Synthesis of Sr Doped HoCrO3 Solid Solution Systems and Their Electrical Properties

PARK, SUNG HO,Kwon, Tae Yun 한국공업화학회 2000 Journal of Industrial and Engineering Chemistry Vol.6 No.4

Ho_(1-x)SrxCrO₃ systems, with perovskite structures, were synthesized for x=0, 0.05, 0.1, 0.2 at 1300 ℃ under atmospheric pressure. The results of X-ray analysis reveals that these prepared systems forms orthorhombic structures. Also, the HoCrO₃ systems which were doped with Sr cations on the site of Ho cations, exhibited a linear increase in their cell volume. It was found that the lattice parameter and reduced volume increased as the doping level of Sr^(2+) increased. From the measurements of D.C conductivity, the activation energy obtained from the conductivity dependence on temperature was 0.18 eV. The conduction mechanism would appear to be the hopping model of electron conduction.

Heme oxygenase-1 (HO-1)/carbon monoxide (CO) axis suppresses RANKL-induced osteoclastic differentiation by inhibiting redox-sensitive NF-κB activation

( Sun-uk Bak ),( Suji Kim ),( Hae-jun Hwang ),( Jung-a Yun ),( Wan-sung Kim ),( Moo-ho Won ),( Ji-yoon Kim ),( Kwon-soo Ha ),( Young-guen Kwon ),( Young-myeong Kim ) 생화학분자생물학회(구 한국생화학분자생물학회) 2017 BMB Reports Vol.50 No.2

Heme oxygenase (HO-1) catalyzes heme to carbon monoxide (CO), biliverdin/bilirubin, and iron and is known to prevent the pathogenesis of several human diseases. We assessed the beneficial effect of heme degradation products on osteoclastogenesis induced by receptor activator of NF-κB ligand (RANKL). Treatment of RAW264.7 cells with CORM-2 (a CO donor) and bilirubin, but not with iron, decreased RANKLinduced osteoclastogenesis, with CORM-2 having a more potent anti-osteogenic effect. CORM-2 also inhibited RANKLinduced osteoclastogenesis and osteoclastic resorption activity in marrow-derived macrophages. Treatment with hemin, a HO-1 inducer, strongly inhibited RANKL-induced osteoclastogenesis in wild-type macrophages, but was ineffective in HO-1^+/-cells. CORM-2 reduced RANKL-induced NFATc1 expression by inhibiting IKK-dependent NF-κB activation and reactive oxygen species production. These results suggest that CO potently inhibits RANKL-induced osteoclastogenesis by inhibiting redox-sensitive NF-κB-mediated NFATc1 expression. Our findings indicate that HO-1/CO can act as an antiresorption agent and reduce bone loss by blocking osteoclast differentiation. [BMB Reports 2017; 50(2): 103-108]

Antioxidant and Anti-Inflammatory Effects of Rhei Rhizoma and Coptidis Rhizoma Mixture on Reflux Esophagitis in Rats

Kwon, O Jun,Kim, Min Yeong,Shin, Sung Ho,Lee, Ah Reum,Lee, Joo Young,Seo, Bu-il,Shin, Mi-Rae,Choi, Hyun Gyu,Kim, Jeong Ah,Min, Byung Sun,Kim, Gyo-Nam,Noh, Jeong Sook,Rhee, Man Hee,Roh, Seong-Soo Hindawi Publishing Corporation 2016 Evidence-based Complementary and Alternative Medic Vol.2016 No.-

