• Preventive Nutrition and Food Science
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• v.2 no.1
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• pp.29-34
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• 1997

In order to determine the effectiveness of linoleic acid(LA) to inhibit carcinogens/mutagens-induced mu-tagenesis, Ames test using Salmonella typhimurium TA100 and the SOS chromotest using E. Coli PQ37, were carried out. The inhibitory effect of LA(1%) on the Ames mutagenicity test were 98%, 78%and 69% mediated by aflatoxin B₁(AFB₁), N-methyl-N'-nitro-N-nitrosoguanidine(MNNG) and 4-nitroquinoline-1-oxide(4-NQO), respectively. LA exhibited a strong antimutagenic activity aganist indirect mutagen, AFB₁whereas exhibited the same concentration of LA showed weaker inhibitory effects on direct mutagens of MNNG and 4-NQO than that AFB₁. LA also reduced the SOS responses induced by MNNG and 4-NQO significantly. This result showed a possibility that LA can be a protective agent in early step of cancinogenesis.

• The Korean Journal of Zoology
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• v.36 no.1
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• pp.84-96
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• 1993

한국산 도롱뇽(Hynobius leechii) 유생의 다리 발생 과정을 관찰하고 잠재적 돌연변이 유발물질인 제-methyl-N'-nitro-N-nitrosoguanidine(MNNG)과 잠재적 기형 유발물질인 retinol palmitate가 다리 발생에 미치는 영향을 알아보았다. 정상적인 개체에서 됫다리의 발생 단계는 외부와 내부의 형태적 특징을 기준으로 하여 7단계로 나누어 볼 수 있었으며 전연골세포의 밀집에 따른 골격형성은 다리 발생아의 근위부에서 시작하여 원위부로 진행됨을 확인할 수 있었다. 도롱뇽 유생을 MNNG(10 rpm)나 retinol palmitate(37.5 lpm)로 처리한 경우, 공통적으로 다리 원위부의 골격 형성이 억제되었으며, 특히 이러한 골격 형성 억제 현상은 처리시기가 이를수록 보다 심하게 나타났다. 이러한 결과는 발생을 저해하는 물질에 대한 미분화 상태의 세포들의 반응성이 발생과정 중 특정 단계에 국한됨을 시사하는 것으로 해석된다.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.556-557
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• 2001

This study was performed to improve the efficency of production of biosudactant which were produced by newly screened MNNGCN-Methyl-N-Nitro- Nitrosoguanidine) mutagenized P. aeruginosa EMS1. A culture grown exponentially for $30^{\circ}C$ in trypic soy brotb is adjusted to pH. MNNG is added and incubated in water bath shaker at about 250 ${\sim}$300rpm. After 20 min, is dilutecl into colded trypic soy broth and centrifugation. The cell pellet is resuspended in 50$m{\ell}$ of trypic soy broth. Cultures are grown at $30^{\circ}C$ overnight. cetyltrimethylammonium bromide-metbylene blue agar plate selected dark blue halo colony. Peanut oil, Castor oil, Olive oil, and so on were compared as carbon source of surface tension and emulsifying activity.

• Journal of Life Science
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• v.23 no.8
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• pp.963-969
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• 2013

