• Journal of Microbiology and Biotechnology
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• v.24 no.3
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• pp.371-378
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• 2014

The aim of the present study was to investigate the antigenotoxic properties of the probiotic Lactobacillus rhamnosus IMC501; DNA damage was induced by one representative food mutagen, 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP). Mice were treated orally with suspensions of lactobacilli for 10 days before administration of food mutagen. During the treatment, the abundance of lactobacilli in feces, as assessed by qPCR analysis, increased, whereas ${\beta}$-glucuronidase and N-acetyl-${\beta}$-glucosaminidase activities decreased. The extent of DNA damage was measured in colon and liver cells by comet assay. In colonocytes, diet supplementation with IMC501 resulted in a significant inhibition of DNA damage induced by PhIP. The results obtained in this in vitro study suggest that Lactobacillus rhamnosus IMC501 used as a dietary supplement can provide a useful integration of antimutagen food components of the normal diet, which are generally lower than the protective level.

• Molecular & Cellular Toxicology
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• v.1 no.2
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• pp.73-77
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• 2005

Nickel is the one of potent environmental, the occupational pollutants and the classified human carcinogens. It is a serious hazard to human health, when the metal exposure. To prevent human diseases from the heavy metals, it is seemingly important that understanding of how nickel exerts their toxicity and carcinogenic effect at a molecular and a genomic level. The process of nickel absorption has been demonstrated as phagocytosis, iron channel and diffusion. Uptaked nickel has been suggested to induce carcinogenesis via two pathways, a direct DNA damaging pathway and an indirect DNA damaging pathway. The former was originated from the ability of metal to generate Reactive Oxygen Species (ROS) and the reactive intermediates to interact with DNA directly. Ni-generated ROS or Nickel itself, interacts with DNAs and histones to cause DNA damage and chromosomal abnormality. The latter was originated from an indirect DNA damage via inhibition of DNA repair, or condensation and methylation of DNA. Cells have ability to protect from the genotoxic stresses by changing gene expression. Microarray analysis of the cells treated with nickel or nickel compounds, show the specific altered gene expression profile. For example, HIF-I (Hypoxia-Inducible Factor I) and p53 were well known as transcription factors, which are upregulated in response to stress and activated by both soluble and insoluble nickel compounds. The induction of these important transcription factors exert potent selective pressure and leading to cell transformation. Genes of metallothionein and family of heat shock proteins which have been known to play role in protection and damage control, were also induced by nickel treatment. These gene expressions may give us a clue to understand of the carcinogenesis mechanism of nickel. Further discussions on molecular and genomic, are need in order to understand the specific mechanism of nickel toxicity and carcinogenicity.

• Journal of Embryo Transfer
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• v.28 no.3
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• pp.265-271
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• 2013

Cryopreservation and in vitro fertilization (IVF) protocols are important in genetic studies and applications to transgenic animals. Various studies about boar sperm cryopreservation have been studied for a long time. Those were about the use of extenders, the choice of sugars, the cooling and warming rates. The factors that influence the boar sperm are the dramatic changes in temperatures, osmotic and toxic stresses, and reactive oxygen species (ROS) generation. Among these factors, ROS generation is the main damage to DNA which is a principal genetic material and the most important for the practical applications. So we wondered whether ROS generation could be reduced. In previous study, monothioglycerol (MTG) was essential for the culture of embryo stem cells. Therefore we added MTG in the freezing extender based on lactose-egg yolk (LEY) with trehalose. For the assessment of the frozen-thawed sperm, we focused onmotility, membrane integrity and DNA damage. First, we used a computer-aided sperm analysis system for overall conditions of sperm such as motility and viability. Then we performed the sperm chromatin structure assay for DNA integrity and hypo-osmotic swelling test for membrane integrity. And our result showed the existence of MTG in the freezing extender caused less damage to DNA and higher motility in frozen-thawed boar sperm. Also we checked a relative antioxidant activity of MTG in modified Modena B extender. We concluded that this reagent can activate sperm mitochondria at MTG $0.2{\mu}M$, contribute to sperm motility and DNA integrity but there was no significant difference on membrane integrity. Also antioxidant activity of MTG in modified Modena B extender was proved.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.16
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• pp.6627-6632
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• 2014

Purpose: The present study concerns molecular mechanisms involved in induction of apoptosis by a fungal taxol extracted from the fungus Cladosporium oxysporum in T47D human breast cancer cells. Materials and Methods: Apoptosis-induced by the fungal taxol was assessed by MTT assay, nuclear staining, DNA fragmentation, flow cytometry and pro- as well as anti-apoptotic protein expression by Western blotting. Results: Our results showed inhibition of T47D cell proliferation with an $IC_{50}$ value of $2.5{\mu}M/ml$ after 24 h incubation. It was suggested that the extract may exert its anti-proliferative effect on human breast cancer cell line by suppressing growth, arresting through the cell cycle, increase in DNA fragmentation as well as down-regulation of the expression of NF-${\kappa}B$, Bcl-2 and Bcl-XL and up-regulation of pro-apoptotic proteins like Bax, cyt-C and caspase-3. Conclusions: We propose that the fungal taxol contributes to growth inhibition in the human breast cancer cell through apoptosis induction via a mitochondrial mediated pathway, with possible potential as an anticancer therapeutic agent.