<P>The purpose of this study was to investigate the antioxidant and anti-inflammatory effects of the combined extract of Rhei rhizoma and Coptidis rhizoma (RC-mix) in experimental model of acute reflux esophagitis. The antioxidant activity was assessed by<I> in vitro</I> 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assays. RC-mix was given at 100, 200, and 400 mg/kg body weight 2 h prior to induction of reflux esophagitis (RE). After 5 h, the effects of RC-mix treated rats were compared with those of normal and control rats. The representative flavonoid contents of RC-mix, such as sennoside A, epiberberine, coptisine, palmatine, and berberine, were detected using HPLC. The elevated esophageal mucosa damage was markedly ameliorated by RC-mix treatment in a dose-dependent manner. Furthermore, the administration of RC-mix reduced the increase of serum reactive oxygen species (ROS) and peroxynitrite (ONOO<SUP>−</SUP>). The improvement of superoxide dismutase (SOD) and heme oxygenase-1 (HO-1) levels were marked in the group given RC-mix. Moreover, the elevation of inflammatory mediators and cytokines by nuclear factor-kappa B (NF-<I>κ</I>B) activation in control rats decreased by RC-mix pretreatment. These results indicate that RC-mix treatment reduces the pathological states of esophagitis<I> via</I> regulating NF-<I>κ</I>B mediated inflammation related to oxidative stress. </P>

제주도 지하수 질산염 농도의 시·공간적 변화 특성: 장기(1993-2015) 모니터링 자료의 평가

김호림(Ho-Rim Kim),오준섭(Junseop Oh),도현권(Hyun-Kwon Do),이경진(Kyung-Jin Lee),현익현(Ik-Hyun Hyun),오상실(Sang-Sil Oh),감상규(Sang-Kyu Kam),윤성택(Seong-Taek Yun) 대한자원환경지질학회 2018 자원환경지질 Vol.51 No.1

1993년부터 2015년까지 관측된 제주도 지하수 장기모니터링 관측정(N = 4,835)에서 수집된 지하수 수질자료(N = 21,568)를 기반으로 질산성질소의 시공간적 변동 특성을 평가하였다. 제주도 지하수의 질산성질소 농도의 중앙값은 2.5 mg/L로서 다른 국가나 대륙의 조사 결과에 비해 다소 높거나 유사한 것으로 나타났다. 또한 지하수 용도, 행정구역 및 고도 별로 유의한 차이를 보였다. 특히, 산간 지역에 비해 저지대 해안가에 위치한 농업 및 주거지역에서 농도가 높음을 확인하였다. Mann-Kendall 및 Sen’s slope 분석을 활용한 질산성질소 농도의 추세 분석 결과, 하류 저지 대에 비해 중산간지역에서의 질산성질소 농도 증가 경향이 뚜렷하였다. 제주도 내 토지 피복의 시계열 변화 특성과 결부 지어 보면, 중산간지역의 오염 증가 추세는 농업지역의 확장 등 인위적 활동 증가에 기인한 결과로 판단된다. 반면,기지정된 지하수자원특별관리구역에서는 전반적으로 질산성질소 농도의 감소 경향이 나타났는데, 이는 지하수 관리 측면에서 수질관리를 위한 적극적인 정책이 유효함을 시사한다. 본 연구에서는 제주도 지하수의 질산성질소 오염관리를 위한 적정 방안을 제안한다. The spatio-temporal variations of nitrate concentrations in groundwater of Jeju Island were evaluated by an analysis of time series groundwater quality data (N = 21,568) that were collected from regional groundwater monitoring (number of wells = 4,835) for up to 20 years between 1993 and 2015. The median concentration of NO 3 -N is 2.5 mg/L, which is slightly higher than those reported from regional surveys in other countries. Nitrate concentrations of groundwater in wells tend to significantly vary according to different water usage (of the well), administrative districts, and topographic elevations: nitrate level is higher in low-lying agricultural and residential areas than those in high mountainous areas. The Mann-Kendall trend test and Sen’s slope analysis show that nitrate concentration in mid-mountainous areas tends to increase, possibly due to the expansion of agricultural areas toward highland. On the other hand, nitrate concentrations in the Specially Designated Groundwater Quality Protection Zones show the temporally decreasing trend, which implies the efficiency of groundwater management actions in Jeju. Proper measures for sustainable groundwater quality management are suggested in this study.

