유전독성물질의 유전체 손상 작용에 대한 Vitamin C의 방호효과

유경진(Gyeong Jin Yu),이천복(Chun Bok Lee) 한국생명과학회 2013 생명과학회지 Vol.23 No.8

비타민 C는 다양한 유전독성에 대하여 방호작용을 할 수 있는 것으로 알려져 있지만, 구체적 방호기작과 방호작용의 정도는 충분히 이해되어 있지 않다. 본 연구는 독성물질 및 환경의 조작에 의해 세포의 유전체가 손상되는 조건에서 비타민 C가 발휘하는 유전독성 방호효과를 정량하고, 그 방호기작을 분석하였다. Chinese hamster ovary 세포(CHO-K1)를 사용한 Comet assay를 수행하여, H₂O₂, HgCl₂, N-methyl-N-nitro-N-nitrosoguanidine (MNNG), 4-nitroquinoline-1-oxide (4NQO)와 자외선에 노출된 세포의 DNA 손상 정도를 측정하였다. 비타민 C 방호효과를 측정한 결과, H₂O₂, HgCl₂, 4NQO를 비타민 C와 함께 처리한 경우, DNA 손상이 대조군 수준으로 감소하였다. 자외선의 경우 비타민 C의 방호효과가 나타났으나 대조군 수준까지 미치지 못하였으며, MNNG의 경우 비타민 C가 전혀 방호하지 못하는 것으로 나타났다. 또한, 비타민 C를 유전독성노출 이전에 처리한 세포들의 DNA 손상 정도가 독성노출 이후에 처리된 경우보다 28~49% 낮은 것으로 측정되었다. 이는 독성노출 이전 시점에 도입된 비타민 C가 세포외액과 세포질에 존재하여, 이후에 도입되는 유전독성물질과 직접적으로 작용하며, 강력한 항산화제로써 1차적인 항산화작용을 담당함을 시사한다. 그러나 MNNG의 경우처럼 비타민 C가 방호효과를 보이지 않는 유전독성물질이 존재하므로, 유전독성물질의 독성기작에 따라 비타민C의 방호효과는 제한되는 것으로 나타났다. 따라서, 각 유전독성물질의 독성기작과 비타민 C의 방호기작과의 상호작용에 대한 연구가 필요하며, 비타민 C의 항산화 방어 기작(antioxidant defense mechanism)의 다양성에 대한 규명이 이루어져야 할 것으로 사료된다. 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, H₂O₂, HgCl₂,N?methyl?N?nitro-N-nitrosoguanidine (MNNG), 4-nitroquinoline?1-oxide (4NQO), and UV-irradiation. In cases cells were treated with H₂O₂, HgCl₂, 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.

S-2 (3-aminopropylamino)ethylphosphorothioic acid (WR-2721)가 방사선에 조사된 흰쥐의 효소 활성에 미치는 영향

고성진(Seong-Jin Ko),김재영(Jai-Young Kim),이천복(Chun-Bok Lee) 대한의생명과학회 1997 Biomedical Science Letters Vol.3 No.1

