• Journal of Applied Biological Chemistry
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• v.63 no.2
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• pp.137-145
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• 2020

Oxidative stress is one of the pathogenic mechanisms of various neurodegenerative diseases, such as Alzheimer's disease. Neuroglia, the most abundant cells in the brain, is thought to play an important role in the antioxidant defense system and neuronal metabolic support against neurotoxicity and oxidative stress. We investigated the protective effect of paeoniflorin (PF) against oxidative stress in C6 glial cells. Exposure of C6 glial cells to hydrogen peroxide (H₂O₂, 500 μM) significantly decreased cell viability and increased amounts of lactate dehydrogenase (LDH) release, indicating H₂O₂-induced cellular damage. However, treatment with PF significantly attenuated H₂O₂-induced cell death as shown by increased cell survival and decreased LDH release. The H₂O₂-stimulated reactive oxygen species production was also suppressed, and it may be associated with improvement of superoxide dismutase activity by treatment with PF. In addition, an increase in ratio of Bcl-2/Bax protein expression was observed after treatment with PF. In particular, the down-stream of the apoptotic signaling pathway was inhibited in the presence of PF, mostly by reduction of cleaved-poly ADP ribose polymerase, cleaved caspase-3, and -9 protein expression. Furthermore, H₂O₂-induced phosphorylation of c-Jun N-terminal kinase and extracellular signal-regulated kinase 1/2 was attenuated by treatment with PF. Taken together, neuroprotective effect of PF against oxidative stress probably result from the regulation of apoptotic pathway in C6 glial cells. In conclusion, our findings suggest that PF may be a potent therapeutic agent for neurodegenerative disorders.

• Korean Journal of Pharmacognosy
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• v.40 no.1
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• pp.6-12
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• 2009

Thirty five methanol extracts from 19 natural local plants, which have been used as traditional anti-cancer medicine, were prepared. They were analyzed the cytotoxic effects on primary fibroblast cells and carcinoma cells. The root extract of Solanum nigrum were highly toxic in both cell lines with $IC_{50}$ values of less than $0.01{\mu}g/{\mu}l$, and 26 of 35 extracts were toxic in all cells with $IC_{50}$ values of $0.1{\sim}2{\mu}g/{\mu}l$. Three extracts including the fruit extracts of Solanum nigrum and Morus alba had no cytotoxic activity in both cell lines. Five of 35 extracts were highly toxic in cancer cells than in primary cells. Because primary cells were more resistant on these extracts, the five extracts were selected for anti-cancer agent candidates. Apoptosis or programmed cell death has an essential role in chemotherapy-induced tumor cell killing. Recently, inducers of apoptosis have been used in cancer therapy. When two of 5 cancer cell-specific cytotoxic extracts (Ulmus parvifolia and Zelkova serrata) were treated in concentration of $0.02{\sim}0.1{\mu}g/{\mu}l$, apoptosis were increased at 3-5 times in cancer cell lines. Finally, the apoptotic effects of these extracts were confirmed by cleavages of both poly-(ADP-ribose)-polymerase and caspase-3 as apoptotic markers. In this report, we suggested that two of 35 medicinal herb extracts can be useful anti-cancer drug candidates inducing apoptosis in several carcinoma cell lines.

• Korean Journal of Pharmacognosy
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• v.40 no.1
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• pp.65-69
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• 2009

The present study investigated the antiproliferative effect of Litsea japonica in HL-60/ADR, adriamycin resistant human promyelocytic leukemia cells. The 80% ethanol extract of L. japonica markedly inhibited the growth of HL-60/ADR cells. When HL-60/ADR cells were treated with the extract, several apoptosis events like as DNA fragmentation, chromatin condensation and the increase of the population of sub-G1 hypodiploid cells were observed. In the mechanism of apoptosis induction by L. japonica, we examined the changes of Bcl-2 and Bax protein expression levels, and activation of caspases. After the HL-60/ADR cells were treated with the extract, the Bcl-2 expression was decreased, whereas the expression of Bax was increased in a time-dependent manner compared to the control. In addition, the active forms of caspase-9 and -3 were increased and the cleavage of poly (ADP-ribose) polymerase, a vital substrate of effector caspase, was observed. The results suggest that the inhibitory effect of L. japonica on the growth of the HL-60/ADR appears to arise from the induction of apoptosis via the down-regulation of Bcl-2 and the activation of caspases.

