• BMB Reports
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• 제38권2호
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• pp.167-176
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• 2005

Nuclear factor-E2-related factor 2 (Nrf2) is known as a key regulator of ARE-mediated gene expression and the induction of Phase II detoxifying enzymes and antioxidant enzymes, which is also a common property of many chemopreventive agents. In the present study, we investigated the regulatory role of different chemopreventive agents including sulforaphane (SUL), allyl isothiocyanate (AITC), indole-3-carbinol (I3C), and parthenolide (PTL), in the expression and degradation of Nrf2 and the induction of the antioxidant enzyme HO-1. SUL strongly induced Nrf2 protein expression and ARE-mediated transcription activation, retarded degradation of Nrf2 through inhibiting Keap1, and thereby activating the transcriptional expression of HO-1. AITC was also a potent inducer of Nrf2 protein expression, ARE-reporter gene and HO-1 but had little effect on delaying the degradation of Nrf2 protein. Although PTL and I3C could induce ARE reporter gene expression and Nrf2 to some extent, they were not as potent as SUL and AITC. However, PTL dramatically induced the HO-1 expression, which was comparable to SUL, while I3C had no effect. In addition, when treated with SUL and PTL, inhibition of proteasome by MG132 did not cause additional accumulation of Nrf2, suggesting the involvement of other degradation mechanism(s) in the presence of these compounds such as SUL and PTL. In summary, the results of our current study indicated that different chemopreventive compounds have different regulatory properties on the accumulation and degradation of Nrf2 as well as the induction of cellular antioxidant enzyme HO-1.

• Nutrition Research and Practice
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• 제8권2호
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• pp.138-145
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• 2014

BACKGROUND/OBJECTIVES: This study was performed to investigate the in vitro antioxidant and cytoprotective effects of fermented sesame sauce (FSeS) against hydrogen peroxide ($H_2O_2$)-induced oxidative damage in renal proximal tubule LLC-PK1 cells. MATERIALS/METHODS: 1,1-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl radical ($^{\bullet}OH$), and $H_2O_2$ scavenging assay was used to evaluate the in vitro antioxidant activity of FSeS. To investigate the cytoprotective effect of FSeS against $H_2O_2$-induced oxidative damage in LLC-PK1 cells, the cellular levels of reactive oxygen species (ROS), lipid peroxidation, and endogenous antioxidant enzymes including catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GSH-px) were measured. RESULTS: The ability of FSeS to scavenge DPPH, $^{\bullet}OH$ and $H_2O_2$ was greater than that of FSS and AHSS. FSeS also significantly inhibited $H_2O_2$-induced ($500{\mu}M$) oxidative damage in the LLC-PK1 cells compared to FSS and AHSS (P < 0.05). Following treatment with $100{\mu}g/mL$ of FSeS and FSS to prevent $H_2O_2$-induced oxidation, cell viability increased from 56.7% (control) to 83.7% and 75.6%, respectively. However, AHSS was not able to reduce $H_2O_2$-induced cell damage (viability of the AHSS-treated cells was 54.6%). FSeS more effectively suppressed $H_2O_2$-induced ROS generation and lipid peroxidation compared to FSS and AHSS (P < 0.05). Compared to the other sauces, FSeS also significantly increased cellular CAT, SOD, and GSH-px activities and mRNA expression (P < 0.05). CONCULUSIONS: These results from the present study suggest that FSeS is an effective radical scavenger and protects against $H_2O_2$-induced oxidative damage in LLC-PK1 cells by reducing ROS levels, inhibiting lipid peroxidation, and stimulating antioxidant enzyme activity.

