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Mutation Research 2024Environmental and occupational exposure to polycyclic aromatic hydrocarbons (PAHs) is associated with adverse health effects in humans. Uncertainty exists regarding the...
Environmental and occupational exposure to polycyclic aromatic hydrocarbons (PAHs) is associated with adverse health effects in humans. Uncertainty exists regarding the causation of urinary bladder cancer by benzo[a]pyrene (B[a]P) due to a lack of sufficient data. In this work, we focused on in-vitro DNA damage and the formation of micronuclei and chromosomal aberrations as predictors of cancer risk, applying a wide range of dosages and time periods to quantify the onset, intensity, and duration of the response. We chose two urothelial cell types to compare susceptibility and the ability to increase the malignity of a pre-existing bladder cancer: a cancer cell line (T24) and a pooled sample of primary urinary bladder epithelia cells (PUBEC) from pigs. The highest level of DNA damage assessed by comet assay was observed following 24-h treatment in both cell types, whereas PUBEC cells were clearly more susceptible. Even 4-h treatment induced DNA damage in PUBEC cells with benchmark doses of 0.0027 µM B[a]P and 0.00023 µM after 4-h and 24-h exposure, respectively. Nearly no effect was observed for periods of 48 h. The frequency of micronucleus formation increased more markedly in T24 cells, particularly with 24-h treatment. In PUBEC cells, 48-h exposure notably induced the formation of nucleoplasmic bridges and nuclear buds. Even though only one biological replicate was studied due to the sophisticated study design, our results give a strong indication of the potential of B[a]P to induce and increase malignity in human-relevant cell types.
Topics: Benzo(a)pyrene; DNA Damage; Pilot Projects; Animals; Urothelium; Chromosomal Instability; Humans; Swine; Micronucleus Tests; Dose-Response Relationship, Drug; Chromosome Aberrations; Urinary Bladder Neoplasms; Time Factors; Comet Assay; Cell Line, Tumor; Urinary Bladder
PubMed: 38569440
DOI: 10.1016/j.mrfmmm.2024.111855 -
Molecules (Basel, Switzerland) Mar 2024Ipê is a plant of the Bignoniaceae family. Among the compounds extracted from this tree, lapachol is notable because its structural modification allows the production...
Ipê is a plant of the Bignoniaceae family. Among the compounds extracted from this tree, lapachol is notable because its structural modification allows the production of β-lapachone, which has anticancer properties. The objective of this work was to test this hypothesis at a cellular level in vitro and assess its potential safety for use. The following tests were performed: MTT cell viability assay, apoptotic index determination, comet assay, and micronucleus test. The results showed that β-lapachone had a high cytotoxic capacity for all cell lines tested: ACP02 (gastric adenocarcinoma cells), MCF7 (breast carcinoma cells), HCT116 (colon cancer cells) and HEPG2 (hepatocellular carcinoma cells). Regarding genotoxicity, the exposure of cells to sublethal doses of β-lapachone induced DNA damage (assessed by the comet assay) and nuclear abnormalities, such as nucleoplasmic bridges and nuclear buds (assessed by the micronucleus test). All tested cell lines responded similarly to β-lapachone, except for ACP02 cells, which were relatively resistant to the cytotoxic effects of the compound in the MTT test. Our results collectively indicate that although β-lapachone showed antiproliferative activity against cancer cell lines, it also caused harmful effects in these cells, suggesting that the use of β-lapachone in treating cancer should be carried out with caution.
Topics: Humans; Apoptosis; Naphthoquinones; Antineoplastic Agents; DNA Damage; Colonic Neoplasms
PubMed: 38543031
DOI: 10.3390/molecules29061395 -
Ecotoxicology and Environmental Safety Apr 2024A risk assessment on the aquatic toxicity of the plant biostimulant strigolactone mimic (2-(4-methyl-5-oxo-2,5-dihydro-furan-2-yloxy)-benzo[de]isoquinoline-1,3-dione...
