• Korean Journal of Environmental Biology
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• v.25 no.1
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• pp.16-26
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• 2007

To study the succession of epilithic diatoms on the artificial substrate, we investigated environmental factors and the diatom assemblages biweekly from Mar. 2004 to Feb. 2005 at 2 stations in the lower part of the Han River. A total of 60 taxa, representing 2 orders, 3 suborders, 8 families, 17 genera, 51 species, 7 varieties and 2 forms were identified, and mean number of species were 19 species in spring, 20 in summer, 22 in autumn and 22 in winter. Standing crops of epilithic diatoms varied extensively by months and stations; mean values of those were $3.2{\times}10^4$ cells $cm^{-2}$ in spring, $1.9{\times}10^4$ in summer, $1.7{\times}10^4$ in autumn and $1.8{\times}10^5$ in winter. Chlorophyll a concentrations were also similarly showed as variations of the diatom assemblages. Succession of the diatoms in St. 1 was as follows; Melosira varians, Fragilaria capucina, Cyclotella comta, Nitzschia palea in spring, Fragilaria capucina in summer, Aulacoseira granulata var. angustissima in autumn, Aulacoseira granulata var. angustissima and Melosira varians, Cymbella minuta in winter. In station 2, Aulacoseira granulata and Nitzschia palea dominated in spring as a pioneer in early stage of succession, Fragilaria capucina in summer, and Nitzschia palea in winter. According to Canonical Correspondence Analysis (CCA), there showed similar to that of succession of epilithic diatoms within St. 1 and St. 2, and they were not changed by stations but seasons. Nitzschia palea belonged to saprophilous taxa correlated with nitrogen sources and suspended solids. Meanwhile, Fragilaria capucina and Cymbella minuta included in xenosaprobic taxa show correlation with DO and pH. Eurysaprobic taxa correlated with all environmental factors.

• Journal of Pharmacopuncture
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• v.19 no.1
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• pp.59-69
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• 2016

Objectives: The mushroom Ganoderma lucidum has been widely used as a traditional herbal medicine for many years. Although several studies have focused on the anti-oxidative activity of this mushroom, the molecular mechanisms underlying its activity have not yet been clearly established. The present study investigated the cytoprotective effect of ethanol extract of Ganoderma lucidum (EGL) against oxidative stress (hydrogen peroxide, $H_2O_2$) and elucidated the underlying mechanisms in a C2C12 myoblast cell line. Methods: Oxidative stress markers were determined by using the comet assay to measure reactive oxygen species (ROS) generation and deoxyribonucleic acid (DNA) damage. Cell viability and Western blotting analyses were employed to evaluate the cellular response to EGL and $H_2O_2$ in C2C12 cells. Transfection with nuclear factor erythroid 2-related factor 2 (Nrf2)-specific small interfering ribonucleic acid (siRNA) was conducted to understand the relationship between Nrf2 expression and $H_2O_2$-induced growth inhibition. Results: The results showed that EGL effectively inhibited $H_2O_2$-induced growth and the generation of ROS. EGL markedly suppressed $H_2O_2$-induced comet-like DNA formation and phosphorylation of histone H2AX at serine 139 ($p-{\gamma}H2AX$), a widely used marker of DNA damage, suggesting that EGL prevented $H_2O_2$-induced DNA damage. Furthermore, the EGL treatment effectively induced the expression of Nrf2, as well as heme oxygenase-1 (HO-1), with parallel phosphorylation and nuclear translocation of Nrf2 in the C2C12 myoblasts. However, zinc protoporphyrin IX, a HO-1 inhibitor, significantly abolished the protective effects of EGL against $H_2O_2$-induced accumulation of ROS and reduced cell growth. Notably, transient transfection with Nrf2-specific siRNA attenuated the cytoprotective effects and HO-1 induction by EGL, indicating that EGL induced the expression of HO-1 in an Nrf2-dependent manner. Conclusion: Collectively, these results demonstrate that EGL augments the cellular anti-oxidant defense capacity through activation of Nrf2/HO-1, thereby protecting C2C12 myoblasts from $H_2O_2$-induced oxidative cytotoxicity.

