• BMB Reports
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• v.31 no.4
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• pp.333-338
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• 1998

The sphingomyelin cycle and ceramide generation have been recognized as potential growth suppression signals in mammalian cells. Ceramide has been shown to induce differentiation, cell growth arrest, senescence, and apoptosis. Although the intracelluar target for the action of ceramide remains unknown, recent studies have demonstrated the role of cytosolic ceramideactivated protein phosphatase(CAPP). In this study, the cytotoxic effect of C2-ceramide, a synthetic cellpermeable ceramide analog, on HEp-2 cells and the mechanism by which ceramide induces cell death were investigated. The addition of exogenous C2-ceramide resulted in a concentration dependent cell death. Okadaic acid, a potent inhibitor of CAPP, enhanced ceramide-mediated cell death, which suggests that CAPP is not involved in this process. To understand the mechanism of action of ceramide, we studied the relationship between ceramide and c-Myc and pRb which are defined components of cell growth regulation. Western blot analyses revealed that C2-ceramide (10${\mu}M$) induced c-Myc down-regulation, but there were no significant changes in pRb. However, treatment of okadaic acid (10 nM) enhanced c-Myc and pRb down-regulation. Reduction of the amount of c-Myc and pRb occurred during HEp-2 cell death. These results suggest that the cytotoxic effect of ceramide in HEp-2 cells may not be mediated through the action of CAPP and that the downstream target for ceramide is c-Myc and pRb.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.18
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• pp.8313-8319
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• 2016

We have recently shown that thymoquinone (TQ) has a potent cytotoxic effect and induces apoptosis via caspase-3 activation with down-regulation of XIAP in mouse neuroblastoma (Neuro-2a) cells. Interestingly, our results showed that TQ was significantly more cytotoxic towards Neuro-2a cells when compared with primary normal neuronal cells. In this study, the effects of TQ on cell-cycle regulation and the mechanisms that contribute to this effect were investigated using Neuro-2a cells. Cell-cycle analysis performed by flow cytometry revealed cell-cycle arrest at G2/M phase and a significant increase in the accumulation of TQ-treated cells at sub-G1 phase, indicating induction of apoptosis by the compound. Moreover, TQ increased the expression of p53, p21 mRNA and protein levels, whereas it decreased the protein expression of PCNA, cyclin B1 and Cdc2 in a dose-dependent manner. Our finding suggests that TQ could suppress cell growth and cell survival via arresting the cell-cycle in the G2/M phase and inducing apoptosis of neuroblastoma cells.

• Biomolecules & Therapeutics
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• v.27 no.1
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• pp.41-47
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• 2019

The apoptotic effects of shikonin (5,8-dihydroxy-2-[(1R)-1-hydroxy-4-methylpent-3-enyl]naphthalene-1,4-dione) on the human colon cancer cell line SNU-407 were investigated in this study. Shikonin showed dose-dependent cytotoxic activity against SNU-407 cells, with an estimated $IC_{50}$ value of $3{\mu}M$ after 48 h of treatment. Shikonin induced apoptosis, as evidenced by apoptotic body formation, sub-G_1$ phase cells, and DNA fragmentation. Shikonin induced apoptotic cell death by activating mitogen-activated protein kinase family members, and the apoptotic process was mediated by the activation of endoplasmic reticulum (ER) stress, leading to activation of the $PERK/elF2{\alpha}/CHOP$ apoptotic pathway, and mitochondrial $Ca^{2+}$ accumulation. Shikonin increased mitochondrial membrane depolarization and altered the levels of apoptosis-related proteins, with a decrease in B cell lymphoma (Bcl)-2 and an increase in Bcl-2-associated X protein, and subsequently, increased expression of cleaved forms of caspase-9 and -3. Taken together, we suggest that these mechanisms, including MAPK signaling and the ER- and mitochondria-mediated pathways, may underlie shikonin-induced apoptosis related to its anticancer effect.

