• Journal of Food Hygiene and Safety
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• v.39 no.4
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• pp.312-321
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• 2024

Tomato is a widely distributed, cultivated, and commercialized vegetable crop. Recently, an increasing trend has been observed in the consumption of transgenic crops with enhanced functional components. However, consumer concerns regarding genotoxicity have been increasing. This study examined the genotoxicity of transgenic tomato (LTT) using the CRISPR/Cas9 system through a bacterial reverse mutation assay, chromosomal aberration assay, and mammalian micronucleus test. In the bacterial reverse mutation assay, LTT did not induce mutagenicity in Salmonella typhimurium strains TA98, TA100, TA1535, and TA1537, or Escherichia coli WP2uvrA, irrespective of the presence or absence of S9. LTT did not cause clastogenic or aneugenic chromosomal abnormalities during metaphase in CHL cells. Moreover, LTT did not increase the frequency of micronucleated polychromatic erythrocytes in the polychromatic erythrocytes. These findings can be used as a foundation to assess the genotoxicity of transgenic crops using the CRISPR/Cas9 system in the future.

• Plant Resources
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• v.4 no.3
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• pp.192-195
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• 2001

Human immunodeficiency virus (HIV), the causative agent of AIDS, still continues to spread rapidly in the world population, especially in Africa and Southeast Asia. At present, two kinds of therapeutic approaches are used for treatment of AIDS. One is to target HIV reverse transcriptase, which is responsible for the viral genome transcription. The other is to inhibit HIV pretense PR, which is essential for the processing of viral proteins. Drug combinations based on these approaches can reduce the blood virus to an undetectable level. However, a small amount of virus may lurk inside the immune cells in a dormant state. Another major obstacle of long-term treatment of the disease is remarkable mutation in HIV. Most of the clinical chemotherapeutic agents have one or more of these problems. High cost and harmful side-effects further reduced the desirability of these drugs. In the course our studies on development of anti-HIV agents from natural products, we investigated various crude drugs for their inhibitory activity against HIV-induced cytopathic effects (CPE) in culture cells, HIV-pretense (PR), HIV-reverse transcriptase (RT) including ribonuclease H (RNase H), and HIV integrase (INT). In the present paper, some inhibitory substances relating to the development of anti-HIV agents are reported.

• Proceedings of the Korea Environmental Mutagen Society Conference
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• 2003.10a
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• pp.119-119
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• 2003

• Korean Journal of Veterinary Research
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• v.38 no.3
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• pp.606-613
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• 1998

Cadmium is one of the well-known environmental toxicants and induces cancer in rodents and human, but its carcinogenic mechanism has not been well demonstrated until now. Genotoxic effects of cadmium in Salmonella typhimurium TA98, TA100 and TA1535/pSK1002 or in WB-F344 rat liver epithelial cells were investigated to elucidate the tumor initiating effects of cadmium. TA98, TA100 and TA1535/pSK1002 tester strains were used to detect frameshift mutation, base-pair mutation and SOS repair response, respectively, in Salmonella mutation test. Reverse mutations from histidine to $histidin^+$ of Salmonella typhimurium TA98 and TA100 by $CdCl_2$ were not significantly different from control up to the maximum doses ($100{\mu}M$ and $200{\mu}M$ in TA98 and TA100, respectively) at which non-cytotoxicity was observed. DNA SOS repair responses(${\beta}$-galactosidase activity) generally did not show significant increases compared to control in both of the conditions with or without metabolic activation in Salmonella typhimurium TA1535/pSK1002 by $CdCl_2$. But the activities of ${\beta}$-galactosidase by $400{\mu}M$ of $CdCl_2$ in metabolic activation condition and by 130 and $400{\mu}M$ of $CdCl_2$ in non-metabolic activation condition were more decreased than those of control. DNA single strand breaks for 4hrs were observed only in WB-F344 rat liver epithelial cells treated with $200{\mu}M$ of $CdCl_2$. As a conclusion, $CdCl_2$ did not induce gene mutation in microbials but induce DNA single strand breaks in rat liver epithelial cells.

