• Journal of the Korean Dietetic Association
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• v.3 no.2
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• pp.105-111
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• 1997

The inhibitory effect of rice(Oryza sartiva L., illpumbyeo) against mutagenicity induced by tryptophan pyrolysates were investigated using Salmonella typhimurium reversion assay. Both methanol extracts of obtained from brown and white rice were found to possess strong activites of inhibiting the mutagenicities of 3-amino-1,4-dimethyl-5H-pyriod[4,3-b]indol(Trp-P-1) and 3-amino-1-methyl-5H-pyrido[4,3-b]indol(Trp-P-2) on Salmonella typhimurium reversion assay. As the concentration of methanol extract increased, inhibitory effect on mutagenicity increased but reached at steady state as inhibition rate of 90% when the concentration was above 10mg/plate. There was no significant difference(p>0.05) in inhibitory effect of methanol extracts between brown and white rice against tryptophan pyrolysates.

• Korean Journal of Food Science and Technology
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• v.28 no.6
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• pp.1065-1070
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• 1996

Antimutagenic effect of chitosan hydrolysates was investigated using Salmonella typhimurium reversion assay and SOS chromotest against 3-amino-1-methyl-5H-pyrido[4,3-b]lindole(Trp-P-2), aflatoxin $B_1$, 2-nitrofluorene and 4-nitroquinoline oxide. After partial acid hydrolysis of chitosan, six fraction of different molecular size were obtained by ultrafiltration. Chitosan hydrolysates showed antimutagenic effect of $0{\sim}78%$ on Trp-P-2, $0{\sim}92%$ on aflatoxin $B_1$ and $0{\sim}51%$ on 2-nitrofluorene in Salmonella typhimurium reversion assay. Inhibitory effect in Salmonella typhimurium reversion assay showed the highest at 5% concentration of fraction 6 in Trp-P-2, 10% concentration of fraction 5 in aflatoxin $B_1$ and 5% concentration of fraction 6 on 2-nitrofluorene. In SOS chromotest, chitosan hydrolysates showed anitimutagenic effect of $0{\sim}54%$ on Trp-P-2 and $0{\sim}77%$ on 4-nitroquinoline oxide, These results suggest that high molecular weight fraction of chitosan hydrolysates (MW>30,000) in most effective to inhibit mutagenicity of tested mutagens.

• Korean Journal of Microbiology
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• v.20 no.2
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• pp.89-97
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• 1982

Mutants of plasmid pKM101 modified to enhance mutagenesis were induced and characterized in Salmonella typhimurium. The pKM101 mutant plasmid were transferred normally and stably maintained in cells. They had modified in their ability (i) to enhance the reversion of both point and frameshift mutations, (ii) to protect the cell against UV-irradiation and chemical mutagen treatment, (iii) of ampicillin resistance. A similar modification in enhancement of reversion was also observed in a $uvrB^-$ strains. These results indicated that mutator effect of pKM101 was coded by one plasmid gene.

• Toxicological Research
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• v.14 no.2
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• pp.211-216
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• 1998

In order to evaluate the mutagenic potential of SDK(skin decontamination kit) produced by Agency for Defense Development(ADD), were performed Salmonella typhimurium reversion assay, chromosomal aberration test on chinese hamster ovarian cells and in vivo micronucleus assay using mouse bone marrow cells according to the established regulation of Korean Food and Drug Administration. In the reverse mutation test using Salmonella typhimurium TA98, TA100, TA1535 and TA1537 did not in-crease the number of revertant at any of the concentration tested in this study. SDK did not increase the number of cells having structural or numerical chromosome aberration in cytogenetic test. In mouse micronucleus test, no significant increase in the occurrence oj micro nucleated polychromatic erythrocytes were observed in ICR male mice intraperitoneally administered with SDK. These results indicate that SDK has no mutagenic effects under these experimental conditions.

• Journal of Food Hygiene and Safety
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• v.15 no.4
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• pp.297-303
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• 2000

Gamma irradiation at 20 kGy was applied to Kanjang (soy sauce), Doenjang (soybean paste), Kochujang (hot pepper pasts) and Chungkukjang for their possible genotoxicity. The genotoxicity of 20 kGy-irradiated samples was evaluated by Salmonella typhimurium reversion assay. The Salmonella tester strains included TA98, TA100, TA1535 and TA1537 in the absence and presence of an exogenous metabolizing system (59 mix). All samples were negative in the bacterial reversion assay with S. typhimurium TA98, TA100, TA1535 and TA1537. The results indicated that 20 kGy of gamma irradiation on water-soluble fraction of Kanjang, Doenjang, Kochujang and Chungkukjang were not shown mutagenicity.