• Korean Journal of Environmental Biology
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• v.28 no.4
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• pp.196-201
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• 2010

The phenethyl ester of caffeic acid (CAPE), an active component of honeybee propolis extract, is shown to inhibit cancer growth previously. However, studies on human ovarian cancer are largely obscure. This study evaluated the effects of CAPE as a potential anti-proliferative and pro-apoptotic agent in the human ovarian cancer line, OVCAR-3. CAPE treated OVCAR-3 cells showed inhibition of cell viability and proliferation in a dose-dependent manner by WST-1 assay, LDH assay and bromodeoxyuridine (BrdU) incorporation assay. Furthermore, CAPE-mediated OVCAR-3 cell growth inhibition was associated with apoptotic changes as evident by cell cycle arrest and accumulation of cells in the apoptotic phase and DNA fragmentation. Taken together, CAPE inhibits cell proliferation via DNA synthesis reduction and induces apoptotic cell death via DNA damage, thus elucidating a novel, plausible mechanism of CAPE anti-tumorigenic property in OVCAR-3 cells.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.1
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• pp.9-21
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• 2015

Cancer, a serious public health problem in worldwide, results from an excessive and uncontrolled proliferation of the body cells without obvious physiological demands of organs. The gastrointestinal tract, including the esophagus, stomach and intestine, is a unique organ system. It has the highest cancer incidence and cancer-related mortality in the body and is influenceed by both genetic and environmental factors. Among the various chemical elements recognized in the nature, some of them including zinc, iron, cobalt, and copper have essential roles in the various biochemical and physiological processes, but only at low levels and others such as cadmium, lead, mercury, arsenic, and nickel are considered as threats for human health especially with chronic exposure at high levels. Cadmium, an environment contaminant, cannot be destroyed in nature. Through impairment of vitamin D metabolism in the kidney it causes nephrotoxicity and subsequently bone metabolism impairment and fragility. The major mechanisms involved in cadmium carcinogenesis could be related to the suppression of gene expression, inhibition of DNA damage repair, inhibition of apoptosis, and induction of oxidative stress. In addition, cadmium may act through aberrant DNA methylation. Cadmium affects multiple cellular processes, including signal transduction pathways, cell proliferation, differentiation, and apoptosis. Down-regulation of methyltransferases enzymes and reduction of DNA methylation have been stated as epigenetic effects of cadmium. Furthermore, increasing intracellular free calcium ion levels induces neuronal apoptosis in addition to other deleterious influence on the stability of the genome.

• The Korea Journal of Herbology
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• v.32 no.3
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• pp.45-53
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• 2017

Objective : Nelumbo nucifera, its rhizome and semen have been used as a traditional medicine which was studied on antioxidant, hepatoprotective effect, anti-obesity and the others. However, Nelumbinis Flos have not studied. We investigated protective effects on oxidative DNA damage and anti-inflammatory effects of Nelumbinis Flos. Methods : The antioxidant activity was conducted by 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical, 2, 2'-Azino-bis (3-ethylbenzothiazoline-6 sulfonic acid) diammonium salt (ABTS) radical scavenging assay and reducing power assay. Total phenolic content was analyzed. Also, phenolic compounds were detected by HPLC/UV. The inhibitory effect on oxidative DNA damage was determined using ${\Phi}X-174$ RF I plasmid DNA cleavage assay. The anti-inflammatory effect of Nelumbinis Flos was measured by the amount of nitric-oxide (NO) produced and protein levels of iNOS, and COX-2 in LPS induced RAW 264.7 cells. Results : The results of DPPH and ABTS radical scavenging activity at $200{\mu}g/m{\ell}$ of extraction were $97.02{\pm}0.88%$ and $96.42{\pm}0.25%$. Reducing power (fold of L-ascorbic acid as control) was $100.14{\pm}0.31$ at $200{\mu}g/m{\ell}$. Total phenol content was $8.70{\pm}0.02mg/g$. Chlorogenic acid, catechin and epicatechin were found by HPLC. Nelumbinis Flos has inhibitory effect in dose-manner against oxidative DNA damage. In addition, it showed the anti-inflammatory effect by suppression of NO production as well as protein levels of iNOS, and COX-2. Conclusion : This study suggested that Nelumbinis Flos showed potential antioxidant and suppression activities of various factors were related in NO produced. Therefore, Nelumbinis Flos as natural plant resources that may help reduce inflammation and alleviate DNA damage.

