• Environmental Analysis Health and Toxicology
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• 제19권2호
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• pp.119-134
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• 2004

Human exposure to highly nickel-polluted environments, such as those associated with nickel refining, electroplating, and welding, has the potential to produce a variety of pathologic effects. Among them are skin allergies, lung fibrosis, and cancer of the respiratory tract. The exact mechanisms of nickel-induced carcinogenesis are not known and have been the subject of numerous epidemiologic and experimental investigations. This review provides the evidence of the current state for the genotoxic and mutagenic activity of Ni (II) particularly at high doses. Such doses are best delivered into the cells by phagocytosis of sparingly soluble nickel-containing dust particles. Ni (II) genotoxicity may be aggravated through the generation of DNA-damaging reactive oxygen species (ROS) and the inhibition of DNA repair by this metal. The epigenetic effects of nickel includes alteration in gene expression resulting from DNA hypermethylation and histone hypoacetylation, as well as activation some signaling pathways and subsequent transcrziption factors.

• Journal of Microbiology and Biotechnology
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• 제10권2호
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• pp.154-160
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• 2000

Aflatoxin B1 is known as the most potent mycotoxin produced by several fungi. It has been demonstrated to be not only carcinogenic but teratogenic and mutagenic as well in humans. To prevent or inactivate aflatoxins, several chemical of physical methods were tested for ammoniation, using insecticides as an wxample, but they were unsuitable for food products. On the contrary, biological control by antagonistic microorgani는 is and ideal method. In order to control aflatoxin B1 biologically, the antagonists #07, #63, #75, #74, and #61 were separated from various samples by using the antagonistic activity test. Among them, culture filtrate part A (non heat-treated) of #63 and #74 on aflatoxin B1 produced by Aspergillus fkavus were shown to be 95% and 75%, respectively. Based on the morphological characteristics, #63 was deduced as an Azospirillum sp.

• 생약학회지
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• 제31권2호
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• pp.240-244
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• 2000

Antimutagenicity profiles of the enzymatic browning reaction products(EBRP) were investigated. The rec-assay with Bacillus subtilis strains $H17(rec^+)$ and $M45(rec^-)$ was carried out using their spores. The biological activities were evaluated for seven different enzymatic browning reaction products, which resulted from the reactions of seven polyphenols with polyphenol oxidase isolated from Ginkgo biloba leaves. In the spore $rec^-$ assay, most of the polyphenolic compounds tested were positive, whereas their enzymatic browning reaction products were tested negative. The mutagenicity of enzymic browning mixtures of the polyphenols and the enzymes obtained from Ginkgo biloba leaves showed negative results in the mutagenicity test using Bacillus subtilis strains $H17(rec^+)$ and $M45(rec^-)$. In the case where polyphenol oxidase inhibitors were added in the enzymatic reaction mixtures with polyphenols, the polyphenols showed mutagenic effect in the spore $rec^-$ assay. This suggests that the activity of polyphenol oxidase is decreased.

• 생약학회지
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• 제21권1호
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• pp.88-91
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• 1990

Potential antimutagenic activities of vegetable plants were investigated. 24 vegetables which are frequently consumed by Korean people were extracted with 70% ethyl alcohol to prepare the extract samples. Then those samples were added to the culture media containing mitomycin C($O.3\;{\mu}g/ml$) and the SOS-Chromotest was performed. Positive control, mitomycin C alone, showed about 330 units of ${\beta}$-galactosidase activities. Among 24 vegetable samples, Saxifraga oblougifolia Nakai (취나물, Saxifragaceae) and Platycodon grandiflorum A. De Candolle(도라지, Campanulaceae) showed 136 and 155 units, respectively when mitomycin C was treated. These results indicate that Saxifragae Herba and Platycodi Radix possess protecting action from mutagenic activity produced by mitomycin C.

• 한국환경보건학회지
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• 제8권1호
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• pp.81-97
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• 1982

Ethylene oxide gas has been used as a cold sterilant for heat-sensitive medical equipments and as a fumigant for food for more than 30 years, and it is used more widely than radiation although radiation sterilization has made significant inroads in recent years. But according to recent studies of toxicities such as mutagenicity, haemolytic effect and possible carcinogenicity of Ethylene oxide (ETO) and its two main reaction products, Ethylene chlorohydrin (ETCH) and Ethylene glycol (ETG), Environmental Protection Agency in U.S.A. has suggested some regulations on residual gas in drug products and medical devices for human use. The mutagenic activity of ETO compared with that of X-ray has an equivalency of 1 ppm/hr for ETO as compared to 20 mrad for X-ray, and one could suggest the present maximum allowable concentration for ETO (50 ppm) should be 400 times lower than the radiation standard (2.5 mrad/hr). Although radiation sterilization has advantages of simplicity of operation and complete reliability, changes of physico-chemical properties with possible formation of toxic substances may occur. It is therefore necessary to make some regulations of our own for residual toxicities orginated from each sterilization method.