성인에서 발생한 발진성 가성 혈관종증

서상희 ( Sang Hee Seo ),장호선 ( Ho Sun Jang ),목혜수 ( Hye Soo Mok ),김성준 ( Sung Jun Kim ),김병수 ( Byung Soo Kim ),김문범 ( Moon Bum Kim ),오창근 ( Chang Keun Oh ),권경술 ( Kyung Sool Kwon ) 대한피부과학회 2007 대한피부과학회지 Vol.45 No.8

Background: Eruptive pseudoangiomatosis (EPA) is a rare, benign, spontaneously regressing childhood exanthem. It is characterized by the sudden onset of several bright red angioma-like papules surrounded by pale halos with a distinct histopathology from true angiomas. Objective: This study was performed to evaluate the clinical and histopathologic characteristics of EPA occuring in adults. Methods: Ten adult patients who visited Pusan National University Hospital and Mok Hye-SooㆍJang Ho-Sun Dermatology Clinic from March 2005 to September 2006 were evaluated. We prospectively evaluated the sex, age, onset season, past medical history including immunosuppressive abnormalities, systemic disorders and other diseases including allergies. We also investigated the relations of mosquito biting, patients` occupations and outdoor activities to occurrence of EPA. In addition, simultaneous occurrence in family members, the clinical, histopathologic, laboratory findings, disease courses and responses to treatment were evaluated. Based on medical records, photographs and pathologic slides, we retrospectively diagnosed another 20 EPA patients suspected as insect bite from October 2003 to March 2005. The same questions were inquired as for the 10 patients who prospectively underwent evaluation. Results: In the study, female predominance (76.7%) was observed and the average age of onset was 54.2 years. Interestingly, there was no child patient during the period of study. Multiple, 2∼5 mm sized, red angiomatous papules surrounded by pale halos occurred on exposed areas such as the arms (86.7%), legs (50%), and face (46.7%), although it could also occur to a non-exposed area. EPA occuring in adults usually appeared in summer (80%). The mean disease duration was 3.4 weeks. Although EPA spontaneously regressed, it had the potential of recurrence (46.7%). Histopathologic findings showed dilated dermal blood vessels without the evidence of increase in numbers, and perivascular lymphocytes infiltration. Inside the lumen of dermal blood vessels, plump endothelial cells were found. Conclusion: EPA occuring in adults usually happened to exposed sites in summer, so it can be misdiagnosed as insect bite. We suggest that dermatologists should be concerned about EPA in adults and conduct further investigation to have a better understanding of the disease. (Korean J Dermatol 2007;45(8):797∼803)

3,4,5-Trihydroxycinnamic Acid Inhibits Lipopolysaccharide-Induced Inflammatory Response through the Activation of Nrf2 Pathway in BV2 Microglial Cells

( Jae Won Lee ),( Yong Jun Choi ),( Jun Ho Park ),( Jae Young Sim ),( Yong Soo Kwon ),( Hee Jae Lee ),( Sung Soo Kim ),( Wan Joo Chun ) 한국응용약물학회 2013 Biomolecules & Therapeutics(구 응용약물학회지) Vol.21 No.1

3,4,5-Trihydroxycinnamic acid (THC) is a derivative of hydroxycinnamic acids, which have been reported to possess a variety of biological properties such as anti-inflammatory, anti-tumor, and neuroprotective activities. However, biological activity of THC has not been extensively examined. Recently, we reported that THC possesses anti-inflammatory activity in LPS-stimulated BV2 microglial cells. However, its precise mechanism by which THC exerts anti-inflammatory action has not been clearly identified. Therefore, the present study was carried out to understand the anti-inflammatory mechanism of THC in BV2 microglial cells. THC effectively suppressed the LPS-induced induction of pro-inflammatory mediators such as NO, TNF-a, and IL-1b. THC also suppressed expression of MCP-1, which plays a key role in the migration of activated microglia. To understand the underlying mechanism by which THC exerts these anti-inflammatory properties, involvement of Nrf2, which is a cytoprotective transcription factor, was examined. THC resulted in increased phosphorylation of Nrf2 with consequent expression of HO-1 in a concentration-dependent manner. THC-induced phosphorylation of Nrf2 was blocked with SB203580, a p38 MAPK inhibitor, indicating that p38 MAPK is the responsible kinase for the phosphorylation of Nrf2. Taken together, the present study for the first time demonstrates that THC exerts anti-inflammatory properties through the activation of Nrf2 in BV2 microglial cells, suggesting that THC might be a valuable therapeutic adjuvant for the treatment of inflammation-related disorders in the CNS.

