Peripheral Blood Micronucleus Research Articles

Correlation analysis of urinary arsenic species and health effect indicators of occupational arsenic exposure workers

Objective: To explore the correlation between urinary arsenic and health effects through the determination and analysis of urinary arsenic levels in occupational arsenic exposed workers. Methods: In November 2021, 95 workers exposed to arsenic and its inorganic compounds and 31 administrative personnel from a non-ferrous metal smelter in Yunnan Province were selected as the contact group and control group, respectively. Urine forms of arsenic, blood tumor markers, liver function were detected, and micronucleus test was used to analyze the chromosome damage. The correlation between urine forms of arsenic and health effects were analyzed. Results: Compared with the control group, the concentrations of urinary trivalent inorganic arsenic (iAs(3+)) , pentavalent inorganic arsenic (iAs(5+)) , inorganic arsenic (iAs=ΣiAs(3+)+iAs(5+)) , monomethyl arsenic (MMA) , dimethyl arsenic (DMA) and urinary arsenic (ΣiAs+MMA+DMA) at the end of class in contact group were higher (P<0.05) . There was no statistically significant difference in blood tumor markers and liver function indicators between the two groups (P>0.05) . Compared with the control group, the peripheral blood micronucleus rate and cell micronucleus rate in the contact group were significantly increased (P<0.05) . The urinary arsenic, iAs(5+), inorganic arsenic and DMA were positively correlated with peripheral blood micronucleus rate in contact group (r(s)=0.48, 0.34, 0.37, 0.23, P<0.05) , and the urinary arsenic, iAs(5+), DMA were positively correlated with peripheral blood micronucleus rate (r(s)=0.48, 0.34, 0.26, P<0.05) . Conclusion: There is a significant correlation between different valence states of arsenic in the urine and abnormal health effects of occupational arsenic exposed workers. It is necessary to strengthen the detection of arsenic species in the urine of occupational arsenic exposed workers to better protect their health.

N-Nitrosodimethylamine investigations in Muta™Mouse define point-of-departure values and demonstrate less-than-additive somatic mutant frequency accumulations.

The N-nitrosamine, N-nitrosodimethylamine (NDMA), is an environmental mutagen and rodent carcinogen. Small levels of NDMA have been identified as an impurity in some commonly used drugs, resulting in several product recalls. In this study, NDMA was evaluated in an OECD TG-488 compliant Muta™Mouse gene mutation assay (28-day oral dosing across seven daily doses of 0.02-4 mg/kg/day) using an integrated design that assessed mutation at the transgenic lacZ locus in various tissues and at the endogenous Pig-a gene-locus, along with micronucleus frequencies in peripheral blood. Liver pathology was determined together with NDMA exposure in blood and liver. The additivity of mutation induction was assessed by including two acute single-dose treatment groups (i.e. 5 and 10 mg/kg dose on Day 1), which represented the same total dose as two of the repeat dose treatment groups. NDMA did not induce statistically significant increases in mean lacZ mutant frequency (MF) in bone marrow, spleen, bladder, or stomach, nor in peripheral blood (Pig-a mutation or micronucleus induction) when tested up to 4 mg/kg/day. There were dose-dependent increases in mean lacZ MF in the liver, lung, and kidney following 28-day repeat dosing or in the liver and kidney after a single dose (10 mg/kg). No observed genotoxic effect levels (NOGEL) were determined for the positive repeat dose-response relationships. Mutagenicity did not exhibit simple additivity in the liver since there was a reduction in MF following NDMA repeat dosing compared with acute dosing for the same total dose. Benchmark dose modelling was used to estimate point of departure doses for NDMA mutagenicity in Muta™Mouse and rank order target organ tissue sensitivity (liver > kidney or lung). The BMD50 value for liver was 0.32 mg/kg/day following repeat dosing (confidence interval 0.21-0.46 mg/kg/day). In addition, liver toxicity was observed at doses of ≥ 1.1 mg/kg/day NDMA and correlated with systemic and target organ exposure. The integration of these results and their implications for risk assessment are discussed.

