• Proceedings of the Korea Environmental Mutagen Society Conference
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• 2003.05a
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• pp.83-83
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• 2003

• Proceedings of the Korean Society of Life Science Conference
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• 2002.09a
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• pp.71-71
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• 2002

• Preventive Nutrition and Food Science
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• v.3 no.3
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• pp.287-291
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• 1998

Brining property and antimutagenic effects of organically cultivaged Chinese cabbage kimchi (OC kimchi) and common Chinese cabbage imchi (CC kimchi) were studied. The salt absorption rate of leaves was faster than that of stems of the Chinese cabbages. Due to the large portion of leaf in organic Chinese cabbage, organic Chinese cabbage(OC) was much faster in terms of salt absorption rate than common Chinese cabbage(CC). The antimutagenic effects of methanol extracts of CC kimchi and OC kimchi were studied against aflatoxin B1(AFB1) using Ames test on Samonella typhimurium TA 100 and N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) using SOS chromotest. Methanol extract from 6 -day fermented OC kimchi at 15 $^{\circ}C$ showed 80% inhibition rate against the indirect mutage, aflatoxin B1 induced mutagenicit where as that from 6-day fermented CC kimchi at 15 $^{\circ}C$ showed 54% inhibition rate in the Ames test. Methanol extracts from 6-day fermented CC kimchi and OC kimchi showed 27 % and 58 % inhibition rate against direct mutagen , N-methyl-N'-nitro-N-nitrosoguanidine induced mutagenicity, respectively in SOS chormotest, thus OC kimchi exhibited higher antimutagenic activity than kimchi.

• The Korean Journal of Mycology
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• v.21 no.3
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• pp.230-234
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• 1993

In order to isolate mutants in Rhizopus nigricans, the optimal treatment conditions for the chemical mutagens, N-Methyl-N'-Nitro-N-Nitrosoguanidine(MNNG) and Ethyl Methane Sulphonate(EMS), were explored. When MNNG was used as the chemical mutagen, the optimum concentration and treatment time for the best mutation frequency were $125{\mu}g/ml$ and 60 minutes, respectively. Under the optimum conditions for MNNG, the survival rate was 0.1-1.0%. The leucine auxotroph could be isolated. The phenotypic characteristics of the three mutants prepared are as follows; shortened sporangiophore, spiral sporangiophore, and reduced size of sporangium and sporangiospore. However, EMS as the chemical mutagen was ineffective for this species.

• Korean Journal of Microbiology
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• v.27 no.2
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• pp.155-161
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• 1989

Lactobacillus sporogenes was treated with N-methyl-N'-nitro-N-nitrosoguanidine (NTG) to obtain resistant mutants to rifampicin. Fifty-eight strains of the NTG-induced mutants showed distinct resistance to rifampicin and nine mutants were selected for further studies. They also exhibited identical characteristics with the parent Lactobacillus sporogenes when they were tested for spore formation, acid formation and growth inhibition of E. coli. From in vitro test it was identified that rifampicin is not inactivated by certain factors of the rifampicin resistant mutants. It is suggested that they can be utilized as efficient normalizing agents for human intestinal flora when they are simultaneously taken with rifampicin

• Journal of Microbiology and Biotechnology
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• v.14 no.3
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• pp.570-575
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• 2004

Three different strains of carotenoid accumulating XantlwphyUomyces dendrorhous mutants, JH1, JH2, and JH3, were isolated by NTG (N-methyl-N'-nitro-N-nitrosoguanidine) mutagenesis, which might potentially be useful for animal feed as well as for studies on the regulation and biosynthesis of astaxanthin. Mutants were selected based on the capability of growth and carotenoid production on the YM agar plate containing chemical inhibitor, $\beta$-ionone. Astaxanthin-overproducing mutant JH1 produced 4.032 mg astaxanthinlg dry cell weight, and this value was about 15-folds higher than that of wild-type. $\beta$-Carotene-overproducing mutant JH2 produced 0.273 mg $\beta$-carotene/g dry cell weight, and this was 4-folds increase from that of wild-type. In contrast, JH3 was a white-colored mutant that was unable to produce carotenoid pigment.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.2
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• pp.305-312
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• 1995