• Korean Journal of Food Science and Technology
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• v.30 no.2
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• pp.450-455
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• 1998

Pine has been known as a traditional medicinal plant and as showing a physically beneficial function to a human being. Therefore, this study was performed to investigate the physiological activities of main pine neddles. Ethanol extracts from pinus needles did net exhibit any mutagenicity. On the contrary, inhibitory effects of ethanol extract were observed on mutagenicity induced by N-methyl-N'-nitro-N-nitrosoguanidine(MNNG), 4-nitroquinoline-1-oxide (4NQO), 3-amino-1,4-dimethyl-5H-pyrido-(4,3-b)indol (Trp-P-1) and benzo(a)pyrene $(B({\alpha})P)$ using Salmonella typhimurium reversion assay. On direct-acting mutagen (MNNG, 4NQO) and indirect-acting mutagen (Trp-P-1, $(B({\alpha})P)$, we observed higher inhibitory effect. Stepwise fractionation of the ethanol extract was done by using ether, chloroform, ethyl acetate, butanol and water to obtain effective fraction. Among them, water fractions $(100\;{\mu}g/plate)$ of Pinus thunbergii, Pinus rigida, Pinus densiflora and Pinus koraiensis showed high inhibition of 91.65%, 94.7%, 84.22% and 79.02%, respectively, on the mutagenicity of MNNG in Salmonella typhimurium TA100.

• Journal of Life Science
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• v.9 no.6
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• pp.728-732
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• 1999

The inhibitory effects of methanol extracts from wild mushrooms on mutagenicity induced by benzo(a)pyrene (B(a)P) and N-methyl-N-nitro- nitrosoguanidine(MNNG) were investigated using Salmonella typhimurium reversion assay. In Ames test, The methanol extracts of 11 mushrooms did not show any mutagenicity but The methanol extracts of Lactarius piperatus, Naematoloma fasciculare and Innotus xeranticus showed 40∼80% of inhibitory effect on the mutagenicity induced by indirect mutagen of B(a)P and also showed 60∼80% of antimutagenic activity toward MNNG irrespective of their concentrations.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.5
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• pp.958-964
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• 1997

The three medicinal herbs-Curcuma longa Linne, Paeonia japonica Miyabe, Scutellaria baikalensis George-irradiated with gamma rays have been tested for their possible genotoxicity. The methanol-soluble and water-soluble fractions of the 10kGy gamma-iradiated herbs were examined in the Salmonella typhimurium histidine reversion assy(Ames test) using S. typhimurium TA98, TA100 and TA102 as tester strains. No mutabenicity was detected in this assay with or without metabolic activation. The safety of the herbs irradiated with gamma rays at practical doses needs to be evaluated in further tests of genotoxicity in vivo and chronic and reproductive toxicity.

• Journal of Food Hygiene and Safety
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• v.10 no.3
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• pp.133-138
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• 1995

In vitro antimutagenic activity of methanol extract from brrwn rice and its physico-chemical characteristics were investigated using Salmonella typhimurium reversion assay and SOS chromotest. Methanol extracts of brown rice were not mutagenic compared with direct and indirect, mutagenicities of 4NQO (4-nitroquinoline oxide), 2NF(2-nitrofluorene), Trp-p-1(3-Amino-1,4-dimethyl-5H-pyrido-[4,3-b]indole), and Trp-p-2(3-Amino-1-methy-5H-pyrido-[4,3-b]indole). Antimutagenic activity against the indirect mutagenicties induced by Trp-p-1, Trp-p-2 and AFB1 (aflatoxin B1) was found in methanol extract. Even though antimutagenic activity showed dose-dependent, it remained constant at inhibition rate ranging 60~90% when the concentration was abov 3mg/plate in the S. typhimurium reversion assay and 0.2~0.6 mg/assay in the SOS chromotest. The antimutagenic activity of the methanol extracts was stable at various pH (2, 7 and 10), temperatures (60, 80 and 10$0^{\circ}C$)and heation times (2, 4, 6, 8, 10 min at 10$0^{\circ}C$).

• Toxicological Research
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• v.13 no.1_2
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• pp.55-60
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• 1997

Gamma irradiation was applied to Angelicae gigantis radix and Aloe to improve their hygienic quality. The effective dose of irradiation was 7 kGy in Angelicae gigantis radlx and 5 kGy in Aloe for the sterilization of all contaminated microorganisms tested. After 8 months of storage at room temperature, no growth of microorganisms was observed in the irradiated products. The safety of these products were evaluated by Salmonella typhimurium reversion assay and in vivo micronucleus assay using mouse bone marrow cells. They were negative in the bacterial reversion assay with S. typhimurium TA 98, TA100, TA1535 and TA1537. In the in vivo mouse micronucleus assay, they did not show any clastogenic effect at all doses tested. These results indicate that the gamma irradiation of Angelicae gigantis radix at 12 kGy and of Aloe at 10 kGy have no genotoxic effects under these experimental conditions.