• KSBB Journal
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• 제14권2호
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• pp.192-197
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• 1999

해양세균 Pseudomonas sp. CHCS-2는 배양과정 중에 포도당 첨가에 의해 생물유화제의생산이 증가되었으며, 196시간 배양시 원유에 포함되어 있는 paraffine계 탄화수소 중에서 $_nC_{12}~_nC_{22}$까지 범위의 carbonchain이 거의 대부분 분해됨을 알 수 있었다. chloroform : metahnol = 1 : 1(V/V)로 추출하여 얻은 8.5g/L의 crude 생물 유화제를, Amberlite XAD-7, Sepharose CL-4B, DEAE-sepharose CL-6B 수지를 사용하여 정제한 결과 최종적으로 0.21g/L의 정제된 생물유화제를 얻었다. 본 균주가 생산하는 생물유화제는 단백질과 octadecanoic acid가 결합된 분자량이 약 67kDa인 lipoprotein으로 확인되었으며, 정재된 생물유화제중 단백질성분만을 분리하여 N-말단 아미노산배열을 분석한 결과, Ser-Val-He-Asn-Thr-Asn-IIe-Thr-X-Met-Ile-Gly-Gin-Gln-의 배열을 가지는 것으로 확인되었다. 이는 기존에 보고된 lipoproten과 다른 형태의 것으로, 본 균주가 생산하는 생물유화제의 경우 구성성분, 분자량 등을 고려해 볼 때 새로운 형태의 lipoprotein 계열 생물유화제로 추정된다.

• Environmental Analysis Health and Toxicology
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• 제20권4호통권51호
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• pp.365-374
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• 2005

Ambient air particulate matters are classified into two distinct modes in sire distribution, namely the coarse and fine particles. Correlation between high particulate concentration and adverse effect on human populations has long been recognized. However, the toxicology of these adverse efforts has not been clarified. We investigated the genotoxic effect of PM 2.5 collected from urban area in Seoul by comet assay (A549 cells), CBMN assay (CHO-K1 cells) and EROD-microbioassay (H4IIE cells). Results from in vitro micronucleus assay and comet assay showed that PM 2.5 samples collected from traffic area, residential area and indoor air induced chromosomal damage and DNA breakage in a non-cytotoxic dose. The complex mixture effect of these PM 2.5 extracts was quantified by EROD-microbioassay in terms of its bio-TEQ (biologiral -TCDD equivalent concentration) which was 70.87$\pm$28.07, 93.55$\pm$21.80 and 14.31 $\pm$ 1.10 ng/g-PM 2.5 in traffic area, residental area and indoor air samples, respectively. Conclusively, we suggested that PM 2.5 collected from traffic area and residential area contains CYPIA inducer and genotoxic materials.

• Environmental Analysis Health and Toxicology
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• 제25권1호
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• pp.85-94
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• 2010

Platycodon grandiflorum, Doraji as Korean name, is one of the most widely used traditional oriental medicine for bronchial diseases and also used as a folk remedy for geriatric diseases and inflammatory diseases. In recent studies, it has been reported that some effect of P. grandiflorum is derived from its antioxidant activity, although there is still a lack of evidence to establish its oxy-radical scavenging activity. In this study, total oxy-radical scavenging capacity (TOSC) assay was used to evaluate antioxidant activity of total extracts (T-PG), polysaccharide fraction (Po-PG), and saponin fraction (Sa-PG) isolated from P. grandiflorum against peroxyl radicals and peroxynitrites. And MTT assay was taken to assess cyto-protective effects of T-PG, Po-PG and Sa-PG in H4IIE cells treated with hydrogen peroxide and tert-butylhydroperoxide. In the TOSC assay, Sa-PG showed strong oxy-radical scavenging capacity compared with T-PG and Po-PG. In cell-based assay, T-PG and Po-PG protected cells from oxidative stress, but Sa-PG did not protect cells because of cytotoxicity of Sa-PG. These results suggest that the saponin components of P. grandiflorum have relatively strong antioxidant capacity and cytotoxicity in rat hepatoma cells.

• Toxicological Research
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• 제23권3호
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• pp.263-269
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• 2007

Although taurine (2-aminoethanesulfonic acid) can inhibit oxidative stress in both animal and epidemiological studies, it is obscure whether taurine directly scavenges oxy-radicals or indirectly regulates oxidant production and/or antioxidant defense system. The reason for this discrepancy remains unknown but may be due, in part, to the lack of a validated assay system for evaluating oxy-radical scavenging capacity. The antioxidant activities of taurine and hypotaurine (2-aminoethanesulfinic acid), a precursor of taurine, against peroxyl radicals, hydroxyl radicals and peroxynitrites were determined by the total oxy-radical scavenging capacity (TOSC) assay and cell-based assay using H4IIE cells. tert-Butylhydroperoxide or hydrogen peroxide-induced cell toxicity determined by MTT assay was markedly inhibited by 10mM taurine or hypotaurine. The tert-butylhydroperoxide- or hydrogen peroxide-induced changes in oxidative stress markers, such as cellular glutathione and malondialdehyde, were ameliorated by 10mM taurine or hypotaurine. However, specific TOSC values calculated from the slope of the linear regression for taurine against peroxyl radicals, hydroxyl radicals or peroxynitrites were all less than 1 TOSC/mM. On the other hand specific TOSC values for hypotaurine against peroxyl radicals, hydroxyl radicals or peroxynitrites were 48, 2096, or 69 TOSC/mM, respectively. These results suggest that taurine protects cells against oxidative insults, which is not ascribed to directly scavenging activity of taurine against oxy-radicals. These results support the idea that the oxidation state of sulfur in antioxidants may be a determinant of oxy-radical scavenging capacity.