A risk assessment on the aquatic toxicity of the plant biostimulant strigolactone mimic (2-(4-methyl-5-oxo-2,5-dihydro-furan-2-yloxy)-benzo[de]isoquinoline-1,3-dione (SL-6) was performed using a suite of standardised bioassays representing different trophic groups and acute and chronic endpoints. In freshwater, three trophic groups of algae, crustacea and fish were used. Whilst in seawater, algae (unicellular and macroalgae), Crustacea and Mollusca were employed. In addition, the genotoxicity of SL-6 was determined with the comet assessment performed on unicellular marine algae, oysters, and fish embryos. This was the first time ecotoxicity tests have been performed on SL-6. In freshwater, the lowest LOEC was measured in the unicellular algae at 0.31 mg/L SL-6. Although, similar LOEC values were found for embryo malformations and impacts on hatching rate in zebrafish (LOEC 0.31-0.33 mg/L). Consistent malformations of pericardial and yolk sac oedemas were identified in the zebrafish embryos at 0.31 mg/L. In marine species, the lowest LOEC was found for both Tisbe battagliai mortality and microalgae growth at an SL-6 concentration of 1.0 mg/L. Significant genotoxicity was observed above control levels at 0.0031 mg/L SL-6 in the unicellular algae and 0.001 mg/L SL-6 in the oyster and zebrafish larvae. When applying the simple risk assessment, based on the lowest NOECs and appropriate assessment factors, the calculated predicted no effect concentration (PNEC), for the ecotoxicity and the genotoxicity tests were 1.0 µg/L and 0.01 µg/L respectively.
Topics: Animals; Zebrafish; Larva; Crustacea; Mutagenicity Tests; Water Pollutants, Chemical; Heterocyclic Compounds, 3-Ring; Lactones
PubMed: 38537480
DOI: 10.1016/j.ecoenv.2024.116244 -
Journal of Xenobiotics Dec 2023Triclosan and Triclocarban, preservatives widely used in cosmetics and other consumer products, underwent evaluation using a battery of new-approach methodologies in...
Triclosan and Triclocarban, preservatives widely used in cosmetics and other consumer products, underwent evaluation using a battery of new-approach methodologies in vitro (NAMs). Specifically, the Microplate Ames Test (MPF™ Test, Xenometrix, Allschwil, Switzerland) was employed to assess mutagenicity, the Comet assay in vitro on the HaCat cell line and the Mammalian Chromosome Aberration Test were utilized to evaluate genotoxicity, and the XenoScreen YES/YAS assay was applied to investigate endocrine disruption. The chemicals did not exhibit any positive responses for mutagenicity. However, the mammalian chromosome aberration test identified both chemicals as being positive for genotoxicity at 10 µg/mL. In the Comet assay, the percentage of DNA in the tail significantly increased in a concentration-dependent manner (at 5 and 10 µg/mL for Triclosan, at 2.5, 5, and 10 µg/mL for Triclocarban). The positive response depended on the increasing concentration and the duration of exposure. Triclosan, but not Triclocarban in any of the endocrine assays performed, indicated a potential for endocrine activity in the anti-estrogenic and anti-androgenic assays. The positive in vitro results detected were obtained for concentrations relevant to final products. The alarming findings obtained with the use of new-approach methodologies (NAMs) justify the current precautionary regulatory approach, limiting the use of these preservatives.
PubMed: 38535491
DOI: 10.3390/jox14010002 -
BMC Oral Health Mar 2024To analyze anti-MMP mode of action of Quaternary Ammonium Silane (QAS, codenamed as k21) by binding onto specific MMP site using computational molecular simulation and...
AIMS AND OBJECTIVES
To analyze anti-MMP mode of action of Quaternary Ammonium Silane (QAS, codenamed as k21) by binding onto specific MMP site using computational molecular simulation and Anti-Sortase A (SrtA) mode of action by binding onto specific site using computational molecular simulation.
