• Journal of Plant Biology
• /
• v.36 no.1
• /
• pp.105-112
• /
• 1993

Selection of glyphosate-resistant clones from MNNG-treated mesophyll protoplasts of haploid tobacco and their differentiation were studied. The protoplasts were treated with 0.1 to 100 $\mu\textrm{g}$/mL N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) for 30 min when they expanded to oval shapes. After the treatment, the protoplasts in 4-16 cell stages were transferred to the selective medium containing 1 mM glyphosate for the selection of the glyphosate-resistant colonies. The efficiency of the cell division of the protoplasts in the selective medium decreased as the MNNG concentrations in creased. Optimal MNNG concentration for induction of the glyphosate-resistant clones was 10$\mu\textrm{g}$/mL and mutation frequency was 2.66$\times$10-6. The stability of the glypohsate-resistance of the clones was examined by prolonged subculture in the medium with 1 mM glyphosate, and the resistant clones were survived more than 10 months. Among them one clone has been proliferating and greening and the others were proliferating without greening or greening with slower proliferating.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.21 no.5
• /
• pp.539-543
• /
• 1992

This study was carried out to investigate the antimutagenic affect of crude and heated comfrey extract on N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), benzo${(\alpha)}$pyrene (B${(\alpha)}$P) and 3-amino-1, 4-dimethyl-5H-pyri-do [4,3-b] indole (Trp-P-1). In spore rec-assay using Bacillus subtilis $H17(rec^+)$ and $M45(rec^-),$ crude comfrey extract showed strong antimutagenic effects on MNNG in the concentration of $40{\mu}l/disc$(p<0.01). In the Ames test using Salmonella typhimurium TA98 and TA100, the crude comfrey extract suppressed about 43% and 52% in the mutagenesis induced by $B{(\alpha)}P.$ However, the heated comfrey extract strongly suppressed about 75% and 76% in the mutagenesis in Salmonella typhimurium TA98 and TA100 induced by Trp-P-1(p<0.01).

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

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.21 no.2
• /
• pp.149-153
• /
• 1992

The antimutagenic effect of green-ye1low vegetables on the mutagenicities induced by N-methyl-N'-nitro-N-nitrosoguanidine(MNNG) and N-nitrosodimethylamine (NDMA) in Salmonella assay system and also their inhibitory effect on AZ-521 human gastric cancer cells were studied. Twenty-four items from twenty six kinds of vegetables(92%) revealed antimutagenic activity toward MNNG (p< 0.0l, 0.05). Perilla leaf, Korean cabbage, cauliflower, lettuce, mustard leaf, water dropwort, small water dropwort, carrot and burdock inhibited the mutagenicity more than 80%. The methanol extracts of the vegetables also showed the antimutagenic activity toward NDMA (p< 0.01, 0.05). Especially, perilla leaf, kale, soybean sprout and onion inhibited more than 80% of the NDMA induced mutagenicity in S. typhimurium TA100. Small water dropwort and perilla leaf exhibited the strong inhibitory effect (97~100%) on the growth of the AZ-521 human gastric cancer cells. Soybean sprout, water dropwort, broccoli, crown daisy, green red pepper, red pepper leaves, spinach, cabbage and sweet potato also inhibited growth of the cancer cells (p < 0.001~0.05).

• Microbiology and Biotechnology Letters
• /
• v.21 no.6
• /
• pp.628-634
• /
• 1993

The inhibitory effects of various extracts from Chinese pepper on the mutagenicity and the growth of MG-63 human osteosarcoma cells were studied. Chinese pepper was extracted with methanol and then the methanol extract was further fractionated by using hexane, chloroform, ethyl acetate and butanol. The methanol extract of Chinese pepper revealed the strong antimutagenic activity on the aflatoxin B1(AFB1) and N-methyl-N'-nitro-N-nitrosoguanidine(MNNG) in Ames mutagenicity test and SOS chromotest.

• Proceedings of the Korea Environmental Mutagen Society Conference
• /
• 2001.10b
• /
• pp.98-98
• /
• 2001

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

• YAKHAK HOEJI
• /
• v.35 no.4
• /
• pp.253-257
• /
• 1991

The anti-mutagenic effect of Orostachys japonicus (OJ) toward aflatoxin (AFB$_{1}$) and N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) in the Salmonella assay system was studied. The methanol extract of OJ inhibited the mutagenicity induced by AFB$_{1}$ about 97% when 5% of the extract added to the system. Butanol fraction from the methanol extract was the most effective against AFB$_{1}$. However, other fractions of hexane, chloroform, and ethylacetate also showed considerable antimutagenic activity against AFB$_{1}$. Several identified compounds from the fractions of OJ exhibited anti-mutagenic effect. $\beta$-Sitosterol, astragalin and kaempferol-3-rhamnosyl-7-glucoside were selected from the compounds, and these compounds inhibited the mutagenicity dose-dependently. These 3 compounds also decreased the mutagenicity induced by MNNG. From these results, it is suggested that the major compounds such as triterpene, sterol and flavonoid in the OJ were responsible for the inhibition of the AFB$_{1}$ and MNNG-induced mutagenicities.

• Korean Journal of Clinical Laboratory Science
• /
• v.53 no.4
• /
• pp.353-362
• /
• 2021

Cancer is a global health problem. There are diverse types of cancers, but there are several common pathways which lead to the development of cancer. Changes in gene expression might be the most common similarity found in almost all cancers. An understanding of the underlying changes in gene expression during cancer progression could lay a valuable foundation for the development of cancer therapeutics and even cancer vaccines. In this study, a well-known carcinogen, N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), was employed to induce changes in gene expression in normal stomach cells. MNNG is known to cause cancer by inducing damage to DNA in MNNG-treated mammalian cells and animals fed with this carcinogen. An analysis was performed by comparing the differentially expressed genes (DEGs) caused by MNNG treatment with DEGs in stomach cancer cell lines. To this end, methods of analysis for functional categorization and protein-protein interaction networks, such as gene ontology (GO), the database for annotation, visualization, and integrated discovery (DAVID), Kyoto encyclopedia of genes and genomics (KEGG) and search tool for the retrieval of interacting genes/proteins (STRING), were used. As a result of these analyses, MNNG-regulated specific genes and interaction networks of their protein products that contributed to stomach cancer were identified.

• Microbiology and Biotechnology Letters
• /
• v.17 no.4
• /
• pp.327-333
• /
• 1989

The purplish-red pigment was formed on agar plate by superimposed streaking of Streptomyces propurpuratus ATCC 21630 and strain R-89, The strain No.89 was ascribable to the genus Bacillus and designated as Bacillus sp. R-89. Both strain did not produced such pigment when cultivated independently. For hyperpigment production, we selected the mutant S.P-6 from Streptomyces propurpuratus ATCC 21630 by MNNG (N-methyl-N'-nitro-N-nitrosoguanidine) treatment. Maximum purplish-red pigment 1420 mg/$m\ell$ were produced, when the mutant of R-16 and Bacillus sp. R-89 were mixed cultured at 3$0^{\circ}C$ for 72 hr.