Toxicity Profile Study of Antihypertensive Drug Prazosin in Pregnant Wistar Rats

The purpose of this research is to investigate and assess the cytotoxicity and genotoxicity of Prazosin HCL in pregnant rats. Prazosin (PZ) was administered to the animals intraperitoneally (IP) at dosages of 5, 15, and 25 mg/kg/body weight for single dose (14-day) toxicity tests. The following parameters have been examined for evaluating genotoxicity: bone marrow micronucleus assay, peripheral blood micronucleus assay, DNA damage is measured using the metaphase chromosomal analysis, DNA damage is measured using the DNA fragmentation test, and cytotoxicity is measured using a histological analysis. The results obtained clearly demonstrate that PZ induced hazardous responses at the higher dose in the hepatocytes, as evidenced by DNA damage, and increased DNA fragmentation in pregnant rats. Observing that PZ significantly increased DNA strand breakage and structural chromosomal aberrations in bone marrow cell lines is also fascinating. As a result, it is thought to be genotoxic to bone marrow and mouse hepatocyte cells. The current study showed that Prazosin had significant genotoxic effects in pregnant rats at the matching hepatotoxic dose level.

Melphalan induced germ cell toxicity and dose-dependent effects of β-aminoisobutyric acid in experimental rat model: Role of oxidative stress, inflammation and apoptosis.

The success of chemotherapy regimens has led to an increase in cancer survival rate over the last decades. Melphalan has been widely used for the treatment of several types of cancers despite its gonadotoxic effects. Due to its ability to cause mutations in the spermatogonial stem cells and spermatids, melphalan can exert a negative impact on male reproductive health in young cancer survivors. β-aminoisobutyric acid (BAIBA), a myokine released by skeletal muscles, has been reported to have beneficial effects in diabetic nephropathy, cardiomyopathy and hepatic toxicity. However, the exact role of BAIBA in chemotherapy-induced germ cell toxicity is still unexplored. The present study aims to determine the dose-dependent (25, 50, and 100 mg/kg) effects of BAIBA on melphalan-induced (1.5 mg/kg) germ cell toxicity in sprague-dawley (SD) rats. The evaluation parameters included quantification of oxidative stress biomarkers, sperm count, sperm motility and head morphology, sperm and testicular DNA damage, sperm mitochondrial membrane potential, ultrastructural changes in sperms, histological and protein expression studies in testes. Melphalan treatment significantly altered all the above-mentioned parameters and the high dose (100 mg/kg) of BAIBA restored melphalan-induced toxicity in a significant manner by exerting antioxidant, anti-inflammatory and antiapoptotic effects. However, the medium dose (50 mg/kg) of BAIBA decreased the toxicity of melphalan and the low dose (25 mg/kg) of BAIBA failed to counteract the melphalan-induced male germ cell toxicity as well as the peripheral blood micronucleus induction. The antioxidant, anti-inflammatory and antiapoptotic role of BAIBA in melphalan-induced gonadal damage is a novel finding in an experimental rat model.

Bauhinia forficata Link, Antioxidant, Genoprotective, and Hypoglycemic Activity in a Murine Model.

Bauhinia forficata L. is a tree used in alternative medicine as an anti-diabetic agent, with little scientific information about its pharmacological properties. The hypoglycemic, antioxidant, and genoprotective activities of a methanolic extract of B. forficata leaves and stems combined were investigated in mice treated with streptozotocin (STZ). Secondary metabolites were determined by qualitative phytochemistry. In vitro antioxidant activity was determined by the DPPH method at four concentrations of the extract. The genoprotective activity was evaluated in 3 groups of mice: control, anthracene (10 mg/kg), and anthracene + B. forficata (500 mg/kg) and the presence of micronuclei in peripheral blood was measured for 2 weeks. To determine the hypoglycemic activity, the crude extract was prepared in a suspension and administered (500 mg/kg, i.g.) in previously diabetic mice with STZ (120 mg/kg, i.p.), measuring blood glucose levels every week as well as the animals' body weight for six weeks. The extract showed good antioxidant activity and caused a decrease in the number of micronuclei. The diabetic mice + B. forficata presented hypoglycemic effects in the third week of treatment, perhaps due to its secondary metabolites. Therefore, B. forficata is a candidate for continued use at the ethnomedical level as an adjuvant to allopathic therapy.

