• Asian Pacific Journal of Cancer Prevention
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• v.16 no.18
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• pp.8503-8512
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• 2016

The purpose of this study was to provide a detailed explanation of the mechanism of bisanthracycline, WP 631 in comparison to doxorubicin (DOX), a first generation anthracycline, currently the most widely used pharmaceutical in clinical oncology. Experiments were performed in SKOV-3 ovarian cancer cells which are otherwise resistant to standard drugs such as cis-platinum and adriamycin. As attention was focused on the ability of WP 631 to induce apoptosis, this was examined using a double staining method with Annexin V and propidium iodide probes, with measurement of the level of intracellular calcium ions and cytosolic cytochrome c. The western blotting technique was performed to confirm PARP cleavage. We also investigated the involvement of caspase activation and DNA degradation (comet assay and immunocytochemical detection of phosphorylated H2AX histones) in the development of apoptotic events. WP 631 demonstrated significantly higher effectiveness as a pro-apoptotic drug than DOX. This was evident in the higher levels of markers of apoptosis, such as the externalization of phosphatidylserine and the elevated level of cytochrome c. An extension of incubation time led to an increase in intracellular calcium levels after treatment with DOX. Lower changes in the calcium content were associated with the influence of WP 631. DOX led to the activation of all tested caspases, 8, 9 and 3, whereas WP 631 only induced an increase in caspase 8 activity after 24h of treatment and consequently led to the cleavage of PARP. The lack of active caspase 3 had no outcome on the single and double-stranded DNA breaks. The obtained results show that WP 631 was considerably more genotoxic towards the investigated cell line than DOX. This effect was especially visible after longer times of incubation. The above detailed studies indicate that WP 631 generates early apoptosis and cell death independent of caspase-3, detected at relatively late time points. The observed differences in the mechanisms of the action of WP631 and DOX suggest that this bisanthracycline can be an effective alternative in ovarian cancer treatment.

• IMMUNE NETWORK
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• v.1 no.2
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• pp.109-115
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• 2001

Background: The role of the interferon consensus sequence binding protein (ICSBP), a member of interferon regulatory factor family, in protecting against a vesicular stomatitis virus (VSV) infection has not been firmly elucidated. Thus, it was investigated utilizing the human promyelocytic leukemia HL-60 cells which do not express ICSBP. Methods: HL-60 cells were stably transfected with plasmid containing cDNA for either ICSBP or DNA binding domain (DBD) and tested for their VSV-susceptibilities. The susceptibility of each transfectant group to a VSV infection was determined by a plaque assay at 1 h, 24 h, and 48 h post-infection in the presence (500 IU/ml) or absence of interferon ${\alpha}$ ($IFN{\alpha}$). Results: In the absence of $IFN{\alpha}$, the three groups showed similar sensitivities to a VSV infection. However, when pre-treated with IFN, the viral titers in both the ICSBP and control clones steadily decreased over 48 h of incubation, indicating the existence of $IFN{\alpha}$-mediated protection against VSV infection. The $IFN{\alpha}$-treated ICSBP clones appeared to be more resistant to infection compared with the control clones, although the difference was not great. On the contrary, the viral titers in the $IFN{\alpha}$-treated DBD clones increased at 24 h then decreased by 48 h. Conclusion: The expression of truncated ICSBP (DBD) does not appear to underlie the impaired protection against a VSV infection in the DBD clones, since even the control clones lacking ICSBP were protected from a VSV infection. This suggests that ICSBP does not play a critical role in the $IFN{\alpha}$- mediated anti-VSV response of HL-60 cells, although it appears to confer some resistance to a VSV infection.

• Journal of Physiology & Pathology in Korean Medicine
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• v.16 no.6
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• pp.1117-1121
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• 2002

To test the protective effect of herbal medicine on myocardial damage against oxygen free radical-induced myocardiotoxicity, cytotoxicity was examined using MTT, Beating rate and DNA synthesis assay in the presence of water extract of three kinds of Radix Rehmanniae. Myocardial toxicity was evaluated in neonatal rat myocardiocytes in cultures. The results of these experiments were obtained as follows : Xanthine oxydase/hypoxanthine resulted in a decrease in viability, beating rate and DNA synthesis in cultured myocardial cells. Radix Rehmanniae Recens(生地黃, RRR) water extract shows effects of protection from the cardiocyte toxicity induced by xanthine oxydase/hypoxanthine treatment such as increases in beating rate. Radix Rehmanniae Preparat(熟地黃, RRP) water extract shows effects of protection from the cardiocyte toxicity induced by xanthine oxydase/hypoxanthine treatment such as increases in DNA synthesis. These results show that xanthine oxydase/hypoxanthine elicits toxic effects in cultured myocardial cells derived from neonatal rat, and suggest that water extract of three kinds of Radix Rehmanniae is very effective in the prevention of xanthine oxydase/hypoxanthine-induced cardiotoxicity.