S-2 (3-aminopropylamino)ethylphosphorothioic acid (WR-2721)이 방사선에 대한 방어효과에 미치는 영향을 규명하고자 Sprague-Dawley계 웅성 흰쥐를 대조군, WR-2721 단독투여군 (200㎎/㎏), X-선 단독조사군, WR-2721투여 (200㎎/㎏)후 X-선 조사한 병용군으로 나누어 X-선 8 Gy선량을 전신조사한 후 1, 3, 7, 10일 간에 각각 혈액을 채취하여 효소활성치와 glucose함량 변화를 측정하여 다음과 같은 결과를 얻었다. X-선 단독조사군에서는 ALP와 AST의 활성치가 대조군에 비하여 감소하였으나 WR-2721을 병용한 군에서는 그 감소폭이 줄어들었고, ALT와 LDH의 활성치는 X-선 단독 조사군에서 대조군에 비하여 증가하였고, WR-2721을 병용한 군에서는 그 증가폭이 감소되었다. 또한 glucose치의 변동은 X-선 단독 조사군에서 대조군에 비하여 유의성 있게 증가하였으나 WR-2721을 병용한 군에서는 그 증가폭이 감소되었다. 이로 미루어 보아 WR-2721이 X-선으로부터 생체내 주요 장기들을 보호하는 작용이 있음을 시사하고 있다. Male rats of Albino strain were divided into four groups, control group, X-irradiated group, WR-2721 treatment group and X-irradiated group treated with WR-2721. The radioprotective effect of treatment with S-2 (3-aminopropylamino)ethylphosphorothioic acid (WR-2721) in the dose of 200㎎/㎏ by intraperitonial injection on rats 20m in prior to wholebody X-irradiation (8Gy) was studied. Each group determined serum alkaline phosphatase (ALP), aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase (LDH) activities and contents of serum glucose after 1, 3, 7 and 10 days. The ALP and AST activities of X-irradiated group were significantly decreased (p<0.05) compared with that of control group, but X-irradated group treated with WR-2721 less decreased those enzyme activities compared with the X-irradiated group. X-irradiated group was signficantly increased (p<0.05) ALT and LDH activities compared with that of control group, but X-irradated group treated with WR-2721 less increased those enzyme activities compared with the X-irradiated group. The concentration of serum glucose of X-irradiated group was signficantly increased (p<0.05) compared with that of control group, but X-irradated group treated with WR-2721 less increased compared with that of X-irradiated group. It may be considered that WR-2721 provided radioprotective effect of organs of body from X-irradiation.

Environmental Toxic Agents on Genetic Material and Cellular Activity : Ⅲ. 포유동물세포에서 돌연변이원에 의한 DNA상해의 회복에 미치는 DNA 중합효소저해제의 영향 Ⅲ. DNA Polymerase Inhibitors on Repair of Mutagen-Induced DNA Damage in Mammalian Cells

李天馥,嚴慶一,鮮于洋一,申恩珠 東亞大學校附設基礎科學硏究所 1988 基礎科學硏究論文集 Vol.5 No.1

Many enzymes are known to be associated with the recognition of specific lesions and incision of the DNA strand in their vicinity(Clarson and Mitchell, 1983), and several enzymes concerned with excision and polymerization have also been identified(Collins & Johnson, 1984; Collins et al., 1984; Downes et al., 1985; Mattern et al., 1982). In a number of studies, controversial results have been obtained on whether DNA polymerase α is(Cleaver, 1984; Collins et al., 1982; Dresler and Frattini, 1986: Dresler and Kimbro, 1987; Johnson et al., 1987; Snyder and Reagan, 1981, 1982) or is not(Giulotto and Mondello, 1981; Hardt et al., 1981; Seki et al., 1980) important in DNA repair, while DNA polymerase β has been postulated to have a role in the repair of DNA(Cleaver, 1983; Dresler and Lieberman, 1983; Miller and Chinault, 1982; Spadari et al., 1982). Many conclusions concerning the functions at these enzymes can be obtained using enzyme inhibitors. Among them, the commonly used inhibitors have been aphidicolin(APC), an inhibitor of DNA polymerase α(Smith and Paterson, 1983; Th'ng and Walker, 1985), and 2',3'-dideoxythymidine(ddThd) or 2',2'-dideoxythymidine 5'-triphosphate(ddTTP), an inhibitor of DNA polymerase β(Dresler and Kimbro, 1987; Th'ng and walker, 1985; Yamada et al., 1985). On the other hands, the studies using APC and ddTTP yielded results that suggest the participation of both polymerases in DNA repair depending on the agent used and the dosage applied(Cleaver, 1983; Dresler and Liberman, 1983; Yamada et al., 1985). Therefore, the same approach, using three differenc assays for DNA repair and two inhibitors, has been undertaken in this study with the view to give insight into the role of specific enzymes in the repair process. The purpose of this study is to elucidate the involvement of DNA polymerase α or β in DNA repair synthesis induced by EMS, an alkylating agent, or BLM, an antibiotics and X-ray mimetic agent, in CHO cells.

