• 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.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.1
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• pp.25-31
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• 2009

This study was carried out to investigate the mutagenic, antimutagenic, cytotoxicity and antitumor effects of Adenophora triphylla (AT). AT was extracted with 70% ethanol and then further fractionated to hexane, chloroform, ethyl acetate, butanol and water. Antimutagenic, cytotoxicity and antitumor effects of AT extracts were measured by using Ames test, SRB method, and the tumor growth inhibition test. AT extracts did not show any mutagenicity in the Ames test; however, 70% ethanol extracts and its fractions had strong antimutagenic effects against mutation induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) and 4-nitroquinoline-1-oxide (4NQO). The ethyl acetate fraction of AT (200 ${\mu}g$/plate) showed approximately 66.5% inhibitory effect on the mutagenesis induced by 4NQO against TA98 strain, whereas 83.3% and 75.1% inhibitions were observed on the mutagenesis induced by MNNG and 4NQO against TA100 strain. In anticancer effects, the cytotoxicity of AT extract and its fractions against cancer cell lines including human cervical adenocarcinoma (HeLa), human hepatocellular carcinoma (Hep3B), human breast adenocarcinoma (MCF-7), human gastric carcinoma (AGS), human lung carcinoma (A549) and transformed primary human embryo kidney (293) were investigated. The treatment of 1 mg/mL AT ethyl acetate faction had the highest cytotoxicity of 79.9%, 74.9%, 66.0%, 71.0% and 74.3% against HeLa, Hep3B, MCF-7, AGS and A549 cells, respectively. In contrast, the extract and its fractions showed only $3{\sim}36%$ cytotoxicity for a normal human kidney cell line (293). In vivo anti-cancer effect of Adenophora triphylla extract was tested using Balb/c mice transplanted sarcoma-180 cells. Adenophora triphylla ethyl acetate fraction showed the highest inhibition rate of 37.2% at the 50 mg/kg concentration.

• Korean Journal of Microbiology
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• v.24 no.3
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• pp.221-227
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• 1986

The strain of Aspergillus nidulans carring a uvsH mutation which had been shown to be absolutely required for UV or 4-NQO induced mutagenic processes was studied on mitotic recombinational behaviour. Although the effect of uvsH locus on spontaneous mitotic crossing over between fpB37 and centromere was not considerable, UV-induced intergenic recombination did not occur in uvsH/uvsH homozygotic diploid. In case of gene conversion at riboflavin locus between a pair of non-complementary alleles, riboA1 and riboA3, the uvsH mutation was not concerned with that process occurred spontaneously or induced by UV irradiation. When the cells were irradiated by UV light, high degrees of aneuploid productions were detected in diploid homozygous for uvsH as compared with wild type, while much difference was not found during normal growth.

• Journal of the East Asian Society of Dietary Life
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• v.18 no.5
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• pp.746-752
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• 2008

In this study, the antioxidative activity and antimutagenic effect of ethanol extracts from Schizandra Chinensis Baillon were assessed with regard to natural antioxidants. The antioxidative activity and antimutagenicity of ethanol extracts from Schizandra chinensis Baillon were evaluated by measuring the radical-scavenging effect on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals, and by performing the Ames test using 4-nitroquinoline-1-oxide (4-NQO) and sodium azaid as a mutagen with Salmonella typhimurium TA100, respectively. The total polyphenolic compound and flavonoid compound contents of Schisandra chinensis Baillon were also assessed. The DPPH radical-scavenging activity of ethanol extracts from Schisandra chinensis Baillon was 57.2% on the $500\;{\mu}g$/assay. The $IC_{50}$ on DPPH radical-scavenging effect of ethanol extract was $435\;{\mu}g$/assay. In addition, the inhibition rates of ethanol extract from Schisandra chinensis Baillon toward mutagenicity induced by 4-NQO and sodium azide were 82.45% and 45.3%, respectively. Furthermore, the total polyphenol and total flavonoid contents of the extract were 9.53 mg/g and 3.97 mg/g, respectively. These results indicate that the ethanol extract from Schisandra chinensis Baillon evidences a fairly good antioxidative and antimutagenic effect.

