• Molecular & Cellular Toxicology
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• v.3 no.4
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• pp.215-221
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• 2007

Neuronal cell toxicity induced by decreased nitric oxide (NO) production may be caused by modulation of constitutive neuronal NO synthase (nNOS). We used lead acetate ($Pb^{2+}$) to modulate physiological NO release and the related pathways of protein kinases like PKC, CaM-KII, and PKA in CATH.a cells, a dopaminergic cell line that has constitutive nNOS activity. In the cells treated with $Pb^{2+}$, cell viability and modulation (phosphorylation) levels of nNOS were determined by MTT assay and Western blot analysis, respectively. nNOS reductase activity (cytochrome c) was also assessed to compare the phosphorylation site-specific nNOS activity. nNOS activity was also determined by NADPH consumption rates. $Pb^{2+}$ treatment alone increased the phosphorylation of nNOS with decreased reductase activity. The phosphorylation levels increased markedly with decreased nNOS reductase activity, when $Pb^{2+}$ was combined with inhibitors for two (PKC and CaM-KII) or three (PKA, PKC and CaM-KII) protein kinases. Interestingly, when the cells were exposed to $Pb^{2+}$ plus PKC or CaM-KII inhibitor, the nNOS was phosphorylated strongly with the lowest activity. However, the levels of phosphorylated nNOS following $Pb^{2+}$ treatment decreased significantly after combined treatment with the PKA inhibitor, and $Pb^{2+}$-induced suppression of reductase activity did not occur. These results demonstrate that physiological NO release in the neuronal cells exposed to $Pb^{2+}$ can be decreased by PKA-mediated nNOS phosphorylation that may be caused by interactions with PKC and/or CaM-KII.

• Korean Journal of Food Science and Technology
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• v.50 no.4
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• pp.444-450
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• 2018

Dendritic cells (DCs) are potent antigen-presenting cells that play a pivotal role in modulating both innate and adaptive immunity. This study examined the immunomodulatory activities of hot-water extracts of bee pollen (BPW) in bone-marrow derived DCs (BMDC) and mice splenocytes. BMDCs isolated from mice were treated with 250 and $500{\mu}g/mL$ BPW for 24 h. BPW, up to $500{\mu}g/mL$, did not display any cellular toxicity against BMDCs. In fact, it functionally induced BMDC activation via augmentation of CD80, CD86, and major histocompatibility complex (MHC) class I/II expression and pro-inflammatory cytokine (tumor necrosis factor; $TNF-{\alpha}$, interleukin; IL-6, and $IL-1{\beta}$) production. Interestingly, BPW treatment significantly increased the production of interferon $(IFN)-{\gamma}$ in splenocytes, suggesting its possible contribution to Th1 polarization in immune response. Taken together, these findings suggest that BPW may regulate innate and adaptive immunity via DC activation and Th1 polarization in immune responses.

• Journal of Life Science
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• v.20 no.12
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• pp.1820-1828
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• 2010

Cobalt(II) chloride, a chemical compound with the formula$CoCl_2$, has been widely used in the treatment of anemia, as a chemical agent for the induction of hypoxia in cell cultures, and is known to activate hypoxic signaling. However, excessive exposure to cobalt is associated with several clinical conditions, including asthma, pneumonia, and hematological abnormalities, and can lead to tissue and cellular toxicity. It is also known to induce apoptosis. One of the questions was that of whether $CoCl_2$ might induce apoptosis via endoplasmic reticulum (ER) stress in neurons. To address this question, first, the level of DNA fragmentation was measured for assay of apoptotic rates using $CoCl_2$ with neuron PC12 cells. After confirmation of apoptosis inductions, under the same conditions, the expression levels of ER stress associated factors [ER chaperones Bip, calnexin, ERp72, ERp29, PDI, and ER membrane kinases (IRE1, ATF6, PERK)] were examined by RT-PCR and Western blotting. These results indicated that apoptosis is induced through activation of ER membrane kinases via ER stress. In conclusion, during induction of apoptosis through $CoCl_2$-induced hypoxia in neuron PC12 cells, ER membrane kinase of IRE1 was dominantly up-expressed, and, consecutively, TRAF2, which has been suggested to be one of the links connecting apoptosis and ER stress, was strongly up-expressed.

