• Korean Journal of Food Science and Technology
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• v.51 no.5
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• pp.499-502
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• 2019

Poly(ADP-ribose) polymerase (PARP) is a nuclear enzyme which is activated in response to DNA damage, and which mediates DNA repair. PARP inhibitors can be used to reduce resistance of cancer cells to anticancer treatments. The objective of this study was to investigate the effects of selected phytochemicals and fruit extracts on PARP activation in MCF-7 breast cancer cells subjected to oxidative stress. Pre-incubation with epigallocatechin gallate (EGCG), apple extract (AE), cranberry extract (CE), or grape extract (GE) for 2 hours at test concentrations reduced PARP activity induced upon treatment with hydrogen peroxide in a dose-dependent manner (p<0.05). GE was found to be the most efficient PARP inhibitor among the fruit extracts examined. These results suggest that phytochemicals of fruit extracts might be used as PARP inhibitors in order to assist anticancer agents.

• Molecules and Cells
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• v.21 no.2
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• pp.218-223
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• 2006

The effect of poly(ADP-ribosyl)ation on the stability of p53 in SK-HEP1 cells treated with UV light was examined. Intracellular levels of p53 increased in cells treated with a low dose of UV light ($20J/m^2$), whereas they increased but then declined after a higher dose of UV ($100J/m^2$). Intracellular levels of p53 in the UV treated SK-HEP1 cells were dependent on the UV dose. Use of proteasome inhibitors revealed that p53 is degraded by proteasomal proteolysis after high doses of UV light. We present evidence that, at low doses, poly(ADP-ribose)polymerase (PARP) poly(ADP-ribosyl) ates p53 and protects it from proteasomal degradation before caspase-3 is activated, whereas at high doses the cells undergo UV induced apoptosis and PARP is cleaved by caspase-3 before it can protect p53 from degradation. Destabilization of p53 by cleavage of PARP may be important in cell fate decision favoring apoptosis.

• Proceedings of the Korean Society of Applied Pharmacology
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• 2002.07a
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• pp.199-199
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• 2002

• Proceedings of the Zoological Society Korea Conference
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• 2000.10a
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• pp.246.1-246
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• 2000

No Abstract, See Full Text

• Bulletin of the Korean Chemical Society
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• v.32 no.5
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• pp.1650-1656
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• 2011

A series of potent tricyclic derivatives with a non-aromatic amide as potent PARP-1 inhibitors were successfully synthesized and their PARP-1 inhibitory activity was evaluated. Among the derivatives, 2-(1-propylpiperidin-4-yloxy)-7,8,9,10-tetrahydrophenanthridin-6(5H)-one 23c displayed potent activity in a PARP-1 enzymatic assay and cell-based assay ($IC_{50}$ = 0.142 ${\mu}M$, $ED_{50}$ = 0.90 ${\mu}M$) with good water solubility. Further, molecular modeling studies confirmed the obtained biological results.

• Journal of Nutrition and Health
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• v.36 no.4
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• pp.382-388
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• 2003

(-)-Epigallocatechin-3-gallate (EGCG) is a polyphenolic compound found in peen tea leaves, and has been known to be one of the most potent catechin species which inhibits cell growth most possibly through an apoptotic cell death. We investigated the apoptotic activity of (-)-EGCG on the human myeloid leukemia cell line, HL-60. Our results of MTT test indicated that (-)-EGCG had a significant antiproliferation effect in HL-60 cells with $IC_{50}$/ (50% inhibition concentration) value of 65 $\mu$M. Giemsa statining of HL-60 cells treated with (-)-EGCG (100 $\mu$M) for 6hrs showed a typical apoptosis-specific morphological change including shrinkage of the cytoplasm, membrane blobbing and compaction of the nuclear chromatin. The DNA fragmentation was observed from the agarose gel electrophoresis of cells treated with (-)-EGCG for 3hrs or longer, and was progressed to a greater degree as treatment time increases. Treatment of the cells with (-)-EGCG (100 $\mu$M) resulted in a rapid release of mitochondrial cytochrome c into the cytosol, and a subsequent cleavage of caspase-3 to an active form in a treatment-time dependent manner. (-)-EGCG (100 $\mu$M) also stimulated proteolytic cleavage of poly-(ADP-ribose) polymerase (PARP) to an active form in HL-60 cells. Tlken together, (-)-EGCG appears to induce the apoptosis in human myeloid leukemia cells via a caspase-dependent pathway. These results suggest the possible application of (-)-EGCG, the major active compound in green tea, as an antiproliferative agent for cancer prevention.

