• Food Science and Biotechnology
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• v.15 no.6
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• pp.942-947
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• 2006

The effect of oat bran extracts on the formation of aberrant crypt foci (ACF) in the colon induced by 1,2-dimethylhydrazine (DMH) was studied in F344 male rats. Extracts were prepared using various combinations of temperature (40, 45, 50, 55, or 60$^{\circ}C:\;X_1$), ethanol concentration (0,5, 10, 15, or 20%: $X_2$), and pH (5, 6, 7, 8, or 9: $X_3$). Among the various extracts tested, one ethanol extract (EE; $45^{\circ}C$, 15% ethanol at pH 6) and one water extract (WE; $50^{\circ}C$ at pH 5) were selected based on their in vitro antitumor activity. The animals were fed with basal diet alone or basal diet supplemented with 0.25 or 0.5% of EE or WE for 6 weeks. During the initial 2 weeks of the 6-week test period, the rats were subcutaneously injected with DMH (30 mg/kg) 4 times for the induction of ACF. DMH induced an average of 322.7 and 142.9 aberrant crypts (AC) and ACF, respectively. A low dose (0.25%) of EE (containing 38.3% ${\beta}$-glucan) and WE (containing 22.8% ${\beta}$-glucan) greatly reduced the numbers of DMH-induced AC and ACF. Significantly, ACF consisting of more than 3 AC were reduced by half in which the effect of EE, containing a higher concentration of ${\beta}$-glucan, was superior to that of WE. These results demonstrate that oat bran extracts may confer protection against colon carcinogenesis.

• 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 Food Hygiene and Safety
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• v.23 no.3
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• pp.264-270
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• 2008

Phytic acid(PA) (Inositol hexaphosphate, $IP_6$) is a naturally occurring polyphosphorylated carbohydrate that is present in substantial amounts in almost all plants and mammalian cells. Recently PA has received much attention for its role in anticancer activity. In the present study, the preventive effects of PA on colon carcinogenesis were investigated. Six-week old Fisher 344 male rats were fed a AIN-93G purified diet and PA(0.5% or 2% PA in water) for 8 weeks. The animals received two ($1^{st}\;and\;2^{nd}$ week) injections of azoxymethane(AOM, 15 mg/kg b.w.) to induce colonic aberrant crypt foci(ACF). After sacrifice, the total numbers of aberrant crypts(AC) and ACF in colonic mucosa were examined after staining with methylene blue. Blood and serum were analyzed with a blood cell differential counter and an automatic serum analyzer. AOM induced the total numbers of $142.3{\pm}22.3$ ACF/colon and $336.6{\pm}55.1$ AC/colon. PA at the doses of 0.5 and 2% decreased the numbers of ACF and AC/colon in a dose-dependent manner. The numbers of ACF/colon and AC/colon by PA at the dose of 0.5% were $124.4{\pm}28.5\;and\;302.7{\pm}67.3$, respectively. PA at the dose of 2% significantly decreased the ACF and AC numbers to $109{\pm}18.1\;and\;254.8{\pm}50.6$, respectively(p<0.01). Especially, 2% PA significantly reduced the number of large ACF(${\geq}4$ AC/ACF) from $26.8{\pm}6.2$ ACF/colon to $15{\pm}6.7$ ACF/colon(p<0.01). Although some parameters in blood counts and serum chemistry were changed compared with the control, no specific toxicity was found. These findings suggest that phytic acid can be a chemopreventive agent for colon carcinogenesis resulting from inhibition of the development of ACF in the F344 rat.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.3
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• pp.947-952
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• 2015

The aim of this study was to evaluate the effects of grape juice on colon carcinogenesis induced by azoxymethane (AOM) and expression of NF-kB, iNOS and TNF-${\alpha}$. Methods: Forty male Wistar rats were divided into 7 groups: G1, control; G2, 15 mg/kg AOM; G3, 1% grape juice 2 weeks before AOM; G4, 2% grape juice 2 weeks before AOM; G5, 1% grape juice 4 weeks after AOM; G6, 2% grape juice 4 weeks after AOM; G7, 2% grape juice without AOM. Histological changes and aberrant crypt foci (ACF) were studied, while RNA expression of NF-kB, TNF- and iNOS was evaluated by qPCR. Results: The number of ACF was higher in G2, and G4 presented a smaller number of crypts per focus than G5 (p=0.009) and G6. Small ACF (1-3) were more frequent in G4 compared to G2, G5 and G6 (p=0.009, p=0.009 and p=0.041, respectively). RNA expression of NF-kB was lower in G3 and G4 compared to G2 (p=0.004 and p=0.002, respectively). A positive correlation was observed between TNF-${\alpha}$ and NF-kB gene expression (p=0.002). In conclusion, the administration of 2% grape juice before AOM reduced the crypt multiplicity, attenuating carcinogenesis. Lower expression of NF-kB was observed in animals exposed to grape juice for a longer period of time, regardless of concentration.

• Journal of Veterinary Science
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• v.23 no.5
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• pp.74.1-74.16
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• 2022

Background: Previous studies have presented evidence to support the significant association between red meat intake and colon cancer, suggesting that heme iron plays a key role in colon carcinogenesis. Epigallocatechin-3-gallate (EGCG), the major constituent of green tea, exhibits anti-oxidative and anti-cancer effects. However, the effect of EGCG on red meat-associated colon carcinogenesis is not well understood. Objectives: We aimed to investigate the regulatory effects of hemin and EGCG on colon carcinogenesis and the underlying mechanism of action. Methods: Hemin and EGCG were treated in Caco2 cells to perform the water-soluble tetrazolium salt-1 assay, lactate dehydrogenase release assay, reactive oxygen species (ROS) detection assay, real-time quantitative polymerase chain reaction and western blot. We investigated the regulatory effects of hemin and EGCG on an azoxymethane (AOM) and dextran sodium sulfate (DSS)-induced colon carcinogenesis mouse model. Results: In Caco2 cells, hemin increased cell proliferation and the expression of cell cycle regulatory proteins, and ROS levels. EGCG suppressed hemin-induced cell proliferation and cell cycle regulatory protein expression as well as mitochondrial ROS accumulation. Hemin increased nuclear factor erythroid-2-related factor 2 (Nrf2) expression, but decreased Keap1 expression. EGCG enhanced hemin-induced Nrf2 and antioxidant gene expression. Nrf2 inhibitor reversed EGCG reduced cell proliferation and cell cycle regulatory protein expression. In AOM/DSS mice, hemin treatment induced hyperplastic changes in colon tissues, inhibited by EGCG supplementation. EGCG reduced the hemin-induced numbers of total aberrant crypts and malondialdehyde concentration in the AOM/DSS model. Conclusions: We demonstrated that EGCG reduced hemin-induced proliferation and colon carcinogenesis through Nrf2-inhibited mitochondrial ROS accumulation.