• The Plant Pathology Journal
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• v.36 no.3
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• pp.231-243
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• 2020

Rice blast, caused by Magnaporthe oryzae, is one of the most destructive rice diseases worldwide. The aim of this study was to screen bacterial isolates to efficiently prevent the occurrence of rice blast. A total of 232 bacterial isolates were extracted from nonrhizospheric rice soil and were screened for antifungal activity against M. oryzae using a leaf segment assay. Strains S170 and S9 showed significant antagonistic activity against M. oryzae in vitro and in leaf disk assays, and controlled M. oryzae infection under greenhouse conditions. The results showed that strains S170 and S9 could effectively control rice leaf blast and panicle neck blast after five spray treatments in field. This suggested that the bacterial strains S170 and S9 were valuable and promising for the biocontrol of rice disease caused by M. oryzae. Based on 16S rDNA, and gyrA and gyrB gene sequence analyses, S170 and S9 were identified as Bacillus amyloliquefaciens and B. pumilus, respectively. The research also demonstrated that B. amyloliquefaciens S170 and B. pumilus S9 could colonize rice plants to prevent pathogenic infection and evidently suppressed plant disease caused by 11 other plant pathogenic fungi. This is the first study to demonstrate that B. amyloliquefaciens and B. pumilus isolated from nonrhizospheric rice soil are capable of recolonizing internal rice stem tissues.

• Journal of Radiation Protection and Research
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• v.30 no.4
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• pp.209-219
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• 2005

This study was carried out to examine the effect of the DNA repair inhibitors, Cytosine Arabinoside(Ara C), 3-Aminobenzamide(3AB) and Hydroxyurea(HU) on the frequencies of radiation-induced micronuclei(MNi) and aneuploidy. Irradiated lymphocytes(1-3Gy) were treated with DNA repair inhibitors, Ara C, 3AB and HU for 3 hours and CBMN assay - FISH technique with DNA probe for chromosome 1 and 4 was performed. The frequencies of x-ray induced MNi and aneuploidy of chromosome 1 and 4 were increased in a dose-dependent manner. Ara C, 3AB and HU enhanced the frequencies of radiation-induced MNi and the frequencies of radiation-induced aneuploidy of chromosome 1 and 4 were enhanced by HU and Ara C while no effect was observed by 3AB. The frequency of radiation-induced aneuploidy of chromosome 1 was higher than that of chromosome 4. These results suggest that there are different mechanisms involved in the formation of MNi and aneuploidy by radiation.

• Korean Journal of Plant Resources
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• v.32 no.6
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• pp.714-722
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• 2019

Oxidative DNA damage negatively affects humans and the research is currently ongoing to find ways to reduce oxidative stress. Oxidative stress has been identified as a key factor in triggering various diseases. Thus, its alleviation is important for human health. Broussonetia kazinoki (B. kazinoki) has been used in traditional Korean medicine as a dermatological therapy to treat burns, pruritus, and acne. B. kazinoki is generally segregated into peeled root (PR), root bark (RB), peeled stem (PS), and stem bark (SB). To assess these components for their antioxidant activity and protection against DNA damage, their ethyl acetate fractions were examined by 1,1-diphenyl-2-picryl hydrazyl (DPPH) and 2,2'-Azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radical scavenging assay. As a result of confirming the expression of factors involved in attenuating DNA damage, the protective effect of SB on oxidative stress suppressed the expression of p-p53 and γ-H2AX. Additionally, the levels of p53 and H2AX mRNA were significantly downregulated. In conclusion, these results indicated that the SB component of B. kazinoki had the potential to be used as an effective natural antioxidant compared to the other parts of the plant.

• Research in Plant Disease
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• v.19 no.4
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• pp.331-337
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• 2013

A disease, supposedly caused by a virus, was observed from Insam (Panax ginseng) fields of Punggi in year 2006. It has long believed to be a physiological disorder. However, the incidence of the disease has increased every year. When several samples were observed under electron microscope, filamentous virus-like particles were observed. The nucleotide sequences of the virus were analyzed by RT-PCR with specific primer sets derived from the results of DNA chip. The results indicated that the disease was caused by Watermelon mosaic virus (WMV). It revealed that the result of the biological assay by the virus was different from that of WMV previously found in other crops. Therefore, this is the first report that WMV causes the disease in P. ginseng and the virus is named to be WMV-Insam.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.1
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• pp.22-27
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• 2004