• Journal of the East Asian Society of Dietary Life
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• v.26 no.2
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• pp.192-199
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• 2016

The antioxidative activity and antimutagenic activity of the ethanol extracts from pericarp and seeds of wild grape (Vitis coignetiea) were analyzed in this study. The antioxidative activity of the extracts from wild grape was determined using 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assay. The antimutagenic activity of the extracts was evaluated on Salmonella typhimurium TA98 and TA100 by Ames test using 4-nitroquinoline 1-oxide (4-NQO) and sodium azide as mutagens. In the antioxidative activity determination, $IC_{50}$ values of the DPPH radical scavenging activity of the extracts from pericarp and seeds were 27.16 ppm and 7.61 ppm, respectively. Additionally, ABTS radical scavenging activities of pericarp and seed extract were 99.75% and 98.87% at 200 ppm, respectively. In the antimutagenic activity determination, pericarp extract at 5 mg/plate inhibited 72.6% and 74.3% of mutagenicity of S. typhimurium TA98 induced by 4-NQO and sodium azaid, respectively. Also, the mutagenicity inhibition rates of seed extract at 5 mg/plate were 77.8% and 74.5% in S. typhimurium TA100 induced by 4-NQO and sodium azaid, respectively. These results demonstrate that the ethanol extract from wild grape has remarkable antioxidant activity and antimutagenicity.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.2
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• pp.322-328
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• 2000

This study was performed to determine the antimutagenic and cytotoxic effect of the Phellinus linteus methanol extract on Salmonella typhimurium TA98, TA100 and human cancer cell lines. In the Ames test, methanol extract of P. linteus alone did not exhibit any mutagenicity but showed substantial inhibitory effects against mutation induced by N-methyl-N'-nitro-N-nitrosoguanidine(MNNG), 4-nitroquinoline-nitroquinoline-1-oxide(4NQO), 3-amino-1,4-dimethyl-5H-pyrdo[4,3-blindol(Trp-P-1) and benzo(α)pyrene(B(α)P). The methanol extracts of P. linteus(200㎍/plate) showed approximately 78.3%, 78.7% and 88.1% inhibitory effect on the mutagenesis induced by 4NQO, Trp-P-1 and B(α)P. The anticancer effects of P. linteus extract against human breast adenocarcinoma(MCF7), human lung carcinoma (A549), human fibrosarcoma (HT1080), human hepatocelular carcinoma (Hep3B) and human epitheloid carcinoma (HeLa) were investigated. The treatment of 1mg/mL P. linteus extracts had the highest cytotoxicity against MCF7 (92.0%), followed by Hep3B (84.9%), A549 (84.2%) and HT1080 (82.9%). In contrast 1mg/mL treatment of P. linteus extracts had only 10∼40% cytotoxicity on normal human liver cell (WRL68).

• Korean Journal of Medicinal Crop Science
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• v.10 no.2
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• pp.132-138
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• 2002

This study was performed to determine the antimutagenic and cytotoxic effect of ,Kalopanacis cortex endothelium. Methanol extract was used on Salmonella typhimurium TA98, TA100 and three cancer cell lines. In the Ames test, methanol extract of Kalopanacis cortex endothelium alone did not exhibit any mutagenicity but showed substantial inhibitory effects against mutation induced by 4-nitroquinoline-l-oxide(4NQO), N'-methyl- N'-nitro-N-nitrosoguanidine(MNNG) and benzo(a)pyrene(B(a)P). The methanol extract of Kalopanacis cortex endothelium showed approximately 79.29% and 75.38% inhibitory effect on the mutagenesis induced by 4NQO and B(a)P, respectively, against TA98 strain. Whereas 79.49%, 89.3% and 68.85% inhibitions were observed on the mutagenesis induced by 4NQO, MNNG and B(a)P against TA100 strain. Methanol extracts from Kalopanacis cortex endothelium showed high antimutagenic effects against 4NQO, MNNG and B(a)P. The anticancer effects of methanol extract from Kalopanacis cortex endothelium against human lung carcinoma(A549), human breast adenocarcinoma (MCF-7) and human hepatocellular carcinoma(Hep3B) were investigated. The treatment of 0.5mg/ml Kalopanacis cortex endothelium methanol extracts had the highest cytotoxicity against A549(81.54%), followed by MCF-7(81.92%) and Hep3B (78.57%). In contrast 0.5mg/ml treatment of methanol extracts from Kalopanacis cortex endothelium had only $4{\sim}25%$ cytotoxicity on normal human liver cell(293).