Neuroprotective mechanisms of dieckol against glutamate toxicity through reactive oxygen species scavenging and nuclear factor-like 2/heme oxygenase-1 pathway

Cui, Yanji,Amarsanaa, Khulan,Lee, Ji Hyung,Rhim, Jong-Kook,Kwon, Jung Mi,Kim, Seong-Ho,Park, Joo Min,Jung, Sung-Cherl,Eun, Su-Yong The Korean Society of Pharmacology 2019 The Korean Journal of Physiology & Pharmacology Vol.23 No.2

Glutamate toxicity-mediated mitochondrial dysfunction and neuronal cell death are involved in the pathogenesis of several neurodegenerative diseases as well as acute brain ischemia/stroke. In this study, we investigated the neuroprotective mechanism of dieckol (DEK), one of the phlorotannins isolated from the marine brown alga Ecklonia cava, against glutamate toxicity. Primary cortical neurons ($100{\mu}M$, 24 h) and HT22 neurons (5 mM, 12 h) were stimulated with glutamate to induce glutamate toxic condition. The results demonstrated that DEK treatment significantly increased cell viability in a dose-dependent manner ($1-50{\mu}M$) and recovered morphological deterioration in glutamate-stimulated neurons. In addition, DEK strongly attenuated intracellular reactive oxygen species (ROS) levels, mitochondrial overload of $Ca^{2+}$ and ROS, mitochondrial membrane potential (${\Delta}{\Psi}_m$) disruption, adenine triphosphate depletion. DEK showed free radical scavenging activity in the cell-free system. Furthermore, DEK enhanced protein expression of heme oxygenase-1 (HO-1), an important anti-oxidant enzyme, via the nuclear translocation of nuclear factor-like 2 (Nrf2). Taken together, we conclude that DEK exerts neuroprotective activities against glutamate toxicity through its direct free radical scavenging property and the Nrf-2/HO-1 pathway activation.

H₂O₂로 산화적 스트레스가 유도된 각질 형성 세포에서 흑삼 추출물의 항노화 효과

안소희(So Hee Ahn),이계원(Gye Won Lee),권득상(Deuk Sang Kwon),신현중(Hyun Joong Shin),조영호(Young Ho Cho) 한국식품영양과학회 2021 한국식품영양과학회지 Vol.50 No.10