MATERIALS AND METHODS
In silico Molecular Dynamics (MD) was used to determine the interactions of K21 inside the pocket of the targeted protein (crystal structure of fibroblast collagenase-1 complexed to a diphenyl-ether sulphone based hydroxamic acid; PDB ID: 966C; Crystal structure of MMP-2 active site mutant in complex with APP-derived decapeptide inhibitor. MD simulations were accomplished with the Desmond package in Schrödinger Drug Discovery Suite. Blood samples (~ 0.5 mL) collected into KEDTA were immediately transferred for further processing using the Litron MicroFlow® PLUS micronucleus analysis kit for mouse blood according to the manufacturer's instructions. Bacterial Reverse Mutation Test of K21 Molecule was performed to evaluate K21 and any possible metabolites for their potential to induce point mutations in amino acid-requiring strains of Escherichia coli (E. coli) (WP2 uvrA (tryptophan-deficient)).
RESULTS
Molecular Simulation depicted that K21 has a specific pocket binding on various MMPs and SrtA surfaces producing a classical clouting effect. K21 did not induce micronuclei, which are the result of chromosomal damage or damage to the mitotic apparatus, in the peripheral blood reticulocytes of male and female CD-1 mice when administered by oral gavage up to the maximum recommended dose of 2000 mg/kg. The test item, K21, was not mutagenic to Salmonella typhimurium (S. typhimurium) strains TA98, TA100, TA1535 and TA1537 and E. coli strain WP2 uvrA in the absence and presence of metabolic activation when tested up to the limit of cytotoxicity or solubility under the conditions of the test.
CONCLUSION
K21 could serve as a potent protease inhibitor maintaining the physical and biochemical properties of dental structures.
Topics: Mice; Male; Female; Animals; Mutagenicity Tests; Ammonium Compounds; Escherichia coli; Mutagens; Matrix Metalloproteinases
PubMed: 38528501
DOI: 10.1186/s12903-024-04069-0 -
Mutation Research. Reviews in Mutation... 2024Humans ingest particles and fibers on daily basis. Non-digestible carbohydrates are beneficial to health and food additives are considered safe. However, titanium... (Review)
Review
Humans ingest particles and fibers on daily basis. Non-digestible carbohydrates are beneficial to health and food additives are considered safe. However, titanium dioxide (E171) has been banned in the European Union because the European Food Safety Authority no longer considers it non-genotoxic. Ingestion of microplastics and nanoplastics are novel exposures; their potential hazardous effects to humans have been under the radar for many years. In this review, we have assessed the association between oral exposure to man-made particles/fibers and genotoxicity in gastrointestinal tract cells and secondary tissues. We identified a total of 137 studies on oral exposure to particles and fibers. This was reduced to 49 papers with sufficient quality and relevance, including exposures to asbestos, diesel exhaust particles, titanium dioxide, silver nanoparticles, zinc oxide, synthetic amorphous silica and certain other nanomaterials. Nineteen studies show positive results, 25 studies show null results, and 5 papers show equivocal results on genotoxicity. Recent studies seem to show null effects, whereas there is a higher proportion of positive genotoxicity results in early studies. Genotoxic effects seem to cluster in studies on diesel exhaust particles and titanium dioxide, whereas studies on silver nanoparticles, zinc oxide and synthetic amorphous silica seem to show mainly null effects. The most widely used genotoxic tests are the alkaline comet assay and micronucleus assay. There are relatively few results on genotoxicity using reliable measurements of oxidatively damaged DNA, DNA double strand breaks (γH2AX assay) and mutations. In general, evidence suggest that oral exposure to particles and fibers is associated with genotoxicity in animals.
Topics: DNA Damage; Animals; Gastrointestinal Tract; Humans; Titanium; Mutagenicity Tests
PubMed: 38522822
DOI: 10.1016/j.mrrev.2024.108491 -
Mutagenesis Apr 2024The current Organisation for Economic Co-Operation and Development test guideline number 487 (OECD TG No. 487) provides instruction on how to conduct the in vitro...
