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In this study, molybdenum(IV) sulfide (MoS2) nanoparticles (97 ± 32 nm) and microparticles (1.92 ± 0.64 μm) stabilized with poly (vinylpolypyrrolidone) (PVP) were administered intratracheally to male and female rats (dose of 1.5 or 5 mg/kg bw), every 14 days for 90 days (seven administrations in total). Blood parameters were assessed during and at the end of the study (hematology, biochemistry including glucose, albumins, uric acid, urea, high density lipoprotein HDL, total cholesterol, triglycerides, aspartate transaminase, and alanine transaminase ALT). Bronchoalveolar lavage fluid (BALF) analyses included cell viability, biochemistry (total protein concentration, lactate dehydrogenase, and glutathione peroxidase activity), and cytokine levels (tumor necrosis factor α, TNF‐α, macrophage inflammatory protein 2‐alpha, MIP‐2, and cytokine‐induced neutrophil chemoattractant‐2, CINC‐2). Tissues were subjected to routine histopathological and electron microscopy (STEM) examinations. No overt signs of chronic toxicity were observed. Differential cell counts in BALF revealed no significant differences between the animal groups. An increase in MIP‐2 and a decrease in TNF‐α were observed in BALF in the exposed males. The histopathological changes in the lung evaluated according to a developed classification system (based on severity of inflammation, range 0–4, with 4 indicating the most severe changes) showed average histopathological score of 1.33 for animals exposed to nanoparticles and microparticles at the lower dose, 1.72 after exposure to nanoparticles at the higher dose, and 2.83 for animals exposed to microparticles at the higher dose. In summary, it was shown that nanosized and microsized MoS2 can trigger dose‐dependent inflammatory reactions in the lungs of rats after multiple intratracheal instillation irrespective of the animal sex. Some evidence indicates a higher lung pro‐inflammatory potential of the microform. Molybdenum(IV) sulfide (MoS2) nanoparticles and microparticles administered intratracheally to rats (1.5 or 5 mg/kg bw), every 14 days for 90 days, induced no overt signs of systemic chronic toxicity. An increase in MIP‐2 and a decrease in TNF‐α were observed in BALF in the exposed males. Based on histopathological examination, nanosized and microsized MoS2 can trigger dose‐dependent inflammatory reactions in the lungs of rats after multiple intratracheal instillations, with a slightly higher lung pro‐inflammatory potential of the microform. [ABSTRACT FROM AUTHOR]

Objectives: Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) has considerable applicative potential for both qualitative and quantitative analyses of elemental spatial distribution and concentration. It provides high resolutions at pg-level detection limits. These qualities make it very useful for analyzing biological samples. The present study responds to the growing demand for adequate analytical methods which would allow to assess the distribution of nanostructured molybdenum(IV) disulfide (MoS 2 ) in organs. It was also motivated by an apparent lack of literature on the biological effects of MoS 2 in living organisms. The study was aimed at using LA-ICP-MS for comparing micro- and nanosized MoS 2 ditribution in selected rat tissue samples (lung, liver, brain and spleen tissues) after the intratracheal instillation (7 administrations) of MoS 2 nano- and microparticles vs. controls., Material and Methods: The experimental study, approved by the Ethics Committee for Animal Experiments was performed using albino Wistar rats. This was performed at 2-week intervals at a dose of 5 mg/kg b.w., followed by an analysis after 90 days of exposure. The MoS 2 levels in control tissues were determined with the laser ablation system at optimized operating conditions. The parameter optimization process for the LA system was conducted using The National Institute of Standards and Technology (NIST) glass standard reference materials., Results: Instrument parameters were optimized. The study found that molybdenum (Mo) levels in the lungs of microparticle-exposed rats were higher compared to nanoparticle-exposed rats. The opposite results were found for liver and spleen tissues. Brain Mo concentrations were below the detection limit., Conclusions: The LA-ICP-MS technique may be used as an important tool for visualizing the distribution of Mo on the surface of soft samples through quantitative and qualitative elemental mapping. Int J Occup Med Environ Health. 2024;37(1):18-33., (This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.)