본 연구에서는 95°C에서 6번 증숙하여 제조한 흑삼 추출물의 항산화 활성과 피부세포에서 산화적 스트레스로부터 보호 효과를 확인하고, 항산화 효소 발현, 주름개선 및 보습관련 단백질 발현에 미치는 영향을 측정하였다. 흑삼 추출물(BGE-A6)의 항산화 활성을 평가하기 위하여 DPPH, ABTS, superoxide anion 라디칼 소거 활성 및 환원력을 측정하였다. 그 결과 증숙 후 흑삼 추출물이 증숙 전에 비하여 DPPH 라디칼 소거 활성은 4배, ABTS 라디칼 소거 활성은 5배 정도 항산화 활성이 증가하는 것으로 나타났다. 피부 각질 형성 세포에서 산화적 스트레스로부터 BGE-A6의 세포보호 효과를 측정하기 위하여 BGE-A6를 1시간 전처리하고 0.5 mM H₂O₂를 6시간 동안 처리하여 분석한 결과, H₂O₂ 처리로 증가된 ROS 생성이 BGE-A6를 100 μg/mL 농도로 처리한 경우 약 40% 정도 감소되는 것으로 나타났다. 또한, BGE-A6의 ROS 소거 효과를 규명하기 위하여 세포 내 존재하는 항산화 효소의 발현량을 western blot으로 평가한 결과 H₂O₂에 의해 유도된 산화 스트레스로부터 감소된 항산화 효소(HO-1, CAT, SOD)의 발현을 농도 의존적으로 회복시켰다. 또한, BGE-A6의 주름 개선 효과를 확인하기 위하여 콜라겐 발현 및 MMP-1 발현 억제 정도를 ELISA와 western blot으로 측정한 결과 0.5 mM H₂O₂를 처리하였을 때 감소된 콜라겐 생성량이 BGE-A6를 100 μg/mL 농도로 처리할 경우 H₂O₂ 처리에 의해 감소된 콜라겐 생성량을 약 20% 정도 회복시키는 것으로 확인되었다(P<0.05). 0.5 mM H₂O₂를 처리하였을 때 증가된 MMP-1의 생성이 BGE-A6 처리 시 농도 의존적으로 억제되는 것으로 나타났다. BGE-A6의 피부보습 관련 단백질 발현에 미치는 영향을 western blot으로 측정한 결과 HAS2와 AQP3 발현량 및 EGFR의 인산화를 처리 시 농도 의존적으로 증가시키는 것으로 나타났다. 결론적으로 피부세포에 H₂O₂를 처리하여 산화적 스트레스를 유도하였을 때 BGE-A6는 항산화 효소의 발현을 통해 세포보호 효과를 나타내고, AQP3, HAS2 및 콜라겐 단백질의 발현은 증가시키고 MMP-1의 발현을 감소시켜 피부보습 및 피부장벽 기능을 유지하는 것으로 사료된다. 또한, AQP3의 증가는 피부조직 및 피부세포막에 발현되는 EGF 수용체의 인산화를 증가시킴으로써 피부 건조에 대한 보호 효과도 있는 것으로 판단된다. 따라서 흑삼 추출물은 항산화 효과, 피부보습 및 장벽기능 유지를 통한 항노화 화장품 소재로 활용이 가능할 것으로 기대된다. In this study, black ginseng extract steamed six times at 95°C (BGE-A6) was evaluated for its antioxidant, anti-wrinkle, and skin moisturizing effects in human keratinocytes. When steamed six times at 95°C, the content of total ginsenosides including minor ginsenosides (Rg3, Rh4, Rk1, and Rg5) was the highest at 14.97 mg/g. The antioxidant properties of BGE-A6 were measured by using different in vitro antioxidant assays such as 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid, ABTS), and superoxide anion radical scavenging activity. The antioxidant activity of BGE-A6 was increased in a dose-dependent manner. A 2′,7′-dichlorofluorescin diacetate (DCFDA) assay and a western blot assay were performed to verify the reactive oxygen species (ROS) scavenging activity of BGE-A6 in H₂O₂-induced human keratinocytes. Pretreatment with 100 μg/mL of BGE-A6 inhibited intracellular ROS production by about 40%. Also, the expression of heme oxygenase-1 (HO-1), catalase (CAT), and superoxide dismutase-1 (SOD-1), very well-known as antioxidant enzymes, was increased by BGE-A6 in a dose-dependent manner. BGE-A6 was shown to significantly inhibit the expression of matrix metalloproteinase-1 and increase the production of type I collagen, thus confirming its anti-wrinkle activity (P<0.05). Furthermore, BGE-A6 significantly increased the phosphorylation of the epidermal growth factor receptors (EGFR) and the expression of moisturizing proteins, such as hyaluronic acid synthase 2 (HAS2) and aquaporin 3 (AQP3), indicating that it is effective in enhancing skin hydration. The results of this study suggest that BGE-A6 has potential for use as an effective compound in anti-aging cosmetics to address wrinkle formation and skin hydration.