The current Organisation for Economic Co-Operation and Development test guideline number 487 (OECD TG No. 487) provides instruction on how to conduct the in vitro micronucleus assay. This assay is one of the gold standard approaches for measuring the mutagenicity of test items; however, it is directed at testing low molecular weight molecules and may not be appropriate for particulate materials (e.g. engineered nanoparticles [ENPs]). This study aimed to adapt the in vitro micronucleus assay for ENP testing and underpins the development of an OECD guidance document. A harmonized, nano-specific protocol was generated and evaluated by two independent laboratories. Cell lines utilized were human lymphoblastoid (TK6) cells, human liver hepatocytes (HepG2) cells, Chinese hamster lung fibroblast (V79) cells, whole blood, and buffy coat cells from healthy human volunteers. These cells were exposed to reference ENPs from the Joint Research Council (JRC): SiO2 (RLS-0102), Au5nm and Au30nm (RLS-03, RLS-010), CeO2 (NM212), and BaSO4 (NM220). Tungsten carbide-cobalt (WC/Co) was used as a trial particulate positive control. The chemical controls were positive in all cell cultures, but WC/Co was only positive in TK6 and buffy coat cells. In TK6 cells, mutagenicity was observed for SiO2- and both Au types. In HepG2 cells, Au5nm and SiO2 showed sub-two-fold increases in micronuclei. In V79 cells, whole blood, and buffy coat cells, no genotoxicity was detected with the test materials. The data confirmed that ENPs could be tested with the harmonized protocol, additionally, concordant data were observed across the two laboratories with V79 cells. WC/Co may be a suitable particulate positive control in the in vitro micronucleus assay when using TK6 and buffy coat cells. Detailed recommendations are therefore provided to adapt OECD TG No. 487 for testing ENP.
Topics: Micronucleus Tests; Humans; Animals; Nanostructures; Cricetinae; Cricetulus; Cell Line; Organisation for Economic Co-Operation and Development; Hep G2 Cells
PubMed: 38502821
DOI: 10.1093/mutage/geae010 -
Indian Journal of Pharmacology Jan 2024Cosmeceuticals are topically applied cosmetic products containing a biologically active ingredient with a pharmaceutical effect that improves, nourishes, and treats the... (Review)
Review
Cosmeceuticals are topically applied cosmetic products containing a biologically active ingredient with a pharmaceutical effect that improves, nourishes, and treats the skin appearance. The trend of cosmeceuticals began during the mid-20th century due to its potent ingredients with therapeutic effects for various skin ailments. Even though there is a great advancement in cosmetics, which shows the risk of cosmetic linked melanoma, endocrine disorders, and birth defects which was one in 1500 people during 1935 have increased to one in 75 people in 2000. Hence, as a part of reducing the harmful effect, natural ingredients were added to the formulation to give the pharmaceutical effect. Thus, natural/herbal cosmeceuticals were introduced. Due to the awareness of the side effects such as photo-toxicity, mutagenicity, irritation by these synthetic products, people started preferring herbal/natural cosmetic products. Moreover, natural cosmeceuticals were proven to be effective against various dermatological conditions as well as have fewer side effects marked the natural/herbal cosmeceuticals in the market. Unlike a drug, cosmeceutical products undergo safety, toxicity, and efficacy tests, but these are not classified under Food and Drug Administration. This review will give an insight into different natural ingredients used in natural/herbal cosmeceutical formulation and their function challenges faced during formulation, advantages of natural cosmeceuticals over regular cosmeceuticals, and regulatory aspects in India.
Topics: Humans; Cosmeceuticals; Cosmetics; Skin; Pharmaceutical Preparations; Pharmaceutical Vehicles; Biological Products
PubMed: 38454588
DOI: 10.4103/ijp.ijp_244_21 -
Environmental Research Jun 2024Several human studies indicate that mobile phone specific electromagnetic fields may cause cancer in humans but the underlying molecular mechanisms are currently not...
