• Asian Pacific Journal of Cancer Prevention
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• v.15 no.12
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• pp.5071-5076
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• 2014

Cholangiocarcinoma (CCA) is one of the aggressive cancers with a very poor prognosis. Several efforts have been made to identify and develop new agents for prevention and treatment of this deadly disease. In the present study, we examined the anticancer effect of luteolin on human CCA, KKU-M156 cells. Sulforhodamine B assays showed that luteolin had potent cytotoxicity on CCA cells with IC50 values of $10.5{\pm}5.0$ and $8.7{\pm}3.5{\mu}M$ at 24 and 48 h, respectively. Treatment with luteolin also caused a concentration-dependent decline in colony forming ability. Consistent with growth inhibitory effects, luteolin arrested cell cycle progression at the G2/M phase in a dose-dependent manner as assessed by flow cytometry analysis. Protein expression of cyclin A and Cdc25A was down-regulated after luteolin treatment, supporting the arrest of cells at the G2/M boundary. Besides evident G2/M arrest, luteolin induced apoptosis of KKU-M156 cells, demonstrated by a distinct sub-G1 apoptotic peak and fluorescent dye staining. A decrease in the level of anti-apoptotic Bcl-2 protein was implicated in luteolin-induced apoptosis. We further investigated the effect of luteolin on JAK/STAT3, which is an important pathway involved in the development of CCA. The results showed that interleukin-6 (IL-6)-induced JAK/STAT3 activation in KKU-M156 cells was suppressed by treatment with luteolin. Treatment with a specific JAK inhibitor, AG490, and luteolin diminished IL-6-stimulated CCA cell migration as assessed by wound healing assay. These data revealed anticancer activity of luteolin against CCA so the agent might have potential for CCA prevention and therapy.

• Korean Journal of Agricultural Science
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• v.49 no.2
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• pp.175-184
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• 2022

The present study investigated the neuroprotective effects of Coreopsis lanceolate extract against hydrogen-peroxide (H₂O₂)-induced oxidative damage and cell death in pheochromocytoma 12 (PC12) cells. Reactive oxygen species (ROS), 2,2'-azinobis (3-ethylbebzothiazoloine-6-sulfonic acid) diammonium salt, and 1,1-diphenyl-2-picrrylhydrazyl radical scavenging activities, as well as the expression levels of proteins associated with oxidative damage and cell death were investigated. According to the results, C. lanceolate extract exhibited inhibitory activity against intracellular ROS generation and cell-damaging effects induced by hydroxyl radicals in a dose-dependent manner. Total phenolic and flavonoid contents were 22.3 mg·g^-1 gallic acid equivalent and 16.2 mg·g^-1 catechin equivalent, respectively. Additionally, a high-performance liquid chromatography (HPLC) assay based on the internal standard method used to detect phenolic compounds. The phenolic compounds identified in C. lanceolata extract contained (+)-catechin hydrate (5.0 ± 0.0 mg·g^-1), ferulic acid (1.6 ± 0.0 mg·g^-1), chlorogenic acid (1.5 ± 0.0 mg·g^-1), caffeic acid (1.2 ± 0.0 mg·g-1), naringin (0.9 ± 0.0 mg·g^-1), and p-coumaric acid (0.5 ± 0.0 mg·g^-1). C. lanceolata extract attenuated pro-apoptotic Bax expression levels and enhanced the expression levels of anti-apoptotic Bcl-2, caspase-3, and caspase-9 proteins. Therefore, C. lanceolata is a potential source of materials with neuroprotective properties against neurodegenerative disorders, such as Alzheimer's and Parkinson's diseases.

• International Journal of Oral Biology
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• v.40 no.1
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• pp.51-61
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• 2015

