The Effects of Coffee on Conjugation Reactions in Human Colon Carcinoma Cells

Okamura, Shingo; Suzuki, Keiko; Yanase, Masayo; Koizumi, Masumi; Tamura, Hiro Omi

doi:10.1248/bpb.28.271

Cited by 21 publications

(20 citation statements)

References 14 publications

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“…The cDNA levels were normalized by b-actin, assessed by quantitative real-time PCR as described previously. 6) Quantitative real-time-PCR was performed with an ABI-Prism 7700 thermal cycler using a SYBR green PCR core reagent kit (Applied Biosystems, Wharmington, U.K.). Calculations of the initial amounts of mRNA were performed according to the cycle threshold method.…”

Section: Methodsmentioning

confidence: 99%

“…Previously we have investigated such herb-drug interactions at the level of conjugation. 5,6) We have also recently established an assay system for conjugation reactions of 1-naphthol using a human adenocarcinoma cell line, Caco-2.7) In our current study, to elucidate the possible interaction of both turmeric and curcumin with the conjugation pathways in cells, which in many cases are involved in the activation of procarcinogens, we measured their effects on the conjugation activity of 1-naphthol in Caco-2 cells. …”

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confidence: 99%

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Turmeric and Curcumin Modulate the Conjugation of 1-Naphthol in Caco-2 Cells

Naganuma

Saruwatari

Okamura

et al. 2006

Biological & Pharmaceutical Bulletin

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Turmeric is the powdered dry rhizome of the plant Curcuma longa and has been widely used as a coloring agent, as a spice and has been utilized in the treatment of inflammatory conditions and other diseases.1) Curcumin is a yellow pigment and is the major anti-oxidant and anti-inflammatory constituent of turmeric. It is present in curry and mustard, and it is used extensively in Asian countries and in traditional medicines. Curcumin and/or turmeric have both been shown to possess cancer chemopreventive activity in addition to anti-inflammatory activity, and these compounds have thus generated considerable attention as alternative medicines in recent years.2-4) The low incidence of colon cancer in Asian countries could be related to low meat intake, but may also be due to the regular use of turmeric in the diet of these regions. As the colon is exposed to turmeric and curcumin, it is a likely target for the anticarcinogenic activity of these compounds. Moreover, since these agents are often administered in combination with conventional therapeutic drugs, it is very important to further explore the potential benefits of herb-drug interactions. Previously we have investigated such herb-drug interactions at the level of conjugation. 5,6) We have also recently established an assay system for conjugation reactions of 1-naphthol using a human adenocarcinoma cell line, Caco-2.7) In our current study, to elucidate the possible interaction of both turmeric and curcumin with the conjugation pathways in cells, which in many cases are involved in the activation of procarcinogens, we measured their effects on the conjugation activity of 1-naphthol in Caco-2 cells. MATERIALS AND METHODS MaterialsPowdered turmeric was obtained from Wako, Ltd. and curcumin was purchased from Sigma. Water-soluble and DMSO-soluble turmeric solutions were prepared by stirring turmeric powder (10 g) in either 100 ml distilled water or DMSO for 3 h at room temperature. Each solution was then filtered.Cell Culture Human adenocarcinoma Caco-2 cells were grown in 12-well plates in 1 ml minimal essential medium (MEM) supplemented with 10% fetal bovine serum and additional non-essential amino acids. The cells were seeded at 5ϫ10 5 cells/ml and cultured for up to 3 weeks with medium changes every 4-5 d.Analyses of 1-Naphthyl Sulfates and Glucuronide 1-Naphthol (200 mM) was added to the culture medium and the cells were further incubated at 37°C. Aliquots of 50 ml of medium were removed at various times, and 30 ml of each of these samples was then filtered and injected into a HPLC apparatus, equipped with an ODS column (Chromolith Performance RP-18e, 100ϫ4.6 mm, Merck). The mobile phase consisted of 2 mM tetrabutylammonium hydrogen sulfate in water and acetonitrile (65 : 35). The flow rate was 1.0 ml/min with a column temperature of 40°C and elution was monitored at 285 nm. The retention times for 1-naphthol, 1-naphthyl sulfate and 1-naphthyl glucuronide were determined to be 19.0 min, 17.6 min and 4.6 min, respectively. The effects of curcumin or turmeric o...