• The Korean Journal of Pharmacology
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• v.32 no.3
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• pp.311-321
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• 1996

Both $M_1$ and $M_2$ muscarinic receptors contain a triplet of amino acid residues consisting of leucine (L), tyrosine (Y) and threonine (T) at C-terminus ends of the second putative transmembrane domains. This triplet is repeated as LYT-LYT in $M_2$ receptors at the interface between the second transmembrane domain and the first extracellular loop. Interestingly, however, it is repeated in a transposed fashion (LYT-TYL) in the sequence of $M_1$ receptors. In this work, we employed site-directed mutagenesis to investigate the possible significance of this unique sequence diversity for determining the distinct differential cellular function at the two receptor subtypes. Mutation of the LYTTYL sequence of $M_1$ receptors to the corresponding $M_2$ receptor LYTLYT sequence did not result in a significant change in the binding affinity of the agonist carbachol. The reverse mutation at the $M_2$ receptor also did not modify agonist affinity. Surprisingly, the LYTLYT $M_1$ receptor mutant demonstrated markedly enhanced coupling to activation of phospholipase C without a change in its coupling to increased cyclic AMP formation. There was also an enhanced receptor sensitivity in transducing elevation of intracellular $Ca^{2+}$. On the other hand, the reverse $LYTLYT{\rightarrow}LYTTYL$ mutation in the $M_2$ receptor did not alter its coupling to inhibition of adenylate cyclase, but slightly enhanced its coupling to stimulation of phosphoinositide (PI) hydrolysis. Our data suggest that the LYTTYL/LYTLYT sequence differences between $M_1$ and $M_2$ muscarinic receptors are not important for specifying ligand binding and coupling of various subtypes of muscarinic receptors to different cellular signaling pathways although they might play a role in the modulation of muscarinic reseptor coupling to PI hydrolysis.

• Molecular & Cellular Toxicology
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• v.1 no.3
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• pp.179-188
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• 2005

To develop the novel anti-allergic drug, many sophoricoside derivatives were synthesized. Among these derivatives, JSH-II-3, VI-3, VII-3, VIII-3, VII-20 and VII-20 (sodium salt) were selected and subjected to high throughput toxicity screening (HTTS) because they revealed strong IL-5 inhibitory activity and limitation of quantity. Single cell gel electrophoresis (Comet) assay, mouse lymphoma thymidine kinase ($tk^{+/-}$) gene assay (MOLY), 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. Through the primary screening using the comet assay, we could choose the first candidates of sophoricoside derivatives with no genotoxic potentials as JSH-VI-3, VII-3, VII-20 and VII-20 (sodium salt). Also JSH-VII-3, VII-20 and VII-20 (sodium salt) are non-mutagenic in MOLY assay, while JSH-II-3 is mutagenic at high concentration with the presence of metabolic activation system in both comet assay and MOLY assay. The selected derivatives (JSH-VI-3, VII-3, VII-20 and VII-20 (sodium salt) are not mutagenic in S. typhimurium TA98 and TA100 strains both in the presence and absence of metabolic activation. From results of chromosomal aberration assay, 6 h treatment of JSH-VI-3, VII-3 and VII-20 (sodium salt) were not revealed clastogenicity both in the presence and absence of S-9 mixture. Therefore, we suggests that JSH-VI-3, VII-3, VII-20 and VII-20 (sodium salt), as the optimal candidates with both no genotoxic potential and IL-5 inhibitory effects must be chosen. To process the development into new anti-inflammatory drug of these derivatives, further investigation will need.

• The Journal of Korean Medicine
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• v.20 no.2
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• pp.121-127
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• 1999

Oriental herbal medicines were examined for mutagenicity in the reverse mutation test on Salmonella typimurium T A98/100 and chromosomal aberration test on cultured mammalian cells (Chinese hamster cell lines). The reverse mutation test was performed by a plate incorporation method with and without a metabolic activation system (S9 mix). The tested herbal medicines did not significantly increase revertible colonies on any of the test strains with and without a metabolic activation system (S9 mix) at concentrations of 1 mg/ml. In the chromosomal aberration test, most tested herbal medicines did not significantly increase the number of aberrant cells on any of the test strains with a metabolic activation system (S9 mix) at concentrations of 1 mg/ml, compared with the vehicle control. However. Ansu Semen significantly increased the number of aberrant cells without a metabolic activation system (S9 mix). Paeoniae Radix. Hoelen, Aurantii nobilis Pericarpium, Cnidii Rhizoma, Angeliacae gigantis Radix, Perillae Herba and Moutan Cortex Radicis slightly increased revertible colonies on any of the test strains with a metabolic activation system (S9 mix), These results indicate that most herbal medicines might be carefully used in obstetrics and gynecology, although they do not have the potent mutagenic potential under the present test conditions.

