Publications by authors named "Tugstenio Lima de Souza"

Many human activities contribute to the pollution of aquatic ecosystems, primarily through agricultural, industrial, mining, and domestic discharges into water bodies. Fish, being highly sensitive to environmental changes, serve as valuable models for monitoring the health of these ecosystems. Metallothionein (Mt), a biomarker for metal contamination, shows variable expression depending on the metal involved.

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Human activities contaminate aquatic ecosystems with chemicals like metals and pesticides. Fish, sensitive to pollution, are key toxicological models. Metallothionein (Mt) expression, a biomarker for metal contamination, varies depending on the chemical exposure.

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Article Synopsis
  • The Iguaçu River basin has a unique fish population but is threatened by chemical pollution, especially from the Jordão River, which drains contaminated agricultural and industrial areas.
  • A study found that while most contaminants were within Brazilian legal limits, cadmium, aluminum, and lead were found at harmful levels in certain locations, affecting fish embryos and larvae.
  • The research demonstrates that even low-level pollutants can increase mortality and deformity rates in aquatic organisms, highlighting the need for conservation efforts to protect local wildlife and maintain ecological health.
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  • - This study explored the toxic effects and potential endocrine disruption of a mixture of polycyclic aromatic hydrocarbons (PAHs) on the liver cells of Nile tilapia, focusing on their impact on the estrogen pathway.
  • - Although the PAH mixture had minimal effects on cell metabolism and adhesion, it significantly increased gene expression related to estrogen, particularly vitellogenin and estrogen receptor 2, indicating potential endocrine disruption.
  • - The study also revealed changes in oxidative stress markers and altered efflux activity, suggesting that the PAH mixture affects both the estrogen pathway and oxidative stress responses in the hepatocytes of O. niloticus.
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The 2,4-Dichlorophenoxyacetic acid (2,4-D) is a low-cost herbicide to eradicate broadleaf weeds. Since the development of 2,4-D resistant transgenic crops, it has been described as one of the most widely distributed pollutants in the world, increasing concern about its environmental impacts. This study aimed to elucidate the antioxidant system response in animals exposed to 2,4-D by different routes of exposure.

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The degradation of water resources available for human consumption is increasing with the continuous release of chemicals into aquatic environments and their inefficient removal in wastewater treatment. Several watersheds in Brazil, such as the Iguaçu River, are affected by multiple sources of pollution and lack information about their pollution status. The Iguaçu River basin (IRB) has great socioeconomic and environmental relevance to both the supply of water resources and its considerable hydroelectric potential, as well as for the high rate of endemism of its ichthyofauna.

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This study aimed to evaluate glyphosate (GLY) and aminomethylphosphonic acid (AMPA) toxicity at 65, 650, and 6500 μg L to the initial stages of development of Steindachneridion melanodermatum, an endangered endemic species from the Iguaçu River, assessing hatching, survival, total larval length, deformities, oxidative stress biochemical biomarkers, and neurotoxicity. Overall, looking at the sum of responses through the integrated biomarker response, the species was more sensitive to AMPA than GLY, especially at the lower concentration of 65 μg L, which induced mortality, deformities, underdevelopment, and oxidative stress. Considering the risk of exposure and the importance of conservation of the highly endemic ichthyofauna of this basin, it is urgent to investigate and regulate both GLY and AMPA levels at the Iguaçu River to protect not only this species, but the entire ecosystem.

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The increased prevalence of human infertility due to male reproductive disorders has been linked to extensive exposure to chemical endocrine disruptors. Acrylamide (AA) is a compound formed spontaneously during the thermal processing of some foods that are mainly consumed by children and adolescents. We previously found that prepubertal exposure to AA causes reduced sperm production and functionality.

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PBDEs are toxic, lipophilic, hydrophobic, and persistent artificial chemicals, characterized by high physical and chemical stability. Although PBDEs are known to disturb hormone signaling, many effects of 2,2',4,4',5 - pentain polybrominated diphenyl ethers (BDE-99) in fish remain unclear. The current study investigates the effects of BDE-99 in Oreochromis niloticus where sixty-four juvenile fish were orally exposed to 0.

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The Iguaçu River basin presents high ecological importance due to its expressive endemic ichthyofauna rate, but chemical pollution may threat this biodiversity. Jordão River is one of the main tributaries of Iguaçu River and contribute to this pollution status, since it drains large agricultural areas receiving domestic and industrial effluents before flowing into the Iguaçu River. The objective of the current study was to evaluate the toxic effects of the Iguaçu, Jordão, and the combination of their waters to the embryo-larval phase of R.

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Background: Silver nanoparticles (AgNP) are largely used in nanotechnological products, but the real risks for human and environment are still poorly understood if we consider the effects of mixtures of AgNP and environmental contaminants, such as non-essential metals.

Methods: The aim of the present study was to investigate the cytotoxicity and toxicological interaction of AgNP (1-4 nm, 0.36 and 3.

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Article Synopsis
  • Polybrominated diphenyl esters, like BDE-47, are new environmental contaminants that raise concerns due to limited toxicological data, prompting this study on their effects on the fish species Oreochromis niloticus.
  • The study exposed fish to various BDE-47 doses over 80 days, finding that these exposures impacted liver and reproductive health, hormone levels, and enzyme activity across different dosages.
  • The results indicate that low doses of BDE-47 can be toxic to this fish species and highlight the importance of using multiple biomarkers in ecotoxicology research and environmental monitoring.
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Polybrominated diphenyl ethers (PBDEs) are brominated, persistent and bioaccumulative flame retardants widely used in the manufacture of plastic products. Decabromodiphenyl ether (BDE-209) is the most prevalent PBDE in the atmosphere and found in human blood, breast milk and umbilical cord. In vitro studies showed that BDE-209 interferes with murine melanoma cells (B16F10), modulating cell death rates, proliferation and migration, important events for cancer progression.

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