-
Journal of Toxicology 2023The results of safety studies performed with Elixinol Hemp Extract, a blend of hemp extract, cannabidiol (CBD) isolate, and copaiba containing approximately 65% total...
The results of safety studies performed with Elixinol Hemp Extract, a blend of hemp extract, cannabidiol (CBD) isolate, and copaiba containing approximately 65% total CBD, are described in this paper. In a 15-day range-finding study in rats, there were no effects of treatment with up to 101.4 mg/kg bw/day of the extract by gavage on any safety parameter measured in the study, with the exception that centrilobular hepatocellular hypertrophy occurred in all treatment groups, which correlated with increases in absolute liver weight in high-dose females and liver to terminal body weight ratio in mid-dose and high-dose females. A GLP-compliant 90-day OECD Guideline 408 study in rats that included a behavioral battery and a 28-day recovery phase was also conducted with Elixinol Hemp Extract administered by gavage. The doses used in the 90-day study were 0 (vehicle), 28.94, 50.64, and 86.81 mg/kg bw/day. The findings were similar to those observed in the range-finding study. There were no effects of the test material on any test parameter in the 90-day study other than findings related to the liver (increased liver weight in high-dose main study males and mid-dose and high-dose main study females and low incidences of hepatocellular hypertrophy and vacuolation in main study high-dose males). Similar findings were not observed in the recovery animals, and there were no alterations in the clinical chemistry suggestive of liver toxicity in any of the main study or recovery animals. Therefore, the liver outcomes observed in the main study were not considered adverse. The test material also tested negative for mutagenicity in bacterial reverse mutation assays (plate incorporation and preincubation) in the absence and presence of metabolic activation. The results indicate that the oral 90-day no observed adverse effect level (NOAEL) of Elixinol Hemp Extract in rats is 86.81 mg/kg bw/day (highest dose administered), and that the extract is not mutagenic.
PubMed: 38111631
DOI: 10.1155/2023/5982883 -
Toxicology Jan 2024DNA damage plays a pivotal role in carcinogenesis and other diseases. The comet assay has been used for more than three decades to measure DNA damages. The 1-2...
Further development of CometChip technology to measure DNA damage in vitro and in vivo: Comparison with the 2 gels/slide format of the standard and enzyme-modified comet assay.
DNA damage plays a pivotal role in carcinogenesis and other diseases. The comet assay has been used for more than three decades to measure DNA damages. The 1-2 gels/slide format is the most used version of the assay. In 2010, a high throughput 96 macrowell format with a spatially encoded array of microwells patterned in agarose was developed, called the CometChip. The commercial version (CometChip®) has been used for the in vitro standard version of the comet assay (following the manufacturer's protocol), although it has not been compared directly with the 2 gels/slide format. The aim of this work is to developed new protocols to allow use of DNA repair enzymes as well as the analysis of in vivo frozen tissue samples in the CometChip®, to increase the throughput, and to compare its performance with the classic 2 gels/slide format. We adapted the manufacturer's protocol to allow the use of snap frozen tissue samples, using male Wistar rats orally dosed with methyl methanesulfonate (MMS, 200 mg/kg b.w.), and to detect altered nucleobases using DNA repair enzymes, with TK6 cells treated with potassium bromate (KBrO, 0-4 mM, 3 h) and formamidopyrimidine DNA glycosylase (Fpg) as the enzyme. Regarding the standard version of the comet, we performed thee comparison of the 2 gel/slide and CometChip® format (using the the manufacturer's protocol), using TK6 cells with MMS (100-800 µM, 1 h) and hydrogen peroxide (HO 7.7-122.5 µM, 5 min) as testing compounds. In all cases the CometChip® was performed along with the 2 gels/slide format. Results obtained were comparable and the CometChip® is a good alternative to the 2 gels/slide format when a higher throughput is required.
Topics: Male; Animals; Rats; Comet Assay; Rats, Wistar; DNA Damage; DNA Repair Enzymes; Gels
PubMed: 38040084
DOI: 10.1016/j.tox.2023.153690 -
Environmental Toxicology and... Jan 2024The present study was aimed at investigating DNA damage, micronuclei frequency and meta-nuclear alterations in buccal cells of workers involved in pigment-grade TiO...