Juvenile exposure and adult risk assessment with single versus repeated exposure of melphalan in the germ cells of male SD rat: Deciphering the molecular mechanisms

Melphalan significantly contributes to the increase in childhood cancer survival rate. It acts as a gonadotoxic agent and leads to testes damage, dysbalance in gonadal hormones, and impairment in the germ cell proliferation. Therefore, it might be a potent threat to male fertility in individuals who have undergone melphalan treatment during childhood cancer. However, the molecular mechanisms of melphalan-induced gonadal damage are not yet fully explored and they need to be investigated to determine the benefit-risk profile. In the present study, juvenile male SD rats were subjected to single and intermittent cycles of melphalan exposure in a dose-dependent (0.375, 0.75 and 1.5 mg/kg) manner. Methods of end-points evaluations were quantification of micronuclei formation in peripheral blood, sperm count, sperm motility and head morphology, sperm and testicular DNA damage, histological studies in testes, oxidative/nitrosative stress parameters. A single cycle of exposure at high dose (1.5 mg/kg) produced significant effect on micronuclei formation only after the first week of exposure, whereas failed to produce significant effect at the end of the sixth week. Intermittent cycles of exposure at the dose of 1.5 mg/kg produced significant alterations in all the parameters (micronuclei in peripheral blood, testes and epididymides weight and length, MDA, GSH and nitrite levels, sperm count and motility, sperm head morphology, testicular and sperm DNA damage, protein expression in testes and histological parameters). So, time of exposure as well as the amount of exposure (total dosage administered) is critical in determining the magnitude of the damage in germ cell risk assessment.

Rate of detection of erythrocytes with micronuclei in peripheral blood of rabbits in spontaneous coccidiosis

Coccidiosis is the most common disease in rabbits, causing great economic damage in rabbit farming. The aim of this work was to study the effect of coccidia on the parameters of the micronucleus test, since the authors did not come across data on the study of the mutagenic effect of Eimeria metabolites on the chromosomal apparatus of somatic cells in rabbits in the literature. For the experiment, 4 groups of rabbits, 10 heads each, with high, medium, low intensity of invasion (II) by oocysts of coccidia and healthy animals were formed. In experimental and control rabbits, blood was taken from the marginal ear vein, smears were prepared and stained with Giemsa dye. To carry out the micronucleus test, microscopy of blood preparations was performed and the frequency of occurrence of erythrocytes with micronuclei was calculated. It was found that in rabbits with low IS, the frequency of occurrence of erythrocytes with micronuclei was 1.49 + 0.10, which was 1.6 times higher than that of the control group (p &lt;0.001). In the group of rabbits with medium IS, the frequency of appearance of erythrocytes with micronuclei was 2.3 times higher than in the control group (p &lt;0.001) and was 2.15 + 0.09. The frequency of occurrence of erythrocytes with micronuclei in the group with high IS exceeded the control indicator by 3.1 times and amounted to 2.88 + 0.13 ‰. According to the results of laboratory studies, it was found that the change in the frequency of occurrence of erythrocytes with micronuclei in the peripheral blood of rabbits depends on the degree of invasion by eimeria, thereby proving the mutagenic effect of eimeria metabolites on the chromosomal apparatus of the host somatic cells.

Safety Assessment of Lactiplantibacillus plantarum TWK10 Based on Whole-Genome Sequencing, Phenotypic, and Oral Toxicity Analysis.

Lactiplantibacillus plantarum TWK10 (TWK10), isolated from Taiwanese pickled cabbage, has been demonstrated to exert beneficial probiotic effects in both mice and humans. Here, we comprehensively assessed the safety of TWK10 using both in vivo and in vitro approaches, including whole-genome sequence analysis, an assessment of hemolytic activity, and performing an antimicrobial susceptibility test, the Ames bacterial reverse mutation assay, the chromosomal aberration test, a rodent peripheral blood micronucleus test, and the 28-day subacute oral toxicity assay. The results showed that there was no significant increase in the incidence of reverse mutations or chromosomal aberrations following exposure to TWK10. Moreover, no significant changes were detected either in the number of reticulocytes or the incidence of micronuclei in ICR mice, and no subacute toxicity was recorded in SD rats at the oral TWK10 dosage of 2000 mg/kg body weight/day repeated for 28 days. Additionally, TWK10 exhibited no hemolytic activity and was susceptible to all the antibiotics tested, except kanamycin. However, no antimicrobial resistance genes, virulence factors, or genes involved in biogenic amine synthesis were found in the genome of TWK10. Our findings demonstrated that TWK10 has high potential of being safe for human consumption as a probiotic.