Ixeris dentata was extracted with methanol and then the methanol extract was further fractionated to hexane, chloroform, ethyl acetate, butanol and aqueous fraction. The methanol extract of lxeris dentata had the strong antimutagenic effect on the aflatoxin B1(AFB1) and N-methyl-N'-nitro-N-nitrosoguanidine(MNNG) in Ames mutagenicity test and SOS chromotest. Among the solvent extracted fractions from the methanol extract, the chloroform fraction exhibited the greatest antimutagenic effect suppressing the mutagenicity of AFB1 with inhibition rate of 74 percent. The methanol extract of Ixeris dentata also revealed the inhibitory effect on the growth of MG-63 human osteosarcoma cells after 6 days of breeding at 37℃. The chloroform fraction and the ethyl acetate fraction from the methanol extract of lxeris dentata were most effective and inhibited the growth of MG-63 cells by 97 and 93 percent, respectively. It is suggested that the inhibitory effects of lxeris dentata on the mutagenicity and the growth of MG-63 human osteosarcoma cells are strong in the lipid soluble fractions.

• Preventive Nutrition and Food Science
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• v.7 no.1
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• pp.67-71
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• 2002

Capsaicin (trans-8-methyl-N-vanillyl-6-nonenarnide), a major pungent component of hot pepper, is known to exert antioxidative properties. In this study, we investigated the protective effects of capsaicin against chemical carcinogen-induced oxidative damage in rats. Male Sprague Dawley rats weighting 230~250 g were treated with chemical carcinogens such as 2-nitropropane (2NP) or n-methyl-N'-nitro-N-nitrosoguanidine (MNNG) after (or before) the administration of capsaicin at doses of 0.5, 1,5 mg/kg. The level of lipid peroxidation in rat liver was estimated by measuring the amounts of thiobarbituric acid reactive substances. The degree of oxidative DNA damage was evacuated by measuring a DNA adduct, 8-hydroxydeoxyguanosine (8-OHdG), in urine. Antioxidative activities of capsaicin and its metabolites in vitro were determined by the measurement of DPPH (1,1-diphenyl-2-picrylhydrazyl), a radical quencher. Significant inhibition of 2-NP induced lipid peroxidation was observed in the liver of the rat when treated with capsaicin. MNNG-induced urinary excretion of 8-OHdG was decreased by capsaicin treatment. Capsaicin and its metabolites inhibited net only the formation of free radicals, but also lipid peroxidation in vitro. Our results show that capsaicin may function as a free radical scavenger against chemical carcinogen-induced oxidative cellular damage in vivo. The observed antioxidative activities of capsaicin may play an important role in the process of chemoprevention.

• Korean Journal of Food Science and Technology
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• v.29 no.6
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• pp.1281-1287
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• 1997

This study was conducted to investigate the antimutagenic effects of methyl alcohol extracts from Auricularia auricula and Gyrophora esculenta on the SOS response induced by 4-nitroquinoline-1-oxide (4NQO), N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), mitomycin C (MMC) and 3-amino-1,4- dimethyl-5H-pyrido-[4,3-b]indol (Trp-P-1) in E. coli PQ37/plasmid pKM101. In the mutagenic test on test strain, both methyl alcohol extracts did not show mutagenic activity. In the antimutagenic test, each sample strongly inhibited the mutagenecity induced by 4NQO, MNNG, MMC and Trp-P-1. Methyl alcohol extracts from Auricularia auricula and Gyrophora esculenta showed inhibitory effects of 52% and 59% against 4NQO, 49% and 58% against MNNG, 53% and 64% against MMC, and 61% and 64% against Trp-P-1, respectively. Gyrophora esculenta extracts on the antimutagenicity showed relatively higher inhibitory effects than that of Auricularia auricula.

• Environmental Mutagens and Carcinogens
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• v.9 no.1
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• pp.33-46
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• 1989

본 연구는 알킬화제를 처리한 CHO-K1 세포에서 DNA 복제억제와 그 회복과정의 분자론적 기작을 규명할 목적으로 방사선 이중 표지에 의한 DNA 합성율의 측정, 알칼리 자당 농도구배 초원심분리법에 의한 DNA 분자량과 후복제 회복율을 측정하여 다음과 같은 결과를 얻었다. (1) 1mM methyl methanesulfonate (MMS)와 1nM N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) 이하의 낮은 농도의 처리군에서는 DNA 합성율이 급격히 감소하였으나, 2 mM MMS, 2mM MNNG이상의 농도에서는 그 감소양상이 둔화되었다, (2) DNA 합성율은 알킬화제의 처리 직후 감소하였다가 시간경과에 따라 회복되어 처리후 4시간 째에는 대조군 수준 또는 그 이상으로 회복되었다.