고등학교 생물 I 교과서에 수록되어 있는 실험 . 관찰 방법의 적합성 조사

강미애,이천복 慶星大學校 1998 論文集 Vol.19 No.2

This study was performed to point some problems that teachers meet when they teach the experiments with high school biology I textbooks and also to suggest the solution. The results are as follow. Because of the lack of the detailed explanations on the 'method' (for example, the method of making the reagent and its concentration, the magnifying scale of the microscope), it is difficult for the teacher to guide the students to get the exact results. And the lack of diagrams, figures, and pictures with which the results are to be compared makes it difficult to judge the credibility of the result. Furthermore for a number of the experiment, it is not possible to get the results within 50 minutes. It is desirable to replace them with the plausible ones.

비타민C가 돌연변이원에 의하여 유발되는 염색체 이상에 미치는 영향

이천복 慶星大學校 1998 論文集 Vol.19 No.1

This study was performed to investigate the effects of vitamin C on the chromosome aberrations caused by UV light and MNNG which were known for a strong mutagen. The results obtained were as follows; 1) Treatment of vitamin C for 48 hours did not affect chromosome aberrations of control group. 2) Chromosome aberrations of vitamin C-pretreated group were decreased compared with those of MNNG-treated alone group. 3) Chromosome aberrations induced by simultaneous treatment or posttreatment of vitamin C and MNNG showed similar levels to those induced by treatment of MNNG alone. 4) When vitamin C was treated before exposure to uv light chromosome aberrations were decreased. 5) Chromosome aberrations were slightly decreased in cases of post-treatment with vitamin C after exposure to uv light. These results suggest that vitamin C may not have a mutagenic effect when it was treated for 48 hours, it has an antimutagenic effect on that are induced by MNNG and uv light, and antimutagenic effect of pretreatment of vitamin C is stronger than that of simultaneous treatment or posttreatment.

염색체 이상과 자매염색분체교환에 미치는 anti-calmodulin drug의 영향

이천복 慶星大學校 1999 論文集 Vol.20 No.1

The present study was performed to elucidate the effects of TFP and W-13(anti calmodulin drug) on chromosome aberrations and sister chromatid exchanges induced by MNNG. The results obtained were as follows: 1) Both the chromosome aberrations and sister chromatid exchanges were not induced by the treatment of various concentration and times of TFP or W-13. 2) TFP and W-13 inhibited chromosome aberrations induced by MNNG regardless of the concentration and times of treatment. 3) In the groups treated with 5 M TFP or 10 M W-13 for 1 hour after treatment of MNNG, sister chromatid exchanges induced by MNNG were little effected. However, in the groups treated with more than 10 M TFP or 20 M W-13, sister chromatid exchanges induced by MNNG increased with TFP OR W-13 treatment unlike chromosome aberrations. 4) TFP or W-13 treatment for 36 hours after treatment of MNNG increased the sister chromatid exchanges induced by MNNG. The aspects of increase were proportional to the concentration of TFP and W-13 treatment. These data indicate that TFP or W-13 itself dose not induce chromosome aberrations and sister chromatid exchanges, but is concerned in chromosome aberrations and sister chromatid exchanges induced by MNNG; that is, it has the ability to decrease chromosome aberrations but to increase sister chromatid exchanges.

