies. The northern muriqui (Brachyteles hypoxanthus), a critically endangered primate endemic to Brazil's Atlantic Forest, currently lacks both nuclear and mitochondrial genome data and species-specific microsatellite markers for population genetic studies. We assembled a 2.52 Gb draft genome for B. hypoxanthus with 202,243 contigs (N50 = 29,134 bp), and BUSCO analyses indicated 52% completeness and 15.5% fragmented genes. The complete 16,635 bp mitochondrial genome retains the conserved mammalian structure with 22 tRNAs, 2 rRNAs, 13 CDS, and an origin of replication. Additionally, we designed 31 SSR primer pairs suitable for non-invasive sampling and genotyping, alongside two mtDNA and two sex-determination primers, configured into three multiplex PCR sets. These genomic resources, including the draft genome, complete mitochondrial genome, and microsatellite markers, provide essential tools for evolutionary analyses and the genetic monitoring of B. hypoxanthus populations, supporting its conservation.
Assessing disaster resilience of concrete with titanium dioxide nanoparticles
(2025) Rodrigues, Matheus Wesley; Matos, Priscila Custódio de; Franchi, Leonardo Pereira; Souza, Tiago Alves Jorge de
In recent decades, the occurrence of extreme events has intensified across diverse regions of the world, inflicting substantial impacts on economies, safety, and the quality of life of affected populations. This reality underscores the urgent requirement for innovative solutions to mitigate such damages. Within this framework, nanotechnology has emerged as a promising paradigm, with nanoadditives distinguished as effective agents for enhancing the durability, impermeability, and mechanical strength of construction materials. Nanoparticles such as titanium dioxide (TiO2), carbon nanotubes (CNTs), silica, clay, and copper (Cu) have been associated with improvements in durability, strength-to-weight ratio, stability, and seismic resilience. The integration of these nanomaterials fosters densification of the concrete matrix by reducing voids and capillaries, thereby enhancing waterproofing and hindering the infiltration of deleterious substances. The present study offers an experimental investigation complemented by a comprehensive literature review, including water-absorption simulations and assessments of surface integrity in both treated and untreated materials. The objective is to evaluate the contributions of nanoadditives to safety, durability, and sustainability in the face of challenges posed by climate change. Results indicate that a 1% addition of nanoTiO2 yields the highest mechanical strength, while higher concentrations tend to reduce benefits due to particle agglomeration. This finding underscores the importance of optimizing nanoparticle content to enhance concrete resilience against natural disasters, contributing to sustainable construction practices. The comparison with copper-based additives reveals that, despite some relative strength gain over time, copper formulations fall short in mechanical performance, highlighting nanoTiO2 as a more promising agent for improving concrete durability in disaster-prone environments. Given the growing frequency of environmental disasters, the adaptation of civil construction through the sustainable incorporation of nanomaterials necessitates careful consideration of synthesis processes, long-term stability, and potential ecological impacts associated with nanoparticle interactions with biotic and abiotic environmental components.
Metalloporphyrin-based photodynamic inactivation of multidrug-resistant environmental mastitis pathogens
(2026) Pires, Luiz Henrique Barbosa; Borsanelli, Ana Carolina; Franchi, Leonardo Pereira; Batista, Alzir Azevedo; Gonçalves, Pablo José; Souza, Guilherme Rocha Lino de
Bacteria such as Klebsiella pneumoniae, Proteus mirabilis and Streptococcus dysgalactiae are often associated with environmental and zoonotic agents causing bovine mastitis. In addition, the emergence of multidrug-resistant (MDR) strains associated with these pathogens poses a significant challenge to the effectiveness of conventional antimicrobial therapies. Thus, this study aimed to evaluate the efficacy of antimicrobial photodynamic inactivation (aPDI) as an alternative for controlling environmental pathogens related to mastitis. Four meso-Tetra-(4-pyridyl)porphyrin/palladium(II) complexes (DPPE, DPPP, DPPB, and DPPF) were used as photosensitizers (PS) against clinical isolates of K. pneumoniae, P. mirabilis, and S. dysgalactiae. Here DPPE, DPPP, DPPB, and DPPF refer to the diphosphine present in the Pd(II) complex (DPPE = . 1,2-bis(diphenylphosphino)ethane; DPPP = 1,3-bis(diphenylphosphino)propane; DPPB = 1,4-bis(diphenylphosphino)butane; DPPF = 1,1′-bis(diphenylphosphino)ferrocene. Antimicrobial susceptibility testing confirmed concerning MDR profiles in P. mirabilis and K. pneumoniae. The aPDI assessments revealed that DPPE, DPPP, and DPPB exhibited a minimum effective concentration (MEC) of 1.56 μM against S. dysgalactiae. For P. mirabilis, the MECs determined were 12.5 μM for DPPP and 100 μM for DPPF. In contrast, against K. pneumoniae, only two PSs exhibited significant activity, with MEC values of 3.12 μM for DPPP and 25 μM for DPPF. In the time kill kinetics assay, the photodynamic activity of the PS DPPP was particularly remarkable, as it effectively inhibited bacterial growth (MIC100) in all tested strains for up to 45 min irradiation. Moreover, the Ames mutagenicity assay revealed that none of the PSs exhibited significant mutagenic activity at the concentrations evaluated, thereby indicating a favorable safety profile. These findings highlight the potential of aPDI as a promising strategy for the control of MDR pathogens implicated in mastitis.