The present study was aimed at investigating DNA damage, micronuclei frequency and meta-nuclear alterations in buccal cells of workers involved in pigment-grade TiO production (15 exposed and 20 not-exposed). We also assessed associations of genotoxicity biomarkers with oxidative stress/inflammatory biomarkers in urine and exhaled breath condensate (EBC), as well as possible associations between biomarkers and reported respiratory symptoms. In spite of compliance with TiO Occupational Exposure Limits, results showed increased direct/oxidative DNA damage and micronuclei frequency in exposed workers. Genotoxicity parameters were associated with oxidative stress/inflammation biomarkers in urine and EBC, thus confirming that TiO exposure can affect the oxidative balance. Workers with higher genotoxic/oxidative stress biomarkers levels reported early respiratory symptoms suggesting that molecular alterations can be predictive of early health dysfunctions. These findings suggest the need to assess early health impairment in health surveillance programs and to address properly safety issues in workplaces where TiO is handled.
Topics: Humans; Mouth Mucosa; Oxidative Stress; Biomarkers; Occupational Exposure; Titanium; Inflammation; DNA Damage; Micronucleus Tests; Comet Assay
PubMed: 38013010
DOI: 10.1016/j.etap.2023.104328 -
Scientific Reports Nov 2023Aniline (CHNH) an important intermediate in the organic and fine chemical industry, is ubiquitously used worldwide. It is one of the important building block for...
Aniline (CHNH) an important intermediate in the organic and fine chemical industry, is ubiquitously used worldwide. It is one of the important building block for manufacturing of 4,4-methylene diphenyl diisocyanate (MDI), accelerators in rubber processing, dyes, tattoo inks, photographic chemicals, antioxidants, corrosion inhibitors, pharmaceuticals and antiseptics. The current study evaluated 96 h LC of aniline and based on this, two sublethal concentrations (4.19 mg/l and 8.39 mg/l) were selected for acute exposure studies in freshwater food fish Channa punctatus. Erythrocytes of fish are nucleated hence they play an important role in physiology, immune system, protein signalling and haemostatic condition along with respiration. Blood samples were collected after 24, 48, 72, and 96 h of exposure to study haematological, cytotoxic and genotoxic effects of sublethal concentrations of aniline in C. punctatus. Symbolic elevation in time and dose dependent DNA damage was observed by comet assay as well as micronuclei assay revealing maximum damage after 96 h of exposure. After aniline exposure, scanning electron microscopy and ATR-FTIR studies showed anomalies in structure and alterations in biomolecules of RBCs of aniline exposed group as compared to control group respectively. Semi prep HPLC studies revealed bioaccumulation potential of aniline in higher concentration exposed group.
Topics: Animals; Spectroscopy, Fourier Transform Infrared; DNA Damage; Comet Assay; Fishes; Blood Cells; Aniline Compounds; Water Pollutants, Chemical
PubMed: 38007596
DOI: 10.1038/s41598-023-48151-z -
Genes and Environment : the Official... Nov 2023tert-Butyl hydroperoxide (TBHP; CAS 75-91-2), a hydroperoxide, is mainly used as a polymerization initiator to produce polyethylene, polyvinyl chloride, and unsaturated...
BACKGROUND
tert-Butyl hydroperoxide (TBHP; CAS 75-91-2), a hydroperoxide, is mainly used as a polymerization initiator to produce polyethylene, polyvinyl chloride, and unsaturated polyester. It is a high-production chemical, widely used in industrial countries, including Japan. TBHP is also used as an additive for the manufacturing of food utensils, containers, and packaging (UCP). Therefore, there could be consumer exposure through oral intake of TBHP eluted from UCPs. TBHP was investigated in various in vitro and in vivo genotoxicity assays. In Ames tests, some positive results were reported with and/or without metabolic activation. As for the mouse lymphoma assay, the positive result was reported, regardless of the presence or absence of metabolic activation enzymes. The results of some chromosomal aberrations test and comet assay in vitro also demonstrated the genotoxic positive results. On the other hand, in in vivo tests, there are negative results in the bone marrow micronucleus test of TBHP-administered mice by single intravenous injection and the bone marrow chromosomal aberration test using rats exposed to TBHP for 5 days by inhalation. Also, about dominant lethal tests, the genotoxic positive results appeared. In contrast, there is little information about in vivo mutagenicity and no information about carcinogenicity by oral exposure.