Toxicological and chemoprevention studies of Dalbergia ecastaphyllum (L.) Taub. stem, the botanical source of Brazilian red propolis.

Dalbergia ecastaphyllum (L.) Taub. is a semi-prostrate species associated with estuaries, mangroves and dunes. This plant species has great ecological and economic importance, especially concerning apiculture pasture and Brazilian red propolis production. In this study, non-clinical toxicological evaluations of the hydroalcoholic extract of D. ecastaphyllum stems (DEHE), the resin production source, were conducted. In addition, the action of DEHE on genomic instability and colon carcinogenesis was investigated. The extract's chemical profile was analysed by HPLC, and medicarpin, vestitol and neovestitol were found as major compounds. DEHE showed an IC50 equivalent to 373.2 µg/ml and LC50 equal 24.4mg/L, when evaluated using the XTT colorimetric test and the zebrafish acute toxicity assay, respectively. DEHE was neither genotoxic nor cytotoxic at the highest dose, 2000mg/kg, by peripheral blood micronucleus test. The treatments DEHE (6 and 24mg/kg) led to the reduction of micronuclei induced by doxorubicin (DXR) in mice. Furthermore, significantly higher serum levels of reduced glutathione were observed in animals treated with DEHE plus DXR, revealing an antioxidant effect. Treatments with DEHE (48mg/kg) led to a significant reduction in pre-neoplastic lesions induced by the 1,2-dimethylhydrazine (DMH) carcinogen in the rat colon. Immunohistochemical analysis revealed significantly lower levels of expression of COX-2 (86%) and PCNA (83%) in the colon of rats treated with DEHE plus DMH, concerning those treated with the carcinogen. These results indicate the involvement of anti-inflammatory and antiproliferative pathways in the protective effect of DEHE.

Betulinic acid exerts antigenotoxic and anticarcinogenic activities via inhibition of COX-2 and PCNA in rodents.

Phytochemicals have been suggested as an effective strategy for cancer prevention. Within this context, triterpene betulinic acid (BA) exhibits several biological properties but its chemopreventive effect has not been fully demonstrated. The present study investigated the antigenotoxic potential of BA against doxorubicin (DXR)-induced genotoxicity using the mouse peripheral blood micronucleus assay, as well as its anticarcinogenic activity against 1,2dimethylhydrazine (DMH)-induced colorectal lesions in rats. Micronuclei (MN) assay and aberrant crypt foci assay were used to assess the antigenotoxic and the anticarcinogenic potential, respectively. The molecular mechanisms underlying the anticarcinogenic activity of BA were evaluated by assessing anti-inflammatory (COX-2) and antiproliferative (PCNA) pathways. The results demonstrated that BA at the dose of 0.5 mg/kg bodyweight exerted antigenotoxic effects against DXR, with a reduction of 70.2% in the frequencies of chromosomal damage. Animals treated with BA showed a 64% reduction in the number of preneoplastic lesions when compared to those treated with the carcinogen alone. The levels of COX-2 and PCNA expression in the colon were significantly lower in animals treated with BA and DMH compared to those treated with the carcinogen alone. The chemopreventive effect of BA is related, at least in part, to its antiproliferative and anti-inflammatory activity, indicating a promising potential of this triterpene in anticancer therapies, especially for colorectal cancer.

Network pharmacology reveals pharmacological effect and mechanism of Panax notoginseng (Burk.) F. H. Chen on reproductive and genetic toxicity in male mice