저선량의 자외선 전처리가 자외선에 의하여 유발되는 염색체 이상과 자매염색문체교환에 미치는 영향

이천복,주성영 慶星大學校 1994 論文集 Vol.15 No.2

본 연구는 저선량의 자외선 전(前)처리가 자외선 후(後)처리에 의하여 유발되는 염색체 이상과 자매염색분체 교환에 미치는 적응반응에 대하여 연구할 목적으로 실시하였으며, 얻어진 결과는 다음과 같다. 1. 2 J/㎡의 자외선을 전처리하고 12∼48시간 경과 후 2 J/㎡의 자외선을 다시 처리하였을 경우의 염색체 이상율은 전처리하지 않은 군에 비하여 감소하였으며, 감소되는 정도는 24시간에서 최대를 보이다 이후 점차 낮아졌다. 2. 2 J/㎡의 자외선을 전처리하였을 경우에, 자외선을 전처리하지 않은 군에 비하여 염색체 이상율의 감소가 가장 많이 일어나는 후처리 선량은 10 J/㎡이었다. 3. 2 J/㎡의 자외선을 전처리하고 12∼48시간 경과 후 2 J/㎡의 자외선을 다시 처리하였을 경우의 자매염색분체 교환율은 전처리를 하지 않은 군에 비하여 감소하였으며, 감소되는 정도는 24시간에서 최대를 보이며, 이후에는 감소율에 별다른 차이를 보이지 않았다. 4. 2 J/㎡의 자외선을 전처리하였을 경우에, 자외선을 전처리하지 않은 군에 비하여 자매염색분체 교환율의 감소가 가장 많이 일어나는 후처리 선량은 20 J/㎡이었다. 이상의 결과는 세포에 저선량의 자외선을 전처리할 경우 이 세포가 다시 자외선에 노출되었을때 염색체 이상율과 자매염색분체 교환율이 낮게 나타나는 적응반응이 일어남을 보여주고 있다. 그러나 적응반응을 가장 많이 일으키는데 필요한 적응시간과 후처리 선량은 연구방법에 따라 차이가 있음을 보여주고 있다. This study was performed to research the adaptive response to chromosome aberration and sister chromatid exchanges which are caused by re-exposure to low-level doses' pre-exposure to UV light. The results obtained were as follows : 1. The frequency of chromosome aberrations in case of pre-exposure to 2 J/㎡ UV light for 12∼48 hours after re-exposure with it was less than that of the group without pre-exposure, and the degree of decrease was increasingly lessen at it's highest degree of 24th hour. 2. In case of the group pre-exposed to 2 J/㎡ UV light, the most reduction rate of chromosome aberrations occurred at the doses of re-exposure to 10 J/㎡, compared with the group without pre-exposure. 3. The frequency of sister chromatid exchanges in case of pre-exposure to 2 J/㎡ UV light for 12-48 hours after re-exposure to it was less than that of the group without pre-exposure, and the degree of decrease was highest at 24th hour after then little effected. 4. In case of the group pre-exposed to 2 J/㎡ UV light, the most reduction rate sister chromatid exchanges occurred at the doses of re-exposure to 20 J/㎡, compared with the group without pre-exposure. The preceding results show this : when the cell which is pre-exposed to low-level doses to UV light is re-exposed to the UV light, the adaptive response occurs that the frequencies of chromosome aberrations and sister chromatid exchanges are less. But the adaptive time and re-exposure doses which needed to cause the most adaptive response are different from each research method.

Effects of MNNG on Ultraviolet Light induced sister chrometid Exchanges.