• Journal of Microbiology and Biotechnology
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• v.31 no.2
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• pp.171-180
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• 2021

Caffeine, a methylxanthine analog of purine bases, is a compound that is largely consumed in beverages and medications for psychoactive and diuretic effects and plays many beneficial roles in neuronal stimulation and enhancement of anti-tumor immune responses by blocking adenosine receptors in higher organisms. In single-cell eukaryotes, however, caffeine somehow impairs cellular fitness by compromising cell wall integrity, inhibiting target of rapamycin (TOR) signaling and growth, and overriding cell cycle arrest caused by DNA damage. Among its multiple inhibitory targets, caffeine specifically interacts with phosphatidylinositol 3-kinase (PI3K)-related kinases causing radiosensitization and cytotoxicity via specialized intermediate molecules. Caffeine potentiates the lethality of cells in conjunction with several other stressors such as oxidants, irradiation, and various toxic compounds through largely unknown mechanisms. In this review, recent findings on caffeine effects and cellular detoxification schemes are highlighted and discussed with an emphasis on the inhibitory interactions between caffeine and its multiple targets in eukaryotic microorganisms such as budding and fission yeasts.

• The Journal of Internal Korean Medicine
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• v.42 no.6
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• pp.1269-1284
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• 2021

Objectives: Phragmitis Rhizoma is the fresh or dried rhizome of Phragmites communis Trin., which has been prescribed in traditional Korean medicine to relieve fever and vomiting and to nourish the body fluids. Recently, the protective effect of Phragmitis Rhizoma extract or its components on myelotoxicity and inflammatory responses have been reported, but no study has yet been conducted on oxidative stress. Methods: The present study investigated whether an ethanol extract of Phragmitis Rhizoma (PR) could protect against cellular damage induced by oxidative stress in Chang liver cells. Results: Pretreatment with PR significantly suppressed the hydrogen peroxide (H₂O₂)-induced reduction of Chang cell viability and generation of reactive oxygen species (ROS), thereby deferring apoptosis. PR also markedly inhibited H₂O₂-induced comet tail formation and phospho-γH2AX expression, suggesting that PR protected against oxidative stress-mediated DNA damage. PR also effectively prevented the inhibition of ATP synthesis in H₂O₂-treated Chang cells by inhibiting the loss of mitochondrial membrane potential, indicating that PR maintains energy metabolism through preservation of mitochondrial function while eliminating ROS generated by H₂O₂. Immunoblotting results indicated that PR attenuated the H₂O₂-induced downregulation of Bcl-2 and upregulation of Bax expression. Conclusions: PR protects against oxidative injury in Chang liver cells by regulating energy homeostasis via ROS generation blockade, which is at least partly mediated through inactivation of the mitochondria-mediated apoptosis pathway.

• Preventive Nutrition and Food Science
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• v.13 no.4
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• pp.313-320
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• 2008

Efficiency of a far-infrared radiation (FIR) dryer for drying of citrus by-products (CBPs) was evaluated through their antioxidant activities. The CBPs dried through FIR were enzymatically digested by six carbohydrases (AMG, Celluclast, Pectinase, Termamyl, Ultraflo and Viscozyme) to prepare digests for evaluation of the activities. The total polyphenolic and total flavonoid contents of the digests were determined by colorimetric assays. The AMG digest was selected for the further experiments. The antioxidant potential of the digests were evaluated by DPPH, superoxide, hydroxyl and alkyl radical scavenging activities, $H_2O_2$ scavenging activity, metal chelating, lipid peroxidation inhibition and the reduction of DNA damage. The AMG digest from CBPs dried through FIR at $50^{\circ}C$ showed strong antioxidant activities in DPPH, superoxide, hydrogen peroxide, alkyl and metal chelating assays while all the digests showed strong lipid peroxidation activities. Further, enzymatic digests showed remarkable inhibitory activities against $H_2O_2$-induced DNA damage. Hence, the data obtained using different in vitro models clearly established the antioxidant potential of enzymatic digests from CBPs dried through FIR. Furthermore, they can be used as a source of natural antioxidants; hence, far-infrared radiation drying is a viable method for transforming wet CBPs into a dried form without destroying the bioactive components.