Pharmacological targeting of nuclear factor (erythroid-derived 2)-like 2 (NRF2): a potential strategy to improve the efficacy of oncological photodynamic therapy
(2026) Klerk, Daniel Johannes de; Keijzer, Mark de; Franchi, Leonardo Pereira; Jiahao, Tian; Gureev, Maxim Alexandrovzch; Yingnan, Ge; Mesquita, Bárbara; Saelman, Gideon Emiel; Herteryck, Isis Van; Dias, Lionel M.
The recalcitrance of tumors to photodynamic therapy (PDT) has been linked to PDT-induced activation of survival pathways in sublethally afflicted cancer cells that modulate cellular responses to oxidative stress and damage. Survival signaling manifests in regions of the tumor where the tumor cells are insufficiently photosensitized or subjected to inadequate fluence rates. The survival signaling in these tumor regions is believed to account for tumor recurrence. Accordingly, PDT efficacy can be improved by intervening in these pathways using molecular inhibitors of key modulators of survival signaling, thereby increasing the number of lethally afflicted cancer cells and with it therapeutic efficacy. A promising target for pharmacological intervention is the nuclear factor (erythroid-derived 2)-like 2 (NRF2) pathway, which induces the antioxidant and xenobiotic stress response that helps cells cope with prolonged periods of hyperoxidative stress after PDT. This review outlines our current understanding of this pathway, how it is activated, and how it confers cytoprotective effects and ensures cell survival. Additional distinguishing features of the review are that (1) studies are addressed in which PDT activation of the NRF2 pathway has been demonstrated; (2) a non-exhaustive overview of NRF2 pathway inhibitors is presented that could serve as potential adjuvants in PDT regimens to augment therapeutic efficacy in treatment-resistant tumors and cancers that recur after PDT; (3) molecular docking analyses are included that show potential interactions between the NRF2 inhibitors and the redox sensor KEAP1; and (4) an elaborate account is provided of the potential bottlenecks and caveats that can be encountered when using NRF2 inhibitors in the development of fourth-generation photosensitizers for oncological PDT.
Occupational exposition to pesticides increases the risk of autoimmunity and autoimmune diseases: a systematic review and meta-analysis
(2025) Silva, Iasmin Ramos da; Paula, Ana Emilia Carvalho de; Nascimento, Felipe de Araújo; Toribio, Marco; Brito, Michelle Bento de; Parise, Michelle Rocha
Studies have suggested the existence of a relationship between exposure to pesticides and autoimmunity as well as autoimmune diseases. Parallel to this, the increase in exposure to pesticides in recent decades and in the identification of autoimmunity such as autoimmune diseases throughout the world is a reality. Given this scenario, more indepth investigations are increasingly necessary to determine this relationship. Thus, we performed a comprehensive meta-analysis from published studies to answer the question: “Is there a higher risk for autoimmunity in farmers/rural workers exposed to pesticides?”. The databases: Pubmed, Embase, Lilacs, Scopus, CAF-e and BVS were searched to identify qualified literatures. The meta-analysis was based on the calculation via Multivariate/Multilevel Linear (Mixed-Effects) Model and a total of 259 parameters in nine articles were included in the study. The results showed that the random effect for all analyses was 0.36 (0.33- 0.39; p<.0001) and the meta-analysis showed a significant heterogeneity among the studies. All together, these results are a consequence of the variation in the immune parameters evaluated by each selected study and in the different groups of individuals evaluated among the included studies. The bias analysis was complemented by the sensibility analysis, which showed that withdrawing one study, the overall effect remains positive, and the heterogeneity does not change significantly. These findings indicated that exposure to pesticides might increase the risk of autoimmunity in farmers and rural workers. Further studies are needed to better understand the underlying mechanisms of immune alterations compatible with autoimmunity due to occupational exposure to pesticides.
