• YAKHAK HOEJI
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• v.46 no.3
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• pp.208-212
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• 2002

Dehydroevodiamine HCl (DHED), which is a component separated from Evodia rutaecarpa Bentham, has novel anticholinesterase and antiamnesic activities in the scopolamine-induced amnesia model. Several studies suggest that DHED might be an effective drug for the Alzheimer's disease and the vascular type of dementia. In order to evaluate the mutagenic potential of DHED, Salmonella typhimurium reversion assay, chromosomal aberration test on Chinese hamster lung cells, in vivo micronucleus assay using mouse bone marrow cells, and comet assay were performed. DHED did not increase the number of revertant in the reverse mutation test using Salmonella typhimurium TA1535, TA1537, TA98, TA100. DHED HCl, at concentration of 5 and 10 $\mu\textrm{g}$/mι, increased the number of chromosome aberrated Chinese hamster lung cells with 5 and 10％, respectively. In mouse micronucleus test, no significant increase in the occurrence of micronucleated polychromatic erythrocyte was observed in ICR mice orally administered with DHED. DHED was tested for ability to induce genotoxic effect in L5178Y cells (mouse lymphoma cells) using the single cell gel electrophoresis assay (comet assay). In comet assay, tail moment did not increase in L5178Y cells treated with 10, 100, 300 $\mu$M DHED.

• Proceedings of the Korean Society of Toxicology Conference
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• 2003.10b
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• pp.133-133
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• 2003

In recent years. attention has focused on the application of the alkaline single cell gel electrophoresis (SCGE or Comet) assay in environmental mutagenesis. To evaluate the suitability of the assay as a monitoring. technique, the DNA damages in liver cells and erythrocytes of carp (Cyprinus carpio) exposed to benzo[${\alpha}$]pyrene (B[${\alpha}$]P) were estimated comparatively with the in vivo Comet assay and the micronucleus test (MNT).(omitted)

• Korean Journal of Veterinary Research
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• v.44 no.1
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• pp.41-47
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• 2004

The alkaline single-cell gel electrophoresis (SCGE) assay, called the comet assay, has been applied to detect DNA damage induced by a number of chemicals and biological factors in vivo and in vitro. The DNA damage was analysed by tail moment (TM) and tail length (TL), which were markers of DNA strand breaks in SCGE. Human, mouse and rat peripheral blood lymphocytes (PBLs) were irradiated with different doses of $^{60}Co$ ${\gamma}$-rays, e.g. 1, 2, 4, and 8 Gy at a dose rate of 1 Gy/min. A dose-dependent increase in TM (p<0.01) and TL (p<0.01) was obtained at all the radiation doses (1-8 Gy) in human, mouse and rat PBLs. Mouse PBLs were more sensitive than human PBLs which were in turn more sensitive than rat PBLs when the treated dosages were 1 and 2 Gy. However, human PBLs were more sensitive than mouse PBLs which were in turn more sensitive than rat PBLs when the irradiation dosages were 4 and 8 Gy. Data from all three species could be fitted to a linear-quadratic model. These results indicated that there may be inherent differences in the radio-sensitivity among PBLs of mammalian species.

• Environmental Analysis Health and Toxicology
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• v.14 no.1_2
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• pp.1-12
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• 1999