In the present study, the protective effects of Artemisia capillaris (AC) on the DNA damage induced by $^{60}$ Co ${\gamma}$-rays were evaluated using alkaline single-cell gel electrophoresis (SCGE, comet assay) in the mouse peripheral lymphocytes and micronuclei (MN) formation test in the Chinese hamster ovary (CHO) cells. We also investigated the effect of AC on 8-hydroxy-2'-deoxyguanosine (8-OHdG) formation in the mouse liver and thymus exposed to ${\gamma}$-ray, The tail moment and the frequency of MN, which were markers of DNA damage in the SCGE and MN formation test, were decreased in the groups treated with AC extract before exposure to 200 cGy of ${\gamma}$-ray. We also observed its activities, lowering 8-OHdG level, an index of oxidative DNA damage, in the groups treated with AC extract before whole body ${\gamma}$-irradiation (800 cGy). It is plausible that scavenging of free radicals by AC may have played an important role in providing the protection against the radiation-induced damage to the DNA. These results indicated that AC protects the DNA damage induced by ${\gamma}$-rays and might be a useful radioprotector, especially since it is a relatively nontoxic product.

• The Korean Journal of Physiology and Pharmacology
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• v.8 no.2
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• pp.95-100
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• 2004

Ischemic preconditioning (IPC) has been accepted as a heart protection phenomenon against ischemia and reperfusion (I/R) injury. The activation of ATP-sensitive potassium $(K_{ATP})$ channels and the release of myocardial nitric oxide (NO) induced by IPC were demonstrated as the triggers or mediators of IPC. A common action mechanism of NO is a direct or indirect increase in tissue cGMP content. Furthermore, cGMP has also been shown to contribute cardiac protective effect to reduce heart I/R-induced infarction. The present investigation tested the hypothesis that $K_{ATP}$ channels attenuate DNA strand breaks and oxidative damage in an in vitro model of I/R utilizing rat ventricular myocytes. We estimated DNA strand breaks and oxidative damage by mean of single cell gel electrophoresis with endonuclease III cutting sites (comet assay). In the I/R model, the level of DNA damage increased massively. Preconditioning with a single 5-min anoxia, diazoxide $(100\;{\mu}M)$, SNAP $(300\;{\mu}M)$ and 8-(4-Chlorophenylthio)-guanosine-3',5'-cyclic monophosphate (8-pCPT-cGMP) $(100\;{\mu}M)$ followed by 15 min reoxygenation reduced DNA damage level against subsequent 30 min anoxia and 60 min reoxygenation. These protective effects were blocked by the concomitant presence of glibenclamide $(50\;{\mu}M)$, 5-hydroxydecanoate (5-HD) $(100\;{\mu}M)$ and 8-(4-Chlorophenylthio)-guanosine-3',5'-cyclic monophosphate, Rp-isomer (Rp-8-pCPT-cGMP) $(100\;{\mu}M)$. These results suggest that NO-cGMP-protein kinase G (PKG) pathway contributes to cardioprotective effect of $K_{ATP}$ channels in rat ventricular myocytes.

• Journal of Radiation Protection and Research
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• v.45 no.4
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• pp.163-170
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• 2020

Background: Gut microflora contributes to the nutritional metabolism of the host and to strengthen its immune system. However, if the intestinal barrier function of the living body is destroyed by radiation exposure, the intestinal bacteria harm the health of the host and cause sepsis. Therefore, this study aims to trace short-term radiation-induced changes in the mouse gut microflora-dominant bacterial genus, and analyze the degree of intestinal epithelial damage. Materials and Methods: Mice were irradiated with 0, 2, 4, 8 Gy X-rays, and the gut microflora and intestinal epithelial changes were analyzed 72 hours later. Five representative genera of Actinobacteria, Firmicutes, and Bacteroidetes were analyzed in fecal samples, and the intestine was pathologically analyzed by Hematoxylin-Eosin and Alcian blue staining. In addition, DNA fragmentation was evaluated by the TdT-mediated dUTP nick-end labeling (TUNEL) assay. Results and Discussion: The small intestine showed shortened villi and reduced number of goblet cells upon 8 Gy irradiation. The large intestine epithelium showed no significant morphological changes, but the number of goblet cells were reduced in a radiation dose-dependent manner. Moreover, the small intestinal epithelium of 8 Gy-irradiated mice showed significant DNA damaged, whereas the large intestine epithelium was damaged in a dose-dependent manner. Overall, the large intestine epithelium showed less recovery potential upon radiation exposure than the small intestinal epithelium. Analysis of the intestinal flora revealed fluctuations in lactic acid bacteria excretion after irradiation regardless of the morphological changes of intestinal epithelium. Altogether, it became clear that radiation exposure could cause an immediate change of their excretion. Conclusion: This study revealed changes in the intestinal epithelium and intestinal microbiota that may pave the way for the identification of novel biomarkers of radiation-induced gastrointestinal disorders and develop new therapeutic strategies to treat patients with acute radiation syndrome.