• Journal of Physiology & Pathology in Korean Medicine
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• v.18 no.1
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• pp.101-109
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• 2004

Spatholobus suberectus belonging the family Leguminosae has been used for promoting blood circulation, removing blood stasis, tonifying the blood, relaxing tendons, stopping internal bleeding and eliminating dampness in oriental traditional medicine. This study investigates whether the water extracts of S. suberectus induce apoptotic cell death in Jurkat T-acute lymphoblastic leukemia (ALL) cells. Jurkat cells were increased inhibitions of cell viability in a concentration-dependent manner by S. suberectus, as measured by cell morphology. The capability of S. suberectus to induce apoptosis was associated with proteolytic cleavage of specific target protein such as poly (ADP­ribose)polymerase protein suggesting the possible involvement of caspases. The purpose of the present study is also to investigate the effect of S. suberectus on cell cycle progression. G1 checkpoin related gene products tested (cyclin D1, cyclin dependent kinase 4, retinoblastoma, E2Fl) were decreased in their protein levels in a dose-dependent manners after treatment of the extract. These results indicate that the increase of apoptotic cell death by S. suberectus may be due to the inhibition of cell cycle progression in wild type p53-lacking Jurkat cells.

• Journal of Physiology & Pathology in Korean Medicine
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• v.19 no.6
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• pp.1552-1556
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• 2005

Silymarin has been known to exert anti-tumoral activity in Korea. However, its molecular mechanism of action is not understood. In this study, we found that silymarin induced apoptosis in androgen-independent prostate cancer DU145 cells as confirmed by DNA fragmentation. Our data demonstrated that silymarin-induced apoptotic cell death was accompanied by activation of caspase-3 and subsequent cleavages of its substrates, poly(ADP-ribose) polymerase (PARP) in a time- and concentration-dependent manner. Also, silymarin-induced apoptotic mechanism of DU145 cells involved the induction of Par-4 protein expression. Taken together, these results suggest that silymarin induces the activation of caspase-3, degradation of PARP, increase of Par-4 expression, and eventually leads to apoptotic cell death.

• Journal of Physiology & Pathology in Korean Medicine
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• v.19 no.6
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• pp.1594-1598
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• 2005

Scopoletin (6-methoxy-7-hydrorycournarin) is a phenolic coumarin and a member of the phytoalexins. In this study we investigated whether scopoletin causes apoptosis in human hepatoma HepG2 cells and, if so, by what mechanisms. We report that scopoletin induced apoptosis as confirmed by a chromatin condensation. The signal cascade acivated by scopoletin included the activation of caspase-3 as evidenced by increased pretense activity. Activation of caspase-3 resulted in the cleavage of 116 kDa poly(ADP-ribose) polymerase (PARP) to 85 kDa cleavage product in a dose-dependent fashion. Also, scopoletin-induced apoptotic mechanism of HepG2 cells involved the generation of hydrogen peroxide. Taken together, these results suggest that scopgletin induces hydrogen peroxide generation, which, in turn, causes activation of caspase-3, degradation of PARP, and eventually leads to apoptotic cell death in HepG2 cells.

• Journal of Physiology & Pathology in Korean Medicine
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• v.19 no.5
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• pp.1370-1374
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• 2005

The Tosyl-JM3 (TJM3) is a modified compound from one of 1,2,3,4-Tetra- hydroisoquinoline (THIQ) derivatives. The THIQs include potent cytotoxic agents that display a range of anti-tumor activities, antimicrobial activity, and other biological properties. In this study, we investigated the effect of TJM3 on the cytotoxicity, induction of apoptosis in human promyelocytic leukemia cells (HL-60 cells). TJM3 showed a significant cytotoxic activity in HL-60 cells (IC50 = approximately $60{\mu}g/m{\ell}$) after a 24 hr incubation. Treatment of HL-60 cells with TJM3 exhibited several features of apoptosis, including formation of DNA ladders in agarose gel electrophoresis, morphological changes of HL-60 cells with DAPI stain. Here we observed that TJM3 caused a decrease of procaspase-3 protein. Further molecular analysis demonstrated that TJM3 led to cleavage of poly(ADP-ribose) polymerase (PARP) by western blot and increase of hypodiploid (Sub-G1) population in the flow cytometric analysis. In conclusion, these above results indicate that TJM3 dramatically suppresses HL-60 cell growth and induces apoptosis. These data may support a possibility for the use of TJM3 in the prevention and treatment of leukemia.

