• The Plant Pathology Journal
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• 제32권3호
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• pp.228-241
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• 2016

In our previous study, we reported that a novel endophytic bacterium Bacillus oryzicola YC7007 has suppressed bacterial diseases of rice via induced systemic resistance and antibiotic production. This endophytic strain, B. oryzicola YC7007 was used as a biological control agent against bakanae disease of rice caused by Fusarium fujikuroi, and its mechanism of interaction with the pathogen and the rice was further elucidated. Root drenching with B. oryzicola YC7007 suspension reduced the disease severity of bakanae significantly when compared with the untreated controls. The treatments of B. oryzicola YC7007 suspension ($2.0{\times}10^7cfu/ml$) to the rice rhizosphere reduced bakanae severity by 46-78% in pots and nursery box tests containing autoclaved and non-autoclaved soils. Moreover, in the detached rice leaves bioassay, the development of necrotic lesion and mycelial expansion of F. fujikuroi were inhibited significantly by spraying the culture filtrate of B. oryzicola YC7007. Drenching of ethyl acetate extracts of the culture filtrate to the rhizosphere of rice seedlings also reduced the bakanae disease severity in the plant culture dish tests. With the root drenching of B. oryzicola YC7007 suspension, the accumulation of hydrogen peroxide was observed at an early stage of rice seedlings, and a hormonal defense was elicited with and without pathogen inoculation. Our results showed that the strain B. oryzicola YC7007 had a good biocontrol activity against the bakanae disease of rice by direct inhibition, and was also capable of inducing systemic resistance against the pathogen via primed induction of the jasmonic acid pathway.

• Asian Pacific Journal of Cancer Prevention
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• 제13권10호
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• pp.5229-5232
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• 2012

The incidence of malignant melanoma increases with age. One significiant effect of aging processes is an accumulation of oxidative damage in the genetical material. In this study, the relationship between malignant melanoma and damage in chromosomes and proliferative effectiveness of human peripheral lymphocytes were investigated by the micronucleus (MN) technique. A total of 15 malignant melanoma patients and appropriately matching 15 healthy controls were involved in the study. MN frequencies and proliferative indexes (PI) after non toxic levels of hydrogen peroxide treatment were also measured to determine damaging effect of oxidative stress in genome in addition to measuring the spontenous levels of micronuclei and PI. The patient group had a significantly higher rate of spontaneous MN than the control group (p<0.01). After treatment with $H_2O_2$, MN frequencies in the patient group was significantly decreased (p<0.01) although there was no difference between the treated and untreated results of control group (p=0.29). There was also difference (p<0.01) between the MN frequencies of the patient and the control group either in the spontaneous levels or in the $H_2O_2$ treated groups. The same significant difference persisted when the PI values were compared between patient and control groups. Increase in the MN frequency in patients could mean the alterations in the chromosomal structure which may lead to the chromosome instability and therefore genetic susceptibility to cancer. This increased number of micronuclei can also be used for cytological marker in identifying high risk cases for malignant melanoma.

• 대한약침학회지
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• 제24권1호
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• pp.24-31
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• 2021

Objectives: Accumulation of cellular reactive oxygen species (ROS) leads to oxidative stress. Increased production of ROS, such as superoxide anion, or a deficiency in their clearance by antioxidant defences, mediates cellular pathology. Grewia Spp fruits are a source of bioactive compounds and have notable antioxidant activity. Although the antioxidant capacity of Grewia Spp has been studied, there is very limited evidence that links the antioxidant activities of Grewia bicolor and Grewia flava to the inhibition of free radical formation associated with damage in biological systems. Methods: This study evaluated the protective effects of Grewia bicolor and Grewia flava extracts against free radical-induced oxidative stress and the resulting cytotoxicity effect using HeLa cells. Antioxidant properties determined using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and total phenolic content (TPC) assays showed significantly higher (p < 0.05) antioxidant activity in Grewia flava (ethanol extract) than Grewia flava (water extract) and Grewia bicolor (ethanol and water extracts). Results: Using 3-(4,5-dimethylthiazol-2-yl)-2,5diphenyltetrazolium bromide or MTT assay, cytotoxicity results showed that extracts of Grewia bicolor and Grewia flava were less toxic to HeLa cells at tested concentrations compared to the untreated control. This confirmed the low toxicity of these edible fruits at the tested concentrations in HeLa cells. Furthermore, hydrogen peroxide (H2O2)-induced cell loss was effectively reduced by pre-incubating HeLa cells with Grewia bicolor and Grewia flava extracts, with Grewia flava (ethanol extract) revealing better protection. Conclusion: The effect was speculated to be associated with the higher antioxidant activity of Grewia flava (ethanol extract). Additional studies will warrant confirmation of the mechanism of action of such effects.

