• Journal of Life Science
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• v.18 no.8
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• pp.1042-1048
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• 2008

Prostate cancer is the most predominant cancer in men and related death rate increases every year. Till date, there is no effective therapy for androgen independent prostate cancer. To investigate the mechanism for cell growth inhibition or apoptosis in human androgen independent prostate cancer PC-3 cells after gamma irradiation. The aim of this study was to examine the potential of gamma irradiation to induce apoptosis in PC-3 cells and to assess the mechanism of gamma irradiation-induced apoptosis. Five different assays were employed in this study: cell proliferation assay, morphological assessments of apoptotic cells, DNA fragmentation analysis, quantification of apoptosis by annexin V (AV) and propidium iodide (PI) staning, and western blot analysis. Cell viability was inversely related to radiation dose. DAPI-positive cells were detected 48 hr after 40 Gy radiation exposure. And nuclear morphological changes of cells were observed by gamma irradiation. DNA ladder patterns in the cells exposed to gamma-radiation were appeared at 24 hr. Also, gamma irradiation induces apoptosis of PC-3 cells via Caspase3, Bax and PARP-dependent fashion.

• The Korea Journal of Herbology
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• v.31 no.1
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• pp.33-40
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• 2016

Objectives : Liver is one of the largest organs in the human, and has a function of detoxification and energy sensing to prevent severe disease. Paeoniae radix has been used to treat a variety of liver diseases such as hepatitis and chronic hepatic failure. Although P. radix has been used as an medicinal herb for a long time, the effects of P. radix on severe oxidative stress and its action mechanism on the liver was not clearly verified.Methods : This study investigated the protective effects of P. radix extract (PRE), and the underlying mechanism of its action in the liver. tert-butyl hydroperoxide (t-BHP) and carbon tetrachlroride (CCl₄) were used to induce oxidative stress in the HepG2 hepatocyte cell line and Sprague-Dawley rats, respectively.Results : t-BHP significantly induced cell death and ROS production in HepG2 cell, as indicated by MTT and FACS analysis. However, pretreatment of PRE inhibited a decrease in cell viability and H₂O₂ production in the HepG2 cells. PRE also blocked the ability of t-BHP to damage in mitochondrial membrane transition. More importantly, PRE induced Nrf2 activation and antioxidant Phase II enzyme, which may have a role in the effects of PRE. In mice, PRE inhibited the liver damage induced by CCl₄.Conclusions : PRE inhibited oxidative stress and hepatic damages as mediated with Nrf2 activation. This study unveil, in part, the effect and mechanism of old medicinal herb, P. radix.

• Food Science and Preservation
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• v.24 no.7
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• pp.1007-1016
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• 2017

Melania snail (Semisulcospira libertina) was traditionally used as the healthy food in Korea. It was generally known to improve liver function and heal a diabetes. The aim of this study was to elucidate the anti-diabetic mechanism of melanian snail hydrolysates treated with protamex (MPH) by investigating the inhibitory action on protein tyrosine phosphatase 1B (PTP1B), the improving effect on the insulin resistance in C2C12 myoblast and the protective effect for pancreatic beta-cell (INS-1) under the glucose toxicity. The melania snail hydrolysates treated with protamex (MPH), which showed the highest degree of hydrolysis (43%), and inhibited effectively PTP1B activity ($IC_{50}=15.42{\pm}1.1{\mu}g/mL$), of which inhibitory effect was higher than usolic acid, positive control ($IC_{50}=16.65{\mu}g/mL$). MPH increased the glucose uptake in C2C12 myoblast treated with palmitic acid. In addition, MPH increased insulin mRNA expression level by over 160% with enhanced cell viability in INS-1 cell under the high glucose concentration (30 mM). These results suggest that MHP may improve the diabetic symptom by the inhibiting the PTP1B activity, increasing the glucose uptake in muscle cell and protecting the pancreatic beta-cell from glucose toxicity.

