• Journal of Nutrition and Health
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• v.27 no.6
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• pp.552-562
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• 1994

The study was designed to observe the effect of different dietary fats on the incidence of colorectal tumor and in vivo cell proliferation in colon carcinogenesis. Male Sprague Dawley rats were intrarectally infused with chemical carcinogen(methylnitrosourea, MNU) and fed 16%(w/w) fat diet containing one of dietary fats(beef tallow, corn oil, perilla oil) for 30 weeks. To measure in vivo cell proliferation, the incorporation of 5-bromo-2-deoxyuridine(BrdU) into DNA was localized using the monoclonal anti-BrdU antibody. Large number of tumors were found in the distal colon and tumor incidence was increased in the order of perilla oil(57.7%)$\alpha$-linolenic acid rich in perilla oil could have a protective effect against colon cancer compared to saturated fatty acid or n-6 linoleic acid.

• Journal of Microbiology and Biotechnology
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• v.28 no.4
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• pp.645-651
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• 2018

The carcinogenicity of chemicals in the environment is a major concern. Recently, numerous studies have attempted to develop methods for predicting carcinogenicity, including rodent and cell-based approaches. However, rodent carcinogenicity tests for evaluating the carcinogenic potential of a chemical to humans are time-consuming and costly. This study focused on the development of an alternative method for predicting carcinogenicity using quantitative PCR (qPCR) and colon cancer stem cells. A toxicogenomic method, mRNA profiling, is useful for predicting carcinogenicity. Using microarray analysis, we optimized 16 predictive gene sets from five carcinogens (azoxymethane, 3,2'-dimethyl-4-aminobiphenyl, N-ethyl-n-nitrosourea, metronidazole, 4-(n-methyl-n-nitrosamino)-1-(3-pyridyl)-1-butanone) used to treat colon cancer stem cell samples. The 16 genes were evaluated by qPCR using 23 positive and negative carcinogens in colon cancer stem cells. Among them, six genes could differentiate between positive and negative carcinogens with a p-value of ${\leq}0.05$. Our qPCR-based prediction system for colon carcinogenesis using colon cancer stem cells is cost- and time-efficient. Thus, this qPCR-based prediction system is an alternative to in vivo carcinogenicity screening assays.

• Nutritional Sciences
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• v.5 no.4
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• pp.175-183
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• 2002

To compare the effects of various types of dietary fiber on microbial production of short-chain fatty acids (SCFA) and on colon cell proliferation which is used as an intermediate biomarker for colon carcinogenesis, groups of 10 male Sprague-Dawley rats were fed one of four fiber-supplemented diets (6% cellulose, 6% pectin, 6% polydextrose, and a mixture of 3% cellulose and 3% polydextrose) for three weeks. As a control, a fiber-free diet was fed to a separate group of 10 rats. Cell proliferation was measured by in vivo incorporation of bromodeoxyuridine into DNA in the proximal and distal colon, respectively. Luminal concentrations of SCFA were measured by gas chromatography. Dietary fiber significantly influenced microbial production of SCFA in the colon; pectin supplementation produced the highest concentrations of luminal SCFA in both the proximal and distal colon (p<0.05). The degree of individual SCFA production was characterized by a relatively higher increase in butyrate production by the pectin-supplemented diet, and in propionate production by the polydextrose-supplemented diet, resulting in alterations of the molar ratios of acetate, propionate and butyrate. There were significant differences in colon cell proliferation among the diet groups; the pectin-supplemented diet produced a significantly higher effect on cell proliferation of distal colonic epithelial cells (p＜0.05), and the polydextrose-supplemented diet produced an intermediate effect compared to the fiber-free or cellulose-supplemented diet. Increased cell proliferation was correlated to increased luminal concentrations of butyrate in the proximal colon and to increased luminal concentrations of propionate and butyrate in the distal colon (p<0.05). Therefore, these data suggest that dietary fiber may modulate colon cell proliferation by altering luminal SCFA concentrations, particularly butyrate and perhaps propionate. In addition, the present study is the first finding that has demonstrated a relative increase in colon cell proliferation due to supplementation with polydextrose, suggesting that the overuse of this artificially synthesized polysaccharide in food processing technology needs to be carefully evaluated from the public health point of view.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.20
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• pp.8581-8586
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• 2014

Activin is a multifunctional growth and differentiation factor of the growth factor-beta (TGF-${\beta}$) superfamily, which inhibits the proliferation of colon cancer cells. It induces phosphorylation of intracellular signaling molecules (Smads) by interacting with its type I and type II receptors. Previous studies showed that human activin receptor-interacting protein 2 (hARIP2) can reduce activin signaling by interacting with activin type II receptors; however, the activity of hARIP2 in colon cancer has yet to be detailed. In vitro, overexpression of hARIP2 reduced activin-induced transcriptional activity and enhanced cell proliferation and colony formation in human colon cancer HCT8 cells and SW620 cells. Also, hARIP2 promoted colon cancer cell apoptosis, suggesting that a vital role in the initial stage of colon carcinogenesis. In vivo, immunohistochemistry revealed that hARIP2 was expressed more frequently and much more intensely in malignant colon tissues than in controls. These results indicate that hARIP2 is involved in human colon tumorigenesis and could be a predictive maker for colon carcinoma aggressiveness.