• Journal of Oriental Neuropsychiatry
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• v.19 no.3
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• pp.179-193
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• 2008

Objective: The antioxidant and anti-Alzheimer effects of Semen Ziziphi Spinosae (SZS) water extract against the amyloid beta peptide (1-42) or H202-induced oxidative damage and cell death were investigated in rat pheochromocytoma line PC 12. Methods: The cells were incubated with SZS water extract and oxidative damage-inducing materials, amyloid beta peptide (1-42) or H2O2 for 24 h. The cellular viability was assessed by WST-1 assay, cytotoxic damage by LDH activity assay, oxidative damages of cells by fluorescence spectrophotometric method, and apoptosis by TUNEL staining assay. Results and Conclusions: 1. Preincubation of the cells with SZS water extract prior to amyloid beta peptide (1-42) (2 uM) or H2O2 (30 uM) exposure elevated the cell survival close to the control and decreased the level of LDH activity and the fluorescence from the cell homogenates and TUNEL staining of the cells, compared to only amyloid beta peptide (1-42) (2 uM) or H2O2 (30 uM) treated conditions. 2. Our study suggests that Semen Ziziphi Spinosae (SZS) water extract has protective effects against amyloid beta peptide (1-42) or H2O2-induced cell toxicity through the antioxidation mechanism, which might be beneficial for the treatment of Alzheimer's disease.

• Toxicological Research
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• v.23 no.2
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• pp.143-150
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• 2007

Although animal and epidemiological studies have suggested oxidative stress as an etiological factor in pathogenesis including cancer, inflammation, sepsis, fibrosis, cardiovascularlneurodegenerative diseases and aging-related disorders, conflicting results have been obtained in clinical trial with antioxidants. The reason for this discrepancy remains unknown but may be due, in part, to the lack of a validated assay system for evaluating antioxidant capacity. The antioxidant activity of a series of sugar alcohols against peroxyl radicals, hydroxyl radicals and peroxynitrites was determined by the total oxy-radical scavenging capacity (TOSC) assay and cell-based assay using H4IIE cells. Specific TOSC values calculated from the slope of the linear regression for erythritol, xylitol, sorbitol or mannitol against peroxyl radicals was $2.1{\pm}0.2,\;3.7{\pm}0.3,\;9.1{\pm}0.3$ or $8.7{\pm}1.1$ TOSC/mM, respectively. Specific TOSC values for erythritol, xylitol, sorbitol or mannitol against peroxynitrite was $1.9{\pm}0.3,\;3.9{\pm}0.4,\;7.8{\pm}0.7$ or $7.7{\pm}0.5$ TOSC/mM, respectively. These results suggest that oxy-radical scavenging capacity is dependent on the number of aliphatic hydroxyl group in sugar alcohols of monosaccharide. Tert-butylhydroperoxide (t-BHP)-induced cell toxicity determined by MTT assay was marginally attenuated by 10 mM erythritol, but completely inhibited by 10 mM xylitol, 2 mM sorbitol or 0.75 mM maltitol, a disaccharide alcohol. Oxidative stress markers, such as glutathione (GSH) and malondial-dehyde (MDA) levels, were measured in t-BHP-treated cells using HPLC equipped with a fluorescence detector and a reverse phase column. Erythritol did not change the levels of GSH and MDA in H411E cells treated with t-BHP. The t-BHP-induced changes in cellular GSH and MDA levels were ameliorated by 10 mM xylitol and completely blocked by 10 mM sorbitol and maltitol. These results indicate that sugar alcohols protect cells against oxidative stress via scavenging oxy-radical and suggest that TOSC assay in conjunction with cell-based assay is a valid method for evaluating antioxidant capacity of natural and synthetic chemicals.

