• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.5
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• pp.671-679
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• 2016

Extracts from spinach, cabbage, and onion are known to possess various instructive characteristics, including antioxidant and anti-inflammation activities. Spinach, cabbage, and onion are consumed worldwide and represent important sources of dietary phytochemicals with proven antioxidant properties, such as flavonoids and phenolic acids. Food-derived flavonoids and phenolic compounds are expected to be promising drugs for cancer. In the present study, we investigated the effects of methanol extracts of spinach, cabbage, and onion on cell proliferation and apoptosis in human gastric and breast cancer cells. Proliferation rates of AGS, MDA-MB-231, and SK-BR-3 cells were determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The methanol extracts of spinach, cabbage, and onion inhibited proliferation of cancer cells in a dose-dependent manner. 4',6-Diamidino-2-phenylindole (DAPI) staining revealed that chromatin condensation significantly increased compared with the control. In the results of MTT assay and DAPI staining, onion extract was the most effective in inhibiting cancer cell proliferation and apoptosis. To assess changes in protein expression level by onion extract, we identified Bax (pro-apoptotic), Bcl-2 (anti-apoptotic), and poly(ADP-ribose) polymerase (PARP) protein by western blot analysis. The expression of Bax and cleaved-PARP increased, whereas expression of Bcl-2 was decreased compared with the control. These results suggest that spinach, cabbage, and onion extracts suppressed growth of human gastric cancer AGS, human breast cancer MDA-MB-231, and SK-BR-3 cells through induction of apoptosis. Among the extracts, onion extract had stronger anti-cancer and apoptosis induction effects than spinach and cabbage extracts. Further, onion extract more effectively induced apoptosis of human gastric cancer cells than human breast cancer cells. Therefore, further studies are needed to determine the anti-cancer effects of onion extracts in vivo. Onion extract can be developed as a chemopreventive or therapeutic agent for gastric cancer.

• Biomolecules & Therapeutics
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• v.16 no.3
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• pp.270-276
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• 2008

In this study we investigated the effects of Magnolia Bark (MB) extract and its constituents, such as honokiol and magnolol, on gastritis in rats and the growth of human gastric cancer cells. The MB extract, honokiol, and magnolol showed the acid-neutralizing capacities, the antioxidant activities, and the inhibitory effect on the growth of Helicobacter pylori (H. pylori.) at the dose of $50\;{\mu}g/ml$ and over, which is equivalent to that of ampicillin ($100\;{\mu}g/ml$). Honokiol and magnolol had no significant cytotoxicity to human gastric caner cells (AGS and SNU638). However, the MB extract had cytotoxic activity against AGS gastric cancer cell. The MB extract, honokiol, and magnolol significantly inhibited HCI-ethanol-induced gastric lesions without clear change of mucus content. In pylorus ligated rats, honokiol significantly decreased the volume of gastric secretion and gastric acid output, and increased the pH. Magnolol increased the mucus content to almost the same as the control group at oral doses of 50 mg/kg. Therefore, we could guess that antigastritic action of honokiol and magnolol may be associated with the antioxidant activities, acid-neutralizing capacities, inhibition of secretion in gastric acid, and anti-H. pylori action. From these results, we could suggest that MB extract and its constituents, such as honokiol and magnolol, may be useful for the treatment and/or protection of gastritis.

• Food Science and Biotechnology
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• v.16 no.6
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• pp.873-878
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• 2007

In this study, we isolated porphyran was isolated from the red seaweed Porphyra yezoensis and assessed in terms of in vitro anti-proliferative activity. Sequential anion-exchange and gel-filtration chromatography led to purification of 3 porphyrans of different molecular masses, which contained <$50\;{\mu}g/mL$ protein and >$10\;{\mu}g/mL$ porphyran. Crude porphyran inhibited cell growth in a dose-dependent manner (0-5 mg/mL). When HT-29 colon cancer cells and AGS gastric cancer cells were cultured with various concentrations of the purified porphyran, cancer cell growth was inhibited by 50% at a low concentration (5 or $10\;{\mu}g/mL$). Furthermore, the polysaccharide portion of the porphyran preparation, rather than the protein portion, is the most effective at inhibiting cancer cell proliferation via apoptosis, as indicated by increased caspase-3 activity. Our results indicate that purified porphyran has significant in vitro anti-proliferative activity (p<0.05).