• Journal of Physiology & Pathology in Korean Medicine
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• v.19 no.6
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• pp.1563-1567
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• 2005

Mori Cortex Radicis is distributed in Northwestern China, northern Asia, northern Europe, North America, and Korea. This extracts drops sugar in bloods and inhibits cyclic AMP phophodiesterase. In this study, we investigated whether Mori Cortex Radicis would cause apoptotic death of A549 lung cancer cells. To examine the apoptotic effect of Mori Cortex Radicis, cytotoxicity assay, DNA fragmentation analysis, caspase-3 activity assay, and Western blotting for caspase-3, caspase-9 and poly(ADP-ribose) polymerase (PARP) and cytochrome c were performed. Treatment of cells with Mori Cortex Radicis was shown to induce cell death in a dose-dependent manner. DNA fragmentation was made in response to Mori Cortex Radicis. The active fragments of caspase-3, caspase-9 and PARP were almost completely induced and cytochrome c was released following exposure to Mori Cortex Radicis. To elucidate the apoptotic mechanisms, RT-PCR and Western blot analyses for the expression of Bcl-2, Bu and Cox-2 were carried out. Treatment with Mori Cortex Radicis was expressed the reduction of Bcl-2 and Cox-2 and the induction of Bax. Especially p21 and p53 were increased prior to untreated control, while cyclin E and cyclin D1 decreased in the cytosol. These results suggest that the effect Mori Cortex Radicis is associated with the cell cycle arrest and pro-apoptotic cell death in A549 lung cancer cells.

• Journal of Physiology & Pathology in Korean Medicine
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• v.19 no.3
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• pp.802-810
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• 2005

The tetrahydroisoquinolines included potent cytotoxic agents that showed antitumor activity,antimicrobial activity, and other biological properties. We studied the effect of CDST, 1-Chloromethyl-6,7-dimethoxy-3,4-dihydro-1H-isoquinoline-2-sulfonic acid amide, a newly synthesized anti-cancer agent. The cytotoxic activity of CDST in HL-60 cells was increased in a dose-dependent manner. CDST, tetrahydroisoquinolines derivative, was cytotoxic to HL-60 cells, with IC50 of $80{\mu}g/ml$. Treatment of CDST to HL-60 cells showed the fragmentation of DNA in a dose- and time dependent manner, suggesting that thesecells underwent apoptosis. Treatment of HL-60 cells with CDST was induced in a dose- and time-dependent activation of caspase-3, caspase-8 and proteolytic cleavage of poly(ADP-ribose) polymerase. In caspase activity assay, caspase-3 and -8 was activated after 12 h and 6 h posttreatment, respectively. CDST also caused the release of cytochrome c from mitochondria into the cytosol. CDST-induced cytochrome c release was mediated by caspase-8-dependent cleavage of Bid and Bax translocation. These results suggest that caspase-8 induced Bid cleavage and Bax translocation, caused mitochondrial cytochrome c release, and induce caspase-3 activationduring CDST-induced apoptosis in HL-60 cells.

• Journal of Physiology & Pathology in Korean Medicine
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• v.20 no.3
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• pp.701-709
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• 2006

The Rhus verniciflua Stokes (乾漆-RVS) has been used in traditional East Asia medicine for the therapy of gastritis, stomach cancer, although the mechanism for the biological activity is unclear. In the present study aims to investigate RVS extract contributes to growth inhibitory effect and it's the molecular mechanism on the human gastric cancer cells. AGS (gastric cancer cells) and RIEI (normal cells) were treated to different concentrations and periods of RVS extract $(10{\;}{\sim{{\;}100{\;}ug/mil)$. Growth inhibitory effect was analyzed by measuring FACS study and MTS assay. Cell cycle inhibition was confirmed by measuring CDK2 kinase activity by immunoprecipitation and kinase assay. And apoptosis was confirmed by surveying caspase cascades activation using a pan caspase inhibitor Exposure to RVS extract (50 ug/mll) resulted in a synergistic inhibitory effect on cell growth in AGS cells. Growth inhibition was related with the inhibition of proliferation and induction of apoptosis. The extract induces Gl -cell cycle arrest through the regulation of cyclins, the induction of p27kip1, and the decrease CDK2 kinase activity. And upregulated p27kip1 level is caused by protein stability increment by the reduction of S-phase kinase-associated protein 2 (Skp2), a key molecule related with p27kip1 ubiquitination and degradation, and do novo protein synthesis. Besides, 乾漆 extract induces apoptosis through the expression of Bax, poly(ADP-ribose) polymerase (PARP) and activation of caspase-3. RVS extract induces Gl -cell cycle arrest via accumulation of p27kip1 and apoptosis in human gastric cancer cells but not in normal cells, therefore we suggest that the extract can be used as a novel class of anti-cancer drugs.