이천복 경성대학교 1985 부산수산대학 논문집 Vol.6 No.2

자매염색분체 교환에 미치는 자외선과 MNNG의 상호작용을 규명하기 위하여 CHO세포를 재료로 자외선과 MNNG를 복잡처리한 후 자매염색분체 교환율을 조사하여 다음과 같은 결론을 얻었다. (1) 자외선 단독 처리군에서의 자매염색분체 교환은 자외선의 선량 증가에 비례하여 증가하였다. (2) MNNG 단독처리군에서도 MNNG 농도증가에 비례하여 자매염색분체 교환율이 증가하였다. (3) 자외선과 MMNG를 복합처리한 군에서의 자매염색분체 교환율은 자외선과 MNNG를 단독처리한 것의 합보다 작았으며 0.01μM MNNG를 복합처리한 군의 경우 자외선 단독처리군보다 오히려 작았다. 이상의 결과는 MNNG가 자외선에 의하여 유발된 자매염색분체 교환을 방해하는 것을 보여주고 있다. The present investigation has been undertaken to determine the interaction between UV-light and MNNG, in inducing SCEs. (1) In UV-light irradiated groups, the rates of SCEs were sharply increased with increasing dose. (2) MNNG induces SCEs in dose-dependent manner. (3) Induction of SCEs exposed to UV-light and MNNG were less than that from the sum of each agent sperately and even lower that produced by single UV-light irradiation (0.01μM MNNG). The present results showed that MNNG interfered with the molecular machinery involved in UV-light induced SCE formation, and indicated that there is a considerable overlap in the mechanisms that regulate the total amount of SCEs performed for each of these agents.

Colloidal Silicone Dioxide와 Aluminum Hydroxide가 간이구강위생지수와 치은지수에 미치는 영향에 관한 연구

이천복,최유진 慶熙大學校 齒科大學 1995 慶熙齒大論文集 Vol.17 No.1

This clinical study was performed for the purpose of investigating the effect of gingival index and simplified oral hygiene index of two dentifrices containing different abrasive agents. 40 dental collage students of age 2 "i-26 were divided 20 members of control group with using dentifrices containing colloidal silicone dioxide(SiO?), and others as experimental group with using dentifrices containing aluminum hydroxide(Al(OH)3) as abrasives. The gingival index and simplified oral hygiene index were analyzed before the experimental and the control dentifrices were supplied and there after 6 weeks. The results were as follows 1. Mean SOW was reduced 20.7% by control group and 31.6% by experimental group stastistical difference was observed: 2. Mean GI was reduced 49.1% by control group and 55.0% by expenmental dentifrices group, but significant difference was not observed. 3. Significant difference in GI and SOW by tooth brushing method was not observed. 4. Factual knowledge about the abrasives, brushing method and pharmacy is scarce and further research on relevant topics seems to be indicated.

자외선에 의하여 유발되는 염색체 이상과 자매 염색 분체 교환에 미치는 calmodulin의 영향

이천복,김장호 慶星大學校 1993 論文集 Vol.14 No.4

The present study was performed to elucidate not only the effects of clamodulin (calcuim receptor) on the damages and their recovery processes at the chromosomal level, but also the possible relationship between chromsome aberration and sister chromatid exchange(SCE). To obtain a clear understanding of them ,the experiment were undertaken to the effects of trifluoperazine (Tfp; calmodulin inhibitor) on chromosome aberrations and sister chromatid exchchanges induced by ultraviolet light(UV). The results obtained were as follows: 1)Both the chromosome aberrations and sister chromatid exchanges were not induced by the treatment of various concentration and hours of Tfp. 2) Tfp inhibited chromosome aberrations induced by UV-light regardless of the concentration and hours of treatment. 3) In the groups treated with 5μM Tfp for 1 hour after exposure to UV-light, sister chromatid exchanges induced by UV-light were little effected. However, in the groups treated with 10μM or 20μM Tfp, sister chromatid exchanges induced by UV-light increased with Tfp unlike chromosome aberrations. 4) Treatment of Tfp for 36 hours after exposure to UV-light increased the sister chromatid exchanges UV-light. The aspects of increase were proportional to the concentration of Tfp. These data indicate that Tfp itself dose not induce chromosome aberrations and sister chromatid exchanges, but is concerned in chromosome aberrations and sister chromatid exchanges induced by UV-light; that is, it has the ability to decrease chromosomal aberrations but to increase sister chromatid exchanges. In conclusion, calmodulin has an effect on the damages and their recovery at the chromosome level, the induction pathways of chromosome aberrations and sister chromatid exchanges seems to be controlled by the different mechanisms.