Although it is popularly believed that vitamin C protects cells from various genotoxicants, the degrees and mechanisms of itsprotective actions are not fully understood. In this study, vitamin C's protective effects against various genotoxicants were quantified, together with subsequent analyses on the mechanisms of these protective effects. Comet assay was employed to measure the degree of DNA damage in Chinese hamster ovary cells (CHO-K1) exposed to five genotoxicants, $H_2O_2$, $HgCl_2$, N-methyl-N-nitro-N-nitrosoguanidine (MNNG), 4-nitroquinoline-1-oxide (4NQO), and UV-irradiation. In cases cells were treated with $H_2O_2$, $HgCl_2$, and 4NQO together with vitamin C, the damage to DNA decreased to the level of the control group. In cases of UV-irradiation, the protective effect of vitamin C appeared, but did not reach the control levels. Interestingly, vitamin C did not have protective effects against the genotoxicity of MNNG. The degrees of DNA damage of cells treated with vitamin C prior to exposure togenotoxicants were 28~49% lower than those of cells treated with vitamin C after being exposed to genotoxicants. In conclusion, vitamin C had strong antioxidanteffects against genotoxicants by being a primary antioxidant blocking genotoxicity reaching the cells, rather than being a secondary antioxidant acting on post-exposure DNA repair processes. However, vitamin C's protective effects appearto be limited, as there are genotoxicants, such as MNNG, whosegenotoxicityis not affected by vitamin C. Therefore, the results of this study warrant furtherstudies on toxic mechanisms of genotoxicants and their interactions with protective mechanisms of vitamin C.

• Korean Journal of Food Science and Technology
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• v.22 no.6
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• pp.625-631
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• 1990

This study was carried out to investigate the antimutagenic effects of five kinds of apple enzymatic browning reaction products(AEBRP) on mitomycin C (MMC), N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), 4-nitroquinoline-1-oxide(4NQO), benzo(${alpha}$)pyrene(B(${alpha}$)P) and 3-amino-1,4-dimethyl-5H-pyri-do [4,3-b]indol (Trp-P-1). In spore rec-assay using B. subtilis Hl7($rec^+$) and M45($rec^-$), homocatechol-AEBRP and hydroquinone-AEBRP showed strong antimutagenic effects on MMC and MNNG as the concentration of AEBRP increased. In the Ames test using S. typhimurium TA98 and TA100, hydroxyhydroquinone-AEBRP and pyrogallol-AEBRP showed strong antimutagenic effects on Trp-p-1 and B(${alpha}$)p in TA98 and TA100 in the presence of S-9 mix. Most of AEBRPs suppressed about 50% to 80% the mutagenesis in S. typhimurium TA98 induced by MNNG, however, AEBRPs except hydroxyhydroquinone-AEBRP showed antimutagenic effects of about 94% in TA100. Antimutagenic effects of the five kinds of AEBRPs on 4-NQO were more or less weak, in particular homocatechol-AEBRP exhibited the inhibitory effect of about 48% in TA98, and homocatechol-AEBRP and hydroquinone-AEBRP showed inhibitory effects of about 46% to 58% in TA 100.

• Korean Journal of Food Science and Technology
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• v.32 no.6
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• pp.1426-1432
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• 2000

The effects of raw anchovy, salted raw anchovy (20% salt+anchovy), 6- and 12-month fermented anchovy (20% salt added) on the N-methyl-N'-nitro-N-nitrosoguanidine (MNNG)-induced mutagenicities were evaluated using Salmonella assay and the SOS chromotest. The methanol extracts from raw, salted and the fermented anchovy (FA) sample increased the revertants of Salmonella typhimurium TA100 at the level of $0.125{\sim}5\;mg/plate$ in Ames test. The salted raw anchovy extract induced the largest number of the revertants. All the FA extracts had comutagenic effect on the MNNG. Twelve-month FA juice exerted the lowest comutagenic activity among the FA samples. The comutagenicity of 12-month FA was due to the synergistic effect of salt and histidine which teem in FA. Thus the Ames test using histidine requiring mutant, S. typhimurium, is not appropriate to determine the mutagenicity of FA which is rich in histidine. In SOS chromotest using E coli, raw, salted and fermented anchovy extracts did not show any mutagenicity in the absence of MNNG. The raw and fermented anchovy samples blocked the SOS response of E. coli PQ37 induced by MNNG, while raw salted anchovy increased the SOS induction factor. Twelve-month FA juice showed higher antimutagenic effects than 6-month FA samples (both solid and liquid). The ripened (12-month) FA along with raw anchovy in the SOS chromotest exhibited antimutagenic activity.

