• 한국식품영양과학회지
• /
• 제35권8호
• /
• pp.1010-1015
• /
• 2006

혼합 두발염색제의 독성을 확인할 목적으로 체중 $230{\pm}20\;g$의 Sprague-Dawley종의 흰쥐를 대조군, 6% 과산화수소 도포 실험군, 2% 암모니아 용액에 5% PPD를 용해시켜 도포한 실험군, 2% 암모니아 용액에 5% PPD와 6% 과산화수소의 동량 혼합액을 도포한 실험군 등 4군으로 분류하여 2일 간격으로 피부 표면적 $16.5\;cm^2$ 당 25 mg이 되게 5회 도포한 다음 피부조직의 손상 정도 및 ROS 생성계와 해독계의 활성변동을 관찰하여 다음과 같은 결과를 얻었다. PPD와 과산화수소 혼합액을 도포한 실험군에서 PPD를 단독 도포한 실험군에 비해 피부조직의 손상 지표인 ACP 활성이 현저하게 증가하였으며, PPD 단독 도포군의 조직병리에서는 관찰되지 않았던 진피층 내 모세혈관의 확장 등이 나타나는 것으로 보아 피부조직의 손상이 심화된 것을 확인할 수가 있었다. 이러한 실험 조건 하에서 ROS 생성계효소인 XO의 활성은 PPD와 과산화수소 혼합액 도포군에서 PPD 단독 도포군에 비해 현저하게 증가하였으며, ROS 해독계 효소들의 활성은 유의하게 감소하였다. 이상의 실험결과를 종합해 볼 때, PPD와 과산화수소 혼합액 도포군이 PPD 단독 도포군에 비해 XO의 활성이 현저하게 증가되어 과잉의 ROS를 생성시켜 ROS 해독계 효소의 활성을 억제함으로서 조직의 손상이 심화된 것으로 생각된다.

• 한국가금학회지
• /
• 제48권1호
• /
• pp.31-39
• /
• 2021

본 연구는 White Leghorn에서 부화 후 일령(0-d, 3-d, 7-d, 14-d 및 21-d)에 따른 소화기관의 발달과 기능 및 항산화 방어작용에 대한 변화를 조사하기 위해 실시하였다. 일령에 따른 체중은 부화 후 0, 3 및 7일령까지는 변화가 적었지만, 7일령 이후에는 유의하게(P<0.05) 증가하였다. 체중에 따른 소화 장기의 상대적 무게(g/100 g BW)에서, 간의 상대적 무게는 0일령에서 현저히 낮았지만 3~7일령에 현저히 증가한 후(P<0.05) 21일령까지 유의차 없이 점차 감소하였다. 상대적 췌장 무게 역시 간 무게의 변화와 유사한 경향을 보이며, 7일령에서 최대 발달을 보였지만(P<0.05) 그 이후에는 점차 감소하는 경향을 보였다. 상대적 소장 무게와 길이의 변화는 부화 후 급격히 증가하여 7일령에서 최대 성장을 보이고(P<0.05) 점차 감소하여 21일령 이후에는 현저히 낮아졌다. 소장 점막세포의 무게는 부화 후 현저히 증가하여(P<0.05) 14일령에 최대 발달률을 보였으나 21일령에는 감소하였다(P<0.05). 이당류 분해효소의 특이적 활성도는 0일령에 가장 낮았으나, 3일령에서 유의적으로 높은 최대 활성도 증가를 보였다(P<0.05). Sucrase 활성도는 14일령 이후 유의하게 감소하였으나(P<0.05), maltase는 지속적으로 높은 활성도를 유지하는 것으로 나타났다. Leucine aminopeptiase 특이적 활성도는 0일령부터 높게 나타나 일령에 상관없이 일정하게 유지되는 것으로 나타났다. SOD와 GST 특이적 활성도는 0일령에서 가장 낮았으나, 7일령 이후 유의적으로 높은 활성도를 보였다(P<0.05). GPX 활성도는 0, 7일령과 비교 시 14일령 이후 활성도가 현저하게 증가하였다(P<0.05). 지질 과산화(MDA) 함량은 모든 일령에서 매우 낮게 나타나 일령에 따른 차이가 없었다. 이상의 결과로 보아, White Leghorn 병아리는 부화 후 3~7일령에서 소화 장기 발달과 소화 효소 활성도가 급격히 증가하며, 7일령 이후 체 성장과 간 조직의 대사 작용이 활발해지면서 항산화 효소의 활성도가 함께 증가하는 것으로 나타났다.