Antioxidant and cytoprotective effects of morin against hydrogen peroxide-induced oxidative stress are associated with the induction of Nrf-2-mediated HO-1 expression in V79-4 Chinese hamster lung fibroblasts

Lee, Moon Hee,Cha, Hee-Jae,Choi, Eun Ok,Han, Min Ho,Kim, Sung Ok,Kim, Gi-Young,Hong, Su Hyun,Park, Cheol,Moon, Sung-Kwon,Jeong, Soon-Jeong,Jeong, Moon-Jin,Kim, Wun-Jae,Choi, Yung Hyun Spandidos Publications 2017 International journal of molecular medicine Vol.39 No.3

<P>Natural phytochemicals of plant origin, including flavonoids, have been found to be potent antioxidants providing beneficial effects against oxidative stress-related diseases. The present study was carried out to investigate the antioxidant properties of morin, a flavonoid originally isolated from the flowering plants of the Moraceae family. Superoxide dismutase (SOD)-like activity and 2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS(center dot+)) radical scavenging activity were determined. We also investigated the cytoprotective effects of morin against hydrogen peroxide (H2O2)-induced DNA damage and apoptosis in V79-4 Chinese hamster lung fibroblasts. Our results demonstrated that morin had strong scavenging effects against ABTS' radicals with enhanced SOD activity, which varied in a dose-dependent manner. Morin was found to reduce H2O2-induced intracellular reactive oxygen species generation and nuclear DNA damage, and it recovered cell viability damaged by H2O2 via inhibition of mitochondrial dysfunction-mediated apoptosis. Notably, the treatment of V79-4 cells with morin markedly enhanced the expression of heme oxygenase-1 (HO-1) but not quinone oxidoreductase-1, which was associated with the increased expression and phosphorylation of nuclear factor-erythroid 2-related factor 2 (Nrf2) and the downregulation of Kelch-like ECH-associated protein 1 expression. Based on our findings, we conclude that morin effectively ameliorated oxidative stress-induced DNA damage through intrinsic free radical scavenging activity and activation of the Nrf2/HO-1 pathway.</P>

Isolation of Megastigmane Sesquiterpenes from the Silkworm (Bombyx mori L.) Droppings and Their Promotion Activity on HO-1 and SIRT1

Ji-Hae Park,Do-Gyeong Lee,Seung-Woo Yeon,Hyuk-Sang Kwon,Jong-Hee Ko,Dong-Jin Shin,Han-Sol Park,Yong-Soon Kim,Myun-Ho Bang,NAM-IN BAEK 대한약학회 2011 Archives of Pharmacal Research Vol.34 No.4

The silkworm (Bombyx mori L.) droppings were extracted with 80% aqueous MeOH, and the concentrated extract was partitioned in succession with EtOAc, n-BuOH, and H_2O. From the EtOAc fraction, five megastigmane sesquiterpenes were isolated through repeated silica gel and ODS column chromatography. According to the results of spectroscopic data, such as NMR, MS, and IR, the chemical structures of the isolated compounds were determined as (3S,5R,8R)-3,5-dihydroxymegastigma-6,7-dien-9-one (1), (S)-dehydrovomifoliol (2), (6R,7E,9R)-9-hydroxy-4,7-megastigmadien-3-one (3), (3S,5R,6S,7E)-3,5,6-trihydroxy-7-megastigmen-9-one (4), (6R,9R)-9-hydroxy-4-megastigmen-3-one (5). Compounds 2 through 5 were isolated for the first time from silkworm droppings. GC/MS analysis indicated silkworm powder contained compound 3, and mulberry leaves contained compound 4. Compounds 1 and 5 increased the expression of heme oxygenase-1 and SIRT1 in HepG2 and HEK239 cells, respectively. Heme oxygenase-1 is considered to be an antioxidant enzyme that catabolizes heme to carbon monoxide, free iron and biliverdin, while SIRT1 is the mammalian homologue of the yeast silent information regulator (Sir)-2, which are involved in the suppression of inflammatory mediators or factors that may be used to improve atopy-related symptoms.