• Microbiology and Biotechnology Letters
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• v.50 no.3
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• pp.387-394
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• 2022

Verotoxin-1 (VT-1) or Shiga-like toxin 1 (Stx-1) is produced by enterohemorrhagic Escherichia coli (EHEC) and is an AB5 holotoxin with a strong inhibitor of protein synthesis. VT-1 is a type 2 ribosome-inactivating protein (RIP) that has been shown to have cytotoxic and anticancer potential by inducing necrosis, apoptosis, and cell cycle arrest, making it a promising antitumor candidate. Here, we tested the cytotoxicity of VT-1 on CaCo2 and NCM425 cell lines and the results showed that VT-1 was more potent on CaCo2. Morphological changes were also evaluated on the cellular level and the results showed that VT-1 caused a decrease in viable cell count, altered cell membrane permeability, and an increase in total nuclear intensity. On the other hand, VT-1 displayed a lesser impact on mitochondrial membrane potential (MMP) and cytochrome c release. On the expression of caspases 3 and 9, VT-1 exhibited an insignificant effect on both which alongside the mitochondrial membrane potential (MMP) and cytochrome c results, might indicate that CaCo2 suffered from the necrosis process as a mechanism of cell death after exposure to VT-1.

• Journal of The Korean Society of Integrative Medicine
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• v.11 no.3
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• pp.159-169
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• 2023

Purpose : Though other Citrus spp. have reported their anti-inflammatory and antioxidative activities in previous studies, the biological activity of Kiyomi (Citrus unshiu × C. sinensis) has not been reported yet. Therefore, this study attempted to analyze the anti-inflammatory mechanisms of Kiyomi leaf ethanol extract (KLEE) in lipopolysaccharide (LPS) stimulated RAW 264.7 cells. Methods : The cytotoxic effect of KLEE in RAW 264.7 cells was determined by WST-1 assay. Bacterial endotoxin, the concentration of nitric oxide (NO) was analyzed by the Griess reaction. In addition, Western blot analysis was applied to measure the protein expression level of inducible NO synthase (iNOS). The phosphorylated status of the critical inflammatory transcription factor, nuclear factor (NF)-𝜅B, and its upstream signaling molecules, phosphoinositide 3-kinase (PI3K)/Akt as well as mitogen-activated protein kinases (MAPKs), were also measured by Western blot analysis. Results : KLEE was not cytotoxic up to a concentration of 200 ㎍/㎖, and protein expression levels of iNOS and cyclooxygenase (COX)-2, enzymes that counteract NO and prostaglandin (PG) E2 production, were inhibited by KLEE treatment. The phosphorylated status of PI3K/Akt as well as MAPKs including extracellular regulated kinase (ERK), c-jun NH2kinase (JNK), and p38, were significantly attenuated by KLEE treatment in LPS stimulated RAW 264.7 cells. Moreover, one of phase II enzymes, heme oxygenase (HO)-1 which has known for its anti-inflammatory capacity, was strongly induced by KLEE treatment. Conclusion : Consequently, KLEE treatment significantly attenuated the production of NO as well as the expression levels of iNOS and COX-2 in LPS-stimulated RAW 264.7 cells. The inflammatory transcription factor, NF-𝜅B, as well as its upstream signaling molecules, PI3K/Akt and MAPKs, were also diminished by KLEE treatment with statistical significance in LPS-stimulated RAW 264.7 cells. These results suggest that KLEE might be a promising candidate for the attenuation of inflammatory disorders.

• YAKHAK HOEJI
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• v.43 no.2
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• pp.173-179
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• 1999

In the present study, we have evaluated cytotoxic effects, antitumor activities and metastasis inhibitory effects of Palsun brewing water in NIH 3T3 cells, human epitheloid carcinoma cells, and human skin melanoma cells. The light microscopic study showed morphological changes, AG-NOR (argyrophylic nucleolar organizer region) by silver chloride stain, and glycoprotein by PAS (periodic acid stain) reaction of the treated cells. Disruptions in cell organelles were determined by colorimetric methods; MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazoliumbromide) and SRB (sulforhodamine B protein) assays. These results suggest that Palsun Brewing Water retains no cytotoxic effects in NIH 3T3 cells and a growth-inhibitory activity in cancer cell lines.