RESULTS
We conducted in vivo gene mutation assay using MutaMice according to the OECD Guidelines for the Testing of Chemicals No. 488 to investigate in vivo mutagenicity of TBHP through oral exposure. After repeated dosing for 28 days, there were no significant differences in the mutant frequencies (MFs) of the liver and glandular stomach up to 300 mg/kg/day (close to the maximum tolerable dose (MTD)). The positive and negative controls produced the expected responses.
CONCLUSIONS
These findings show that orally administrated TBHP is not mutagenic in the mouse liver and glandular stomach under these experimental conditions.
PubMed: 37990244
DOI: 10.1186/s41021-023-00285-2 -
Revista Da Associacao Medica Brasileira... 2023The objective of this study was to evaluate cytogenetic changes in individuals submitted to oral human immunodeficiency virus pre-exposure prophylaxis use through the... (Randomized Controlled Trial)
Randomized Controlled Trial
OBJECTIVE
The objective of this study was to evaluate cytogenetic changes in individuals submitted to oral human immunodeficiency virus pre-exposure prophylaxis use through the micronucleus test in oral mucosa.
METHODS
This study consisted of 37 individuals, of whom 17 comprised the pre-exposure prophylaxis group and 20 comprised the control group. A total of 2,000 cells per slide were analyzed for the determination of micronuclei, binucleation, nuclear buds, and cytotoxicity parameters: pyknosis, karyolysis, and karyorrhexis (KR), in a double-blind manner. The repair index was also evaluated in this setting.
RESULTS
In the mutagenicity parameters, the pre-exposure prophylaxis group showed increased frequencies of micronuclei (p=0.0001), binucleation (p=0.001), and nuclear buds (p=0.07). Regarding the cytotoxicity parameters, there was an increase with a statistical difference (p≤0.05) in the karyorrhexis frequency (p=0.001). Additionally, the repair system efficiency decreased in the pre-exposure prophylaxis group.
CONCLUSION
These results indicate that individuals undergoing pre-exposure prophylaxis use have geno- and cytotoxicity in oral mucosal cells.
Topics: Humans; Micronuclei, Chromosome-Defective; HIV; Mouth Mucosa; Pre-Exposure Prophylaxis; Cytogenetic Analysis; DNA Damage
PubMed: 37971137
DOI: 10.1590/1806-9282.20230961 -
Brazilian Oral Research 2023The aim of this systematic review was to evaluate published papers regarding the micronucleus assay in oral mucosal cells of patients undergoing orthodontic therapy... (Meta-Analysis)
Meta-Analysis
The aim of this systematic review was to evaluate published papers regarding the micronucleus assay in oral mucosal cells of patients undergoing orthodontic therapy (OT). A search of the scientific literature was made in the PubMed, Scopus, and Web of Science databases for all data published until November, 2021 using the combination of the following keywords: "fixed orthodontic therapy," "genetic damage", "DNA damage," "genotoxicity", "mutagenicity", "buccal cells", "oral mucosa cells," and "micronucleus assay". The systematic review was designed according to the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines. Nine studies were retrieved. Some authors demonstrated that OT induces cytogenetic damage in oral mucosal cells. Out of the nine studies included, two were classified as strong, five as moderate, and two as weak, according to the quality assessment components of the Effective Public Health Practice Project (EPHPP). Meta-analysis data revealed no relationship between mutagenicity in oral cells and OT in different months of treatment. At one month, the SMD = 0.65 and p = 0.08; after three months of OT, the SMD = 1.21 and p = 0.07; and after six months of OT, the SMD = 0.56 and p = 0.11. In the analyzed months of OT, I2 values were >75%, indicating high heterogeneity. In summary, this review was not able to demonstrate that OT induces genetic damage in oral cells. The study is important for the protection of patients undergoing fixed OT, given that mutagenesis participates in the multi-step process of carcinogenesis.
Topics: Humans; Micronucleus Tests; DNA Damage; Mouth Mucosa
PubMed: 37970936
DOI: 10.1590/1807-3107bor-2023.vol37.0116 -
Journal of Toxicology 2023The present work was carried out to investigate the toxic effects of Activated Curcumin C3 Complex (AC®) through the methods of acute, subacute, subchronic,...