• Archives of Pharmacal Research
• /
• 제23권1호
• /
• pp.1-16
• /
• 2000

Many natural products elicit diverse pharmacological effects. Using two classes of potential chemopreventive compounds, the phenolic compounds and the isothiocyanates, we review the potential utility of two signaling events, the mitogen-activated protein kinases (MAPKs) and the ICE/Ced-3 proteases (caspases) stimulated by these agents in mammalian cell lines. Studies with phenolic antioxidants (BHA, tBHQ), and natural products (flavonoids; EGCG, ECG, and isothiocyanates; PEITC, sulforaphane), provided important insights into the signaling pathways induced by these compounds. At low concentrations, these chemicals may activate the MAPK (ERK2, JNK1, p38) leading to gene expression of survival genes (c-Fos, c-Jun) and defensive genes (Phase II detoxifying enzymes; GST, QR) resulting in survival and protective mechanisms (homeostasis response). Increasing the concentrations of these compounds will additionally activate the caspase pathway, leading to apoptosis (potential cytotoxicity). Further increment to suprapharmacological concentrations will lead to nonspecific necrotic cell death. The wider and narrow concentration ranges between the activation of MAPK/gene induction and caspases/cell death exhibited by phenolic compounds and isothiocyanates, respectively, in mammalian cells, may reflect their respective therapeutic windows in vivo. Consequently, the studies of signaling pathways elicited by natural products will advance our understanding of their efficacy and safety, of which many man become important therapeuitc drugs of the future.

• Food Science and Biotechnology
• /
• 제17권2호
• /
• pp.367-372
• /
• 2008

Cellular protection against carcinogens could be achieved by the induction of phase 2 detoxifying and antioxidant enzymes such as glutathione S-transferase (GST), NAD(P)H:quinone oxidoreductase 1 (NQO1) and heme oxygenase 1 (HO1). Nuclear transcription factor E2-related factor 2 (Nrf2) binds to antioxidant response element (ARE) in the promoter region of these genes and the resulting transactivation occurs. In the present study the effect of gujeolcho (Chrysanthemum zawadskii) roots on the Nrf2-ARE pathway were investigated. C. zawadskii root extract was fractionated with a series of organic solvents and their ability to induce Nrf2-ARE pathway was examined. We separated the most potent dichloromethane (DCM) fraction into 12 sub-fractions and found several sub-fractions with strong effects on the Nrf2-ARE pathway. Fraction 4 strongly induced the ARE-reporter gene activity as well as Nrf2 expression. Sitosterol was isolated as a major compound in fraction 4 although its activity was not as potent as its mother fraction. These results indicate that C. zawadskii roots might be used as a potential natural chemopreventive source.

• JSTS:Journal of Semiconductor Technology and Science
• /
• 제8권2호
• /
• pp.128-133
• /
• 2008

Phase-change random access memory (PRAM) chip cell phase of amorphous state is rapidly changed to crystal state above 160 Celsius degree within several seconds during Infrared (IR) reflow. Thus, on-board programming method is considered for PRAM chip programming. We demonstrated the functional 512Mb PRAM with 90nm technology using several novel core circuits, such as metal-2 line based global row decoding scheme, PN-diode cells based BL discharge (BLDIS) scheme, and PMOS switch based column decoding scheme. The reverse-state standby current of each PRAM cell is near 10 pA range. The total leak current of 512Mb PRAM chip in standby mode on discharging state can be more than 5 mA. Thus in the proposed BLDIS control, all bitlines (BLs) are in floating state in standby mode, then in active mode, the activated BLs are discharged to low level in the early timing of the active period by the short pulse BLDIS control timing operation. In the conventional sense amplifier, the simultaneous switching activation timing operation invokes the large coupling noise between the VSAREF node and the inner amplification nodes of the sense amplifiers. The coupling noise at VSAREF degrades the sensing voltage margin of the conventional sense amplifier. The merit of the proposed sense amplifier is almost removing the coupling noise at VSAREF from sharing with other sense amplifiers.