Shikonin, a major ingredient in the traditional Chinese herb Lithospermumerythrorhizon, exhibits multiple biological functions including antimicrobial, anti-inflammatory, and antitumor effects. It has recently been reported that shikonin displays antitumor properties in many cancers. This study was aimed to investigate whether shikonin could inhibit oral squamous carcinoma cell (OSCC) growth via mechanisms of apoptosis and cell cycle arrest. The effects of shikonin on the viability and growth of OSCC cell line, SCC25 cells were assessed by MTT assay and clonogenic assays, respectively. Hoechst staining and DNA electrophoresis indicated that the shikonin-treated SCC25 cells were undergoing apoptosis. Western blotting, immunocytochemistry, confocal microscopy, flow cytometry, MMP activity, and proteasome activity also supported the finding that shikonin induces apoptosis. Shikonin treatment of SCC25 cells resulted in a time- and dose-dependent decrease in cell viability, inhibition of cell growth, and increase in apoptotic cell death. The treated SCC25 cells showed several lines of apoptotic manifestation as follows: nuclear condensation; DNA fragmentation; reduced MMP and proteasome activity; decrease in DNA contents; release of cytochrome c into cytosol; translocation of AIF and DFF40 (CAD) onto the nuclei; a significant shift in Bax/Bcl-2 ratio; and activation of caspase-9, -7, -6, and -3, as well as PARP, lamin A/C, and DFF45 (ICAD). Shikonin treatment also resulted in down-regulation of the G1 cell cycle-related proteins and up-regulation of $p27^{KIP1}$. Taken together, our present findings demonstrate that shikonin strongly inhibits cell proliferation by modulating the expression of the G1 cell cycle-related proteins, and that it induces apoptosis via the proteasome, mitochondria, and caspase cascades in SCC25 cells.

• The Korean Journal of Physiology and Pharmacology
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• v.20 no.6
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• pp.613-619
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• 2016

Diabetic cardiomyopathy (DCM), a serious complication of diabetes mellitus, is associated with changes in myocardial structure and function. This study sought to explore the ability of insulin-like growth factor-1 (IGF-1) to modulate DCM and its related mechanisms. Twenty-four male Wistar rats were injected with streptozotocin (STZ, 60 mg/kg) to mimic diabetes mellitus. Myocardial fibrosis and apoptosis were evaluated by histopathologic analyses, and relevant proteins were analyzed by Western blotting. Inflammatory factors were assessed by ELISA. Markers of oxidative stress were tested by colorimetric analysis. Rats with DCM displayed decreased body weight, metabolic abnormalities, elevated apoptosis (as assessed by the bcl-2/bax ratio and TUNEL assays), increased fibrosis, increased markers of oxidative stress (MDA and SOD) and inflammatory factors (TNF-${\alpha}$ and IL-$1{\beta}$), and decreased phosphorylation of Akt and glycogen synthase kinase (GSK-$3{\beta}$). IGF-1 treatment, however, attenuated the metabolic abnormalities and myocardial apoptosis, interstitial fibrosis, oxidative stress and inflammation seen in diabetic rats, while also increasing the phosphorylation levels of Akt and GSK-$3{\beta}$. These findings suggest that IGF-1 ameliorates the pathophysiological progress of DCM along with an activation of the Akt/GSK-$3{\beta}$ signaling pathway. Our findings suggest that IGF-1 could be a potential therapeutic choice for controlling DCM.

• Journal of Life Science
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• v.28 no.1
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• pp.50-57
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• 2018

Millettia erythrocalyx, a species of plant in the Fabaceae family, is widely distributed in the tropical and subtropical regions of the world, such as the Indies, China, and Thailand. The antiviral activity of flavonoids from M. erythrocalyx has been reported; however, the antioxidative and anticancer activities of M. erythrocalyx remain unclear. In this study, we evaluated the antioxidative and anticancer effects of ethanol extract of M. erythrocalyx (EEME) and the molecular mechanism of its anticancer activity in human hepatocellular carcinoma HepG2 cells. EEME exhibited significant antioxidative effects, with a concentration at 50% inhibition ($IC_{50}$) value of $2.74{\mu}g/ml$, as measured by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay; moreover, it inhibited cell proliferation in a dose-dependent manner in HepG2 cells. Cell cycle analyses showed that EEME induced HepG2 cell accumulation in the subG1 phase in a dose-dependent manner. EEME also induced apoptosis of HepG2 cells, with increases in apoptotic cells and apoptotic bodies, as detected by Annexin V and 4,6-diamidino-2-phenylindole (DAPI) staining, respectively. Treatment with EEME resulted in increased expression of First apoptosis signal (Fas), a death receptor, and Bcl-2-associated X protein (Bax), a proapoptotic protein, and the activation of caspase-3, 8, and 9, resulting in the cleavage of poly (Adenosine diphosphate-ribose) polymerase (PARP). Collectively, these results suggest that EEME may exert an anticancer effect in HepG2 cells by inducing apoptosis via both the intrinsic and extrinsic pathways.