• Development and Reproduction
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• v.8 no.1
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• pp.1-9
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• 2004

The potential importance of proteomic approaches has been clearly demonstrated in other fields of human medical research, including liver and heart disease and certain forms of cancer. However, reproductive researches have been applied to proteomics poorly. Proteomics can be defined as the systematic analysis of proteins for their identity, quantity, and function. It could increase the predictability of early drug development and identify non-invasive biomarkers of toxicity or efficacy. Proteome analysis is most commonly accomplished by the combination of two-dimensional gel electrophoresis(2DE) and MALDI-TOF(matrix-assisted laser desorption ionization-time of flight) MS(mass spectrometry) or protein chip array and SELDI-TOF(surface-enhanced laser desorption ionization-time of flight) MS. In addition understanding the possessing knowledge of the developing biomarkers used to assess reproductive biology will also be essential components relevant to the topic of reproduction. The continued integration of proteomic and genomic data will have a fundamental impact on our understanding of the normal functioning of cells and organisms and will give insights into complex cellular processes and disease and provides new opportunities for the development of diagnostics and therapeutics. The challenge to researchers in the field of reproduction is to harness this new technology as well as others that are available to a greater extent than at present as they have considerable potential to greatly improve our understanding of the molecular aspects of reproduction both in health and disease.

• Journal of Applied Biological Chemistry
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• v.61 no.1
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• pp.1-8
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• 2018

The objective of this study was to compare the antihyperlipidemic effects of different Dendropanax morbifera leaf extracts in vitro. The extracts differed in terms of specimen age, harvesting season, and extraction method. RAW 264.7 cells were pretreated with these extracts and stimulated by oxidized low-density lipoprotein. Ethanol was used to induce toxicity in HepG2 cells. Cellular lipid accumulation was quantified using oil red O staining in both these cells. The extracts were evaluated for their inhibitory effects on 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase. RAW 264.7 cells treated with the 60% ethanol extract of an 8-year-old specimen harvested in November exhibited the lowest lipid accumulation. The 30% ethanol extract of a 5-year-old specimen harvested in May exhibited the greatest protection from ethanol-induced cytotoxicity in HepG2 cells. The hot water extract of an 8-year-old specimen harvested in May showed the greatest inhibition of HMG-CoA reductase. These results showed that D. morbifera extracts prepared from leaves that are harvested in May possess the highest antihyperlipidemic effects.

• Journal of Biomedical Engineering Research
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• v.38 no.1
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• pp.43-48
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• 2017

Chemotherapy, radiation therapy, and surgery are major methods to treat cancer. However, current cancer treatments report severe side effects and high recurrences. Recent studies about engineering nanoparticles as a drug carrier suggest possibilities in terms of specific targeting and spatiotemporal release of drugs. While many nanoparticles demonstrate lower toxicity and better targeting results than free drugs, they still need to improve their performance dramatically in terms of targeting accuracy, immune responses, and non-specific accumulation at organs. One possible way to overcome the challenges is to make precisely controlled nanoparticles with respect to size, shape, surface properties, and mechanical stiffness. Here, we demonstrate $500{\times}200nm$ discoidal polymeric nanoconstructs (DPNs) as a drug delivery carrier. DPNs were prepared by using a top-down fabrication method that we previously reported to control shape as well as size. Moreover, DPNs have multiple payloads, poly lactic-co-glycolic acid (PLGA), polyethylene glycol (PEG), lipid-Rhodamine B dye (RhB) and Salinomycin. In this study, we demonstrated a potential of DPNs as a drug carrier to treat cancer.