There is still little literature data on the toxicity and safety of the commonly used molybdenum (Mo) disulfide which is present in the working as well as living environments. Thus, an experiment was carried out involving rats, with single and repeated intratracheal exposure (in the latter case, 7 administrations at 2-week intervals with the analysis performed after 90 days) to lower (1.5 mg Mo kg -1 b.w.) and higher (5 mg Mo kg -1 b.w.) doses of molybdenum(IV) sulfide nanoparticles (MoS 2 -NPs) and microparticles (MoS 2 -MPs). The analysis of Mo concentrations in the tail and heart blood as well as in soft tissues (lung, liver, spleen, brain), after mineralization and bioimaging, was meant to facilitate an assessment of its accumulation and potential effects on the body following short- and long-term exposure. The multi-compartment model with an exponential curve of Mo concentration over time with different half-lives for the distribution and elimination phases of MoS 2 -MPs and MoS 2 -NPs was observed. After 24 h of exposure, a slight increase in Mo concentration in blood was observed. Next, Mo concentration indicated a decrease in blood concentration from 24 h to day 14 (the Mo concentration before the second administration), below the pre-exposure concentration. The next phase was linear, less abrupt and practically flat, but with an increasing trend towards the end of the experiment. Significantly higher Mo concentrations in MoS 2 -NPs and MoS 2 -MPs was found in the lungs of repeatedly exposed rats compared to those exposed to a single dose. The analysis of Mo content in the liver and the spleen tissue showed a slightly higher concentration for MoS 2 -NPs compared to MoS 2 -MPs. The results for the brain were below the calculated detection limit. Results were consistent with results obtained by bioimaging technique., Competing Interests: Conflict of interestThe authors declared no conflict of interest., (© The Author(s) 2023.)

Objectives: 1-Methylnaphthalene (1-MN) is composed of 2 benzene rings and belongs to polycyclic aromatic hydrocarbons. The metabolism of 1-MN in laboratory animals and bacteria leads to the formation of 1-naphthoic acid (1-NA)., Material and Methods: In this study the distribution of 1-NA in lung, liver, spleen, kidney and urinary excretion of 1-NA in rats after single and repeated inhalation exposure to 1-MN vapors were investigated. The activity of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and cytochrome were measured of the rats. Genotoxic effects were evaluated with the in vitro micronucleus test on V79 hamster fibroblasts., Results: The concentrations of 1-NA in the tissues of rats after single and repeated exposure to 1-MN were dependent on the exposure dose. High levels of 1-NA were found in kidneys of animals after the single and repeated exposure to 1-MN. With an increase of 1-MN dose, an increase in the activity of cytochrome P450 (CYP1A1 and CYP1A2) was observed in the liver of rats. Compared to control animals, significantly higher ALT activity was noted in serum of rats exposed to 1-MN. The micronuclei frequency in V79 cells exposed to 1-MN (in the range of analyzable concentrations; i.e., 5-25 μg/ml) did not differ significantly from the vehicle control, whereas urine extracts from rats exposed to 1-MN induced a significant increase in the frequency of micronuclei compared to urine extracts from the group of control animals., Conclusions: Metabolism of 1-MN in rats after the inhalation exposure leading to 1-NA was mainly observed during the first day after the end of exposure. It is likely that 1-MN metabolites present in rat urine can induce the increased micronuclei frequency as was shown in V79 cells. Int J Occup Med Environ Health. 2022;35(6):731-46., (This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.)