Mobile phone specific radiation disturbs cytokinesis and causes cell death but not acute chromosomal damage in buccal cells: Results of a controlled human intervention study.
Several human studies indicate that mobile phone specific electromagnetic fields may cause cancer in humans but the underlying molecular mechanisms are currently not known. Studies concerning chromosomal damage (which is causally related to cancer induction) are controversial and those addressing this issue in mobile phone users are based on the use of questionnaires to assess the exposure. We realized the first human intervention trial in which chromosomal damage and acute toxic effects were studied under controlled conditions. The participants were exposed via headsets at one randomly assigned side of the head to low and high doses of a UMTS signal (n = 20, to 0.1 W/kg and n = 21 to 1.6 W/kg Specific Absorption Rate) for 2 h on 5 consecutive days. Before and three weeks after the exposure, buccal cells were collected from both cheeks and micronuclei (MN, which are formed as a consequence of structural and numerical chromosomal aberrations) and other nuclear anomalies reflecting mitotic disturbance and acute cytotoxic effects were scored. We found no evidence for induction of MN and of nuclear buds which are caused by gene amplifications, but a significant increase of binucleated cells which are formed as a consequence of disturbed cell divisions, and of karyolitic cells, which are indicative for cell death. No such effects were seen in cells from the less exposed side. Our findings indicate that mobile phone specific high frequency electromagnetic fields do not cause acute chromosomal damage in oral mucosa cells under the present experimental conditions. However, we found clear evidence for disturbance of the cell cycle and cytotoxicity. These effects may play a causal role in the induction of adverse long term health effects in humans.
Topics: Humans; Cell Phone; Mouth Mucosa; Adult; Male; Cytokinesis; Cell Death; Young Adult; Female; Chromosome Aberrations; Micronucleus Tests; Electromagnetic Fields; Micronuclei, Chromosome-Defective
PubMed: 38452915
DOI: 10.1016/j.envres.2024.118634 -
International Archives of Occupational... May 2024Several studies investigated the link between agricultural occupational exposures and DNA damage, in an attempt to bring elements of biological plausibility to the...
OBJECTIVE
Several studies investigated the link between agricultural occupational exposures and DNA damage, in an attempt to bring elements of biological plausibility to the increased cancer risk associated with them. However, only a few of these studies focused on females.
METHODS
The comet assay was performed on PBMC (Peripheral Blood Mononuclear Cells) samples from 245 females working in open field farming and cattle raising, located in the Normandy area of France. Individual questionnaires on tasks performed were administered at the time of sampling to directly assess exposures. Environmental exposures were issued from a questionnaire assessing the farm productions. Linear regression analyses were done using the DNA damage scores.
RESULTS
Regarding direct exposures, several tasks associated with exposure to potentially harmful chemicals were not associated with DNA damage, but a longer duration of use of herbicide on meadows (p = 0.05) or of cleaning and upkeep of agricultural equipment (p = 0.06) revealed higher DNA damage levels, although the number of exposed women was low. Several indirect and/or environmental exposures were associated with DNA damage in multivariate analyses: a larger surface of meadows (p = 0.006) or the presence of poultry (p = 0.03) was associated with less DNA damage, while the presence of swine (p = 0.01) was associated with higher DNA damage. Smokers and former smokers had less DNA damage than non-smokers (p = 0.0008 and p = 0.03).
CONCLUSIONS
We report modified levels of DNA damage for those environmentally exposed to meadows, poultry and pig farming, underlining the need for a better knowledge of the potential health risks experienced by females in this setting.
Topics: Female; Humans; Animals; Cattle; Swine; Comet Assay; Leukocytes, Mononuclear; Farmers; DNA Damage; Occupational Exposure; Agriculture
PubMed: 38430240
DOI: 10.1007/s00420-024-02049-z