Ethnopharmacological relevanceCisplatin (CP), one of the most commonly used antitumor drugs in clinic, could induce reproductive and genetic toxicity. Traditional Chinese medicine believed that this side effect might be caused by the deficiency of both qi and blood. Panax notoginseng (Burk.) F. H. Chen (PN) is a traditional precious Chinese medicine for nourishing blood and hemostasis, which had the synergistic antitumor and reducing toxicity effects. However, the protective effect and mechanism of PN on CP-induced reproductive and genetic toxicity were still unknown.Aim of the study: This study was designed to illuminate the possible protective effect and mechanism of PN on CP-induced reproductive and genetic toxicity. Materials and methodsNetwork pharmacology was first applied to analyze the potential components and targets of PN against CP-induced reproductive and genetic toxicity. Then, the results of network pharmacology were validated in a mouse model of reproductive and genotoxicity induced by CP. Body weight, testis weight, epididymis weight, sperm count, sperm viability and sperm morphology were used to assess protective effects of PN on CP-induced reproductive toxicity. Tail moment in peripheral blood cells and micronucleus in bone marrow cells were used to assess protective effects of PN on CP-induced genetic toxicity. Finally, possible protective targets obtained from network pharmacology, including 8-hydroxy-2-deoxyguanosine (8-OHdG), malondialdehyde (MDA), total superoxide dismutase (T-SOD) and glutathione peroxidase (GSH-Px), were experimentally validated by ELISA. ResultsOne hundred and nineteen components of PN and sixty-eight targets of reproductive/genetic toxicity were acquired and constituted as the component-target network. Network pharmacology analysis showed alleviating oxidative stress might play important role in therapeutic mechanism of PN. In verified experiments, PN significantly improved the decline of body weight, testis weight and epididymis weight, increased sperm count and viability, decreased abnormal sperm morphology rate induced by CP in mice. Moreover, PN also significantly decreased the tail moment in peripheral blood cells and micronucleus formation rate in bone marrow cells in CP-induced mice. Finally, not only the decrease of T-SOD and GSH-Px level but also the increase of 8-OHdG and MDA level in serum were restored under PN treatment. ConclusionCurrent study found that PN could improve CP-induced reproductive and genetic toxicity, which were probably attributed to alleviating oxidative stress. This finding provided the new perspective for understanding the therapeutic effect of PN on CP-induced reproductive and genetic toxicity and facilitating the clinical use of PN.

Assessment of DNA damage through micronucleus studies in subjects exposed to formalin

Background: Formaldehyde (FA) is the reactive and simplest of all the aldehydes. It is used as a preservative in anatomy, pathology and forensic laboratories. The international agency for research on cancer has classified FA as a carcinogen that can cause nasopharyngeal carcinoma, Leukaemia, Liver and pancreatic cancer. Objective And Method: The aim of the study was to assess the DNA damage in peripheral blood lymphocytes and in buccal cells by Micronucleus assay in Formalin exposed workers of Anatomy, Pathology and Forensic laboratories and compare with the control group, and also to analyze the relationship between frequency of Micronuclei and duration of exposure to formalin. Results: The mean and standard deviation (SD) of micronuclei in peripheral blood of exposed was 8.35 and in controls was 4.18. There was a significant increase in the frequency of MN in exposed group when compared with the comparison group (p&lt;0. 5876). Pearson’s correlation test showed a positive correlation between the years of FA exposure and the number of micronuclei in buccal cells and peripheral blood indicating that DNA damage due to FA was directly proportional to the duration of exposure (r=0.8, 0.9). Conclusion: The present study was done to assess the DNA damage in people who were exposed to FA and a control group not exposed to FA by buccal cell and peripheral blood Micronucleus Assay. There was a significant increase in the MN in people exposed to FA which was directly proportional to the duration of exposure.

Functionality and DNA-damage properties of blood cells in lactating cows exposed to glyphosate contaminated feed at different feed energy levels

ABSTRACTGlyphosate (GL) inhibits the aromatic amino acid biosynthesis in plants and is worldwide the most used non-selective herbicide. Less is known about in vivo effects of GL contaminated feedstuffs on the health of dairy cows. The aim of this study was to examine the effects of GL residues in feed at different concentrate feed proportions (CFP) on haematology, immunological and redox parameters and on DNA-damage of blood cells in lactating dairy cows. During a 16-trial, 61 German Holstein cows (207 ± 49 d in milk; mean ± SD) were fed the same ration in week 0. Afterwards, they were assigned to either a group receiving a GL contaminated or a group receiving an uncontaminated total mixed ration (CON). Each group was subdivided into a “low concentrate” group (LC) and a “high concentrate” group (HC) with an energy content of 6.63 MJ NEL and 7.18 MJ NEL/kg dry matter, respectively. The diets were offered for ad libitum consumption. Blood samples were taken at weeks 0, 4, 8, 12 and 16. All blood samples were analysed for white and red blood cell counts. T-cell subpopulations, oxidative burst capability of leukocytes, apoptosis rate, phagocytic activity, activities of superoxide dismutase and glutathione peroxidase, the total non-enzymatic antioxidative capacity, viability and stimulation capacity of peripheral blood mononuclear cells and micronucleus- and comet assay on bovine leukocytes were measured only in week 16. The average individual GL intake of groups CON, GLLC and GLHC was 1.2 µg, 112.6 µg and 132.8 µg per kg body weight and day, respectively. GL contamination did not affect any of the tested parameters whereas CFP and time-influenced leukocytes, granulocytes, red blood cells, haemoglobin, haematocrit, mean corpuscular volume, mean corpuscular haemoglobin and CD4+ T-cells in an interactive manner characterised by a time-dependent increase in HC groups. It can be concluded that GL and GL in combination with different CFP showed no influence on any of the tested endpoints, whereas CFP and time influenced most parameters in an interactive manner.