Genotoxic, mutagenic, and biomass effects on Eisenia fetida exposed to the fungicides triadimefon and triadimenol
(2026) Souza, Marcelino Benvindo de; Souza, Áureo Barbosa de; Fernandes, Amanda Silva; Bailão, Elisa Flávia Luiz Cardoso; Almeida, Luciane Madureira de; Borges, Leonardo Luiz; Aguiar, Antônio Sérgio Nakao de
Triadimefon and triadimenol are broad-spectrum fungicides widely used in agriculture. This study assessed their genotoxic and biomass effects on Eisenia fetida earthworms exposed for 7, 14 and 21 days to concentrations of triadimefon (0.006, 0.12, 0.24 mg/kg), triadimenol (1.5, 3, 6 mg/kg), and their mixture (0.012 + 3.0 mg/kg). At 14 and 21 days, weight loss exceeded 20%, reaching over 40% at the highest concentrations of both triazoles. Genotoxic effects were detected at 6 mg/kg triadimefon and 0.024 mg/kg triadimenol, individually and in mixture, particularly after 14 and 21 days. A slight mutagenic increase was observed only at the highest triadimefon concentration. Exposure to the fungicides promoted significant biomass reduction from day 14 onward. These results reinforce the need for monitoring triazoles' environmental impact, as even at relevant concentrations, they can induce genotoxic damage in soil organisms.
Antimicrobial residues in a key cerrado river: distribution, persistence, and effects on zebrafish embryo-larval development
(2026) Simão, Náthala Maria; Santos, Igor Romeiro dos; Oliveira Neto, Jerônimo Raimundo de; Sanches Neto, Flávio Olimpio; Dias, Felipe Cirqueira; Morais, Jéssyca Moreira; Valadares, Lorranny Pereira de Assis; Oliveira, Naiara Raica Lopes de; Bailão, Mirelle Garcia Silva; Cunha, Luiz Carlos da
The current study aimed to quantify the antimicrobials amoxicillin (AMX), cefazolin (CFZ), chloramphenicol (CHL), metroni- dazole (MTZ), and sulfamethoxazole (SX) in effluents and surface water of an important Cerrado river, calculate their half-lives, and analyze their ecotoxicity following single and combined exposures. Four sampling surveys were carried out to identify the antimicrobials employing HPLC-MS/MS. Surface water was collected from the river's spring to the mouth, and effluent samples were taken at a sewage treatment plant (STP). The pySiRC tool was used to predict the half-life of antimicrobials in aqueous media under •OH-attack. Ecotoxicity was assessed using a zebrafish embryo-larval toxicity assay at environmentally relevant concentrations of the detected antimicrobials. Just MTZ (0.1 to 45.5ngL−1) and SX (0.1 to 502.7ngL−1) were detected in this study. The persistence of MTZ and SX in the aqueous environment was estimated at 14 to 139days and 9 to 88days, respectively. The single exposure to MTZ induced cardiotoxicity and changes in the swim bladder and tail curvature. MTZ and SX induced sensory and physiological morphometric changes compared to the control. MTZ, alone or combined with SX, affected the larvae's behavior. Our findings contribute to the understanding of the presence, persistence, and ecotoxicity of antimicrobials in aquatic environments.
Lithium chloride at environmental concentrations impairs microtubule function and promotes genotoxicity in Allium cepa
(2025) Lima, Gabriela Gomes; Cotrim, Carlos Filipe Camilo; Silva, Junilson Augusto de Paula; Firmino, Myllena Tolentino; Silva, Natanael Alves; Aguiar, Antônio Sérgio Nakao de; Souza, Marcelino Benvindo de; Borges, Leonardo Luiz; Caramori, Samantha Salomão; Bailão, Elisa Flávia Luiz Cardoso
The growing demand for lithium, driven by the energy transition and widespread use of rechargeable batteries, has raised concerns about its environmental release. This study assessed the toxicological effects of lithium chloride (LiCl) at environmentally relevant concentrations using the Allium cepa bioassay. While lithium’s genotoxicity at high concentrations is known, its effects at levels typical of aquatic systems (up to 4 mg/L) remain poorly understood. A set of biomarkers was applied to evaluate cytotoxicity, genotoxicity, oxidative stress, and in silico molecular interactions. LiCl exposure significantly reduced the mitotic index, indicating cytotoxic effects via impaired cell division. Increased chromosomal aberrations and nuclear abnormalities were observed, particularly at 4 mg/L, suggesting genotoxicity. However, the Comet assay revealed minimal DNA strand breaks, pointing to an aneugenic mechanism likely caused by mitotic spindle disruption rather than clastogenic effects. Cell cycle analysis showed reduced metaphase and increased anaphase frequencies, reinforcing the hypothesis of chromosomal missegregation. In silico modeling demonstrated strong interactions between Li+ ions and tubulin, potentially affecting spindle stability. Additionally, altered superoxide dismutase (SOD) activity indicated oxidative stress involvement. Overall, lithium at environmentally realistic concentrations induces cytotoxic and genotoxic effects in A. cepa, primarily through aneugenic mechanisms linked to oxidative stress and microtubule disruption.