The aim of this study was to assess whether silver nanoparticles (AgNP) or selected cosmetic ingredients may modify functions of various immunocompetent cell populations. To this end, the effect of two AgNP (size of 15 nm or 45 nm), alone and in combination with aluminium chloride, butyl paraben, di-n-butyl phthalate or diethyl phthalate was assessed on: (1) migration and invasion of MDA-MB-231 human breast cancer cells; (2) M1/M2 polarization of phorbol 12-myristate 13-acetate (PMA)-differentiated THP-1 macrophages (M0) and (3) activation/maturation of monocyte-derived dendritic cells (DCs). The results of this study showed that neither any of the test chemicals alone nor the mixtures significantly changed the migration or invasion ability of MDA-MB-231 cells following, both 72-h and 21-day exposure. Analysis of the expression of marker genes for both M1 (IL-1B, CXCL9, TNF) and M2 (DCSIGN, MRC1) polarization revealed that the chemicals/mixtures did not activate M1/M2 differentiation of the M0 macrophages. In addition, no significant changes were observed in the expression of CD86, HLA-DR and CD54 surface markers and phagocytic activity of DCs following 48-h exposure to AgNP alone or in combination with test compounds. Our study suggests that AgNP alone or in combination with tested cosmetic ingredients do not alter function of immunocompetent cells studied., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Objectives: Welding processes that generate fumes containing toxic metals, such as hexavalent chromium (Cr(VI)), manganese, and nickel (Ni), have been implicated in lung injury, inflammation, and lung tumor promotion in animal models. Bronchiolar epithelium Clara cells/club cells, coordinate these inflammatory responses. Clara cells secretory protein (CC16) with ant-inflammatory role., Material and Methods: The pulmonary toxicity of welding dust (WD) was assessed for Wistar rats exposed to 60 mg/m 3 of respirable-size welding dust (mean diameter 1.17 μm for 1 and 2 weeks (6 h/day, 5 days/week)) or the aerosols of soluble form (SWD) in the nose-only exposure chambers. Additionally the effect of antiinflammatory betaine supplementation was assessed. Clara cells secretory protein, differential cell counts, total protein concentrations and cellular enzyme (lactate dehydrogenase - LDH) activities were determined in bronchoalveolar lavage fluid, and corticosterone and thiobarbituric acid reactive substances (TBARS) and prolactin concentrations were assessed in serum. Histopathology examination of lung, brain, liver, kidney, spleen was done. Additionally slices of brain and lung were exanimated in laser ablation inductively coupled plasma mass spectrometry., Results: Both WD and SWD exposure evoked large bronchiolar infiltration shoved in histopathology examination. In this study, TBARS inversely correlated with a significant decrease of CC16 concentration that occurred after instillation of both WD and SWD indicating decreased anti- inflammatory potential in the lung. In WD exposed rats prolactin correlated with nuclear factor-kappa B (NF-κB), LDH, TBARS and serum levels Cr, Ni and inversely with c-Jun. In SWD exposed rats prolactin correlated with CC16 indicated effect of prolactin on the population of epithelial cells., Conclusions: In the current study, deleterious effects of repeated inhalation stainless steel welding dust form on club (Clara) cell secretory protein (CC16) were demonstrated. Clara cells secretory protein relation with prolactin in exposed rats to welding dust were shown and explored whether the NF-κB and c-Jun/activator protein 1 related pathway was involved. Int J Occup Med Environ Health 2018;31(5):613-632., (This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.)

Hexachloronaphthalenes (HxCNs) are the most toxic congeners of polychlorinated naphthalenes, a group of compounds lately included into the list of persistent organic pollutants (POPs). This study presents the effects of 90-day intragastric administration of HxCN to female Wistar rats at doses of 0.03, 0.1, and 0.3 mg/kg body weight. The study examined selected parameters of the heme synthesis pathway, oxidative stress, hepatic cytochromes level, and basic hematology indicators. A micronucleus test was also performed. The subchronic exposure of rats to HxCN resulted in disruption of heme biosynthesis, hematological disturbances, and hepatotoxicity. The highest dose of HxCN inhibited aminolevulinic acid dehydratase (ALA-D) and uroporphyrinogen decarboxylase (URO-D). Accumulation of higher carboxylated porphyrins in the liver and increased excretion of 5-aminolevulinic acid in the urine was observed after a dose of 0.1 mg/kg body weight. The most sensitive effect of HxCN in rats was very strong induction of hepatic CYP1A1 activity, which was observed after the lowest dose. The highest dose of HxCN induced significant thrombocytopenia, thymic atrophy and hepatotoxicity, expressed as hepatomegaly and hepatic steatosis., (© 2018 Wiley Periodicals, Inc.)