In vitro and in vivo effects of 5-aminotetrazole (5-AT), an energetic compound

Perchlorate is an important oxidizer used in propellants, pyrotechnics, and as a gas generator in commercial airbags, fireworks, and roadside flares. It is highly water soluble, interferes with thyroidal iodide uptake and is an environmental contaminant. By changing the reaction chemistry, 5-aminotetrazole (5-AT) and nitrates replace perchlorate in some propellants. The short term toxicity of 5-AT was evaluated. Using a modified Ames assay, 5-AT was not mutagenic with or without S9 metabolic activation. 5-AT was considered “slightly toxic” with an EC50 of 28.8 mg 5-AT/L for a 15 min exposure in Aliivibrio fischeri. In the in vitro sodium iodide symporter test, 5-AT did not inhibit the uptake of iodine. In the acute rat oral test, no adverse effects and no mortalities were observed at the limit dose of 2000 mg 5-AT/kg. In the 14-day sub-acute study, there were no clinical signs of toxicity or morbidity up to 623 mg 5-AT/kg-day; the highest dose tested. No differences were observed in hematology, clinical chemistry, organ weight, body weight, food consumption, histopathology, or DNA damage (peripheral blood micronucleus assay) of treatments compared with controls. The No Observed Adverse Effect Level (NOAEL) was 623 mg 5-AT/kg-day, the highest dose in the subacute oral bioassay.

Monitoring of cytogenetic instability by micronuclei assay of both immunocompetent and non-immunocompetent cells in tick-borne encephalitis patients depending on variants of glutathione-S-transferase genes in the genotype

Aim of this study was to study the dynamics of the frequency of cytokinesis-blocked T-lymphocytes with micronuclei in peripheral blood and the frequency of buccal micronucleated epithelium cells for a period of half a year in patients with acute tick-borne encephalitis, depending on burden of active and inactive variants of glutathione-S-transferase genes (GSTM1 and GSTT1) in the patient's genotype. We carried out micronucleus assay in immunocompetent and non-immunocompetent cells in 54 patients with acute tick-borne encephalitis and 35 healthy persons (control) residing in the Tomsk and Tyumen regions. To analyze the frequency of cytokinesis-blocked micronucleated T-lymphocytes was used venous peripheral blood as material for phytohemagglutinin-stimulated cultures, and to study the frequency of buccal micronucleated cells, samples of the buccal mucous membrane epithelial cells were obtained. To carried out both techniques of micronucleus assay, cytological preparations were prepared, which were stained using the Giemsa or Felgen methods. The material for the study was obtained repeatedly during admission of patients to treatment, and also after 1 week, 1, 3 and 6 months. Polymerase chain reaction was used to analyze the alleles of the GSTM1 and GSTT1 genes. As a result of this analysis was found a significant increase in the frequency of micronucleated cells in tick-borne encephalitis patients compared with the control group. In addition, the frequency of cytokinesis-blocked micronucleated T-lymphocytes was increased significantly higher than the one of micronucleated buccal cells. The most significant and prolonged increase in the frequency of micronucleated cells was associated with the mutant inactive variants of the genes GSTM1 (0/0) and GSTT1 (0/0). In the patients with burden the inactive forms of these genes, the cytogenetic instability of the cytokinesis-blocked blood T-lymphocytes could persist for up to six months. In case of buccal cells, the frequency of micronucleated cells was close to the one in the control group as early as 1-3 months after a course of treatment. Conclusion. It was found that the most increased and prolonged frequency of cytogenetically instable cells persisted in cytokinesis-blocked T-lymphocytes of peripheral blood of patients with tick-borne encephalitis who were carriers of the genotype with inactive variants of both GSTM1 (0/0) and GSTT1 (0/0 ) glutathione-S-transferase genes.