• The Journal of Korean Medicine
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• v.25 no.2
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• pp.33-40
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• 2004

Objective : This study investigated the apoptotic effect and its mechanism of Radix Aconiti (RA) extract and aconitine, which is a major constituent of RA, in HepG2 human hepatoma cells. Methods : We used MTT and DNA fragmentation assay to investigate cell viability and apoptotic effect on RA extract-treated HepG2 cells. In addition, to clarify the mechanism of RA extract-induced apoptosis, we applied caspase-3 enzyme activity assay and Western blotting method on poly-(ADP-ribose) polymerase (PARP) protein expression. Results : Treatment with RA extract resulted in the decrease of cell viability, and this effect was caused from apoptosis as confirmed by discontinuous fragmentation of DNA in HepG2 cells, but aconitine did not. Also, RA extract-treated HepG2 cells induced the activation of caspase-3 enzyme activity in time- and dose-dependent manners, which was accompanied by the cleavage of 116 kD PARP to 85 kD product. Conclusions : These results suggest that the apoptotic effects of RA extract on HepG2 cells could not be explained by aconitine. Additionally, RA extract induced apoptosis in hepatoma cells through caspase-3 activation and subsequent PARP cleavage.

• Biomedical Science Letters
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• v.12 no.4
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• pp.349-354
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• 2006

Induction of apoptosis allows the organism to get rid of abnormal cells and also of tumor cells. Understanding the mechanism involved in Ultraviolet radiation (UV) induced apoptosis may improve its therapeutic efficacy. In this study, we present expression of poly (ADP-ribose) polymerase (PARP) during apoptosis induced by UV in HeLa $S_3$ cells. Four different assays were performed in this study: morphological assessment of apoptotic cells and cell viability, DNA fragmentation analysis by agarose gel electrophoresis, quantitative assay of fragmented DNA, and expression of PARP by the western blot analysis. The percentages of apoptotic HeLa $S_3$ cells irradiated with $75J/m^2$ UV was increased continuously from 3 hrs incubation. DNA ladder pattern was appeared at 6 hrs. The amount of nucleosomal DNA fragments in cells treated UV increased from 3 to 12 hrs incubation and gradually decreased. The cleavage of PARP in HeLa $S_3$ cells irradiated with UV was induced, and the cleavage of PARP was more delayed in the cells pretreated with $5J/m^2$ UV and subsequently irradiated with $75J/m^2$ UV. than that in the cells only irradiated with $75J/m^2$ UV. Thus these data suggest that the cleavage of PARP relates with DNA fragmentation associated with apoptosis.

• Journal of Physiology & Pathology in Korean Medicine
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• v.24 no.3
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• pp.385-389
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• 2010

Butein(3,4,2',4-tetrahydroxychalcone) has been reported anticancer effects in several cancer type, which is prostate, bladder cancer but breast cancer is not. This study was to investigate the antiproliferative effects by butein(3,4,2',4-tetrahydroxychalcone) in MCF-7 human breast carcinoma cells. We invastigated the effects of dose-dependently cell growth inhibition by butein, which could be proved by WST-1 assay. Also, flow cytometry analysis was butein increase percentage of subG1 phase. As well as, butein induces apoptosis through the expression of caspase-8,-3 and poly(ADP-ribose) polymerase(PARP) activation but not in DMSO treated cells. Taken together, this results suggest that butein induced MCF-7 apoptosis through extrinsic pathway and thus may have potential tumor suppressor in breast cancer.

• YAKHAK HOEJI
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• v.47 no.5
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• pp.319-324
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• 2003

This study examined the inhibitory effect of extracts of Trichosanthes kirilpwii sorted according to the parts on the growth of HL-60 cells. The growth of HL-60 leukemia cells was markedly inhibited by the treatment of the 80％ methanol extract of roots (10 $\mu\textrm{g}$/mι), stems (50$\mu\textrm{g}$/mι), pips (10$\mu\textrm{g}$/mι), and gourds (100 $\mu\textrm{g}$/mι), or the ethylacetate fraction of leaves (100 $\mu\textrm{g}$/mι). when the HL-60 cells were treated with the extracts of T. kirilpwii sorted according to the parts, DNA fragmentation and sub-G1 hypodiploid cells were observed. Moreover, T. kirilpwii extracts increased the level of the expression of the active form of caspase-3 and the activation of caspase-3 was demonstrated by the cleavage of poly(ADP-ribose) polymerase, a vital substrate of effector caspase. The results suggest that the inhibitory effect of extracts of T. kirilpwii sorted according to the parts on the growth of HL-60 cells seems to arise from the induction of apoptosis.