• BMB Reports
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• v.48 no.8
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• pp.467-472
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• 2015

Heat shock increases skin temperature during sun exposure and some evidence indicates that it may be involved in skin aging. The antioxidant response mediated by the transcription factor NF-E2-related factor 2 (Nrf2) is a critically important cellular defense mechanism that serves to limit skin aging. We investigated the effects of heat shock on collagenase expression when the antioxidant defense system was downregulated by knockdown of Nrf2. GSH and collagenases were analyzed, and the expression of inducible Nrf2, HO-1, and NQO1 was measured. HS68 cells were transfected with small interfering RNA against Nrf2. Heat shock induced the downregulation of Nrf2 in both the cytosol and nucleus and reduced the expression of HO-1, GSH, and NQO1. In addition, heat-exposed Nrf2-knockdown cells showed significantly increased levels of collagenase protein and decreased levels of procollagen. Our data suggest that Nrf2 plays an important role in protection against heat shock-induced collagen breakdown in skin. [BMB Reports 2015; 48(8): 467-472]

• Applied Biological Chemistry
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• v.48 no.3
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• pp.222-227
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• 2005

To evaluate the antimutagenic activity of the specialty rices, a giant embryonic rice and a pigmented rice, we measured the inhibitory effect on the chemically induced mutagenesis in E. coli and V79 cultured cell system, as well as on DNA strand scission induced by oxidative damages in vitro. When the inhibitory activity to mitomycin C-induced mutagenesis using SOS chromotest in E. coli cell was measured, the activities decreased in the following order: germinated pigmented rice (40.4%) > germinated giant embryonic rice (37.1%) > pigmented rice (35.5%) > germinated brown rice (15.7%) > giant embryonic rice (14.0%) > brown rice (0.8%). The activities for inhibiting mitomycin C-induced DNA strand scission decreased in the order of pigmented rice > giant embryonic rice > germinated pigmented rice > germinated brown rice > brown rice > germinated giant embryonic rice. We also determined antimutagenic activities of the specialty rices using the suppressing effect on 6-TG resistant colony formation by 4-NQO in V79 cells as a mutagenicity index. The order of antimutagenicity was germinated giant embryonic rice (53.2%) > pigmented rice (40.0%) > brown rice (21.2%) > germinated brown rice (14.4%) > giant embryonic rice (0.23%); in contrast, germinated pigmented rice showed promoting effect on 4-NQO-induced mutagenesis.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.7
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• pp.1088-1094
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• 2003

This study was performed to determine the antimutagenic and cytotoxic effects of ethanol extract, ethylacetate fraction, water fraction and water soluble and insoluble polysaccharides I and II isolated from Inonotus obliquus using Ames test and SRB assay. Each sample itself did not show mutagenic effect. Among samples, the water unsoluble polysaccharides II in the presence of 50 $\mu\textrm{g}$/plate showed the strongest antimutagenic effect with over 90% against MNNG, 4NQO, B(a)P and Trp-P-l. However, ethyl acetate fraction (1 mg/mL) which had 90.8%, 94.3% and 83.5% inhibitory effect against on MCF-7, A549, AGS showed the strong cytotoxic effect compared to other samples.