Micronucleus Assay with Tetrad Cells of Tradescantia

Author(s):  
Miroslav Mišík ◽  
Clemens Pichler ◽  
Bernhard Rainer ◽  
Armen Nersesyan ◽  
Siegfried Knasmueller
Keyword(s):  
2019 ◽  
Vol 7 (2A) ◽  
Author(s):  
Leticia Bonfim ◽  
Luma Ramirez de Carvalho ◽  
Daniel Perez Vieira

Micronucleus assay is a test used to evaluate genotoxic damage in cells, which can be caused by various factors, like ionizing radiation. Interactions between radiation energies and DNA can cause breakage, leading to use chromosomal mutations or loss of genetic material, important events that could be induced in solid tumors to mitigate its expansion within human body.  Melanoma has been described as a tumor with increased radio resistance.  This work evaluated micronuclei percentages (%MN) in human melanoma cells (SK-MEL-37), irradiated by gamma radiation, with doses between 0 and 16Gy.  Cell suspensions were irradiated in PBS by a 60Co source in doses between 0 and 16Gy, and incubated by 48h.  Then cell membranes were lysed in the presence of SYTOX Green and EMA dyes, preserving nuclear membranes.  Using this method, EMA-stained nuclei could be discriminated as those derived from dead cells, and SYTOX nuclei and micronuclei could be quantified.  Micronuclei percentages were found to be proportional to dose, (R2 = 0.997).  Only the highest dose (16Gy) could induce statistically significant increase of MN (p<0.0001), although cultures irradiated by 4, 8 and 16Gy showed significant increase of dead cell fractions.  Calculation of the nuclei-to-beads ratio showed that 8 and 16Gy could reduce melanoma cell proliferation.  Results showed that although cell death and loss of proliferative capacity could be observed on cultures irradiated at lower doses, genotoxic damage could be induced only on a higher dose. Resistance to radiation-induced genotoxicity could explain a relatively high radio resistance of melanoma tumors.


2019 ◽  
Vol 19 (5) ◽  
pp. 667-676
Author(s):  
José R. Santin ◽  
Gislaine F. da Silva ◽  
Maria V.D. Pastor ◽  
Milena F. Broering ◽  
Roberta Nunes ◽  
...  

Background: It was recently demonstrated that the phthalimide N-(4-methyl-phenyl)-4- methylphthalimide (MPMPH-1) has important effects against acute and chronic pain in mice, with a mechanism of action correlated to adenylyl cyclase inhibition. Furthermore, it was also demonstrated that phthalimide derivatives presented antiproliferative and anti-tumor effects. Considering the literature data, the present study evaluated the effects of MPMPH-1 on breast cancer bone metastasis and correlated painful symptom, and provided additional toxicological information about the compound and its possible metabolites. Methods: In silico toxicological analysis was supported by in vitro and in vivo experiments to demonstrate the anti-tumor and anti-hypersensitivity effects of the compound. Results: The data obtained with the in silico toxicological analysis demonstrated that MPMPH-1 has mutagenic potential, with a low to moderate level of confidence. The mutagenicity potential was in vivo confirmed by micronucleus assay. MPMPH-1 treatments in the breast cancer bone metastasis model were able to prevent the osteoclastic resorption of bone matrix. Regarding cartilage, degradation was considerably reduced within the zoledronic acid group, while in MPMPH-1, chondrocyte multiplication was observed in random areas, suggesting bone regeneration. Additionally, the repeated treatment of mice with MPMPH-1 (10 mg/kg, i.p.), once a day for up to 36 days, significantly reduces the hypersensitivity in animals with breast cancer bone metastasis. Conclusion: Together, the data herein obtained show that MPMPH-1 is relatively safe, and significantly control the cancer growth, allied to the reduction in bone reabsorption and stimulation of bone and cartilage regeneration. MPMPH-1 effects may be linked, at least in part, to the ability of the compound to interfere with adenylylcyclase pathway activation.


2019 ◽  
Vol 19 (14) ◽  
pp. 1695-1702 ◽  
Author(s):  
Mohsen Cheki ◽  
Salman Jafari ◽  
Masoud Najafi ◽  
Aziz Mahmoudzadeh

Background and Objective: Glucosamine is a widely prescribed dietary supplement used in the treatment of osteoarthritis. In the present study, the chemoprotectant ability of glucosamine was evaluated against cisplatin-induced genotoxicity and cytotoxicity in rat bone marrow cells. Methods: Glucosamine was orally administrated to rats at doses of 75 and 150 mg/kg body weight for seven consecutive days. On the seventh day, the rats were treated with a single injection of cisplatin (5 mg/kg, i.p.) at 1h after the last oral administration. The cisplatin antagonistic potential of glucosamine was assessed by micronucleus assay, Reactive Oxygen Species (ROS) level analysis, hematological analysis, and flow cytometry. Results: Glucosamine administration to cisplatin-treated rats significantly decreased the frequencies of Micronucleated Polychromatic Erythrocytes (MnPCEs) and Micronucleated Normchromatic Erythrocytes (MnNCEs), and also increased PCE/(PCE+NCE) ratio in bone marrow cells. Furthermore, treatment of rats with glucosamine before cisplatin significantly inhibited apoptosis, necrosis and ROS generation in bone marrow cells, and also increased red blood cells count in peripheral blood. Conclusion: This study shows glucosamine to be a new effective chemoprotector against cisplatin-induced DNA damage and apoptosis in rat bone marrow cells. The results of this study may be helpful in reducing the harmful effects of cisplatin-based chemotherapy in the future.


Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 389
Author(s):  
Kukka Aimonen ◽  
Satu Suhonen ◽  
Mira Hartikainen ◽  
Viviana R. Lopes ◽  
Hannu Norppa ◽  
...  