• Journal of Digestive Cancer Research
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• v.5 no.2
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• pp.105-112
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• 2017

Background: The expression of miRNAs in response to Helicobacter pylori infection has not been well explored. The aims of this study were to evaluate the H. pylori associated miRNAs in the gastric epithelial cells. Methods: We investigated gastric epithelial cell-line (HS3C) exposed H. pylori over 3 months and AGS cell-line (AGS) exposed H. pylori for 6 hour. After the extraction of miRNA from these cell-lines, microarray and real time PCR were performed to confirm the alteration of expression. Results: All 12 miRNAs chosen for real-time PCR are based on the result of microarray and their potential functions related to H. pylori infection. miR-21, miR-221, miR-222 were upregulated in the H. pylori infected AGS cell for 6 hours and HS3C cells. miR-99b, miR-200b, miR-203b and miR-373 were downregulated in the H. pylori infected AGS cell for 6 hours and HS3C cells. miR-23a, miR-23b, miR-125b, miR-141 and miR-155 were upregulated in HS3C cell line but not in H. pylori infected AGS cell for 6 hours. Conclusion: miR-21, miR-99b, miR-125b, miR-200b, miR-203b, miR-221, miR-222, and miR-373 are supposed to be related with oncogenesis of H. pylori infection. Further studies are needed for the evaluation of the function of these confirmed miRNAs.

• Preventive Nutrition and Food Science
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• v.12 no.2
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• pp.84-88
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• 2007

In this study, we investigated antimutagenic and anticancer activities of leaf mustard (LM, Brassica juncea) and leaf mustard kimchi (LMK) during their fermentation period. Methanol extracts were prepared from raw mustard, brined leaf mustard in 10% Gueun salt solution for 2 hrs, leaf mustard fermented at 15$^{\circ}C$ for 5 days after brined in 10% Guenun salt solution for 2 hrs (Fr-LM), fresh leaf mustard kimchi (Fresh-LMK) and optimally ripened leaf mustard kimchi fermented at 5$^{\circ}C$ for 30 days (OR-LMK). OR-LMK showed the strongest inhibitory activities against the mutagenicities induced by aflatoxin B1 in Salmonella Typhimurium TA100. LMs and LMKs inhibited the survival or growth of AGS human gastric adenocarcinoma cells and HT-29 human colon carcinoma cells in MTT assay and growth inhibition test. Among the extracts, OR-LMK and FR-LM exhibited strong antiproliferative effect against cancer cells, especially HT-29 cells. DAPI staining assay showed that OR-LMK induced apoptosis cell death of HT-29 cells in a dose-dependent manner. These results suggest that leaf mustards and leaf mustard kimchi have chemopreventive activities.

• Journal of Life Science
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• v.20 no.4
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• pp.528-534
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• 2010

Garlic (Allium sativum) has been well-known as a folk remedy for a variety of ailments since ancient times, and it is well documented that enhanced garlic consumption leads to a decrease in incidences of cancer. Tight junctions (TJs) are critical structures for the maintenance of cellular polarity, acting as paracellular permeability barriers and playing an essential role in regulating the diffusion of fluid, electrolytes and macromolecules through the paracellular pathway. Matrix metalloproteinases (MMPs) have been implicated as possible mediators of invasiveness and metastasis in some cancers. In this study, we investigated the potential effects of water extract of aged black garlic (ABG) on the correlation between tightening of TJs and anti-invasive activity in human gastric carcinoma AGS cells. The inhibitory effects of ABG on cell motility and invasiveness were found to be associated with increased tightness of TJs, which was demonstrated by an increase in transepithelial electrical resistance. Additionally, the activities of MMP-2 and -9 in AGS cells were inhibited by treatment with ABG, and this was also correlated with a decrease in the expression of their mRNA and proteins. Furthermore, RT-PCR and immunoblotting results indicated that ABG repressed the levels of the claudin proteins, major components of TJs that play a key role in the control and selectivity of paracellular transport. In conclusion, these results suggest that ABG treatment may inhibit tumor metastasis and invasion, and therefore may act as a dietary source to decrease the risk of developing cancer.