• 원예과학기술지
• /
• 제31권3호
• /
• pp.275-281
• /
• 2013

Low temperature is one of the major environmental factors that affect productivity including reduced growth and budding of vines, and changes of metabolic processes in grape (Vitis spp.). To screen the specific expression of abiotic stress-related genes against cold treatment in 'Kyoho' and 'Campbell Early' grapevines, expression of various defense-related genes was investigated by RT-PCR and real-time PCR. Among the 67 genes analyzed by RT-PCR and real-time PCR, 17 and 16 types of cDNA were up-regulated, while 5 and 6 types were down-regulated in cold-treated 'Kyoho' and 'Campbell Early' grapevines, respectively. Genes encoding carotene (Cart3564 and Cart4472), chalcone isomerase (CHI), cytochrome P450 (CYP), flavonol synthase (FLS), endo-${\beta}$-glucanase precursor (Glu), glutathione peroxidase (GPX), glutathione-S-transferase (GST), leucine-rich repeats (LRR), manganese superoxide dismutase (Mn-SOD), phenylalanine ammonia lyase (PAL), polygalacturonase-inhibiting protein (PGIP), proline rich protein 2 (PRP2), small heat shock protein (sHSP), temperature induced lipocalin (TIL), and thaumatin-like protein (TLP) were up-regulated, while those encoding CBF like transcription factor (CBF1), chitinase-like protein (CLP), cold induced protein (CIP), glycerol-3-phosphate acyltransferase (GPAT), and mitogen-activated protein kinase (MAPK) were down-regulated by low temperature treatment in both in 'Kyoho' and 'Campbell Early'.

• Parasites, Hosts and Diseases
• /
• 제39권2호
• /
• pp.171-176
• /
• 2001

Western blot analysis was performed to diagnose vivax malaria using stage-specific recombinant antigens. Genomic DNA from the whole blood of a malaria patient was used as templates to amplify the coding regions for the antigenic domains of circumsporozoite protein (CSP-1), meroxoite surface protein (MSP-1), apical merozoite antigen (AMA- 1), serine repeat antigen (SERA), and exported antigen (EXP- 1) of Plasmodium vivax. Each amplified DNA fragment was inserted into a pGEX-4T plasmid to induce the expression of GST fusion protein in Escherichia coli by IPTG. The bacterial cell extracts were separated on 10% SDS-PAGE followed by western blot analysis with patient sera which was confirmed by blood smear examination. When applied with patient sera, 147 (91.9%) out of 160 vivax malaria, 12 (92.3%) out of 13 falciparum malaria, and all 9 vivax/falciparum mixed malaria reacted with at least one antigen, while no reactions occurred with 20 normal uninfected sera. In the case of vivax malaria, CSP-1 reacted with 128 (80.0%) sera, MSP-1 with 102 (63.8%), AMA-1 with 128 (80.0%), SERA with 115 (71.9%), and EXP-1 with 89 (55.6%), respectively. We obtained higher detection rates when using S antigens (91.9%) rather than using each antigen solely (55.6 - 80%), a combination of 2 (76.3 - 87.5%), 3 (85.6 - 90.6%), or 4 antigens (89.4 - 91.3%). This method can be applied to serological diagnosis, mass screening in endemic regions, or safety test in transfusion of prevalent vivax malaria.

• Asian Pacific Journal of Cancer Prevention
• /
• 제15권6호
• /
• pp.2911-2916
• /
• 2014

Oxaliplatin is a first-line therapy for colorectal cancer, but cancer cell resistance to the drug compromises its efficacy. To explore mechanisms of drug resistance, we treated colorectal cancer cells (HCT116 and SW620) long-term with oxaliplatin and established stable oxaliplatin-resistant lines (HCT116-OX and SW620-OX). Compared with parental cell lines, $IC_{50}$s for various chemotherapeutic agents (oxaliplatin, cisplatin and doxorubicin) were increased in oxaliplatin-resistant cell lines and this was accompanied by activation of nuclear factor erythroid-2 p45-related factor 2 (Nrf2) and NADPH quinone oxidoreductase 1 (NQO1). Furthermore, luteolin inhibited the Nrf2 pathway in oxaliplatin-resistant cell lines in a dose-dependent manner. Luteolin also inhibited Nrf2 target gene [NQO1, heme oxygenase-1 (HO-1) and $GST{\alpha}1/2$] expression and decreased reduced glutathione in wild type mouse small intestinal cells. There was no apparent effect in Nrf2-/- mice. Luteolin combined with other chemotherapeutics had greater anti-cancer activity in resistant cell lines (combined index values below 1), indicating a synergistic effect. Therefore, adaptive activation of Nrf2 may contribute to the development of acquired drug-resistance and luteolin could restore sensitivity of oxaliplatin-resistant cell lines to chemotherapeutic drugs. Inhibition of the Nrf2 pathway may be the mechanism for this restored therapeutic response.