The present work was carried out to investigate the toxic effects of Activated Curcumin C3 Complex (AC®) through the methods of acute, subacute, subchronic, reproductive/developmental toxicity, and genotoxicity when administered orally in experimental rodents. The studies were carried out in line with OECD principles of good laboratory practice. A single-dose acute oral toxicity study was conducted on female Wistar rats that produced no toxic effects after 14 days (the observation period) of treatment. Subacute, subchronic, and reproductive/developmental studies were conducted in Wistar rats, divided equally into vehicle control, 125, 250, and 500 mg/kg dose groups along with recovery groups for vehicle control and high dose. In all the studies, there were no abnormal clinical signs/behavioral changes, reproductive and developmental parameters, or gross and histopathological changes. Likewise, no alteration was found in the body weight, hematology, and other biochemical parameters. Also, it did not show mutagenicity in the AMES test or clastogenicity and aneugenicity in the micronucleus test, indicating that AC® did not induce any genotoxic effects. This revealed that oral administration of AC® is safe in rodents, nonmutagenic, and had no observed adverse effects under experimental conditions.
PubMed: 37941801
DOI: 10.1155/2023/3729399 -
Toxicology Nov 20231,4-Anhydro-4-seleno-D-talitol (SeTal) is a highly water-soluble selenosugar with interesting antioxidant and skin-tissue-repair properties; it is highly stable in...
1,4-Anhydro-4-seleno-D-talitol (SeTal) is a highly water-soluble selenosugar with interesting antioxidant and skin-tissue-repair properties; it is highly stable in simulated gastric and gastrointestinal fluids and is a potential pharmaceutical ingredient that may be administered orally. Hepatic toxicity is often a major problem with novel drugs and can result in drug withdrawal from the market. Predicting hepatotoxicity is therefore essential to minimize late failure in the drug-discovery process. Herein, we report in vitro studies to evaluate the cytotoxic and genotoxic potential of SeTal in HepG2 and hepatocyte-like differentiated HepaRG cells. Except for extremely high concentrations (10 mM, 68 h-treatment in HepG2), SeTal did not affect the viability of each cell type. While the highest examined concentrations (0.75 and 1 mM in HepG2; 1 mM in HepaRG) were observed to induce primary DNA damage, SeTal did not exhibit clastogenic or aneugenic activity toward either HepG2 or HepaRG cells. Moreover, no significant cytostasis variations were observed in any experiment. The clearly negative results observed in the CBMN test suggest that SeTal might be used as a potential active pharmaceutical ingredient. The present study will be useful for the selection of non-toxic concentrations of SeTal in future investigations.
Topics: Humans; Liver; Hexoses; DNA Damage; Hep G2 Cells; Pharmaceutical Preparations; Micronucleus Tests; Comet Assay
PubMed: 37924933
DOI: 10.1016/j.tox.2023.153663 -
Scientific Reports Nov 2023Neutral comet assay has been available for two decades to evaluate sperm double-strand breaks (DSBs). However, its clinical usability is limited due to its complex and...
Neutral comet assay has been available for two decades to evaluate sperm double-strand breaks (DSBs). However, its clinical usability is limited due to its complex and time-consuming procedure, as well as the lack of a standardized scoring system. The aim of this study was to: develop a rapid diagnostic method for DSBs, Sperm DNA Fragmentation Releasing Assay (SDFR), and explore the association between DSBs and reproductive outcomes. We pioneered the use of polyacrylamide (PA) for embedding sperm chromatin and optimized the porosity of PA to be between 10 and 13%. The refined PA network allowed the trapping of DSBs, which dispersed halo on an immunological slide; in contrast, intact chromatin failed to develop a halo. A strong correlation was showed between reproducible values obtained from SDFR and neutral comet assay. SDFR were responsive to dose-/time-dependent simulated DSBs, indicating high sensitivity and specificity. Furthermore, we conducted a retrospective study of couples with embryonic aneuploidy screening, and recording DSB profiles of the male partners. Our findings revealed that DSB enabled to predict embryonic aneuploidy whereas basic semen parameters did not. In conclusion, SDFR offers a rapid and user-friendly approach for evaluating DSBs, with potential implications for predictive healthcare in reproductive medicine.
Topics: Male; Humans; DNA Breaks, Double-Stranded; Semen; Retrospective Studies; Infertility, Male; Spermatozoa; Comet Assay; DNA Fragmentation; Chromatin; Aneuploidy; DNA
PubMed: 37923811
DOI: 10.1038/s41598-023-46049-4