• Asian Pacific Journal of Cancer Prevention
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• 제15권23호
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• pp.10187-10192
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• 2015

Cytochrome P450 (CYP) enzymes are a large family of constitutive and inducible mono-oxygenase enzymes that play a central role in the oxidative metabolism of both xenobiotic and endogenous compounds. Several CYPs are involved in metabolism of oxysterols, which are cholesterol oxidation products whose expression may be dysregulated in inflammation-related diseases including cancer. This study focused on CYP39A1, which can metabolize 24-hydroxycholesterol (24-OH) that plays important roles in the inflammatory response and oxidative stress. We aimed to investigate the expression status of CYP39A1 and its transcription factor (RUNX2) in relation to clinical significance in cholangiocarcinoma (CCAs) and to determine whether 24-OH could induce oxidative stress in CCA cell lines. Immunohistochemistry showed that 70% and 30% of CCA patients had low and high expression of CYP39A1, respectively. Low expression of CYP39A1 demonstrated a significant correlation with metastasis. Our results also revealed that the expression of RUNX2 had a positive correlation with CYP39A1. Low expression of both CYP39A1 (70%) and RUNX2 (37%) was significantly related with poor prognosis of CCA patients. Interestingly, oxidized alpha-1 antitrypsin (ox-A1AT), an oxidative stress marker, was significantly increased in CCA tissues in which CYP39A1 and RUNX2 were down regulated. Additionally, immunocytochemistry showed that 24-OH could induce ox-A1AT in CCA cell lines. In conclusion, our study revealed putative roles of the CYP39A1 enzyme in prognostic determination of CCAs.

• Journal of Nutrition and Health
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• 제44권5호
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• pp.366-377
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• 2011

Glutathione S-transferase (GST) is a multigene family of phase II detoxifying enzymes that metabolize a wide range of exogenous and endogenous electrophilic compounds. GSTM1 and GSTT1 gene polymorphisms may account for inter-individual variability in coping with oxidative stress. We investigated the relationships between the level of lymphocyte DNA and antioxidative parameters and the effect on GST genotypes. GSTM1 and GSTT1 were characterized in 301 young healthy Korean adults and compared with oxidative stress parameters such as the level of lymphocyte DNA, plasma antioxidant vitamins, and erythrocyte antioxidant enzymes in smokers and non smokers. GST genotype, degree of DNA damage in lymphocytes, erythrocyte activities of superoxide dismutase, catalase, and glutathione peroxidase (GSH-Px), and plasma concentrations of total radical-trapping antioxidant potential (TRAP), vitamin C, ${\alpha}$- and ${\gamma}$-tocopherol, ${\alpha}$- and ${\beta}$-carotene, and cryptoxanthin were analyzed. Lymphocyte DNA damage assessed by the comet assay was higher in smokers than that in non-smokers, but the levels of plasma vitamin C, ${\beta}$-carotene, TRAP, erythrocyte catalase, and GSH-Px were lower than those of non-smokers (p < 0.05). Lymphocyte DNA damage was higher in subjects with the GSTM1- or GSTT1-present genotype than those with the GSTM1-present or GSTT1- genotype. No difference in erythrocyte antioxidant enzyme activities, plasma TRAP, or vitamin levels was observed in subjects with the GSTM1 or GSTT1 genotypes, except ${\beta}$-carotene. Significant negative correlations were observed between lymphocyte DNA damage and plasma levels of TRAP and erythrocyte activities of catalase and GSH-Px after adjusting for smoking pack-years. Negative correlations were observed between plasma vitamin C and lymphocyte DNA damage only in individuals with the GSTM1-present or GSTT1- genotype. The interesting finding was the significant positive correlations between lymphocyte DNA damage and plasma levels of ${\alpha}$-carotene, ${\beta}$-carotene, and cryptoxanthin. In conclusion, the GSTM1- and GSTT1-present genotypes as well as smoking aggravated antioxidant status through lymphocyte DNA damage. This finding confirms that GST polymorphisms could be important determinants of antioxidant status in young smoking and non-smoking adults. Consequently, the protective effect of supplemental antioxidants on DNA damage in individuals carrying the GSTM1- or GSTT1-present genotypes might show significantly higher values than expected.