• 대한본초학회지
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• 제28권6호
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• pp.79-86
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• 2013

Objectives : The purpose of this study is to investigate neuroprotective effects and molecular mechanisms of luteolin against ${\beta}$-amyloid ($A{\beta}_{25-35}$)-induced oxidative cell death in BV-2 cells. Methods : The protective effects of luteolin against $A{\beta}_{25-35}$-induced cytotoxicity and apoptotic cell death were determined by MTT dye reduction assay and TUNEL staining, respectively. The apoptotic cell death was further analyzed by measuring mitochondrial transmembrane potential and expression of pro- and/or anti-apoptotic proteins. To elucidate the molecular mechanisms underlying the protective effects of luteolin, intracellular accumulation of reactive oxygen species, oxidative damages, and expression of antioxidant enzymes were examined. Results : Luteolin pretreatment effectively attenuated $A{\beta}_{25-35}$-induced apoptotic cell death indices such as DNA fragmentation, dissipation of mitochondrial transmembrane potential, increased Bax/Bcl-2 ratio, and activation of c-Jun N-terminal kinase and caspase-3 in BV-2 cells. Furthermore, $A{\beta}_{25-35}$-induced intracellular formation of reactive oxygen species and subsequent oxidative damages such as lipid peroxidation and depletion of endogenous antioxidant glutathione were suppressed by luteolin treatment. The neuroprotective effects of luteolin might be mediated by up-regulation of cellular antioxidant defense system via up-regulation of ${\gamma}$-glutamylcysteine ligase, a rate-limiting enzyme in the glutathione biosynthesis and superoxide dismutase, an enzyme involved in dismutation of superoxide anion into oxygen and hydrogen peroxide. Conclusions : These findings suggest that luteolin has a potential to protect against $A{\beta}_{25-35}$-induced neuronal cell death and damages thereby exhibiting therapeutic utilization for the prevention and/or treatment of Alzheimer's disease.

• Journal of Chest Surgery
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• 제35권7호
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• pp.501-510
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• 2002

배경: 급성 호흡곤란증후군은 다양한 병인에 의해 발병하지만 그 병인론이 아직까지 확립되어 있지 않다. 본 연구에서는 장의 허혈-재관류시에 발병하는 급성 호흡곤란증후군에서 group II phospholipase $A_2$ ($PLA_2$)의 역할을 알아보기 위하여 시행되었다. 특히 폐장내의 호중구의 침윤과 더불어 유발되는 산화성 스트레스에서 group II $PLA_2$의 역할을 규명하려 하였다. 대상 및 방법: 체중 300g 내외의 Sprague-Dawley 종 흰쥐에서 급성 폐손상을 유발하기 위하여 상장간막동맥을 60분간 차단한 후 120분간 재관류를 시행하였다. Group II $PLA_2$가 폐장의 손상, 특히 혈관 내피세포의 손상에 미치는 영향을 호중구의 작용과 연관하여 알아보기 위하여 폐누출지수, 폐장내 myeloperoxidase의 활성도, 폐포세척액내의 단백함량을 측정하였다. 또한 장의 허혈-재관류에 따른 폐장내 $PLA_2$ 활성도의 변화를 검사하였고, 호중구에서의 산소기 형성에 미치는 group II $PLA_2$의 역할은 분리된 호중구에 rutin, manoalide, scalaradial과 같은 group II $PLA_2$ 억제제를 이용하여 산소기 생성이 억제됨을 확인함으로써 알아보았다. 장의 허혈-재관류에 따른 폐장 조직의 산화성 스트레스를 확인하기 위해 광학현미경법 및 cerium chloride를 이용한 세포화학적인 전자현미경법을 이용하여 폐장내 산소기의 생성을 확인하였다. 결과: 장의 허혈-재관류 후 폐장내 호중구의 침윤과 함께 급성 폐손상이 유발되었고, 폐장내 myeloperoxidase 활성도, 폐누출지수 및 폐세척액내의 단백함량이 대조군에 비해 유의하게 증가하였다(p<0.001). 폐장 및 장에서의 group II $PLA_2$ 활성도는 허혈-재관류 후 폐장, 장 모두에서 유의하게 증가하였고, rutin에 의해서 현저히 감소하였다(p<0.001). 사람의 혈액에서 분리된 호중구에서의 산소기 생성을 cytocrhome-c reduction assay를 통해 알아본 결과 rutin, manoalide, scalaradial 같은 group II PLA, 억제제에 의해 호중구의 산소기 생성이 감소함을 알 수 있었다. 허혈-재관류 후 광학현미경적 소견은 폐장내 염증세포의 침윤 및 모세혈관 주위의 부종이 관찰되었으나 rutin에 의해 이러한 변화는 억제되었다. $CeCl_3$을 이용한 세포화학적 전자현미경 실험에서 허혈-재관류 후 과산화수소의 생성이 증가하고 rutin에 의해서는 억제됨을 확인하였다. 결론: Croup II $PLA_2$의 억제는 침윤된 호중구로부터 산화기 생성을 억제함으로써 급성 폐손상을 완화하는 것으로 보이며, 따라서 group II $PLA_2$는 장 허혈-재관류로 유도된 급성 폐손상의 산화성 스트레스에서 중요한 역할을 하는 것으로 보인다.