DNA damage induced by fungicides triadimefon, triadimenol, and their mixture in human lymphocytes: cytogenotoxicity and computational analysis of metabolic pathways
(2026) Fernandes, Amanda Silva; Souza, Áureo Barbosa de; Souza, Marcelino Benvindo de; Almeida, Luciane Madureira de; Franco, Octavio Luiz; Bailão, Elisa Flávia Luiz Cardoso; Borges, Leonardo Luiz; Aguiar, Antônio Sérgio Nakao de
Triadimefon (TF) and triadimenol (TN) are triazole fungicides widely used to prevent fungal infections in cereals, fruits, and other economically important crops. Their harmful effects on non-target organisms have been reported. This study investigated the cytogenotoxic effects of TF and TN, isolated and combined, at environmentally relevant concentrations (TF: 0.006, 0.012, and 0.024 mg/mL; TN: 1.5, 3.0, and 6.0 mg/mL; and 0.012 mg/mL TF + 3.0 mg/mL TN) on human lymphocytes using the trypan blue exclusion test and the comet assay. Additionally, in silico tools, BioTransformer and DIGEP-Pred, were employed to elucidate metabolic pathways more effectively for detoxifying these xenobiotics and to evaluate their putative effects on gene transcription, respectively. Exposure to TF and TN, either alone or in combination, did not affect lymphocyte viability at the tested concentrations. However, both compounds induced an increase in the percentage of DNA strand breaks after treatment. The in silico predictions suggested that the interaction with the cytochrome P450 isoforms (CYP1A2, CYP2A6, CYP2C9, and CYP2D6) differed for each compound analyzed. Gene expression prediction indicated that TF and TN may up-regulate genes involved with hormonal alterations, Alzheimer’s disease risk, and cancer progression (SF1, SPON1, ADGRF5, and RORB). While they may down-regulate a gene involved with changes in heart rhythm and neurotoxicity (HCN1). In conclusion, our findings reinforced that the triazole fungicides TF and TN, while effective in agriculture, may pose risks to genomic stability in humans, highlighting the importance of biomonitoring studies in exposed populations.
Hepatoprotective potential of Vernonanthura polyanthes against doxorubicin-induced oxidative stress in a murine model
(2026) Rocha, Jamira Dias; Rodrigues, Lara Lorhany Gomes da Costa; Campos, Hericles Mesquita; Pereira, Robbert Mota; Melo Bisneto, Abel Vieira de; Caramori, Samantha Salomão Caramori; Lee, Chen Chen; Ghedini, Paulo César; Biancardi , Manoel Francisco; Bailão, Elisa Flávia Luiz Cardoso
The present study aimed to evaluate the redox activity of Vernonanthura polyanthes leaf aqueous extract (VpLAE) and its n-butanol fraction (n-BF) in mouse liver in the absence or in the presence of doxorubicin (DXR). For this, the concentration of malondialdehyde (MDA), the activities of superoxide dismutase (SOD), catalase (CAT), glutathione S-transferase (GST), and glutathione peroxidase (GPx) were determined in the liver of Swiss Webster mice (n = 5 animals per group). Immunohistochemical analyses on hepatocytes labeled with anti-4- hydroxynonenal (4HNE) were also performed to confirm the decrease in lipid peroxidation in animals treated with DXR and VpLAE or n-BF. MDA levels and GST activity increased in the livers of mice that received just VpLAE at a dose of 1000 mg/kg compared with the negative control. Moreover, n-BF alone increased CAT ac- tivity at 250 mg/kg, SOD and GST at 1000 mg/kg, and MDA at 250, 500, and 1000 mg/kg. These data indicate that VpLAE or n-BF alone can promote oxidative stress in hepatocytes. In contrast, when VpLAE was associated with DXR in a pre-treatment regimen, or when n-BF was associated with DXR in co- or pre-treatment regimens, MDA levels decreased, suggesting a protective effect against DXR-induced damage. The decrease in 4HNE la- beling in the livers of mice treated with DXR and VpLAE or n-BF confirmed that pre-treatment with VpLAE or pre- and co-treatments with n-BF reduced DXR-induced lipid peroxidation. In conclusion, VpLAE and n-BF could present a dual behavior, promoting oxidative stress in hepatocytes in the absence of DXR or reducing oxidative stress in the livers of mice treated with DXR. This shift in perspective motivates future studies of VpLAE and n-BF as promising candidates to overcome DXR-induced hepatotoxicity.

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