Recently, several new methods for the detection of genetic damages in vitro and in vivo based on molecular biological techniques were introduced according to the rapid progress in toxicology combined with cellular and molecular biology. Among these methods, mouse lymphoma thymidine kanase (tk) gene forward mutation assay, single cell gel electrophoresis (comet assay) and transgenic animal and cell line model as a target gene of lac I (Big Blue) and lac Z (Muta Mouse) gene mutation are newly introduced based on molecular toxicological approaches. The mouse lymphoma tk$\^$+/-/ gene assay (MOLY) using L5178Y tk$\^$+/-/ mouse lymphoma cell line is one of the mammalian forward mutation assays, and has many advantages and more sensitive than hprt assay. The target gene of MOLY is a heterozygous tk$\^$+/-/ gene located in 11 chromosome, so it is able to detect the wide range of genetic changes like point mutation, deletion, rearrangement, and mitotic recombination within tk gene or deletion of entire chromosome 11. The comet assay is a rapid, simple, visual and sensitive technique for measuring and analysing DNA breakages in mammalian cells, Also, transgenic animal and cell line models, which have exogenous DNA incorporated into their genome, carry recoverable shuttle vector containing reporter genes to assess endogenous effects or alteration in specific genes related to disease process, are powerful tools to study the mechanism of mutation in vivo and in vitro, respectively. Also in vivo acridine orange supravital staining micronucleus assay by using mouse peripheral reticulocytes was introduced as an alternative of bone marrow micronucleus assay. In this respect, there was an International workshop on genotoxicity procedure (IWGTP) supported by OECD and EMS (Environmental Mutagen Society) at Washington D. C. in March 25-26, 1999. The objective of IWGTP is to harmonize the testing procedures internationally, and to extend to finalization of OECD guideline, and to the agreement of new guidelines under the International Conference of Harmonization (ICH) for these methods mentioned above. Therefore, we introduce and review the principle, detailed procedure, and application of MOLY, comet assay, transgenic mutagenesis assay and supravital staining micronucleus assay.

• Toxicological Research
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• v.20 no.2
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• pp.89-100
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• 2004

The comet assay (also called the single-cell gel electrophoresis assay) has been widely used for detecting DNA damage and repair in individual cells. Since the conventional methods of evaluating comet assay data using frequency statistics are unsatisfactory we developed a new quantitative measure of DNA damage/repair that is based on all information residing in the dose/time-response curves of a comet experiment. Blood samples were taken from 25 breast cancer patients before undergoing radiotherapy. The comet assay was performed under alkaline conditions using isolated lymphocytes. Tail DNA, tail length, tail moment and tail inertia of the comet were measured for each patient at four doses of $\gamma$-rays (0, 2, 4 and 8 Gy) and at four time points after irradiation (0, 10, 20 and 30 min) using 100 cells each. The resulting three-dimensional dose-time response surface was modeled by multiple regression, and the second derivative, termed 2D, on dose and time was determined. A software module was programmed in SAS/AF to compute 2D values. We applied the new method successfully to data obtained from cancer patients to be assessed for their radiation sensitivity. We computed the 2D values for the four damage measures, i.e., tail moment, tail length, tail DNA and tail inertia, and examined the pairwise correlation coefficients of 2D both on the log scale and the unlogged scale. 2D values based on tail moment and tail DNA showed a high correlation and, therefore, these two damage measures can be used interchangeably as far as DNA repair is concerned. 2D values based on tail inertia have a correlation profile different from the other 2D values which may reflect different facets of DNA damage/repair. Using the dose-time response surface, other statistical models, e.g., the proportional hazards model, become applicable for data analysis. The 2D approach can be applied to all DNA repair measures, Le., tail moment, tail length, tail DNA and tail inertia, and appears to be superior to conventional evaluation methods as it integrates all data of the dose/time-response curves of a comet assay.

• Proceedings of the PSK Conference
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• 2000.04a
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• pp.133.3-134
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• 2000

• Korean Journal of Food Science and Technology
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• v.31 no.4
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• pp.1071-1076
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• 1999

This study was carried out to isolate the colonies of dominant fermented bacteria from Kimchi (Korean native fermented foodstuffs) and investigate their inhibitory potentials on mutagenesis and carcinogenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) as direct carcinogen. For this purpose, single cell gel electrophoresis technique (SCGE assay, or comet assay) which is a sensitive and rapid technique for detecting the presence of DNA strand breaks in individual cells was used. DNA damages of Kimchi isolates were compared with that of the positive control, MNNG. Among 3 isolates from Tongbaechu Kimchi, two isolates B-1 and B-2 showed antigenotoxicities (p<0.01). All 4 isolates from Yulmu Kimchi had antigenotoxicities (p<0.05). Also, 3 of 5 isolates from Chonggak Kimchi and 2 of 9 isolates from Kaktugi were antigenotoxic (p<0.05 and p<0.01, respectively).