• Herbal Formula Science
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• v.25 no.1
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• pp.1-10
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• 2017

Objectives : The fruit of Prunus mume Siebold & Zucc. has been used as an alternative medicine and functional food in Korea and Japan for preventive and therapeutic purposes. However, its molecular actions and mechanism on anti-inflammatory activity have not been clearly investigated. The aim of this study was to clarify the anti-inflammatory activity of the ethanol extract of P. mume fruit (EEPM) in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells, and sought to understand the associated molecular mechanisms. Methods : Cytotoxicity was assessed by an MTT assay. The amount of nitric oxide (NO) production was determined by nitrite assay. The mRNA expression of inducible nitric oxide synthase (iNOS) was analyzed by RT-PCR. In addition, expression levels of iNOS, nuclear factor-erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) protein were detected by Western blotting. Results : Our data indicated that EEPM inhibited NO production in LPS-stimulated RAW264.7 cells in a concentration-dependent manner. At the mRNA and protein levels, EEPM suppressed LPS-induced iNOS expression. On the other hand, EEPM markedly enhanced HO-1 expression, which was associated with an induction and nuclear translocation of Nrf2. Moreover, the inhibitory effect of EEPM against LPS‑induced NO production was significantly enhanced by hemin, a HO-1 inducer; however, EEPM's effect on the production of NO was abolished by zinc protoporphyrin IX, a HO-1 inhibitor. Conclusion : The results suggest that EEPM can act as a suppressor agent on NO production through an activation of Nrf2/HO-1 signaling pathway, and may be a promising candidate for the treatment of inflammatory diseases.

• The Korea Journal of Herbology
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• v.20 no.3
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• pp.29-41
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• 2005

Objectives : The use of natural products with therapeutic properties is as ancient as human civilisation and, for a long time, mineral, plant and animal products were the main sources of drugs. Catalposide, the major iridoid glycoside isolated from the stem bark of Catalpa ovata G. Don (Bignoniceae) has been shown to possess anti-microbial and anti-tumoral properties. Heme oxygenase-1 (HO-1) is a stress response protein and is known to play a protective role against the oxidative injury. In this study, we examined whether catalposide could protect Neuro 2A cells, a kind of neuronal cell lines, from oxidative damage through the induction of HO-1 protein expression and HO activity. We also examined the effects of catalposide on the productions of tumor necrosis $factor-{\alpha}\;(TNF-{\alpha})$ and nitric oxide (NO) on RAW 264.7 macrophages activated with the endotoxin lipopolysaccharide. Methods : HO-1 expression in Neuro 2A cells was measured by Western blotting analysis. NO and $TNF--{\alpha}$ produced by RAW 264.7 macrophage were measured by Griess reagent and enzyme-linked immunosorbent assay, respectively. Results : The treatment of the cells with catalposide resulted in dose- and time-dependent up-regulations of both HO-1 protein expression and HO activity. Catalposide protected the cells from hydrogen peroxide-induced cell death. The protective effect of catalposide on hydrogen peroxide-induced cell death was abrogated by zinc protoporphyrin IX, a HO inhibitor. Additional experiments revealed the involvement of CO in the cytoprotective effect of catalposide-induced HO-1. In addition, catalposide inhibited the productions of $TNF--{\alpha}$ and NO with significant decreases in mRNA levels of $TNF--{\alpha}$ and inducible NO synthase. Conclusions : Our results indicate that catalposide is a potent inducer of HO-1 and HO-1 induction is responsible for the catalposide-mediated cytoprotection against oxidative damage and that catalposide may have therapeutic potential in the control of inflammatory disorders.

• Biomedical Science Letters
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• v.8 no.3
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• pp.115-125
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• 2002

Gram-negative septicemia, which continues to be a serious clinical problem, is one of the major causes of morbidity and mortality in hospitalized patients. Endotoxin of gram-negative bacteria is a pivotal pathogen of sepsis. To understand the effect of endotoxin on hematological aspect and the time course in early childhood, this study was designed with experimental septic model of young rabbits (8 week-old). Rabbits were divided into control (n=7) and endotoxin group (0.50 mg/kg of endotoxin). The endotoxin group was subdivided into six groups by the sampling times: 3, 6, 12, 24, 48 and 72 hr-group (E-G$_{3}$, E-G$_{6}$, E-G$_{12}$, E-G$_{24}$, E-G$_{48}$ and E-G$_{72hrs}$, each n=7). The evaluation of CBC, activated partial thromboplastin time (APTT), prothrombin time (PT), fibrinogen concentration, coagulation factors and D-dimer were taken from the bloods. The number of leukocytes was lower in E-G$_{3}$ and E-G$_{6hrs}$ (due to pantocytopenia), whereas it was higher in E-G$_{24}$ and E-G$_{48}$ (due to neutrophilia and/or lymphophilia) than in control group (P<0.05). Platelet counts in E-G$_{3}$, E-G$_{6}$, E-G$_{12}$, E-G$_{24}$ and E-G$_{48hrs}$ were lower than those of control group (P<0.05). Normoblast counts in E-G$_{3}$, E-G$_{6}$, E-G$_{12}$, E-G$_{24}$ and E-G$_{48hrs}$ were higher than those of control group (p<0.01). APTT in E-G$_{3}$, E-G$_{6}$, E-G$_{12}$, E-G$_{24}$ and E-G$_{72hrs}$ were longer while PT in E-G$_{3}$, E-G$_{6}$, E-G$_{48}$ and E-G$_{72hrs}$ were higher than those of control group (p<0.05). Fibrinogen concentrations were lower in E-G$_{3}$, E-G$_{6}$ and E-G$_{12}$ but higher in E-G$_{48}$ and E-G$_{72hrs}$ than those of control (p<0.05). Intrinsic coagulation factors (XII, XI, IX, VIII) in all endotoxin groups were significantly lower than those of control group (p<0.05). Extrinsic coagulation factor (X, VII, V, II) were lower in E-G$_{3}$, E-G$_{6}$, E-G$_{12}$ and E-G$_{24hrs}$ whereas they were higher in E-G$_{48}$ and E-G$_{72hrs}$ than in control group (p<0.05). D-dimer concentrations in E-G$_{48}$ and E-G$_{72hrs}$ were higher than those of control group (P<0.001). We concluded that endotoxin led to extensive hematological disturbances including disseminated intravascular coagulation in the young rabbits and that this pathologic condition in the infant and childhood groups will cause the grave results.