• Journal of Plant Biotechnology
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• 제30권4호
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• pp.411-419
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• 2003

GC-MS/SIM를 통하여 옥수수 유식물 신초로부터 해 castasterone (CS)과 6-deoxocastasterone (6-deoxoCS)을 동정하였다. 또한 BRs의 생합성 전구물질인 24$\alpha$-methylcholesterol과 24$\alpha$-methylcholestanol이 동정하였다. 이들 BRs와 생합성 전구물질은 BRs의 생합성과정 중 후기 C6산화과정에 속하는 화합물로서, 옥수수 유식물 줄기에서는 BRs의 생합성 과정으로 후기 C6산화과정이 주된 생합성 과정임을 알 수 있었다. 다음으로 옥수수 유식물 줄기내의 BRs가 발아와 더불어 종자에서부터 이동해 온 것인지, 아니면 줄기 생장 시 줄기 자체가 생합성된 것인지를 조사하기 위하여 몇몇 중요한 후기 C6산화과정의 반응을 촉매하는 효소의 활성이 유식물 줄기에 존재하는지를 조사하였다. 그 결과 후기 C6산화과정에 포함되는 24$\alpha$-methylcholestanol에 서 6-deoxocathasterone (6-deoxoCT), 6-deoxoteasterone (6-deoxoTE) 에서 6-deoxo-3-dehydroteasterone (6-deoxo-3-DHT)을 거쳐 6-deoxotyphasterol (6-deoxoTY),그리고 6-deoxoCS에서 CS로의 과정을 촉매하는 24$\alpha$-methylcholestanol 22(R)-hydroxlyase, 6-deoxoTE dehydrogenase/6-deoxo-3-DHT reductase, 6-deoxoCS oxidase의 활성이 옥수수 유식물 줄기에 존재하고 있음이 확인되었다. 이는 유식물 줄기 생장 시 필요한 BRs가 발아종자로부터 이동되는 것이 아니라, 유식물 줄기 자체에서 생합성 될 가능성이 높음을 나타내는 결과라 할 수 있다. 또한 옥수수 유식물 줄기에서 CS를 brassinolide(BL)로 전환하는 BL synthase의 활성이 검출되지 않아, 옥수수 유식물 줄기에서의 활성형 BR은 BL이 아닌 CS임을 밝혔다.

• 대한화장품학회지
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• 제36권1호
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• pp.79-87
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• 2010

자외선은 생체 내 활성산소 생성 증가와 내인성 항산화 효소 및 항산화제 감소를 통하여 광노화 과정을 촉진하는 대표적인 외부 환경인자로 알려져 있다. 그러므로 본 연구에서는 12종의 다양한 해양소재 추출물(김, 다시마, 모려, 모자반, 미역, 석결명, 청각, 해룡, 해마, 해삼, 파래, 톳)을 이용하여 기본적인 자유라디칼 소거능 실험을 바탕으로, 자외선 B 조사로 인한 세포독성 및 산화적 사멸을 억제하고 세포 내 항산화 기능을 강화시킬 수 있는 천연 항산화 피부보호소재를 발굴하고자 하였다. 해양소재 추출물의 라디칼 소거능을 1,1-diphenyl-2-picrylhydrazyl (DppH) assay로 비교 측정한 결과 미역, 모자반, 다시마, 해마, 석결명 모려, 해룡의 순으로 항산화력을 나타내었다. 이후 in vitro 세포 실험에서 자외선 B를 섬유아세포주인 HS68 세포에 노출시킨 경우 세포 독성이 유발되어 사멸이 진행되었으며 이는 모자반, 석결명, 청각, 해마 열수 추출물을 처리한 경우 현저히 억제되었다. 특히, 자외선 B로 인한 세포손상은 세포 내 활성산소종의 축적으로 인한 것임을 2',7'-dichlorodihydrofluorescein diacetate (DCF-DA) 형광염색법으로 확인할 수 있었으며, 활성산소종의 생성은 모자반, 석결명, 청각, 해마 열수 추출물을 처리한 경우 유의적으로 감소되었다. 한편, 이러한 항산화 작용은 대표적인 내인성 항산화 효소인 catalase, superoxide dismutase 및 heme oxygenase-1의 발현 증가로 매개되었다. 이상의 결과는 모자만, 석결명, 정각, 해마 풍의 해양소재가 항산화 작용을 통하여 산화적 스트레스가 매개하는 피부손상과 노화과정을 예방 및 보호하는 새로운 화장품 천연소재로의 활용 가능성을 제시한다.

