• Korean Journal of Food Science and Technology
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• v.31 no.1
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• pp.246-251
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• 1999

This study was designed to evaluate the mutagenicity and the primary mutagenic mechanism of chloropropanols by using various genotypes of E. coli WP2, E. coli TK and E. coli GW series strains. Chloropropanols showed the low mutagenic activities in E. coli WP2s and WP2 establishing the following order; 2,3-DCP> 3-MCPD>1,3-DCP. As compared with E. coli WP2s, the decrease of mutagenic activity and the increase of survival rate in E. coli WP2 $(WP2s\;uvrA^+)$ suggest that DNA lesions produced by chloropropanols could be easily removed by excision-repair system. From the diminution of mutagenic activity and survival rate in E. coli CM611 (WP2s lexA), it was confirmed that the mutagenesis by chloropropanols was dependent on the SOS-repair system. This fact could be also confirmed from the result that both the mutagenic activity and survival rate in E. coli TK610 (umuC) were much lower than those in E. coli TK603 $(umuC^+)$. In the experiment to examine the possibility that chloropropanols might have effects on the LexA of SOS response negative regulator, there was no variation in ${\beta}-galactosidase$ activities of E. coli GW1105 $[lexA3\;(Ind^-)]$ and GW1107 [lexA51 (Def)] by addition of the compounds, indicating that chloropropanols do not have any effects on the LexA, itself.

• Bulletin of the Korean Chemical Society
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• v.24 no.6
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• pp.731-732
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• 2003

Mutagen X (MX), 3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone is one of the most potent directing acting mutagen ever tested in SAL TA100 assay. Although MX analogues have been synthesized, tested for mutagenicity and modeled by structure-activity relationship (SAR) methods, the mechanism of interaction of these compounds with DNA to produce their remarkable mutagenic potency remains unresolved. MX exists as an equilibrium mixture of both ring and open form in water. This equilibrium is very fast for Ames test. Because the mixture is not separable by experimental methods, it is not clear which one is really responsible for the observed mutagenicity. There have been many debates that which one is really responsible for the observed mutagenicity. We used ab initio methods for the MX analogues. It seems both ring and open form could react with DNA bases as electrophiles. However, every open form has consistently lower LUMO energy than corresponding ring form. It is reasonable to assume that the major reaction will go through via open form for MX analogues. This suggest that the open form is more likely really mutagenic.

• Journal of the Korean Society of Tobacco Science
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• v.13 no.1
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• pp.19-26
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• 1991

Ames test using special strains which are histidine requiring mutant of Salmonella typhimufium , is widely utilized as short-term bioassay to evaluate the genotoxicity of chemicals. This method requires the liver microsome(5-9 fraction) to provide mammalian metabolism of the compounds, Therefore, the mutagenic potency of the chemicals is affected by not only the intrinsic properties of them but also the efficiency of the in vitro microsomal activation system. For this reason, the complex mixtures such as environmental pollutants from occupational sources, natural products or cigarette smoke condensates(CSC) , might be often appeared the false results. Induction of sister chromatid exchange(SCE) in cultured cells is known as another sensitive and powerful tool for the measurement of genotoxicity and the method has also an advantage which is able to apply to the in vitro and in vivo systems. In the present study, the inducibilities of revertant colonies in tester strain TA98 and SCE in human Iymphocytes by positive controls and total particulated materials(TPM) obtained from various brand(domastic and imported) cigarettes were compared in order to investigate whether the results in Ames test are in agreement with those in SCE analysis. The mutagenic activities of well known mutagens such as B(a)P showed excellent dose-response in the both methods although the induction mechanism was different each other, but cyclophosphamide resulted such effect only in SCE analysis. Most TPM tested showed a similar pattern in the mutagenic activities in those methods. However, only two(one imported brand and one domestic sample cigarettes) among the TMP obtained from various cigarettes appeared the higher induction in SCE than Ames test.

• Toxicological Research
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• v.17
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• pp.319-321
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• 2001

Taihu Lake is a major water source for part of Yangtze Delta, which is one of the most urbanized and economically prosperous areas in China. In last couple of decades, some parts of the lake were highly polluted due to eutrophication. This study analyzed dioxin-like potential and mutagenic potential in surface water samples from Taihu Lake. The samples were prepared by XAD-2 resin procedure. A batch of biological assays, including dioxin-like potential microassay with the rat hepatocyte cell line H411E, and Ames test was employed in the research. Results showed that jour water samples have high content of dioxin-like biological potential, the highest activity TEQ to 2,3,7,8-TCDD was 48 pg/ι in sample 1. The mutagenic effect with reading-frame shifting mechanism was confirmed in 3 of 4 samples. The effective sewage treatment facilities and reliable monitoring surveillance system are urgently needed for this area.

• Environmental Mutagens and Carcinogens
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• v.16 no.2
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• pp.117-123
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• 1996

This study was carried out to examine the mechanism of Arsenic cytotoxicity through several in vitro test systems. Dose-dependent decrease of cell survival by Arsenic was observed by colony forming assay. Arsenic was weak mutagenic in inducing HGPRT point mutation in CHO cells. The frequency of chromosomal aberrations increased in a dose-dependent manner and the most frequent type of chromosomal aberrations induced by Arsenic were chromatid type deletions. U!trafiltrates of culture media from CHO cells treated with Arsenic induced sister chromatid exchanges(SCE) in CHO cells and Arsenic was able to induce lipid peroxidation in CHO cells. The results suggested that the ultrafiltrates of media from CHO cells treated with Arsenic contain clastogenic factor(CF) and Iipid peroxidation might be involved in the formation of CF.