Wood-derived nanofibrillated cellulose (NFC) has emerged as a sustainable material with a wide range of applications and increasing presence in the market. Surface charges are introduced during the preparation of NFC to facilitate the defibrillation process, which may also alter the toxicological properties of NFC. In the present study, we examined the in vitro toxicity of NFCs with five surface chemistries: nonfunctionalized, carboxymethylated, phosphorylated, sulfoethylated, and hydroxypropyltrimethylammonium-substituted. The NFC samples were characterized for surface functional group density, surface charge, and fiber morphology. Fibril aggregates predominated in the nonfunctionalized NFC, while individual nanofibrils were observed in the functionalized NFCs. Differences in surface group density among the functionalized NFCs were reflected in the fiber thickness of these samples. In human bronchial epithelial (BEAS-2B) cells, all NFCs showed low cytotoxicity (CellTiter-GloVR luminescent cell viability assay) which never exceeded 10% at any exposure time. None of the NFCs induced genotoxic effects, as evaluated by the alkaline comet assay and the cytokinesis-block micronucleus assay. The nonfunctionalized and carboxymethylated NFCs were able to increase intracellular reactive oxygen species (ROS) formation (chloromethyl derivative of 2′,7′-dichlorodihydrofluorescein diacetate assay). However, ROS induction did not result in increased DNA or chromosome damage.


Agronomy ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 321
Author(s):  
Perrine Klein ◽  
Lorelei Chauvey ◽  
Jean Kallerhoff ◽  
Eric Pinelli ◽  
Marie Morard ◽  
...  

The increased use of biostimulants in conventional agriculture and organic farming requires the implementation of rapid tests to determine their effectiveness in enhancing plant growth and protection against abiotic stresses. However, their innocuity to plant health has rarely been demonstrated. We used the Vicia faba Micronucleus Assay, as described by the standard AFNOR EN ISO 29200(2020-05) to reveal biostimulant, genotoxic and cytotoxic effects of four commercialized wood-based products by comparing mitotic indices and micronucleus frequencies with respect to the controls. Neither genotoxicity, as measured by micronucleus frequency (MN), nor cytotoxicity, assessed by Mitotic index counts, was observed. Additionally, one of these stimulants (BHS®) conferred protective effects against contaminants (maleic hydrazide or lead nitrate). We describe that plotting micronuclei frequency against mitotic indices allows discrimination between cytotoxic/genotoxic effects from growth levels. Vicia faba experiments were successfully transposed to other agronomical important crops such as corn and sunflower. This technique can be valuable to industrials, to assess growth, potential cytoxicity and genotoxicity effects of any new biostimulant or organic.


Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1929
Author(s):  
Tereza Cervena ◽  
Andrea Rossnerova ◽  
Tana Zavodna ◽  
Jitka Sikorova ◽  
Kristyna Vrbova ◽  
...  

The evaluation of the frequency of micronuclei (MN) is a broadly utilised approach in in vitro toxicity testing. Nevertheless, the specific properties of nanomaterials (NMs) give rise to concerns regarding the optimal methodological variants of the MN assay. In bronchial epithelial cells (BEAS-2B), we tested the genotoxicity of five types of NMs (TiO2: NM101, NM103; SiO2: NM200; Ag: NM300K, NM302) using four variants of MN protocols, differing in the time of exposure and the application of cytochalasin-B combined with the simultaneous and delayed co-treatment with NMs. Using transmission electron microscopy, we evaluated the impact of cytochalasin-B on the transport of NMs into the cells. To assess the behaviour of NMs in a culture media for individual testing conditions, we used dynamic light scattering measurement. The presence of NMs in the cells, their intracellular aggregation and dispersion properties were comparable when tests with or without cytochalasin-B were performed. The genotoxic potential of various TiO2 and Ag particles differed (NM101 < NM103 and NM302 < NM300K, respectively). The application of cytochalasin-B tended to increase the percentage of aberrant cells. In conclusion, the comparison of the testing strategies revealed that the level of DNA damage induced by NMs is affected by the selected methodological approach. This fact should be considered in the interpretation of the results of genotoxicity tests.


2009 ◽  
Vol 25 (7) ◽  
pp. 467-471 ◽  
Author(s):  
BN Mojidra ◽  
K. Archana ◽  
AK Gautam ◽  
Y. Verma ◽  
BC Lakkad ◽  
...  

Pan masala is commonly consumed in south-east Asian and other oriental countries as an alternate of tobacco chewing and smoking. Genotoxic potential of pan masala (pan masala plain and pan masala with tobacco known as gutkha) was evaluated employing chromosome aberration (CA) and micronucleus (MN) assay in vivo. Animals were exposed to three different doses (0.5%, 1.5% and 3%) of pan masala plain (PMP) and gutkha (PMT) through feed for a period of 6 months and micronucleus and chromosomal aberrations were studied in the bone marrow cells. Induction of mean micronuclei in polychromatic erythrocytes (MNPCE) and normochromatic erythrocyte (MNNCE) was higher in both types of pan masala treated groups with respect to control group. Both pan masala plain and gutkha treatment significantly induced the frequency of MNPCE and MNNCE in the bone marrow cells, indicating the genotoxic potential. Furthermore, slight decline in the ratio of polychromatic erythrocytes to normochromatic erythrocytes was also noticed, suggesting the cytotoxic potential even though the ratio was statistically non significant. A dose-dependent, significant increase in chromosome aberration was observed in both types of pan masala treated mice with respect to control. However, no significant difference in micronucleus and chromosomal aberration induction was noticed between two types of pan masala exposed (PMP and PMT) groups. Results suggest that both types of pan masala, i.e. plain and gutkha, have genotoxic potential.


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