• BMB Reports
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• v.55 no.7
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• pp.348-353
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• 2022

Gastrointestinal cancer is associated with a high mortality rate. Here, we report that the splice variant of NRP/B contributes to tumorigenic activity in highly malignant gastric cancer through dissociation from the tumor repressor, HDAC5. NRP/B mRNA expression is significantly higher in the human gastric cancer tissues than in the normal tissues. Further, high levels of both the NRP/B splice variant and Lgr5, but not the full-length protein, are found in highly tumorigenic gastric tumor cells, but not in non-tumorigenic cells. The loss of NRP/B markedly inhibits cell migration and invasion, which reduces tumor formation in vivo. Importantly, the inhibition of alternative splicing increases the levels of NRP/B-1 mRNA and protein in AGS cells. The ectopic expression of full-length NRP/B exhibits tumor-suppressive activity, whereas NRP/B-2 induces the noninvasive human gastric cancer cells tumorigenesis. The splice variant NRP/B-2 which loses the capacity to interact with tumor repressors promoted oncogenic activity, suggesting that the BTB/POZ domain in the N-terminus has a crucial role in the suppression of gastric cancer. Therefore, the regulation of alternative splicing of the NRP/B gene is a potential novel target for the treatment of gastrointestinal cancer.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.7
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• pp.907-913
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• 2012

Piceatannol (trans-3,4,3',5'-tetrahydroxystilbene) is a polyphenol detected in grapes, rhubarb, and sugarcane. Although recent experimental data revealed that this compound is known to exhibit immunosuppressive and antitumorigenic activities in several cell lines, the molecular mechanisms underlying anticancer activity are poorly understood. In the present study, we investigated possible further mechanisms by which piceatannol exerts its anti-proliferative action in cultured human gastric cancer AGS cells. Piceatannol treatment resulted in the inhibition of growth and G1 arrest of the cell cycle in a concentration-dependent manner, as determined by MTT assay and flow cytometry analysis. The induction of G1 arrest by piceatannol was associated with the modulation of cyclin-dependent kinases (Cdks) and cyclins, up-regulation of the expression of Cdk inhibitor p21 (WAF1/CIP1) in both transcriptional and translational levels, and the inhibition of phosphorylation of retinoblastoma proteins and E2F1 expression. In addition, piceatannol treatment caused a progressive decrease in the expression levels of cyclooxygenase (COX)-2 without significant changes in the levels of COX-1, which was correlated with a decrease in prostaglandin $E_2$ synthesis.

• Biomolecules & Therapeutics
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• v.24 no.5
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• pp.501-509
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• 2016

Shikonin, which derives from Lithospermum erythrorhizon, has been traditionally used against a variety of diseases, including cancer, in Eastern Asia. Here we determined that shikonin inhibits proliferation of gastric cancer cells by inducing apoptosis. Shikonin's biological activity was validated by observing cell viability, caspase 3 activity, reactive oxygen species (ROS) generation, and apoptotic marker expressions in AGS stomach cancer cells. The concentration range of shikonin was 35-250 nM with the incubation time of 6 h. Protein levels of Nrf2 and p53 were evaluated by western blotting and confirmed by real-time PCR. Our results revealed that shikonin induced the generation of ROS as well as caspase 3-dependent apoptosis. c-Jun-N-terminal kinases (JNK) activity was significantly elevated in shikonin-treated cells, thereby linking JNK to apoptosis. Furthermore, our results revealed that shikonin induced p53 expression but repressed Nrf2 expression. Moreover, our results suggested that there may be a co-regulation between p53 and Nrf2, in which transfection with siNrf2 induced the p53 expression. We demonstrated for the first time that shikonin activated cell apoptosis in AGS cells via caspase 3- and JNK-dependent pathways, as well as through the p53-Nrf2 mediated signal pathway. Our study validates in partly the contribution of shikonin as a new therapeutic approaches/agent for cancer chemotherapy.

• Food Science and Preservation
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• v.23 no.1
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• pp.104-109
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• 2016

The purpose of this study was to evaluate the inhibitory effect of commercial Makgeolli on tumor growth in human gastric adenocarcinoma cells (AGS) in a xenograft cancer model, transplanted with AGS cells. Commercial Makgeolli was first dealcoholized by evaporation and used as the test sample. We detected a significant increase in the volume and weight of tumor in nude mice (induction) that were transplanted with AGS cells. Administration of $100mg/kg{\cdot}day$ group (ML), and $500mg/kg{\cdot}day$ group (MH) dealcoholized commercial Makgeolli significantly decreased tumor growth. In this study, 5-FU $18mg/kg{\cdot}day$ was used as a positive control for tumor growth inhibition. Additionally, determination of the body weight of both the groups revealed no side effects after the administration of dealcoholized commercial Makgeolli. Using the cell culture system, we also evaluated the effect of dealcoholized commercial Makgeolli on caspase-3/7 activity in the AGS cells. Treatment with dealcoholized commercial Makgeolli increased the activation of caspase-3/7 and the apoptotic markers in AGS cells in a dose-dependent manner. Therefore, dealcoholized commercial Makgeolli can be used for cancer prevention.