• International Journal of Oral Biology
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• 제34권4호
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• pp.205-213
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• 2009

The mechanisms underlying the actions of the antioxidants upon reactive oxygen species (ROS) generation by NADPH oxidase complex have remained uncertain. In this study, we investigated NADPH oxidase activity and the role of antioxidant enzymes upon the generation of ROS during hypoxic stress. ROS generation was found to increase in the mouse kidney under hypoxic stress in a time-dependent manner. Moreover, we found in MCT cells that hypoxia-induced hydrogen peroxide production was decreased by NAC pretreatment. We further analyzed HIF-$1{\alpha}$, PHD2 and VHL expression in the NAC-pretreated MCT cells and assessed the response of antioxidant enzymes at the transcriptional and translational levels. SOD3 and Prdx2 were significantly increased during hypoxia in the mouse kidney. We also confirmed in hypoxic $Prdx2^{-/-}$ and SOD3 transgenic mice that erythropoietin (EPO) is transcriptionally regulated by HIF-$1{\alpha}$. In addition, although EPO protein was found to be expressed in a HIF-$1{\alpha}$ independent manner in three mouse lines, its activity differed markedly between normal and $Prdx2^{-/-}$/SOD3 transgenic mice during hypoxic stress. In conclusion, our current results indicate that NADPH oxidase-mediated ROS generation is associated with hypoxic stress in the mouse kidney and that SOD3 and Prdx2 cooperate to regulate cellular redox reactions during hypoxia.

• 생명과학회지
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• 제28권8호
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• pp.908-916
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• 2018

모발의 검정색은 노화됨에 따라 백색으로 변화된다. 이러한 현상은 모낭내 tyrosinase 활성의 감소와 $H_2O_2$에 의한 축적에 의하여 기인된다. 따라서 본 연구의 목적은 현미주정추출물(OREE)를 이용하여 백발화의 원인인 과산화 수소에 대한 항산화 활성과 멜라닌 생성 촉진 효과를 조사한 것이다. 본 연구에서 OREE은 낮은 DPPH radical 소거능과 환원력을 보여주었다. 그러나 B16F1 세포내에서 $H_2O_2$ 소거에 대해서는 높은 항산화효과를 나타내었다. 그리고 OREE는 in vitro에서 DOPA 산화 활성은 나타나지 않았지만 $64{\mu}g/ml$에서 tyrosinase 활성을 증가시켰다. MTT assay에서 OREE는 $32{\mu}g/ml$ 이상의 농도에서 세포독성을 나타내었다. 또한 OREE는 $8{\mu}g/ml$ 이상의 농도에서 멜라닌 합성은 농도에 비례하여 증가하였고, $H_2O_2$로 멜라닌 생성을 저하시킨 세포에서도 멜라닌 합성을 증가시켰다. 멜라닌 합성에 대한 OREE의 효과를 확인하기 위하여 Western blot 분석이 수행되었다. $H_2O_2$로 멜라닌 생성을 저하시킨 세포에서 멜라닌 합성 기전 관여하는 tyrosine hydroxylase와 tyrosinase-related protein-2 (TRP-2) 발현은 OREE의 존재 하에서 증가하였다. 이상의 발견들은 OREE가 멜라닌 합성을 촉진시킬 수 있어 이와 관련된 모발화장품의 개발에 적용시킬 수 있다는 것을 시사하고 있다.

• 원예과학기술지
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• 제34권4호
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• pp.564-577
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• 2016