In this study the effect of silver nanoparticles (AgNPs) on proliferation of estrogen receptor (ER)-positive human breast cancer MCF-7/BUS cells was assessed by means of in vitro assay. The cells were exposed in the absence of estrogens to AgNPs alone or in combination with aluminum chloride (AlCl 3 ), butyl paraben (BPB) and di-n-butyl phthalate (DBPh). The results revealed that AgNPs at the non-cytotoxic concentrations (up to 2μg/mL) and AlCl 3 (up to 500μM) did not induce proliferation of MCF-7/BUS cells whereas BPB and DBPh showed strong estrogenic activity with the highest effect at 16μM and 35μM, respectively. AgNPs inhibited the proliferation of the cells induced by DBPh, BPB or even with 17β-estradiol (E2) during 6-day incubation in the absence of estrogens. ICI 182,780 (10nM), a known estrogen receptor (ER) antagonist, induced strong inhibitory effect. AgNPs also decreased transcription of the estrogen-responsive pS2 and progesterone receptor (PGR) genes but modulated expression neither of ERα nor ERβ in MCF-7/BUS cells exposed to BPB, DBPh or E2 for 6h. Our results indicate that AgNPs may inhibit growth of breast cancer cells stimulated by E2 or estrogenic chemicals, i.e. BPB and DBPh., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Some reports indicate that the silver released from dermally applied products containing silver nanoparticles (AgNP) (e.g. wound dressings or cosmetics) can penetrate the skin, particularly if damaged. AgNP were also shown to have cytotoxic and genotoxic activity. In the present study percutaneous absorption of AgNP of two different nominal sizes (Ag15nm or Ag45nm by STEM) and surface modification, i.e. citrate or PEG stabilized nanoparticles, in combination with cosmetic ingredients, i.e. aluminum chloride (AlCl 3 ), methyl paraben (MPB), or di-n-butyl phthalate (DBPH) was assessed using in vitro model based on dermatomed pig skin. The inductively coupled plasma mass spectrometry (ICP-MS) measurements after 24h in receptor fluid indicated low, but detectable silver absorption and no statistically significant differences in the penetration between the 4 types of AgNP studied at 47, 470 or 750μg/ml. Similarly, no significant differences were observed for silver penetration when the AgNP were used in combinations with AlCl 3 (500μM), MPB (1250μM) or DBPH (35μM). The measured highest amount of Ag that penetrated was 0.45ng/cm 2 (0.365-0.974ng/cm 2 ) for PEG stabilized Ag15nm+MPB., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Objectives: The objective of the study was to assess prenatal toxicity of N-methylaniline (NMA) administered by gavage to pregnant female rats., Material and Methods: Pregnant female rats were administered N-methylaniline in corn oil by gavage at daily doses of 0.8 mg/kg of body weight (b.w.), 4 mg/kg b.w., 20 mg/kg b.w. and 100 mg/kg b.w. from implantation (the 5th day post mating) to the day prior to the scheduled caesarean section (the 20th day of pregnancy). General behavior, body weight, food and water consumption, hematological, biochemical analyses and pathomorphological changes of the dams were recorded., Results: All the females survived until the end of the study. The test substance was toxic to pregnant females, even at the lowest of the used doses, i.e., 0.8 mg/kg b.w./day. Lower weight gain during pregnancy and significantly higher NMA-dose-dependent absolute weight of the organs were noted in the exposed females. The females from the groups exposed at doses of 20 mg/kg b.w./day and 100 mg/kg b.w./day developed anemia and showed higher concentrations of free thyroxine (FT3) and free triiodothyronine (FT4) thyroid hormones. Total protein concentration exhibited an increase in all the exposed groups of females. In the prenatal toxicity study, administration of N-methylaniline throughout the embryonic and fetal periods produced embryotoxic effects at doses ranging 4-100 mg/kg b.w./day., Conclusions: Considering the data obtained in this study, it is reasonable to assume that N-methylaniline administered orally to pregnant rats is toxic for mothers even at a low dose of 0.8 mg/kg b.w./day. However, this dose was not associated with any significant effects to their offspring. This prenatal exposure level may be considered as no-observed-adverse-effect level (NOAEL) for the progeny and a dose of 4 mg/kg b.w./day as the lowest-observed-adverse-effect level (LOAEL) for the progeny., (This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.)