Study of the Individual Radiosensitivity in Humans Based on the Assessment of the Frequency of Chromosome Aberrations and Micronuclei in Peripheral Blood T Lymphocytes

The influence of low-dose ionizing radiation on a human being is increasing in the modern world (medical diagnostics etc.). The issue of the effect of low-doses on human health is topical and controversial. It is known that in the population up to 15% of people react to radiation exposure differently from what has been expected, which, according to the published data, happens owing to their genome peculiarities. The objective of the current study was to investigate the influence of chronic lowdose rate exposure (doses to red bone marrow varied within the range 3—4600 mGy) of the Techa River residents (South Urals) on the radiosensitivity of T cells in vivo and in vitro under additional gamma exposure of peripheral blood T lymphocytes (0.5, 1, and 2 Gy). Such cytogenetic parameters as frequency of unstable chromosome aberrations and micronuclei were used as irradiation markers. Persons were considered radiosensitive if the obtained values of the analyzed parameters for them exceeded the 90% percentile. On the basis of the findings of the performed study, the following conclusions were drawn: about 10% of donors demonstrated increased radiosensitivity; moreover, the effect did not depend on the dose of chronic exposure; no age dependence of radiosensitivity in the studied age range (49–89 years) of the donors was revealed. In most cases, we did not detect a reproducible radiosensitivity effect in the same donor under different irradiation regimes.

Integration of micronucleus, comet, and Pig-a gene mutation endpoints into rat 15-day repeat-treatment studies: Proof-of-principle with Auramine O

A series of genotoxicity assessments were conducted on male Sprague Dawley rats treated with Auramine O (AO) to establish a multiple-endpoint assay. The rat liver micronucleus assay, in combination with the comet assay, peripheral blood micronucleus assay, and erythrocyte Pig-a assay in the same experiment, comprehensively assess the genotoxicity of AO. Rats were orally exposed to 0, 100, 200, or 400 mg/kg/day AO for 15 consecutive days. The blood was sampled on Days -1 and 15 for the erythrocyte Pig-a assay and peripheral blood micronucleus assay. Livers were sampled on Day 15 for the liver micronucleus assay and comet assay. Based on the liver micronucleus assay and liver comet assay, AO induced a significant dose-related increase of micronucleated hepatocyte frequencies, and tail DNA percentages, respectively in the middle- and high-dose groups. On the blood micronucleus test and Pig-a assay, no significant increases were observed for the micronucleated reticulocyte frequencies, mutant erythrocyte frequencies (RBCCD59−) or mutant reticulocyte frequencies (RETCD59−) at any of the time points studied. In conclusion, using a multiple-endpoint genotoxicity assay method can reduce the number of experimental animals, boost the efficiency of the experiment, and improve the accuracy of investigations of genotoxicity.

The effect of lycopene supplementation on radiation-induced micronuclei in mice reticulocytes in vivo

Lycopene (LYC) is a natural pigment present in tomatoes and other red fruits and vegetables including red carrots, red peppers, watermelons, pink grapefruits, apricots, pink guavas, and papaya. There is some evidence that LYC may provide protection against mutations induced by ionizing radiation. The study aimed to investigate whether the genetic material of reticulocytes (RET) could be protected from radiation-induced damage by LYC. Mice were treated with LYC [0.15 mg/kg bodyweight (bw), 0.30 mg/kg bw], acute and fractionated irradiation (0.5 Gy, 1 Gy applied daily), or with both agents (0.5 Gy + 0.15 mg/kg bw LYC, 0.5 Gy + 0.30 mg/kg bw LYC, 1 Gy + 0.15 mg/kg bw LYC, 1 Gy + 0.30 mg/kg LYC). LYC supplementation was started at 24 h or 1 week after the first irradiation. Irradiation significantly enhanced the frequency of micronuclei (MN) in RET. LYC treatment at a dose of 0.15 mg/kg bw 24 h after starting fractionated radiation at 1 Gy significantly decreased (41–68%, p < 0.0125) the level of MN in peripheral blood and bone marrow RET. LYC supplementation at 0.30 mg/kg bw did not significantly alter the frequency of MN in peripheral blood, but significantly increased the frequency of bone marrow RET MN. LYC treatment on day 8 following the first radiation exposure showed results similar (92–117%, p > 0.24) to those obtained with irradiation alone. Lycopene may act as a radiomitigator but must be administered at low doses and as soon as possible after irradiation. Contrary, combined exposure with high doses of irradiation and LYC may enhance the mutagenic effect of irradiation.