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Section: Methodsmentioning

confidence: 99%

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confidence: 99%

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Turmeric and Curcumin Modulate the Conjugation of 1-Naphthol in Caco-2 Cells

Naganuma

Saruwatari

Okamura

et al. 2006

Biological & Pharmaceutical Bulletin

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“…24) However, our current study showed that coffee strongly inhibits in vitro UGT activity of TR-TBT cells. This discrepancy might be due to the species difference of UGT enzyme structures between human and rat, or due to the difference of assay conditions.…”

Section: Discussionmentioning

confidence: 52%

Coffee Inhibits the Glucuronidation of 1-Naphthol in Rat Syncytiotrophoblast Cells

Ueno

Nakashima

Tamura

2008

JOURNAL OF HEALTH SCIENCE

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The placenta acts as a barrier that protects the fetus from xenobiotics in the maternal blood. Phase II conjugation reactions in the placenta are considered to play an important role in this protective process by transferring polar hydroxyl groups and thereby imparting water solubility that facilitates the excretion of xenobiotics. Since coffee consumption during pregnancy is reported to affect fetal growth and development, we examined its effects upon the conjugation reactions in the rat syncytiotrophoblast cell line TR-TBT 18d-1. We detected a high level of glucuronidation for 1-naphthol, a model compound, in both a dose-and culture time-dependent manner in the TR-TBT 18d-1 cells. However, no sulfation was detected in any of our analyses. Coffee was found to inhibit the glucuronidation of 1-naphthol with an IC 50 of 4.5 % (v/v). In contrast however, caffeine, which is a major bioactive constituent of coffee, did not show any inhibition at doses of up to 100 µM. Coffee was also found to inhibit UDP-glucuronosyl transferase (UGT) activity towards 1-naphthol in vitro to a similar extent [IC 50 = 1.5 % (v/v)] as in intact cells. Moreover, the expression of the UGT 1A6, which is known to mainly catalyze the glucuronidation of 1-naphthol, was not affected by coffee. If coffee inhibits placental glucuronidation during pregnancy, its consumption would increase the fetal plasma concentrations of harmful xenobiotics, potentially affecting normal fetal growth and development.

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“…11 Besides a minor decreased distal colon cancer risk among coffee consuming men, we found no significant protective effect of coffee in the present study. It is hypothesized that the possibly protective effect of coffee against CRC found in some studies may be related to antioxidant and antimutagenic effects of phenolic compounds (mainly chlorogenic acid), 6,33 inhibition of colon cancer cell growth by caffeine, 8,9 and cafestol and kahweol mediated reduction of bile acid synthesis 2,34,35 and inhibition of CYP1A2 and NAT2 activity. [36][37][38][39] In addition, caffeine may specifically protect against distal colon cancer by increasing the motility of the distal colon and, as a consequence, lowering carcinogen exposure of colonic epithelial cells.…”

Section: Discussionmentioning

confidence: 99%

Coffee and tea consumption, genotype-basedCYP1A2andNAT2activity and colorectal cancer risk-Results from the EPIC cohort study

et al. 2013

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Coffee and tea contain numerous antimutagenic and antioxidant components and high levels of caffeine that may protect against colorectal cancer (CRC). We investigated the association between coffee and tea consumption and CRC risk and studied potential effect modification by CYP1A2 and NAT2 genotypes, enzymes involved in the metabolization of caffeine. Data from 477,071 participants (70.2% female) of the European Investigation into Cancer and Nutrition (EPIC) cohort study were analyzed. At baseline (1992–2000) habitual (total, caffeinated and decaffeinated) coffee and tea consumption was assessed with dietary questionnaires. Cox proportional hazards models were used to estimate adjusted hazard ratio's (HR) and 95% confidence intervals (95% CI). Potential effect modification by genotype‐based CYP1A2 and NAT2 activity was studied in a nested case–control set of 1,252 cases and 2,175 controls. After a median follow‐up of 11.6 years, 4,234 participants developed CRC (mean age 64.7 ± 8.3 years). Total coffee consumption (high vs. non/low) was not associated with CRC risk (HR 1.06, 95% CI 0.95–1.18) or subsite cancers, and no significant associations were found for caffeinated (HR 1.10, 95% CI 0.97–1.26) and decaffeinated coffee (HR 0.96, 95% CI 0.84–1.11) and tea (HR 0.97, 95% CI 0.86–1.09). High coffee and tea consuming subjects with slow CYP1A2 or NAT2 activity had a similar CRC risk compared to non/low coffee and tea consuming subjects with a fast CYP1A2 or NAT2 activity, which suggests that caffeine metabolism does not affect the link between coffee and tea consumption and CRC risk. This study shows that coffee and tea consumption is not likely to be associated with overall CRC.

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The Effects of Coffee on Conjugation Reactions in Human Colon Carcinoma Cells

Cited by 21 publications

References 14 publications

Turmeric and Curcumin Modulate the Conjugation of 1-Naphthol in Caco-2 Cells

Turmeric and Curcumin Modulate the Conjugation of 1-Naphthol in Caco-2 Cells

Coffee Inhibits the Glucuronidation of 1-Naphthol in Rat Syncytiotrophoblast Cells

Coffee and tea consumption, genotype-basedCYP1A2andNAT2activity and colorectal cancer risk-Results from the EPIC cohort study

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