• Animal Bioscience
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• 제34권9호
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• pp.1514-1524
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• 2021

Objective: This study investigated the meat quality characteristics, endogenous proteolytic enzymes, collagen content, and myosin heavy chain (MyHC) isoforms of different muscles of Thai native cattle (TNC). Methods: Infraspinatus (IF), Longissimus thoracis (LT), and Supraspinatus (SS) muscles were obtained from two TNC breeds, Kho-Lan (KL, n = 7) and Kho-Isaan (KI, n = 7). The muscle and meat characteristics of TNC breeds and their relationship with MyHC expression were examined. Results: Three MyHC isoforms namely MyHC I, MyHC IIa, and MyHC IIx were detected in the muscles. The KL had higher (p<0.05) MyHC IIx than the KI. The IF muscle had higher (p<0.05) MyHC I compared to other muscles. The LT muscle had the least MyHC I. The LT had higher (p<0.05) MyHC IIx than the IF and SS muscles. The IF presented the least MyHC IIx. The KL had higher (p<0.05) lightness and moisture content and lower crude protein, redness, cooking loss, shear force, and calpastatin than the KI. The glycogen, total collagen, soluble collagen, crude protein, ash contents, and troponin T degradation product of IF and SS were lower (p<0.05) than that of LT. Ether extract in LT was lower (p<0.05) than that of IF and SS. The percentage of MyHC I, MyHC IIa, and MyHC IIx were significantly correlated with muscle and meat characteristics of TNC. Conclusion: These results suggest that the differences in the MyHC isoforms may partly account for the variation in meat quality between breeds and among muscles of TNC.

• Asian Pacific Journal of Cancer Prevention
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• 제13권1호
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• pp.157-163
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• 2012

Objective: Glutathione S-transferases (GSTs) are multifunctional enzymes that play a crucial role in the detoxification of both the endogenous products of oxidative stress and exogenous carcinogens. Recent studies investigating the association between genetic polymorphisms in GSTs and the risk of adult brain tumors have reported conflicting results. The rationale of this pooled analysis was to determine whether the presence of a GST variant increases adult glioma susceptibility by combining data from multiple studies. Methods: In our meta-analysis, 12 studies were identified by a search of the MEDLINE, HIGHWIRE, SCIENCEDIRECT and EMBASE databases. Of those 12, 11 evaluated GSTM1, nine evaluated GSTT1 and seven evaluated GSTP1 Ile105Val. Between-study heterogeneity was assessed using ${\chi}^2$-based Q statistic and the $I^2$ statistic. Crude odds ratios (ORs) with corresponding 95% confidence intervals (CIs) were used to estimate the association between GSTM1, GSTT1 and GSTP1 polymorphisms and the risk of adult gliomas. Results: The quantitative synthesis showed no significant evidence to indicate an association exists between the presence of a GSTM1, GSTT1 or GSTP1 Ile105Val haplotype polymorphism and the risk of adult gliomas (OR, 1.008, 1.246, 1.061 respectively; 95% CI, 0.901-1.129, 0.963-1.611, 0.653-1.724 respectively). Conclusions: Overall, this study did not suggest any strong relationship between GST variants or related enzyme polymorphisms and an increased risk of adult gliomas. Some caveats include absence of specific raw information on ethnic groups or smoking history on glioma cases in published articles; therefore, well-designed studies with a clear stratified analysis on potential confounding factors are needed to confirm these results.