• Journal of Environmental Health Sciences
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• v.27 no.2
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• pp.82-91
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• 2001

This study was carried out to elucidate the protective effect of zinc chloride(ZnCl$_2$) and its mechanism against the immuno-cytotoxicity of methylmercury chloide($CH_3$HgCl). This study was observed in the culture of EMT-6 cells which are originated from mammary adenocarcinoma of Balb/c mouse. Cytotoxicity of metals was measured by cell viability and NO$_2$$^{[-10]}$ , and mitochondrial function was evaluated by adenosine triphosohate (ATP) production. $CH_3$HgCl significantly decreased the sythesis of nitric oxide(NO), ATP and glutathione(GSH) in a dose-dependent manner. ZnCl$_2$ significantly increased the synthesis of GSH in a dose-dependent manner, but synthesis of NO and ATP were not changed. The immuno-cytotoxicity of $CH_3$HgCl was not fully protected when combined addition of ZnCl$_2$, whereas ZnCl$_2$ prior to addition of $CH_3$HgCl completly protected the Hg-induced immuno-cytotoxicity. Similarly, intracellular accumulation of mercury significantly decreased by ZnCl$_2$. Degree of diminution of intracellular mercury was larger in ZnCl$_2$ prior to addition of $CH_3$HgCl than in combined addition of ZnCl$_2$ and $CH_3$HgCl.. Dithiothreitol(DTT) or buthionine sulfoximine(BSO) addition at 50$\mu$M or less, which was not toxic to the cells, did not affect synthesis of NO and ATP. DTT increased intracellular GSH level and DTT pretreatment protected toxicity induced by $CH_3$HgCl as shown complete recover in the NO and ATP values. BSO decreased intracellular GSH level and BSO pretreatment exaggerated toxicity induced by $CH_3$HgCl as shown synergistic reduction in the NO and ATP values. These results indicated that the protective effects of zinc against immuno-cytotoxicity of methylmercury associated with increasing cellular level of GSH. Increased intracellular GSH transports methylmercury to out of cells. In accordance with intracellular level of mercury decreased, immuno-cytotoxicity of methylmercury decreased. These result also suggest that the protective mechanism of zinc against the mercury toxicity would be exerted in the immune system in vivo.

• Journal of Gastric Cancer
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• v.8 no.3
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• pp.120-128
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• 2008

Purpose: Mistletoe extract was widely used for cancer treatment as complementary or alternative therapy in European area from early twenty century. It is currently used as alternative anti-cancer remedy by piecemeal in domestic medical group, however, the anti-cancer mechanism of mistletoe extract was not known precisely until now. In this study the effect of mistletoe extract on gastric cancer was studied vis cell line experiments. Materials and Methods: The SNU719 gastric cancer cell line was used, and ABNOBAviscum-Q and ABNOBAviscum-F were treated to cells as mistletoe extract, or 5-FU and cisplatin were used with mistletoe extract. The cell viability and cell death rate were estimated by CCK-8 assay kit and lactate dehydrogenase (LDH) assay kit in each. Caspase 3 assay kit was used to measure caspase 3 activity. The protein expression amounts of Bcl2, p53, and PTEN were estimated through Western blot analysis. Results: The co-treatments of mistletoe extract Q/F and 5-FU/cisplatin decreased lesser cell viability than only mistletoe treat. Caspase 3 activity was increased 4~6 times in co-treatment of mistletoe extracts and 5-FU than control. Bcl2 protein expression was reduced by mistletoe extracts or anti-cancer drugs, further more, the co-treatment of mistletoe extracts and 5-FU/cisplatin diminished more the expression than only mistletoe treatment. Mistletoe extracts did not affect the protein expressions of p53 and PTEN. Conclusion: It was concluded that the anti-cancer mechanism of mistletoe extracts was made by caspase 3 activation and lowered Bcl2 expression, and this apoptosis inducing mechanism was independent to p53.

• Journal of Microbiology and Biotechnology
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• v.18 no.3
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• pp.523-531
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• 2008