• Korean Journal of Oriental Medicine
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• v.14 no.1
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• pp.49-58
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• 2008

Objective : To provide information about the accessory product of Broussonetia kazinoki Siebold or Broussonetia papyrifera (L.) Vent by analyzing old books of oriental medicine, domestic/international papers and related patents Methods : Old books related to the accessory product in the field of oriental medicine were reviewed. Research papers regarding the pharmacological activity of the by-products were reviewed and analyzed. Patents about the residual products were examined and classified by year and subject Results : Seven kinds of by-products from Broussonetia kazinoki Siebold or Broussonetia papyrifera (L.) Vent has been used as medicines in oriental medicine. Recently, anti-oxidating, anti-cancer, anti-mutagenic and anti-inflammation activity of the residual product of these plants has been investigated through scientific research. There were 19 patents related with the accessory products of these plants, which were in the subjects of functional cosmetics, anti-inflammation, cleansing goods, hair restorers or improvement of learning ability. Further investigations about the activity of these plants are needed in bone metabolism, water balance and hemostasis in the future. Conclusion : Residual products from these plants is being used in various ways. However, more studies on the efficacy and mechanism, as well as safety, of these plants should be conducted precisely in the future.

• Environmental Mutagens and Carcinogens
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• v.18 no.1
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• pp.15-21
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• 1998

Transgenic animal and cell line models which are recently developed and used in toxicology fields combined with molecular biological technique, are powerful tools to study the mechanism of mutation in vivo and in vitro, respectively. Transgenic 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 processes. The lac I and lac Z gnee most widely used as a mutational target in transgenic systems. The assay is performed by treatment with putative mutagenic agents, isolation of genomic DNA from cells or tissues, exposure the isolated DNA to in vitro packaging extract, plating and sequencing. The results from these processes provide not only mutant frequency as quantitative evaluation but also mutational spectrum as qualitative evaluation of various agents. Therefore we introduce and review the principle, detailed procedure and application of transgenic mutagenesis assay system in toxicology fields especially in mutagenesis and carcinogenesis.

• Korean Journal of Plant Resources
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• v.33 no.3
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• pp.183-193
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• 2020

Recently, as a natural substance has been emphasized interest in research to enhance the immune function. Green lettuce (Lactuca sativa L.) is a popular vegetable used fresh and it contains various phytochemicals and antioxidant compounds, and has been reported to have various physiological activities such as antibacterial, antioxidant, antitumor and anti-mutagenic. However, only a few studies have investigated on the mechanism of action of immune-enhancing activity of lettuce. Therefore, in this study, the immunomodulatory activities and potential mechanism of action of Green lettuce extracts (GLE) were evaluated in the murine macrophage cell line RAW264.7. GLE significantly increased NO levels by RAW264.7 cells, as well as expressions of immunomodulators such as iNOS, COX-2, IL-1β, IL-6, IL-12, TNF-α and MCP-1. Although GLE activated ERK1/2, p38, JNK and NF-κB, GLE-mediated expressions of immunomodulators was dependent on p38, JNK and NF-κB. In addition, TLR4 inhibition blocked GLE-mediated expressions of immunomodulators and activation of p38, JNK and NF-κB. Taken together, these results demonstrated that TLR4-MAPK/NF-κB signalling pathways participated in GLE-induced macrophage activation and GLE could be developed as a potential immunomodulating functional food.

• The Korean Journal of Food And Nutrition
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• v.9 no.3
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• pp.294-298
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• 1996

By the 505 chromotest which utilized Escherichia bolt PQ 37, Korean medicinal plants had been screened to Investigate the antimutagenic effect to aflatoxin B1(AFBl). Ikmocho(IMC, Leonurus sibiricus L.) was extracted with hot water. The extract was not found to be mutagenic in the Salmonella mutation test with or without metabolic activation, and the extract was showed to possess the antimutagenic properties towards AFB1-induced metation. The mutagenicity of AFB1 was inhibited by methanol soluble fracstion (IMC-MS) in dose-dependent. However, water-soluble fraction exhibited comutagenic activity. The greatest inhibitory effect of IMC-MS on AFB1 mutagenicity occurred when IMC-MS was first incubated, AFB1 followed by a second incubation with the cells and 59 mixture. Also lower inhibition was occurred when S9 mixtures were first incubated, with IMC-MS followed by a second incubation with AFBI. The results of the sequential incubation study support the probability that one mechanism of inhibition could involve the formation of chemical complex between IMC-MS and AFB1 rather than deactivation of S9 enzyme.

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.99.1-99.1
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• 2003

Cinnamaldehyde is the main component of cinnamon bark oil and show several biological activities such as anti-tumor, anti-fungal, anti-mutagenic and anti-inflammatory effects. A couple of studies have investigated how the natural compound exerts its anti-inflammatory effect. In despite of numerous investigations, the biological mechanism of effects belong to cinnamaldehyde remain unclear. We isolated 2-hydroxycinnamaldehyde(HCA) from the bark of Cinnamomun cassia Blume and reported a various of biological activities of HCA. (omitted)