• Toxicological Research
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• 제17권
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• pp.127-133
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• 2001

Together with cytochrome P450 (CYP), flavin-containing monooxygenase (FMO) present in liver microsomes oxidizes various endogenous and exogenous chemicals. In an effort to determine the human FMO activity, we have developed two non-invasive urine analysis methods using caffeine (CA) and ranitidine (RA) as the probe compounds. As the production of theobromine (TB) and ranitidine N-oxide (RANO) from CA and RA is catalyzed primarily by the hepatic FMO, we have assigned the urinary molar ratios of TB/CA and RA/RANO as the in vivo FMO activity. In 200 age-matched Korean volunteers, the obtained TB/CA ratio ranged from 0.4 to 15.2 (38-fold difference) and the RA/RANO ratio from 5.7 to 27.2 (4.8-fold). The FMO activity of 20's, determined by caffeine metabolism, was the highest (2.5$\pm$l.9) and those of 30's, 40's, 50's, 60's and 70's were 40%, 50%, 24%, 39% and 36% of the 20's, respectively. Intake of grapefruit juice, known to contain flavonoids, inhibited the in vivo FMO (TB/CA) activity by 79%. Addition of the flavonoids like naringin, quercitrin and kaempferol, present in grapefruit juice, to the in vitro microso-mal FMO assay, thiobenzamide S-oxidation, produced 75%, 70% and 60% inhibition, respectively. Obtained Ki values of quercitrin, kaempferol and naringin on the in vitro FMO activity were 6.2, 12.0 and 13.9 $\mu\textrm{M}$, respectively. This suggested that the dose of drug should need to be adjusted to suit the individual FMO activities when the drugs metabolized by FMO are given to patients. As the intake of grapefruit juice has been identified to inhibit the FMO as well as CYP3A4 and lA2 activities, patients taking drugs metabolized by these enzymes should not drink grapefruit juice as the carrier.

• Nutrition Research and Practice
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• 제6권2호
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• pp.155-161
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• 2012

Excessive oxidative stress and abnormal blood lipids may cause chronic diseases. This risk can be reduced by consuming an antioxidant- and fiber-rich vegetarian diet. We compared biomarkers of oxidative stress, antioxidant capacity, and lipid profiles of sex- and age-matched long-term vegetarians and omnivores in Korea. Forty-five vegetarians (23 men and 22 women; mean age, $49.5{\pm}5.3$ years), who had maintained a vegetarian diet for a minimum of 15 years, and 30 omnivores (15 men and 15 women; mean age, $48.9{\pm}3.6$ years) participated in this study. Their 1-day, 24-h recall, and 2-day dietary records were analyzed. Oxidative stress was measured by the levels of diacron reactive oxygen metabolites (d-ROM). Antioxidant status was determined by the biological antioxidant potential (BAP) and levels of endogenous antioxidant enzymes such as superoxide dismutase, catalase, and glutathione peroxidase. We observed that vegetarians had a significantly lower body fat percentage ($21.6{\pm}6.4%$) than that of omnivores ($25.4{\pm}4.6%$; $P$ < 0.004). d-ROM levels were significantly lower in vegetarians than those in omnivores ($331.82{\pm}77.96$ and $375.80{\pm}67.26$ Carratelli units; $P$ < 0.011). Additionally, total cholesterol levels in the vegetarians and omnivores were $173.73{\pm}31.42$ mg/dL and $193.17{\pm}37.89$ mg/dL, respectively ($P$ < 0.018). Low-density lipoprotein cholesterol was $101.36{\pm}23.57$ mg/dL and $120.60{\pm}34.62$ mg/dL ($P$ < 0.005) in the vegetarians and omnivores, respectively, indicating that vegetarians had significantly lower lipid levels. Thus, oxidative stress, body fat, and cholesterol levels were lower in long-term vegetarians than those in omnivores.