• YAKHAK HOEJI
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• v.38 no.3
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• pp.332-337
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• 1994

Using germinal and somatic cell mutation assaying systems of Drosophila melanogaster, effects of Ginseng and Salvia miltiorrhiza extracts on the in vivo mutagenicity induced by N-methyl-N'-nitro-N-nitrosoguanidine(MNNG) were investigated. For these purpose, the attached-X method and the mwh/flr spot test system which are an X-linked lethal mutation and a somatic chromosome mutation assaying system, respectively, were used. In the induction of X-linked lethal mutations during the spermatogenesis, MNNG showed more actions in the sperm and spermatid stages, in which Ginseng and Salvia miltiorrhiza extracts had remarkable inhibitory effects than other stages. Ginseng and Salvia miltiorrhiza extracts reduced the mutagenicity by MNNG in the mwh/flr system, which reveal that they can inhibit gene mutation, deletion and mitotic chromosomal recombination. These results seem to suggest that Ginseng and Salvia miltiorrhiza extracts may exert their inhibitory effects to in vivo mutagenic and/or carcinogenic properties of DNA-damaging agents.

• 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.23 no.6
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• pp.916-921
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• 1994

The inhibitory effects of the juice and boiling water extract of Houttuyina cordata Thunb., which has been known as a traditional folk antitumor agent, on the genotxicity induced by mutagens were investigated . For this purpose, Salmonella typhimurium TA98 and TA100, and the transheterozygous (mwh/+) third larvae of Drosophila melanogaster were used. The juice of fresh H. cordata 9JHC) and boiling H. cordata extract (BHC) showed antimutagenicities toared alfatoxin B₁ in S. typhimurium TA 98 and TA100. The JHC's inhibitory effect increased by 76% to 98% as the adding concentrations increased, and the BHC had a 86-97% inhibitory effect. however, in the case of N-methyl-N'-nitro-N nitrosoguanidine (MNNG), the JHC's inhibitory effect was 52-60% irrespectively of its concentrations and the BHC had a low inhibitory effect. The JHC and BHC slightly reduced the somatic chromosomal mutagenicity by MNNG in the wing hair spot test system (mwh/+) of D. melanogaster, which suggests that they can inhibit gene mutation , deletion and mitotic chromosomal recomgination.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1994.04a
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• pp.325-325
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• 1994

본 연구에서는 먼저 14종의 flavonoid화합물을 대상으로 발암물질로서 잘 알려져있는 benzo(a)pyrene[B(a)P]에 대한 소핵생성억제효과를 관찰하였다. 소핵시험을 이용한 유전독성억제실험에서 비적적 큰 활성을 보이는 flavonoid는 2,3 이중결합과 3,5,7-trihydroxyl기를 갖는 polyhydroxy flavonol화합물들이었다. 이중에서 galangin은 활성이 비교적 컸으며, 이같은 유전독성억제효과는 galangin투여시 B(a)P의 대사활성화가 감소되고 활성본태산물들의 DNA binding을 저해함으로서 나타났다. 한편, galangin은 대사활성화가 필요없는 1차 발암물질인 N-methyl-N'-nitro-N-nitrosoguanidine(MNNG)에 의한 소핵생성도 감소시켰다. 이러한 galangin의 alkylating agent에 대한 유전독성억제효과는 calf thymus DNA를 이용한 실험에서 DNA의 메칠화를 저해하는 기전으로 나타나는 것으로 판단되었다. galangin은 mitouycin과 같은 DNA cross-linking agent에 의한 소핵생성에도 억제효과를 나타내었다. 특히 동시투여(simultaneous treatment)나 사후투여(post-treatment)시보다 사전투여(pre-treatment)시에 소핵생성억제효과가 컸으며 사전연속투여(multiple Pre-treatment)시에는 낮은 용량에서도 효과가 컸다. 이러한 저용량의 사전연용투여에 의한 유전독성억제효과들은 B(a)P나 MNNG에 대해서도 잘 나타났다.