• Nutrition Research and Practice
• /
• 제8권3호
• /
• pp.272-277
• /
• 2014

BACKGROUND/OBJECTIVES: This study investigated the antioxidant activities and hepatoprotective effects of Schisandra chinensis Baillon extract (SCE) against tert-butyl hydroperoxide (t-BHP)-induced oxidative hepatic damage in rats. MATERIALS/METHODS: Sprague-Dawley (SD) rats were pretreated with SCE (300, 600, and 1,200 mg/kg BW) or saline once daily for 14 consecutive days. On day 14, each animal, except those belonging to the normal control group, were injected with t-BHP (0.8 mmol/kg BW/i.p.), and all of the rats were sacrificed 16 h after t-BHP injection. RESULTS: Although no significant differences in AST and ALT levels were observed among the TC and SCE groups, the high-dose SCE group showed a decreasing tendency compared to the TC group. However, erythrocyte SOD activity showed a significant increase in the low-dose SCE group compared with the TC group. On the other hand, no significant differences in hepatic total glutathione (GSH) level, glutathione reductase (GR), and glutathione peroxidase (GSH-Px) activities were observed among the TC and SCE groups. Hepatic histopathological evaluation revealed that pretreatment with SCE resulted in reduced t-BHP-induced incidence of lesions, such as neutrophil infiltration, swelling of liver cells, and necrosis. In particular, treatment with a high dose of SCE resulted in induction of phase II antioxidant/detoxifying enzyme expression, such as glutathione S-transferase (GST) and glutamate-cysteine ligase catalytic subunit (GCLC). CONCLUSIONS: Based on these results, we conclude that SCE exerts protective effects against t-BHP induced oxidative hepatic damage through the reduction of neutrophil infiltration, swelling of liver cells, and necrosis. In addition, SCE regulates the gene expression of phase II antioxidant/detoxifying enzymes independent of hepatic antioxidant enzyme activity.

• Journal of Plant Biology
• /
• 제38권2호
• /
• pp.173-180
• /
• 1995

We investigated levels and distribution of genetic variation in Korean populations of Calystegia soldanella and C. japonica, clonally reproducing herbaceous perennials. Calystegia soldanella is one ofecologically important beach plants growing only on sand and beach dunes in Europe, East Asia, the Pacific Islands, and the west coast of North America. In contrast, C. japonica usually grows on small mounds of paddy fields, roadsides, and waste places with patchy distribution. Starch gel electrophoresis was conducted on leaves collected from 13 populations of C. soldanella and eight populations of C. japonica. The levels of genetic variation of the two species are very comparable; means of expected heterozygosity (Hep) were 0.100 and 0.099 for C. soldanella and C. japonica, respectively. These values were also very similar to those for species with similar life-history and ecological traits. However, the proportion of total genetic diversity partitioned among populations (GST) of C. soldanella (0.146) was considerably lower than that of C. japonica (0.383). In addition, means of Nei's genetic identity (Ⅰ) for C. soldanella and C. japonica were 0.985 and 0.900, respectively, which supports a restricted gene flow resulting from obligate clonal reproduction of C. japonica. Significant differences in allele frequency were detected among populations at eight and nine of nine polymorphic loci for C. soldanella and C. japonica (P<0.01), respecitvely. Considering the ecological importance of C. soldanella, the isolated beach populations coupled with present destruction of natural habitats of the species may result in erosion of genetic diversity in the near future. In this respect, conservation efforts should be focused on those populations that currently maintain the most genetic diversity such as those populations in the eastern and southeastern Korean Peninsula and Hamduck Beach, Cheju Island.