• Environmental Analysis Health and Toxicology
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• v.28
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• pp.3.1-3.8
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• 2013

Objectives We investigated the genotoxic effects of 40-59 nm silver nanoparticles (Ag-NPs) by bacterial reverse mutation assay (Ames test), in vitro comet assay and micronucleus (MN) assay. In particular, we directly compared the effect of cytochalasin B (cytoB) and rat liver homogenate (S9 mix) in the formation of MN by Ag-NPs. Methods Before testing, we confirmed that Ag-NPs were completely dispersed in the experimental medium by sonication (three times in 1 minute) and filtration ($0.2{\mu}m$ pore size filter), and then we measured their size in a zeta potential analyzer. After that the genotoxicity were measured and especially, S9 mix and with and without cytoB were compared one another in MN assay. Results Ames test using Salmonella typhimurium TA98, TA100, TA1535 and TA1537 strains revealed that Ag-NPs with or without S9 mix did not display a mutagenic effect. The genotoxicity of Ag-NPs was also evaluated in a mammalian cell system using Chinese hamster ovary cells. The results revealed that Ag-NPs stimulated DNA breakage and MN formation with or without S9 mix in a dose-dependent manner (from $0.01{\mu}g/mL$ to $10{\mu}g/mL$). In particular, MN induction was affected by cytoB. Conclusions All of our findings, with the exception of the Ames test results, indicate that Ag-NPs show genotoxic effects in mammalian cell system. In addition, present study suggests the potential error due to use of cytoB in genotoxic test of nanoparticles.

• Toxicological Research
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• v.20 no.1
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• pp.43-47
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• 2004

In order to investigate the safety of a water extract (ADP) of 1 : 1 mixture of Anemarrhena rhizoma and Phellodendron cortex for alleviating benign prostate hyperplasia, genotoxicity studies in bacterial and mammalian cell assay systems, namely, the Ames bacterial reverse mutation and chromosomal aberration assays were performed. As shown by the results of the Ames bacterial reversion assay, ADP in the range of 625-5000 $\mu\textrm{g}$/plate did not induce mutagenicity in Salmonella typhimurium TA 98, TA 100, TA 1535 and TA 1537 strains in the absence or in the presence of S9 (the microsomal fraction of rat liver homogenate) metabolic activation. The $IC_{50}$ (50% cell growth inhibition concentration) values of ADP for the chromosomal aberration assay were determined; these were 2425 $\mu\textrm{g}$/ml in the absence and 8126 $\mu\textrm{g}$/ml in the presence of S9 metabolic activation in Chinese hamster lung (CHL) fibroblast cell culture. No chromosomal aberration was observed in CHL cells treated with ADP at 2425, 1212.5 and 606.25 $\mu\textrm{g}$/ml in the absence, or at 8126, 4063 and 2031.5 $\mu\textrm{g}$/ml in the presence of S9 metabolic activation. These results show that under the conditions used, ADP does not harmfully affect the bacterial or mammalian cell system at the gene level.

• Journal of Physiology & Pathology in Korean Medicine
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• v.28 no.6
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• pp.621-629
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• 2014

This study aimed to evaluate the genotoxicity of GST (Gamisasangja-tang). For examining genotoxicity, we carried out bacterial reverse mutation assay, chromosome aberration assay, micronucleus induction test according to OECD guidelines. Bacterial reverse mutation assay: In GST treating group, regardless of existence S9 mix, revertant colonies counts appeared to be less than twice of negative control group and dose dependent increase. In positive control group, revertant colonies counts were shown to be more than twice of negative control croup. Chromosome aberration assay: All cell line showed repetition rate of abnormal chromosome aberration less than 5%, regardless of treating time, existence of S9 mix, and no significant change ($p{\succeq}0.05$) compared with negative control group. Micronucleus induction test: Micronucleated polychromatic erythrocytes (MNPCE) repetition rate of Polychromatic erythrocytes (PCE) showed no significant changes compared with negative control group ($p{\succeq}0.05$). PCE portion of total erythrocytes also showed no significant changes ($p{\succeq}0.05$). Our results showed that GST didn't induce any genotoxicity.