2-Hydroxypyridine N-Oxide is not genotoxic in vivo.

2-Hydroxypyridine N-oxide (HOPO) is an important coupling reagent used in pharmaceutical synthesis. Our laboratory previously reported HOPO as equivocal in the Ames assay following extensive testing of multiple lots of material. Given the lack of reproducibility between lots of material and the weak increase in revertants observed, it was concluded that it would be highly unlikely that HOPO would pose a mutagenic risk in vivo. The purpose of the current investigation was to assess experimentally in rats the mutagenic (Pig-a mutation induction) and more broadly genotoxic (micronucleus and comet induction) potential of HOPO. Rats were administered HOPO (0, 50, 150, 300, and 500 mg/kg/day) by oral gavage for 28 days. At the end of study, the following parameters were assessed: frequency of Pig-a mutant red blood cells and reticulocytes, frequency of peripheral blood micronuclei, and the incidence of comet formation in liver. Toxicokinetic data collected on study Days 1 and 28 demonstrated systemic exposure to HOPO. Although there were no overt clinical signs, animals treated with HOPO showed a dose-related decrease in body weight gain. There were no increases observed in any of the genotoxicity endpoints assessed. The results from this study further support the conclusion that in the context of pharmaceutical synthesis, HOPO should not be considered a mutagenic impurity but rather controlled as a normal process-related impurity. Environ. Mol. Mutagen. 2019. © 2019 Wiley Periodicals, Inc.

Inhibitory effect of Salvadora persica (Miswak) against cigarette smoke-induced mutagenicity and sperm abnormalities in rats

Pharmacognosy Research,2019,11,4,384-388.DOI:10.4103/pr.pr_65_19Published:November,2019Type:Original ArticleAuthors:Syed Imam Rabbani, Sultan Sajid, Vasudevan Mani, Omar Khan, and M. A. A. Salman Author(s) affiliations:Syed Imam Rabbani1, Sultan Sajid1, Vasudevan Mani1, Omar Khan2, M A. A. Salman1 1Department of Pharmacology, College of Pharmacy, Qassim University, Buraidah, Kingdom of Saudi Arabia. 2Department of Pharmaceutics, College of Pharmacy, Qassim University, Buraidah, Kingdom of Saudi Arabia. Abstract:Objective: The objective of the study is to evaluate the inhibitory effect of Salvadora persica against the cigarette smoke‑induced mutagenicity and sperm damages in rats. Materials and Methods: Young male Wistar rats of weight 120–140 g were exposed to the cigarette smoke for 8 weeks. The lyophilized decoction of S. persica was administered daily for 4 weeks by oral route at the doses 50, 100, and 200 mg/kg. The somatic and germinal cells damages were determined by peripheral blood micronucleus and sperm abnormalities tests, respectively. In vitro antioxidant activity of the decoction was determined by hydrogen peroxide scavenging assay. Ginseng was used as a standard herbal agent. The results were analyzed statistically by one‑way ANOVA followed by Tukey test. P <0.05 was considered to indicate the significance of results. Results: The data from the present study indicated that cigarette smoke exposure significantly (P < 0.01) increased the population of micronucleated erythrocytes and sperm shape abnormalities and, reduced the polychromatic: normochromatic (P/N) ratio, and total sperm count compared to control. The administration of S. persica produced a dose‑dependent inhibition on somatic and male germinal cell damages induced by cigarette smoke and the significant (P < 0.05) activity was observed at 200 mg/kg. However, none of the tested doses enhanced significantly the P/N ratio. Ginseng at 100 mg/kg significantly (P < 0.01) prevented the cigarette smoke‑mediated damages. The in‑vitro antioxidant activity indicated both S. persica and ginseng possess scavenging activity against the hydrogen peroxide free radicals. Conclusion: The observation suggests that the decoction of S. persica can prevent the somatic and germinal cell nuclear damages induced by cigarette smoke exposure. These actions could be related to its antioxidant property. Keywords:Antioxidant, Cigarette smoke, Micronuclei, Salvadora persica, Sperm abnormalities.View:PDF (854.28 KB)