• Nutrition Research and Practice
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• v.8 no.2
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• pp.132-137
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• 2014

BACKGROUND/OBJECTIVES: In this study, the apoptogenic activity and mechanisms of cell death induced by hexane extract of aged black garlic (HEABG) were investigated in human leukemic U937 cells. MATERIALS/METHODS: Cytotoxicity was evaluated by MTT (3-(4, 5-dimethyl-thiazol-2-yl)-2, 5-diphenyl tetrazoliumbromide) assay. Apoptosis was detected using 4,6-diamidino-2-phenyllindile (DAPI) staining, agarose gel electrophoresis and flow cytometry. The protein levels were determined by Western blot analysis. Caspase activity was measured using a colorimetric assay. RESULTS: Exposure to HEABG was found to result in a concentration- and time-dependent growth inhibition by induction of apoptosis, which was associated with an up-regulation of death receptor 4 and Fas legend, and an increase in the ratio of Bax/Bcl-2 protein expression. Apoptosis-inducing concentrations of HEABG induced the activation of caspase-9, an initiator caspase of the mitochodrial mediated intrinsic pathway, and caspase-3, accompanied by proteolytic degradation of poly(ADP-ribose)-polymerase. HEABG also induced apoptosis via a death receptor mediated extrinsic pathway by caspase-8 activation, resulting in the truncation of Bid, and suggesting the existence of cross-talk between the extrinsic and intrinsic pathways. However, pre-treatment of U937 cells with the caspase-3 inhibitor, z-DEVD-fmk, significantly blocked the HEABG-induced apoptosis of these cells, and increased the survival rate of HEABG-treated cells, confirming that HEABG-induced apoptosis is mediated through activation of caspase cascade. CONCLUSIONS: Based on the overall results, we suggest that HEABG reduces leukemic cell growth by inducing caspase-dependent apoptosis through both intrinsic and extrinsic pathways, implying its potential therapeutic value in the treatment of leukemia.

• Archives of Pharmacal Research
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• v.27 no.1
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• pp.68-76
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• 2004

Mistletoe lectin has been reported to induce apoptosis in different cancer cell lines in vitro and to show antitumor activity against a variety of tumors in animal models. We previously demonstrated the Korean mistletoe lectin (Viscum album var. coloratum, VCA)-induced apoptosis by down-regulation of Bcl-2 and telomerase activity and by up-regulation of Bax through p53- and p21-independent pathway in hepatoma cells. In the present study, we observed the induction of apoptotic cell death through activation of caspase-3 and the inhibition of telomerase activity through transcriptional down-regulation of hTERT in the VCA-treated A253 cells. We also observed the inhibition of telomerase activity and induction of apoptosis resulted from dephosphorylation of Akt in the survival signaling pathways. In addition, combining VCA with the inhibitors of phosphatidylinositol 3-kinase (PI3-kinase) upstream of Akt, wortmannin and LY294002 showed an additive inhibitory effect of telomerase activity. In contrast, the inhibitor of protein phosphatase 2A (PP2A), okadaic acid inhibited VCA-induced dephosphorylation of Akt and inhibition of telomerase activity. Taken together, VCA induces apoptotic cell death through Akt signaling pathway in correlated with the inhibition of telomerase activity and the activation of caspase-3. From these results, together with our previous studies, we suggest that VCA triggers molecular changes that resulting in the inhibition of cell growth and the induction of apoptotic cell death of cancer cells, which suggest that VCA may be useful as chemotherapeutic agent for cancer cells.