• Natural Product Sciences
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• v.27 no.3
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• pp.176-182
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• 2021

The phytochemical investigation of Broussonetia kazinoki roots led to the isolation of ten compounds, including six flavonoids (1-6), two lignans (7 and 8), and two coumarins (9 and 10) by comparing their ¹H and ¹³C NMR spectra with reference values. To the best of our knowledge, compounds 9 and 10 were isolated from this plant for the first time. Among the ten isolates, compounds 2, 4, and 6 exhibited inhibitory effects against lipopolysaccharide (LPS)-induced nitric oxide (NO) production in macrophage RAW264.7 cells with IC₅₀ values of 11.98, 10.16, and 24.06 μM, respectively. Furthermore, compounds 2, 4, and 6 reduced LPS-induced inducible nitric oxide synthase (iNOS) expression in a dose-dependent manner. Pre-incubation of cells with these compounds also significantly suppressed LPS-induced COX-2 protein expression. Compounds 2, 4, and 6 also showed cytotoxic activity against HL-60 cells with IC₅₀ values ranging between 46.43 and 94.06 μM.

• Korean Journal of Animal Reproduction
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• v.17 no.1
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• pp.13-19
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• 1993

We investigated the effects of CP-2 extracted from the mixture of Copis and Croton tiglium L, which showed very high cytotoxic effect to the various tumor cells, on the growth and steroidenesis of primary and transformed cell lines PA-GS6 and PO-GRS1 by cotransfectionwith SV40 and Ha ras oncogenes. CP-2 inhibited the growth of PA-GS6 and PO-GRS1 in a dose dependent manner when the growth of them was measured by cell number and by protein content, while CP-2 did not affect the growth of primary granulose cells. Productions of progesterone ofprimary and transformed granulosa cells were stimulated by forskolin, but this stimulatory effect was blocked by treatment of CP-2. Clinical application of CP-2 asa new anti-cancer drug and utilization of transformed granulosa cells as a model system for the screening of anti-cancer drug were also discussed.

• Korean Journal of Pharmacognosy
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• v.29 no.3
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• pp.198-203
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• 1998

In the present study, we have evaluated cytotoxic effects of Taraxaci herba extract on human skin melanoma cells. The light microscopic study showed morphological changes of the treated cells. Disruptions in cell organelles were determined by calorimetric methods: MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazoliumbromide), NR (Neutral red) and SRB (Sulforhodamine B protein) assay. These results suggest that Taraxaci herba retains a potential antitumor activity.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.6 no.1
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• pp.31-52
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• 1993

The object of thes research is to lucidate the clinical effects of Gami-Cheongshimyeonjayeum on the anti-allergic and gimmune response to rats and mice. The obtaind results of Gami-Cheongshimyeonjayeum administration are as follows : 1. The cytotoxic index increased slightly at over concentration $1{\times}10^{-2}/ml$, but it is thought that the cytotoxic effect show no significant value under the concentration $1{\times}10^{-3}/ml$. 2. Gami-Cheongshimyeonjayeum water extract seems to suppress the leakage volume of Evans blue to decrease the vascular permeability. 3. Gami-Cheongshimyeonjayeum show the inhibitory effect of footpad edema. 4. Protein leakage is inhibited by the administration of Gami-Cheongshimyeonjayeum. 5. The delayed type hypersensitivity to SRBC is suppressed at the 24hours after the administration of Gami-Cheongshimyeonjayeum on the experimental group 1, 2. 6. Hemolysin and hemagglutinin titer, and RFC increase to bulid up the immune function.