Salinity stress limits plant cultivation in many areas worldwide; however, persimmon (Diospyros spp.) has high tolerance to salt. Five accessions of Diospyros [three of Diospyros lotus (accession numbers 824, 846, and 847); one of Diospyros kaki var. sylvestris (869); and one of Diospyros virginiana (844)] were chosen for analysis of salinity stress. We compared the effects of salt stress on plant growth, relative water content (RWC), malondialdehyde (MDA), electrolyte leakage (EL), hydrogen peroxide content ($H_2O_2$), and antioxidative enzyme activities (superoxide dismutase, SOD; catalase, CAT; peroxidase, POD; and ascorbate peroxidase, APX) in leaves of healthy potted seedlings from each of the five accessions after salt treatment for 25 days. Salt stress affected the growth of plants in all five accessions, with all three D. lotus accessions showing the most severe effect. Salt stress increased membrane lipid peroxidation in all accessions, but a stronger increase was observed in the three D. lotus accessions. Moreover, accumulation of $H_2O_2$ was faster in salt-sensitive D. lotus compared to salt-tolerant D. virginiana 844. The activities of all antioxidant enzymes increased in D. virginiana 844 and in D. kaki var. sylvestris 869; the activities of SOD, CAT, and APX were at similar levels in D. virginiana 844 and D. kaki var. sylvestris 869, but POD activity was stimulated to a greater extent in D. virginiana 844. The activities of all antioxidant enzymes (except POD) decreased in D. lotus 824 and increased (except for SOD) in D.lotus 846. The activities of SOD and APX decreased in D. lotus 847, whereas POD and CAT activities both increased. Relative water content decreased significantly in D. lotus. No significant changes in lipid peroxidation or relevant antioxidant parameters were detected in any of the accessions in controls treated with 0.0% NaCl. D. virginiana 844 had higher antioxidant capacity in response to salinity compared to other persimmon rootstocks. These results indicate that changes of these key physiological variables are related to salinity resistance in different accessions of persimmon.

• 공업화학
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• 제26권2호
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• pp.138-144
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• 2015

Co가 첨가된 SAPO-34 촉매(CoAPSO-34)상의 DTO 반응에서 촉매의 수명 향상에 미치는 Co/Al 및 Si/Al 몰 비의 영향을 연구했다. 제조된 CoAPSO-34 촉매들의 특성은 XRD, SEM, $^{29}Si$ MAS NMR 및 $NH_3$-TPD 기법에 의해 확인했다. 먼저 Co/Al 몰 비를 변화시키며 제조한 CoAPSO-34 촉매들의 수명은 SAPO-34와 비교하여 향상된 것으로 나타났으며, 가장 높은 수명을 갖는 촉매의 Co/Al 몰 비는 0.0025로 나타났다. Co/Al 몰 비를 0.0025로 고정하고 Si/Al 몰 비를 0.05에서 0.20으로 증가시킴에 따라 총 산점량은 0.432에서 1.111 mmol/g까지 증가하였다. 그러나 총 산점량이 너무 큰 촉매들은 둥지 내 다환 방향족 화합물들의 급속한 축척으로 인한 기공 막힘으로 빠르게 비활성화되었다. 따라서 0.1의 적절한 Si/Al 몰 비를 갖는 CoAPSO-34 촉매가 수명이 가장 우수한 것으로 나타났으며, SAPO-34 촉매의 수명과 비교하여 약 87% 향상되었다.

• 동의생리병리학회지
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• 제27권5호
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• pp.611-616
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• 2013

Alcoholic liver disease (ALD) is a major cause of morbidity and mortality around the world. Although much progress has been made in understanding the pathogenesis of ALD, there remains no effective therapy for it. Accumulated evidence indicates that oxidative stress is the main pathological factors in the development of ALD. Ethanol administration causes accumulation of reactive oxygen species (ROS), including superoxide, hydroxyl radical, and hydrogen peroxide. ROS, in turn, cause lipid peroxidation of cellular membranes, and protein and DNA oxidation, which results in hepatocyte injury. In addition to pro-oxidants formation, antioxidants depletion caused by ethanol administration also results in oxidative stress. The objective of this study is to investigate the effects of Shiryung-tang extract on the chronic alcoholic liver injury induced by EtOH. Male Sprague Dawley rats were used in this study. All rats were maintained under standard laboratory conditions ($23{\pm}1^{\circ}C$, 12h light/12h dark cycles). All animals (n=30) were randomly divided into following groups: (1) Normal group, treated with distilled water (n=10); (2) Control group, treated with ethanol (n=10); (3) Sample group, treated with ethanol + pharmacopuncture (n=10). For oral administration of ethanol in Control and Sample group, the ethanol was dissolved in distilled water in concentrations of 25%(v/v). Throughout the experiment of 8 week, the rats were allowed free access to water and standard chow. Sample group were administrated by Shiryung-tang extract daily for 8 weeks. Control group were given normal saline for same weeks. As a results, the oral administration of ethanol for 8 weeks leads to hepatotoxicity. The levels of hepatic marker such as HDL-cholesterol, triglyceride, aspartate aminotransferase and alanine aminotransferase were altered. The ethanol also increased lipid peroxidation and depletion of antioxidant enzyme activities as well as hepatic tissue injury. However, the treatment of Shiryung-tang extract prevented all the alterations induced by ethanol and returned their levels to near normal. These data suggest that Shiryung-tang extract could have a beneficial effect in inhibiting the oxidative damage induced by chronic ethanol administration. Therefore, Shiryung-tang extract can be a candidate to protect against EtOH-induced liver injury.