• Nutrition Research and Practice
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• v.10 no.1
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• pp.115-124
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• 2016

BACKGROUND/OBJECTIVES: This is the first study to identify common genetic factors associated with the basal metabolic rate (BMR) and body mass index (BMI) in obese Korean women including overweight. This will be a basic study for future research of obese gene-BMR interaction. SUBJECTS/METHODS: The experimental design was 2 by 2 with variables of BMR and BMI. A genome-wide association study (GWAS) of single nucleotide polymorphisms (SNPs) was conducted in the overweight and obesity (BMI > $23kg/m^2$) compared to the normality, and in women with low BMR (< 1426.3 kcal/day) compared to high BMR. A total of 140 SNPs reached formal genome-wide statistical significance in this study (P < $1{\times}10^{-4}$). Surveys to estimate energy intake using 24-h recall method for three days and questionnaires for family history, a medical examination, and physical activities were conducted. RESULTS: We found that two NRG3 gene SNPs in the 10q23.1 chromosomal region were highly associated with BMR (rs10786764; $P=8.0{\times}10^{-7}$, rs1040675; $2.3{\times}10^{-6}$) and BMI (rs10786764; $P=2.5{\times}10^{-5}$, rs10786764; $6.57{\times}10^{-5}$). The other genes related to BMI (HSD52, TMA16, MARCH1, NRG1, NRXN3, and STK4) yielded P < $10{\times}10^{-4}$. Five new loci associated with BMR and BMI, including NRG3, OR8U8, BCL2L2-PABPN1, PABPN1, and SLC22A17 were identified in obese Korean women (P < $1{\times}10^{-4}$). In the questionnaire investigation, significant differences were found in the number of starvation periods per week, family history of stomach cancer, coffee intake, and trial of weight control in each group. CONCLUSION: We discovered several common BMR- and BMI-related genes using GWAS. Although most of these newly established loci were not previously associated with obesity, they may provide new insights into body weight regulation. Our findings of five common genes associated with BMR and BMI in Koreans will serve as a reference for replication and validation of future studies on the metabolic rate.

• BMB Reports
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• v.35 no.1
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• pp.116-126
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• 2002

Nitric oxide (NO), synthesized from L-arginine by NO synthases, is a small, lipophilic, diffusible, highly reactive molecule with dichotomous regulatory roles in many biological events under physiological and pathological conditions. NO can promote apoptosis (pro-apoptosis) in some cells, whereas it inhibits apoptosis (anti-apoptosis) in other cells. This complexity is a consequence of the rate of NO production and the interaction with biological molecules such as metal ion, thiol, protein tyrosine, and reactive oxygen species. Long-lasting overproduction of NO acts as a pro-apoptotic modulator, activating caspase family proteases through the release of mitochondrial cytochrome c into cytosol, up-regulation of the p53 expression, and alterations in the expression of apoptosis-associated proteins, including the Bcl-2 family. However, low or physiological concentrations of NO prevent cells from apoptosis that is induced by the trophic factor withdrawal, Fas, $TNF{\alpha}$/ActD, and LPS. The anti-apoptotic mechanism is understood on the basis of gene transcription of protective proteins. These include: heat shock protein, hemeoxygenase, or cyclooxygenase-2 and direct inhibition of the apoptotic executive effectors caspase family protease by S-nitrosylation of the cysteine thiol group in their catalytic site in a cell specific way. Our current understanding of the mechanisms by which NO exerts both pro- and anti-apototic action is discussed in this review article.

• Natural Product Sciences
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• v.24 no.3
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• pp.148-154
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• 2018

Chronic oxidative stress due to the accumulation of reactive oxygen species (ROS) in neuronal cells ultimately leads to neurodegenerative diseases. The use of natural therapies for the prevention of ROS-induced cell damage and for the treatment of neurodegenerative disorders has shown promising results. In this study, we evaluated the neuroprotective effects of the ethyl acetate (EtOAc) fraction of A. okamotoanum against the hydrogen peroxide ($H_2O_2$)-induced oxidative stress in C6 glial cells. Results show that cell viability was decreased in cells incubated with $H_2O_2$, whereas the addition of EtOAc fraction treatments in such cells significantly increased viability. The EtOAc fraction showed the highest inhibitory activity against ROS production and it also decreased the expressions of inflammatory proteins including cyclooxygenase-2, inducible nitric oxide synthase and interleukin-$1{\beta}$. Furthermore, the EtOAc fraction inhibited apoptosis by regulating the protein expressions cleaved caspase -9, -3, poly ADP ribose polymerase, Bax and Bcl-2. Therefore, these results show that the EtOAc fraction of A. Okamotoanum exhibits neuroprotective effects against $H_2O_2$ induced oxidative damage by regulating the inflammatory reaction and apoptotic pathway.