• Korean Journal of Environmental Agriculture
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• v.34 no.4
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• pp.350-354
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• 2015

BACKGROUND: Botanical insecticides, especially Azadirachta Indica extract (AIE) and Sophorae radix extract (SRE) are widely used in Agriculture field. In our previous studies on genotoxicity test of AIE and SRE samples, a suspicious clastogenic properties was shown. Herein, we investigated the DNA damage effect of these botanical insecticide samples through the in vitro comet assay. METHODS AND RESULTS: Chinese hamster lung (CHL) fibroblast cell line was used, and methyl methanesulphonate was as positive control. Respective two samples of AIE and SRE were evaluated using Single Cell Gel Electrophoresis (Comet) assay and measured as the Olive tail moment (OTM). Results from this study indicated that all tested AIE and SRE samples did not show DNA damage in comet assay using CHL cells, compared with control. CONCLUSION: AIE and SRE samples used in this study were not cause genetic toxicity and are suitable for use as organic materials.

• Molecular & Cellular Toxicology
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• v.2 no.3
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• pp.151-158
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• 2006

Khal was a synthetic congener of halocidin, a heterodimeric peptide consisting of 19 and 15 amino acid residues detected in Halocynthia aurantium. This compound was considered a candidate for the development of a novel peptide antibiotic. The genotoxicity of Khal was subjected to high throughput toxicity screening (HTTS) because they revealed strong antibacterial effects. Mouse lymphoma thymidine kinase ($tk^{+/-}$) gene assay (MOLY), single cell gel electrophoresis (Comet) assay and chromosomal aberration assay in mammalian cells and Ames reverse mutation assay in bacterial system were used as simplified, inexpensive, short-term in vitro screening tests in our laboratory. These compounds are not mutagenic in S. typhimurium TA98 and TA100 strains both in the presence and absence of metabolic activation. Before performing the comet assay, $IC_{20}$ of Khal was determined the concentration of $25.51\;{\mu}/mL\;and\;21.99\;{\mu}g/mL$ with and without S-9, respectively. In the comet assay, Khal was not induced DNA damage in mouse lymphoma cell line. Also, the mutation frequencies in the Khal-treated cultures were similar to the vehicle controls. It is suggests that Khal is non-mutagenic in MOLY assay. And no clastogenicity was observed in Khal-treated Chinese hamster lung cells. The results of this battery of assays indicate that Khal has no genotoxic potential in bacterial or mammalian cell systems. Therefore, we suggest that Khal, as the optimal candidates with both no genotoxic potential and antibacterial effects must be chosen.

• Environmental Mutagens and Carcinogens
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• v.21 no.2
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• pp.99-105
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• 2001

Sophoricoside was isolated as the inhibitor of IL-5 bioactivity from Sophora japonica (Leguminosae). It has been reported to has an anti-inflammatory effect on rat paw edema model. To develope as an anti-allergic drug, genotoxicity of sophoricoside was investigated in bacterial and mammalian cell system such as Ames bacterial reversion test, chromosomal aberration assay and single cell gel electrophoresis (Comet) assay. As results, in the range of 1,250~40 $\mu\textrm{g}$/plate sophoricoside concentrations was not shown significant mutagenic effects in Salmonella typhimurium TA 98, TA 100, TA 1535 and TA 1537 strains in Ames test. The 80% cell growth inhibition concentration (IC/SUB 80/) of sophoricoside was determined as above 5,000 $\mu\textrm{g}$/$m\ell$ in Chinese hamster lung (CHL) fibroblast cell and L5178Y mouse lymphoma cell line for the chromosomal aberration and comet assay, respectively. Sophoricoside was not induced chromosomal aberration in CHL fibroblast cell at concentrations of 700, 350 and 175 $\mu\textrm{g}$/$m\ell$ or 600, 300 and 150 $\mu\textrm{g}$/$m\ell$ in the absence or presence of S-9 metabolic activation system, respectively. Also, in the comet assay, the induction of DNA damage was not observed in L5178Y mouse lymphoma cell line both in the absence or presence of S-9 metabolic activation system. From these results, no genotoxic effects of sophoricoside were observed in bacterial and mammalian cell systems used in these experiments.