4-Nitrophenol at environmentally relevant concentrations mediates reproductive toxicity in Caenorhabditis elegans via metabolic disorders-induced estrogen signaling pathway.

4-Nitrophenol (4-NP), as a toxic and refractory pollutant, has generated significant concern due to its adverse effects. However, the potential toxic effects and mechanism remained unclear. In this study, the reproduction, development, locomotion and reactive oxygen species (ROS) production of Caenorhabditis elegans were investigated to evaluate the 4-NP toxicity. We used metabolomics to assess the potential damage mechanisms. The role of metabolites in mediating the relationship between 4-NP and phenotypes was examined by correlation and mediation analysis. 4-NP (8 ng/L and 8 µg/L) caused significant reduction of brood size, ovulation rate, total germ cells numbers, head thrashes and body bends, and an increase in ROS. However, the oosperm numbers in uterus, body length and body width were decreased in 8 µg/L. Moreover, 36 differential metabolites were enriched in the significant metabolic pathways, including lysine biosynthesis, ß-alanine metabolism, tryptophan metabolism, pentose phosphate pathway, pentose and glucuronate interconversions, amino sugar and nucleotide sugar metabolism, starch and sucrose metabolism, galactose metabolism, propanoate metabolism, glycerolipid metabolism, and estrogen signaling pathway. The mechanism of 4-NP toxicity was that oxidative stress caused by the perturbation of amino acid, which had effects on energy metabolism through disturbing carbohydrate and lipid metabolism, and finally affected the estrogen signaling pathway to exert toxic effects. Moreover, correlation and mediation analysis showed glycerol-3P, glucosamine-6P, glucosamine-1P, UDP-galactose, L-aspartic acid, and uracil were potential markers for the reproduction and glucose-1,6P2 for developmental toxicity. The results provided insight into the pathways involved in the toxic effects caused by 4-NP and developed potential biomarkers to evaluate 4-NP toxicity.

Toxicity of bisphenol A and p-nitrophenol on tomato plants: Morpho-physiological, ionomic profile, and antioxidants/defense-related gene expression studies.

Bisphenol A (BPA) and p-nitrophenol (PNP) are emerging contaminants of soils due to their wide presence in agricultural and industrial products. Thus, the present study aimed to integrate morpho-physiological, ionic homeostasis, and defense- and antioxidant-related genes in the response of tomato plants to BPA or PNP stress, an area of research that has been scarcely studied. In this work, increasing the levels of BPA and PNP in the soil intensified their drastic effects on the biomass and photosynthetic pigments of tomato plants. Moreover, BPA and PNP induced osmotic stress on tomato plants by reducing soluble sugars and soluble proteins relative to control. The soil contamination with BPA and PNP treatments caused a decline in the levels of macro- and micro-elements in the foliar tissues of tomatoes while simultaneously increasing the contents of non-essential micronutrients. The Fourier transform infrared analysis of the active components in tomato leaves revealed that BPA influenced the presence of certain functional groups, resulting in the absence of some functional groups, while on PNP treatment, there was a shift observed in certain functional groups compared to the control. At the molecular level, BPA and PNP induced an increase in the gene expression of polyphenol oxidase and peroxidase, with the exception of POD gene expression under BPA stress. The expression of the thaumatin-like protein gene increased at the highest level of PNP and a moderate level of BPA without any significant effect of both pollutants on the expression of the tubulin (TUB) gene. The comprehensive analysis of biochemical responses in tomato plants subjected to BPA and PNP stress illustrates valuable insights into the mechanisms underlying tolerance to these pollutants.

Nitrophenols disrupt the expression and activity of biotransformation enzymes (CYP3A and COMT) in chicken ovarian follicles in vivo and in vitro.

Nitrophenols are environmental pollutants and xenobiotics, the main sources of which are diesel exhaust fumes and pesticides. The biotransformation processes that take place in the liver are defence mechanisms against xenobiotics, such as nitrophenols. Our previous study showed that the chicken ovary is an additional xenobiotic detoxification place and that nitrophenols disrupt steroidogenesis in chicken ovarian follicles. Therefore, the present study aimed to determine the in vivo and in vitro effects of 4-nitrophenol (PNP) and 3-methyl-4-nitrophenol (PNMC) on the expression and activity of phase I (CYP3A) and phase II (COMT) biotransformation enzymes in chicken ovary. In an in vivo study, hens were treated with a vehicle or 10 mg PNP or PNMC/kg b.wt. per day for 6 days. In an in vitro study, prehierarchical white and yellowish follicles, as well as the granulosa and theca layers of the three largest preovulatory follicles (F3, F2 and F1), were isolated and then incubated in a control medium or medium supplemented with PNP (10-6 M) or PNMC (10-6 M) for 24 or 48 h. Both in vivo and in vitro studies showed that nitrophenols exert tissue- and compound-dependent (PNP or PNMC) effects on CYP3A and COMT gene (real-time PCR) protein (Western blot) expression and their activity (colorimetric methods). The inhibitory effect of nitrophenols in vivo on the activity of biotransformation enzymes suggest that the ovary has the capacity to metabolise PNP and PNMC.

Outro inferno de Dante numa mina de ouro na época de Vargas: Nova Lima, Minas Gerais / Another Dante's inferno in a gold mine during the Vargas era: Nova Lima, Minas Gerais

O artigo analisa as estratégias de controle existentes no trabalho na mina de Morro Velho, Minas Gerais, e as mudanças resultantes da implementação da legislação trabalhista durante o governo Vargas. Discute as doenças causadas pelo trabalho na mina, silicose e arsenicismo, através de depoimentos de ex-mineiros e do livro de um autor anônimo que aborda as doenças e as relações de poder entre patrões e empregados, apontando os limites da legislação e das lutas operárias. O livro traz um depoimento contundente de como a empresa proprietária, inglesa, burlou, durante muito tempo, leis como a da taxa de insalubridade. Direito que outras mineradoras, não só de propriedade inglesa, costumavam e até hoje costumam desrespeitar pelo mundo.

This article analyzes the control strategies in place at Morro Velho mine in the Brazilian state of Minas Gerais, and the changes after the implementation of labor legislation during the Vargas administration. The diseases common amongst mine workers, silicosis and arsenicosis, are investigated through statements given by former miners and a book by an anonymous author that discusses the diseases and the power relations between employers and employees, identifying the limitations of the legislation and the workers’ struggles. The book presents a striking story of how for many years the British company side-stepped laws such as the insalubrity premium, a right which other mining companies, not only of British ownership, flouted and still flout in different parts of the world.