• Preventive Nutrition and Food Science
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• v.19 no.2
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• pp.82-88
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• 2014

Yam (Dioscorea batatas Decne.) has long been used as a health food and oriental folk medicine because of its nutritional fortification, tonic, anti-diarrheal, anti-inflammatory, antitussive, and expectorant effects. Reactive oxygen species (ROS), which are known to be implicated in a range of diseases, may be important progenitors of carcinogenesis. The aim of this study was to investigate the modulatory effect of yam on antioxidant status and inflammatory conditions during azoxymethane (AOM)-induced colon carcinogenesis in male F344 rats. We measured the formation of aberrant crypt foci (ACF), hemolysate antioxidant enzyme activities, colonic mucosal antioxidant enzyme gene expression, and colonic mucosal inflammatory mediator gene expression. The feeding of yam prior to carcinogenesis significantly inhibited AOM-induced colonic ACF formation. In yam-administered rats, erythrocyte levels of glutathione, glutathione peroxidase (GPx), and catalase were increased and colonic mucosal gene expression of Cu/Zn-superoxide dismutase (SOD), Mn-SOD, and GPx were up-regulated compared to the AOM group. Colonic mucosal gene expression of inflammatory mediators (i.e., nuclear factor kappaB, inducible nitric oxide synthase, cyclooxygenase-2, tumor necrosis factor alpha, and interleukin-1beta) was suppressed by the yam-supplemented diet. These results suggest that yam could be very useful for the prevention of colon cancer, as they enhance the antioxidant defense system and modulate inflammatory mediators.

• Korean Journal of Veterinary Pathology
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• v.5 no.1
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• pp.23-28
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• 2001

This study was conducted to assess the chemopreventive effects of sodium selenite in the rat medium-term multi-organ bioassay using a DMBDD model (DEN+MNU+BBN+DMH+DHPN). Seventy five,6-week-old, male SD rats were divided into 3 groups. The animals in group 1 received DEN(diethylnitrosamine,100 mg/kg bw, single i.p., in saline), MNU (N-methyl-nitrosourea,20 mg/kg bw, i.p.,4 times for 2 weeks), BBN (N-butyl-N-(4-hydroxybutyl) nitrosamine, 0.2% in drinking water for 2 weeks), DMH (1,2-dimethylhydrazine, 40 mg/kg bw, s.c., in saline.4 times (or 2 weeds), and DHPN (N-bis(2-hydroxy-pro-pal)nitrosamine,0.1% in drinking water for 2 weeks), then were placed on sodium selenite (4 ppm in drinking water) for 22 weeks from weeks 4 to 26. The animals in group 2 were given DMBDD alone. The animals in group 3 were given sodium selenite alone. Animals were sacrificed at week 12 for ACF quantitative analysis and at week 26 for tumor induction. The body weights in the group 1 were significantly decreased compared with those of group 2. The tumor multiplicities of large intestine in the group 1 were significantly decreased compared with those of group 2 (P<0.05). These results indicate that sodium selenite may have a potential as chemopreventive agents of colon carcinogenesis.

• Nutritional Sciences
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• v.7 no.2
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• pp.76-82
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• 2004

Pine needles are known as a traditional medicine and their ingestion has been shown to be beneficial to human beings. Following induction of the neoplastic process in rats by azoxymethane (AOM), we determined the effects of pine needle supplementation on colon carcinogenesis and on antioxidant systems in the blood and liver. Five week old male Fisher 344 rats were injected with AOM (15 mg/kg) once a week for two weeks. After the second injection, 18 rats were randomly assigned into two groups and were fed a casein-based high-fat diet (120 g fat and 1 g cholesterol/kg diet) with or without pine needle powder (10%w/w). After 6 weeks, rats receiving pine needle powder showed a 40% lower incidence of the number of colonic preneoplastic lesions (aberrant crypts) and a 52% lower incidence of aberrant crypt foci (p<0.01). A significantly elevated level of erythrocyte catalase activity was observed in the pine needle supplemented group (17.4$\pm$1.1 vs. 24.5$\pm$1.5, p<0.01). Pine needle supplementation also increased liver glutathione peroxidase activity (7.5$\pm$0.6 vs. 14.6$\pm$0.6, p<0.01). Other antioxidant parameters such as erythrocyte glutathione peroxidase, liver catalase activity, and plasma total antioxidant potential (TRAP), showed no statistical differences between the two groups. Our data demonstrate that pine needle supplementation improves the antioxidant system and suppresses the formation of colonic preneoplastic lesions in AOM-treated rats. This result provides additional insights into the chemo-preventative properties of pine needles.