Radiotherapy is currently applied in the treatment of human cancers. We studied whether genistein would enhance the radiosensitivity and explored its precise molecular mechanism in cervical cancer cells. After co-treatment with genistein and irradiation, the viability, cell cycle analysis, and apoptosis signaling cascades were elucidated in CaSki cells. The viability was decreased by co-treatment with genistein and irradiation compared with irradiation treatment alone. Treatment with only ${\gamma}$-irradiation led to cell cycle arrest at the $G_1$ phase. On the other hand, co-treatment with genistein and ${\gamma}$-irradiation caused a decrease in the $G_1$ phase and a concomitant increase up to 56% in the number of $G_2$ phase. In addition, co-treatment increased the expression of p53 and p21, and Cdc2-tyr-15-p, supporting the occurrence of $G_2/M$ arrest. In general, apoptosis signaling cascades were activated by the following events: release of cytochrome c, upregulation of Bax, down regulation of Bcl-2, and activation of caspase-3 and -8 in the treatment of genistein and irradiation. Apparently, co-treatment downregulated the transcripts of E6*I, E6*II, and E7. Genistein also stimulated irradiation-induced intracellular reactive oxygene, species (ROS) production, and co-treatment-induced apoptosis was inhibited by the antioxidant N-acetylcysteine, suggesting that apoptosis has occurred through the increase in ROS by genistein and ${\gamma}$-irradiation in cervical cancer cells. Gamma-irradiation increased cyclooxygenase-1 (COX-2) expression, whereas the combination with genistein and ${\gamma}$-irradiation almost completely prevented irradiation-induced COX-2 expression and $PGE_2$ production. Co-treatment with genistein and ${\gamma}$-irradiation inhibited proliferation through $G_2/M$ arrest and induced apoptosis via ROS modulation in the CaSki cancer cells.

• Journal of The Korean Dental Society of Anesthesiology
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• v.14 no.1
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• pp.49-56
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• 2014

Background: Propofol (2.6-diisopropylphenol) is a widely used intravenous anesthetic agent for the induction and maintenance of anesthesia during surgeries and sedation for ICU patients. Propofol has a structural similarity to the endogenous antioxidant vitamin E and exhibits antioxidant activities.13) However, the mechanism of propofol on hypoxia/reoxygenation (H/R) injury has yet to be fully elucidated. We investigated how P-PostC influences the autophagy and cell death, a cellular damage occurring during the H/R injury. Methods: The groups were randomly divided into the following groups: Control: cells were incubated in normoxia (5% CO2, 21% O2, and 74% N2) without propofol treatment. H/R: cells were exposed to 24 h of hypoxia (5% CO2, 1% O2, and 94% N2) followed by 12 h of reoxygenation (5% CO2, 21% O2, and 74% N2). H/R + P-PostC: cells post-treated with propofol were exposed to 24 h of hypoxia followed by 12 h of reoxygenation. 3-MA + P-PostC: cells pretreated with 3-MA and post-treated propofol were exposed to 24 h of hypoxia followed by 12 h of reoxygenation Results: The results of our present study provides a new direction of research on mechanisms of propofol-mediated cytoprotection. There are three principal findings of these studies. First, the application of P-PostC at the onset of reoxygenation after hypoxia significantly increased COS-7 cell viability. Second, the cellular protective effect of P-PostC in H/R induced COS-7 cells was probably related to activation of intra-cellular autophagy. And third, the autophagy pathway inhibitor 3-MA blocked the protective effect of P-PostC on cell viability, suggesting a key role of autophagy in cellular protective effect of P-PostC. Conclusions: These data provided evidence that P-PostC reduced cell death in H/R model of COS-7 cells, which was in agreement with the protection by P-PostC demonstrated in isolated COS-7 cells exposed to H/R injury. Although the this study could not represent the protection by P-PostC in vivo, the data demonstrate another model in which endogenous mechanisms evoked by P-PostC protected the COS-7 cells exposed to H/R injury from cell death.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.11
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• pp.4671-4676
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• 2014

Background: MicroRNA-200a (miR-200a) has been reported to regulate tumour progression in several tumours but little is known about its role in neuroblastoma. Our aim was to investigate the potential role and mechanism of miR-200a in neuroblastomas. Materials and Methods: Expression levels of miR-200a in tissues were determined using RT-PCR. The effect of miR-200a and shAP-$2{\gamma}$ on cell viability was evaluated using MTS assays, and target protein expression was determined using Western blotting and RT-PCR. Luciferase reporter plasmids were constructed to confirm direct targeting. Results were reported as mean${\pm}$S.E.M and differences were tested for significance using the 2-tailed Students t-test. Results: We determined that miR-200a expression was significantly lower in neuroblastoma tumors than the adjacent non-cancer tissue. Over-expression of miR-200 are reduced cell viability in neuroblastoma cells and inhibited tumor growth in mouse xenografts. We identified AP-$2{\gamma}$ as a novel target for miR-200a in neuroblastoma cells. Thus miR-200a targets the 3'UTR of AP-$2{\gamma}$ and inhibits its mRNA and protein expression. Furthermore, our result showed that shRNA knockdown of AP-$2{\gamma}$ in neuroblastoma cells results in significant inhibit of cell proliferation and tumor growth in vitro, supporting an oncogenic role of AP-$2{\gamma}$ in neuroblastoma. Conclusions: Our study revealed that miR-200a is a candidate tumor suppressor in neuroblastoma, through direct targeting of AP-$2{\gamma}$. These findings re-enforce the proposal of AP-$2{\gamma}$ as a therapeutic target in neuroblastoma.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.3
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• pp.419-427
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• 2016