• 대한미생물학회지
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• 제22권2호
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• pp.185-193
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• 1987

Ten species of herbae, which have been used to treat cancers in Chinese medicine, were tested to investigate their mutagenicity or antimutagenicity in S. typhimurium TA97, TA98, TA100, TA1535, and TA1538. Scolopendra centipede was weakly active in reversion of the frameshift mutation in S. typhimurium TA97 strain and the base-pair substitution in TA100 and TA1535 strains. Other herbae such as Coix lachryma, Dianthus superbus, Tricanthoshse kirilowii, Eupatorium formosanum, Lithospermum erythrorhizon, Ansaema japonicum, Curcuma zedoaria, Helicteres angustifolia, and Euonymus sieboldianus did not show any of the mutagenic potential, regardless of the metabolic activation with rat hepatic microsomal fraction. Dianthus superbus, Eupatorium formosanum, and Euonymus sieboldianus exhibited suppressive activities on microbial mutagenesis of N-methyl-N'-nitrosoguanidine, a base-pair substitution mutagen, in TA1535 and TA100 tester strains. The antimutagenic activities of Dianthus superbus and Euonymus sieboldianus appeared to be dose-dependant.

• Journal of Microbiology and Biotechnology
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• 제6권4호
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• pp.255-259
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• 1996

$\beta$-Glucosidase was known to be involved in the mutagenic activation of $\beta$-glucosides. The level of $\beta$-glucosidase in the feces of adults was 2.7 times higher than that of infants. There was no difference in the percentage of $\beta$-glucosidase positive strains among Bifidobacterium isolates between adults and infants, corresponding to 90 and 92$%$, respectively. However, the strains from adults showed 1.9 times higher enzyme activity than those from infants when grown in Brain Heart Infusion medium. $\beta$-Glucosidase negative strains could not ferment $\beta$-glucosidase substrates, such as cellobiose, salicin, naringin, esculin and arbutin. Presence of $\beta$-glucosidase in Bifidobacterium did not alter the degree of growth in reconstituted skim milk. The $\beta$-glucosidase level was much lower in milk and vegetable medium, although cells grew above $10^8$cfu/ml, than in BHI medium. This study suggests that metabolic activation of the $\beta$-glucosides by Bifidobacterium $\beta$-glucosidase varies significantly depending on types of growth medium.

• 한국환경성돌연변이발암원학회지
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• 제21권2호
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• pp.113-117
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• 2001

The screening of various molecular descriptors for predicting carcinogenic, mutagenic and teratogenic activities of chlorinated aliphatic compounds as drinking water disinfection byproducts (DBPs) has been investigated for the application of quantitative structure-activity relationships (QSAR). The present work embodies the study of relationship between molecular descriptors and toxicity parameters of the genotoxicity endpoints for the screening of relevant molecular descriptors. The toxicity Indices for 29 compounds constituting the testing set were computed by the PASS program and active values were chosen. We investigate feasibility of screening descriptors and of their applications among different genotoxic endpoints. The correlation to teratogenicity of all 29 compounds was significantly improved when the same analysis was done with 20 alkanes only without alkene compounds. The HOMO (highest occupied molecular orbital) energy and number of Cl parameters were dominantly contributed.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2003년도 생물공학의 동향(XII)
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• pp.445-449
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• 2003

As for the purpose, we first introduce an random mutation into wild-type gene to expand a mutation space, and then further recombine the mutant genes by staggered extension process PCR. As a result, we obtained the best clones 6-52 that showed a high activity and stability, from a round of error prone and staggered extension process PCR. The purified enzyme showed a similar pH stability to the wild-type enzyme and reveal a slightly high optimum pH at 12. In the optimum temperature, an identical dependency was also showed and a quite high stability in the thermal stability was obtained. Along with this, the enzyme was also stable at a reaction that supplement with a 15 % of ethanol as an additive. The addition of other solvents and surfactants did not improve the reaction and thus resulted in a similar profile to those of wild-type enzyme. The specific activity on the target compound rac-ketoprofen ethyl ester was calculated to be about 85, 000 unit, and the kinetic constants Km and Vmax were determined to be 0.2 mM and 90 mM/mg-protein/min respectively. The deduced amino acid alignment with the wild type enzyme revealed five mutations at L120P, I208V, T249A, D287H and T357A. Based on these observations, the site directed mutagenesis to delineate the mutagenic effect is under progress.

• Applied Biological Chemistry
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• 제39권6호
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• pp.419-423
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• 1996

SOS chromotest 방법을 이용하여 천연물에 포함된 항변이원성 물질의 활성을 정량화 할 수 있는 항변이원 활성단위 측정법을 개발하였다. 이 방법에 의하여 시료의 항변이원 활성을 특정 화학적 변이원이 유도하는 변이원성이 표준측정 조건하에서 50% 억제되는 시료의 양으로 수치화하는 것이 가능하게 되었다. 확립된 방법으로 쌀의 품종별 항변이원 활성 및 기타 곡류의 항변이원 활성을 조사하였다. 그 결과 변이품종 쌀인 자도와 향도가 취반용으로 사용되는 추청보다 항변이원 활성이 높았고, 일반적으로 검정콩이나 팥과 같은 잡곡의 항변이원 활성이 현미보다 높았다.