• Toxicological Research
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• 제23권2호
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• pp.143-150
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• 2007

Although animal and epidemiological studies have suggested oxidative stress as an etiological factor in pathogenesis including cancer, inflammation, sepsis, fibrosis, cardiovascularlneurodegenerative diseases and aging-related disorders, conflicting results have been obtained in clinical trial with antioxidants. The reason for this discrepancy remains unknown but may be due, in part, to the lack of a validated assay system for evaluating antioxidant capacity. The antioxidant activity of a series of sugar alcohols against peroxyl radicals, hydroxyl radicals and peroxynitrites was determined by the total oxy-radical scavenging capacity (TOSC) assay and cell-based assay using H4IIE cells. Specific TOSC values calculated from the slope of the linear regression for erythritol, xylitol, sorbitol or mannitol against peroxyl radicals was $2.1{\pm}0.2,\;3.7{\pm}0.3,\;9.1{\pm}0.3$ or $8.7{\pm}1.1$ TOSC/mM, respectively. Specific TOSC values for erythritol, xylitol, sorbitol or mannitol against peroxynitrite was $1.9{\pm}0.3,\;3.9{\pm}0.4,\;7.8{\pm}0.7$ or $7.7{\pm}0.5$ TOSC/mM, respectively. These results suggest that oxy-radical scavenging capacity is dependent on the number of aliphatic hydroxyl group in sugar alcohols of monosaccharide. Tert-butylhydroperoxide (t-BHP)-induced cell toxicity determined by MTT assay was marginally attenuated by 10 mM erythritol, but completely inhibited by 10 mM xylitol, 2 mM sorbitol or 0.75 mM maltitol, a disaccharide alcohol. Oxidative stress markers, such as glutathione (GSH) and malondial-dehyde (MDA) levels, were measured in t-BHP-treated cells using HPLC equipped with a fluorescence detector and a reverse phase column. Erythritol did not change the levels of GSH and MDA in H411E cells treated with t-BHP. The t-BHP-induced changes in cellular GSH and MDA levels were ameliorated by 10 mM xylitol and completely blocked by 10 mM sorbitol and maltitol. These results indicate that sugar alcohols protect cells against oxidative stress via scavenging oxy-radical and suggest that TOSC assay in conjunction with cell-based assay is a valid method for evaluating antioxidant capacity of natural and synthetic chemicals.

• 한국식품과학회지
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• 제39권6호
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• pp.688-693
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• 2007

아세트아미노펜(APAP)으로 유도된 간독성 모델에 미치는 잔대를 주재료로 하는 추출물(ATJH)의 간보호 효능을 관찰하기 위하여 동물모델에서 혈청 간기능 지표효소의 활성도를 측정하고 조직학적인 변화를 관찰하였다. APAP를 투여한 동물군은 ALT와 AST활성을 현저하게 증가시켰다. ATJH를 1000 mg/kg의 용량으로 3일간 전투여한 후 APAP로 간 독성을 유도한 동물은 증가된 AST, ALT활성을 약 60-80% 감소시켰으며, 500 mg/kg의 용량으로 장기간(7일간) 전투여한 동물에서도 APAP독성방어효과가 현저하였다. APAP를 고농도(450 mg/kg)로 투여하여 간손상에 의한 사망을 유도한 동물군에서 ATJH는 생존율을 대조군에 비하여 130% 증가시켰다. APAP 단독 투여한 군에서 80-90% 정도 간세포 괴사가 관찰되었으나 ATJH(500, 1000 mg/kg)를 3일간 전투여 한 군에서는 간조직 손상이 억제되었다. 동물모델에서 ATJH에 의한 간독성 방어효능의 기전을 연구하기 위하여 간세포에서 제2상 해독화 효소인 GST의 단백 발현 변화를 면역화학적으로 관찰하였다. ATJH는 농도의존적으로 GSTA2, GSTA3/5의 단백 발현을 유의성있게 유도하였다. 본 연구에서는 잔대를 주원료로 한 추출물이 간세포의 해독화효소의 발현을 증가시킴으로서 APAP에 의해 유발된 간손상을 억제함을 처음으로 증명하였고, 간조직 보호를 위한 화학적 예방 효능을 갖는 활성물질로서 ATJH의 가능성을 제시한다.