There is a high association of heat shock on the alteration of energy and lipid metabolism. The alterations associated with thermal stress are composed of gene expression changes and adaptation through biochemical responses. Previous study showed that Angelica gigas Nakai (AGN) root extract promoted adipogenic differentiation in murine 3T3-L1 preadipocytes under the normal temperature condition. However, its effect in heat shocked 3T3-L1 cells has not been established. In this study, we investigated the effect of AGN root hot water extract in the adipogenic differentiation of murine 3T3-L1 preadipocytes following heat shock and its possible mechanism of action. Thermal stress procedure was executed within the same stage of preadipocyte confluence (G0) through incubation at $42^{\circ}C$ for one hour and then allowed to recover at normal incubation temperature of $37^{\circ}C$ for another hour before AGN treatment for both cell viability assay and Oil Red O. Cell viability assay showed that AGN was able to dose dependently (0 to $400{\mu}g/mL$) increase cell proliferation under normal incubation temperature and also was able to prevent cytotoxicity due to heat shock accompanied by cell proliferation. Confluent preadipocytes were subjected into heat shock procedure, recovery and then AGN treatment prior to stimulation with the differentiation solution. Heat shocked preadipocytes exhibited reduced differentiation as supported by decreased amount of lipid accumulation in Oil Red O staining and triglyceride measurement. However, those heat shocked preadipocytes that then were given AGN extract showed a dose dependent increase in lipid accumulation as shown by both evaluation procedures. In line with these results, real-time polymerase chain reaction (RT-PCR) and Western blot analysis showed that AGN increased adipogenic differentiation by upregulating heat shock protection related genes and proteins together with the adipogenic markers. These findings imply the potential of AGN in heat shock amelioration among 3T3-L1 preadipocytes through heat shock factor and proteins augmentation and enhanced adipogenic marker expression.

• Journal of Dental Anesthesia and Pain Medicine
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• v.16 no.4
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• pp.295-302
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• 2016

Background: Reactive oxygen species play critical roles in homeostasis and cell signaling. Dexmedetomidine, a specific agonist of the ${\alpha}2$-adrenoceptor, has been commonly used for sedation, and it has been reported to have a protective effect against oxidative stress. In this study, we investigated whether dexmedetomidine has a protective effect against $H_2O_2$-induced oxidative stress and the mechanism of $H_2O_2$-induced cell death in normal human fetal osteoblast (hFOB) cells. Methods: Cells were divided into three groups: control group-cells were incubated in normoxia without dexmedetomidine, hydrogen peroxide ($H_2O_2$) group-cells were exposed to $H_2O_2$ ($200{\mu}M$) for 2 h, and Dex/$H_2O_2$ group-cells were pretreated with dexmedetomidine ($5{\mu}M$) for 2 h then exposed to $H_2O_2$ ($200{\mu}M$) for 2 h. Cell viability and apoptosis were evaluated. Osteoblast maturation was determined by assaying bone nodular mineralization. Expression levels of bone-related proteins were determined by western blot. Results: Cell viability was significantly decreased in the $H_2O_2$ group compared with the control group, and this effect was improved by dexmedetomidine. The Hoechst 33342 and Annexin-V FITC/PI staining revealed that dexmedetomidine effectively decreased $H_2O_2$-induced hFOB cell apoptosis. Dexmedetomidine enhanced the mineralization of hFOB cells when compared to the $H_2O_2$ group. In western blot analysis, bone-related protein was increased in the Dex/$H_2O_2$ group. Conclusions: We demonstrated the potential therapeutic value of dexmedetomidine in $H_2O_2$-induced oxidative stress by inhibiting apoptosis and enhancing osteoblast activity. Additionally, the current investigation could be evidence to support the antioxidant potential of dexmedetomidine in vitro.