• Biomolecules & Therapeutics
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• v.23 no.5
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• pp.471-478
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• 2015

Colon cancer is considered as the precarious forms of cancer in many developed countries, with few to no symptoms; the tumor is often diagnosed in the later stages of cancer. Monoterpenes are a major part of plant essential oils found largely in fruits, vegetables and herbs. The cellular and molecular activities show therapeutic progression that may reduce the risk of developing cancer by modulating the factors responsible for colon carcinogenesis. Colon cancer was induced with DMH with a dose of (20 mg/Kg/body weight) for 15 weeks by subcutaneous injection once in a week. Myrtenal treatment was started with (230 mg/Kg/body weight) by intragastric administration, one week prior to DMH induction and continued till the experimental period of 30 weeks. The Invivo results exhibit the elevated antioxidant and lipid peroxidation levels in DMH treated animals. The Histopathological analysis of colon tissues well supported the biochemical alterations and inevitably proves the protective role of Myrtenal. Treatment with myrtenal to cancer bearing animals resulted in a remarkable increase in the inherent antioxidants and excellent modulation in the morphological and physiological nature of the colon tissue. It is thus concluded that myrtenal exhibits excellent free radical scavenging activity and anticancer activity through the suppression of colon carcinoma in Wistar albino rats.

• Toxicological Research
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• v.23 no.4
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• pp.321-330
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• 2007

Garlic (Allium sativum L.) with the food supplement material and medicine was used traditionally in Asia and Europe. Epidemiological studies revealed that the intake of garlic reduced incidences of various cancer including digestive system. The present study was designed to investigate the effect of garlic ethanol extract on the development of colonic aberrant crypt foci (ACF) induced by 1,2-dimethylhydrazine (DMH) in male F344 rats. Five-week-old rats were given four times for two weeks to subcutaneous injections by DMH (30 mg/kg body weight) to induce ACF. The animals were divided into groups that fed diet containing garlic ethanol extract at five different doses (0.1, 0.2, 0.5, 2, 5%), respectively, animals were evaluated for the total number of ACF and total aberrant crypts (AC) per colon detected from methylene blue-stained rat colon. ACF were formed in animals in DMH-treated group. The feeding suppressed potently the appearance ACF in the colon of rats. Especially, fed diet containing garlic ethanol extract at intermediate dose (0.5%) significantly reduced the number of ACF and AC per colon (p < 0.05). Garlic ethanol extract inhibited DMH-induced overexpression of Activator Protein-1 (AP-1) and ${\beta}-catenin$ genes related to cell proliferation that also upregulated the expression of p21Waf1/Cip1 mRNA, a cell cycle-regulating gene. These results suggested that garlic ethanol extract may inhibit ACF formation, ${\beta}-catenin$ gene as the early preneoplastic marker of malignant potential in the process of colon carcinogenesis.

• Journal of Nutrition and Health
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• v.51 no.1
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• pp.14-22
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• 2018

Purpose: Colorectal cancer, which is one of the most commonly diagnosed cancers in developing and developed countries, is highly associated with obesity. The association is largely attributed to changes to western style diets in those countries containing high-fat and high-energy. Luteolin (LUT) is a known potent inhibitor of inflammation, obesity, and cancer. In this study, we investigated the effects of LUT on chemical-induced colon carcinogenesis in high fat diet (HFD)-fed obese mice. Methods: Five-week-old male C57BL/6 mice received a single intraperitoneal injection of azoxymethane (AOM) at a dose of 12.5 mg/kg body weight. Mice were then divided into four groups (n = 10) that received one of the following diets for 11 weeks after the AOM injection: normal diet (ND); HFD; HFD with 0.0025% LUT (HFD LL); HFD with 0.005% LUT (HFD HL). One week after AOM injection, animals received 1~2% dextran sodium sulfate in their drinking water over three cycles consisting of five consecutive days each that were separated by 16 days. Results: Body weight, ratio of colon weight/length, and tumor multiplicity increased significantly in the HFD group compared to the ND group. Luteolin supplementation of the HFD significantly reduced the ratio of colon weight/length and colon tumors, but not body weight. The levels of plasma $TNF-{\alpha}$ and colonic expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 protein increased in response to HFD, but were suppressed by LUT supplementation. Immunohistochemistry analysis also showed that iNOS expression was decreased by LUT. Conclusion: Consumption of LUT may reduce the risk of obesity-associated colorectal cancer by suppression of colonic inflammation.