• Molecular & Cellular Toxicology
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• v.2 no.4
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• pp.236-243
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• 2006

Microarray analysis of gene expression has become a powerful approach for exploring the biological effects of drugs, particularly at the stage of toxicology and safety assessment. Acetaminophen (APAP) has been known to induce necrosis in liver, but the molecular mechanism involved has not been fully understood. In this study, we investigated gene expression changes of APAP using microarray technology. APAP was orally administered with a single dose of 50 mg/kg or 500 mg/kg into ICR mice and the animals were sacrificed at 6, 24 and 72 h of APAP administration. Serum biochemical markers for liver toxicity were measured to estimate the maximal toxic time and hepatic gene expression was assessed using high-density oligonucleotide microarrays capable of determining the expression profile of >30,000 well-substantiated mouse genes. Significant alterations in gene expression were noted in the liver of APAP-administered mice. The most notable changes in APAP-administered mice were the expression of genes involved in apoptosis, cell cycle, and calcium signaling pathway, cystein metabolism, glutatione metabolism, and MAPK pathway. The majority of the genes upregulated included insulin-like growth factor binding protein 1, heme oxygenase 1, metallothionein 1, S100 calcium binding protein, caspase 4, and P21. The upregulation of apoptosis and cell cycle-related genes were paralleled to response to APAP. Most of the affected gene expressions were returned to control levels after 72 hr. In conclusion, we identified potential hepatotoxicity makers, and these expressions profiling lead to a better understanding of the molecular basis of APAP-induced hapatotoxicity.

• Molecular & Cellular Toxicology
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• v.5 no.2
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• pp.126-132
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• 2009

The usage and types of chemicals are advancing, specializing, large-scaled increasing, and new chemical exposed workers are concerning to occupational disease. The generation of reactive oxygen in the body from carcinogen, mutation and DNA damage in cancer is protected by natural antioxidants (phytochemicals) with antimutagenic effect. There were many reports of ginsenoside Rb$_1$, Rg$_1$ grievances of the genetic mutation to suppress the effect confirm the genetic toxicity test with chromosomal aberration test and the Comet (SCGE) assay confirmed the suppression effect occurring chromosomal DNA damage. We had wanted to evaluate the compatibility and sensitivity between the chromosomal aberration (CA) test and the Comet assay. We used the CA test and Comet assay to evaluate the anti-genotoxicity of ginsenoside Rb$_1$ and Rg$_1$, in CHO-K1 (Chinese hamster ovary fibroblast) cell in vitro, composed negative control (solvent), positive control (benzo[a]pyrene), test group (carcinogen+variety concentration of ginsenoside) group. The positive control was benzo[a]pyrene (50 $\mu$M), well-known carcinogen, and the negative control was the 1 % DMSO solvent. The test group was a variety concentration of ginsenoside Rb$_1$, Rg$_1$ with 10$^{-8}$%, 10$^{-6}$%, 10$^{-4}$%, 10$^{-2}$%, 1%, 10%. In chromo-somal aberration test, we measured the number of cells with abnormally structured chromosome. In Comet assay, the Olive tail moment (OTM) and Tail length (TL) values were measured. The ratio of cell proliferation was increased 8.3% in 10$^{-8}$%, 10$^{-6}$%, 10$^{-4}$%, 10$^{-2}$%, 1%, 10% Rb$_1$ treated groups, and increased 10.4% in 10$^{-10}$%, 10$^{-8}$%, 10$^{-6}$%, 10$^{-4}$%, 10$^{-2}$%, 1% Rg$_1$ treated groups. In the CA test, the number of chromosomal aberration was decreased all the Rb$_1$ and Rg$_1$ treated groups. In the Comet assay, the OTM values were decreased in all the Rb$_1$ and Rg$_1$ treated groups. To evaluate the compatibility between CA and Comet assay, we compared the reducing ratio of chromosomal abnormalities with its OTM values, it was identified the antimutagenicity of ginsenoside, but it was more sensitive the CA test than the Comet assay. Ginsenoside Rb$_1$ and Rg$_1$ significantly decrease the number of cells with chromosomal aberration, and decrease the extent of DNA migration. Therefore, ginsenoside Rb$_1$, Rg$_1$ are thought as an antioxidant phytochemicals to protect mutagenicity. The in vitro Comet assay seems to be less sensitive than the in vitro chromosomal aberration test.