• Korean Journal of Plant Tissue Culture
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• v.27 no.6
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• pp.423-428
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• 2000

In 1997 when cloned sheep Dolly and soon after Polly were born, it had become head-line news because in the former the nucleus that gave rise to the lamb came from cells of six-year-old adult sheep and in the latter case a foreign gene was inserted into the donor nucleus to make the cloned sheep produce human protein, factor IX, in e milk. In the last few years, once the realm of science fiction, cloned mammals especially in livestock have become almost commonplace. What the press accounts often fail to convey, however, is that behind every success lie hundreds of failures. Many of the nuclear-transferred egg cells fail to undergo normal cell divisions. Even when an embryo does successfully implant in the womb, pregnancy often ends in miscarriage. A significant fraction of the animals that are born die shortly after birth and some of those that survived have serious developmental abnormalities. Efficiency remains at less than one % out of some hundred attempts to clone an animal. These facts show that something is fundamentally wrong and enormous hurdles must be overcome before cloning becomes practical. Cloning researchers now tent to put aside their effort to create live animals in order to probe the fundamental questions on cell biology including stem cells, the questions of whether the hereditary material in the nucleus of each cell remains intact throughout development, and how transferred nucleus is reprogrammed exactly like the zygotic nucleus. Stem cells are defined as those cells which can divide to produce a daughter cell like themselves (self-renewal) as well as a daughter cell that will give rise to specific differentiated cells (cell-differentiation). Multicellular organisms are formed from a single totipotent stem cell commonly called fertilized egg or zygote. As this cell and its progeny undergo cell divisions the potency of the stem cells in each tissue and organ become gradually restricted in the order of totipotent, pluripotent, and multipotent. The differentiation potential of multipotent stem cells in each tissue has been thought to be limited to cell lineages present in the organ from which they were derived. Recent studies, however, revealed that multipotent stem cells derived from adult tissues have much wider differentiation potential than was previously thought. These cells can differentiate into developmentally unrelated cell types, such as nerve stem cell into blood cells or muscle stem cell into brain cells. Neural stem cells isolated from the adult forebrain were recently shown to be capable of repopulating the hematopoietic system and produce blood cells in irradiated condition. In plants although the term$\boxDr$ stem cell$\boxUl$is not used, some cells in the second layer of tunica at the apical meristem of shoot, some nucellar cells surrounding the embryo sac, and initial cells of adventive buds are considered to be equivalent to the totipotent stem cells of mammals. The telomere ends of linear eukaryotic chromosomes cannot be replicated because the RNA primer at the end of a completed lagging strand cannot be replaced with DNA, causing 5' end gap. A chromosome would be shortened by the length of RNA primer with every cycle of DNA replication and cell division. Essential genes located near the ends of chromosomes would inevitably be deleted by end-shortening, thereby killing the descendants of the original cells. Telomeric DNA has an unusual sequence consisting of up to 1,000 or more tandem repeat of a simple sequence. For example, chromosome of mammal including human has the repeating telomeric sequence of TTAGGG and that of higher plant is TTTAGGG. This non-genic tandem repeat prevents the death of cell despite the continued shortening of chromosome length. In contrast with the somatic cells germ line cells have the mechanism to fill-up the 5' end gap of telomere, thus maintaining the original length of chromosome. Cem line cells exhibit active enzyme telomerase which functions to maintain the stable length of telomere. Some of the cloned animals are reported prematurely getting old. It has to be ascertained whether the multipotent stem cells in the tissues of adult mammals have the original telomeres or shortened telomeres.