Query: Prolonged Liver Function Enhancement From Broccoli

Relevant passages:
Effect of cruciferous vegetable consumption on heterocyclic aromatic amine metabolism in man. <=SEP=> The consumption of cooked meat appears to predispose individuals to colonic cancer and heterocyclic aromatic amines (HA), formed during the cooking of meat, have been suggested as aetiological agents. Consumption of cruciferous vegetables is thought to protect against cancer. To study the effect of cruciferous vegetables on heterocyclic aromatic amine metabolism in man, a three-period, dietary intervention study has been carried out with 20 non-smoking Caucasian male subjects consuming cooked meat meals containing known amounts of these carcinogens. A high cruciferous vegetable diet (250 g each of Brussels sprouts and broccoli per day) was maintained during period 2 but such vegetables were excluded from periods 1 and 3. At the end of each period, subjects consumed a cooked meat meal and urinary excretion of the HA 2-amino-3,8-dimethylimidazo(4,5-f)quinoxaline (MeIQx) and 2-amino-1-methyl-6-phenylimidazo(4,5-b)pyridine (PhIP) was measured. Following a 12 day period of cruciferous vegetable consumption (period 2), induction of hepatic CYP1A2 activity was apparent from changes in the kinetics of caffeine metabolism. Excretion of MeIQx and PhIP in urine at the end of this period of the study was reduced by 23 and 21%, respectively, compared with period 1. This reduction in excretion is probably due to an increase in amine metabolism that might be expected given the observed increase in CYP1A2 activity, since this enzyme has been shown to be primarily responsible for the oxidative activation of MeIQx and PhIP in man. In period 2, urinary mutagenicity was increased relative to period 1 by 52 and 64% in the absence and presence, respectively, of a human liver microsomal activation system, yet no evidence was found of PhIP adduction to lymphocyte DNA, a potential biomarker of the activation process. After another 12 days without cruciferous vegetables (period 3 of the study), the kinetics of caffeine metabolism had returned to original values but excretion of MeIQx and PhIP was still reduced by 17 and 30%, respectively, and urinary mutagenicity (with metabolic activation) was still elevated compared with period 1. This prolonged response of amine metabolism to the cruciferous vegetable diet, shown especially with PhIP, suggests that enzyme systems other than CYP1A2 are involved and affected by a cruciferous vegetable diet.

Airborne mutagens produced by frying beef, pork and a soy-based food. <=SEP=> Airborne cooking by-products from frying beef (hamburgers), pork (bacon strips) and soybean-based food (tempeh burgers) were collected, extracted, tested for mutagenicity and chemically analysed. The fumes generated by frying pork and beef were mutagenic, with 4900 and 1300 revertants/g of food cooked, respectively. No mutagenicity was detected in fumes from frying tempeh burgers. Bacon fried to a well-done but non-charred state was eight times more mutagenic in a microsuspension Ames/Salmonella test (TA98 with S-9) than hamburgers and about 350 times more mutagenic than tempeh burgers. Among food samples cooked to a well-done, non-charred state, bacon strips had almost 15-fold more mass (109.5 ng/g) than that of the beef, whereas no heterocyclic amine (HCA) was detected in the fried tempeh burgers. 2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) was the most abundant HCA, followed by 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) and 2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline (DiMeIQx). No 2-amino-9H-pyrido[2,3-b]indole (A alpha C) was detected in the food samples fried at about 200 degrees C, although it was present in the collected airborne products. The total amounts of HCAs in the smoke condensates were 3 ng/g from fried bacon, 0.37 ng/g from fried beef and 0.177 ng/g from fried soy-based food. This study indicates that cooks are potentially exposed to relatively high levels of airborne mutagens and carcinogens and that long-term sampling inside restaurants and kitchens may be warranted in order to assess the potential risk of prolonged exposure.

Cooked meat and risk of breast cancer--lifetime versus recent dietary intake. <=SEP=> BACKGROUND: Polycyclic aromatic hydrocarbons (PAHs) and heterocyclic amines (HCAs) are carcinogens formed in or on the surface of well-done meat, cooked at high temperature. METHODS: We estimated breast cancer risk in relation to intake of cooked meat in a population-based, case-control study (1508 cases and 1556 controls) conducted in Long Island, NY from 1996 to 1997. Lifetime intakes of grilled or barbecued and smoked meats were derived from the interviewer-administered questionnaire data. Dietary intakes of PAH and HCA were derived from the self-administered modified Block food frequency questionnaire of intake 1 year before reference date. Unconditional logistic regression was used to estimate adjusted odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: Modest increased risk was observed among postmenopausal, but not premenopausal, women consuming the most grilled or barbecued and smoked meats over the life course (OR = 1.47; CI = 1.12-1.92 for highest vs. lowest tertile of intake). Postmenopausal women with low fruit and vegetable intake, but high lifetime intake of grilled or barbecued and smoked meats, had a higher OR of 1.74 (CI = 1.20-2.50). No associations were observed with the food frequency questionnaire-derived intake measures of PAHs and HCAs, with the possible exception of benzo(alpha)pyrene from meat among postmenopausal women whose tumors were positive for both estrogen receptors and progesterone receptors (OR = 1.47; CI = 0.99-2.19). CONCLUSIONS: These results support the accumulating evidence that consumption of meats cooked by methods that promote carcinogen formation may increase risk of postmenopausal breast cancer.

Intervention of human breast cell carcinogenesis chronically induced by 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine <=SEP=> More than 85% of breast cancers are sporadic and attributable to long-term exposure to environmental carcinogens, such as those in the diet, through a multistep disease process progressing from non-cancerous to premalignant and malignant stages. The chemical carcinogen 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) is one of the most abundant heterocyclic amines found in high-temperature cooked meats and is recognized as a mammary carcinogen. However, the PhIP’s mechanism of action in breast cell carcinogenesis is not clear. Here, we demonstrated, for the first time, that cumulative exposures to PhIP at physiologically achievable, pico to nanomolar concentrations effectively induced progressive carcinogenesis of human breast epithelial MCF10A cells from a non-cancerous stage to premalignant and malignant stages in a dose- and exposure-dependent manner. Progressive carcinogenesis was measured by increasingly- acquired cancer-associated properties of reduced dependence on growth factors, anchorage-independent growth, acinar-conformational disruption, proliferation, migration, invasion, tumorigenicity with metastasis and increased stem-like cell populations. These biological changes were accompanied by biochemical and molecular changes, including upregulated H-Ras gene expression, extracellular signal-regulated kinase (ERK) pathway activation, Nox-1 expression, reactive oxygen species (ROS) elevation, increased HIF-1α, Sp1, tumor necrosis factor-α, matrix metalloproteinase (MMP)-2, MMP-9, aldehyde dehydrogenase activity and reduced E-cadherin. The Ras-ERK-Nox-ROS pathway played an important role in not only initiation but also maintenance of cellular carcinogenesis induced by PhIP. Using biological, biochemical and molecular changes as targeted endpoints, we identified that the green tea catechin components epicatechin-3-gallate and epigallocatechin-3-gallate, at non-cytotoxic doses, were capable of suppressing PhIP-induced cellular carcinogenesis and tumorigenicity.

Occurrence of heterocyclic amines in cooked meat products. <=SEP=> Heterocyclic amines (HCAs), potent mutagens and a risk factor for human cancers, are produced in meats cooked at high temperature. The aim of this study was to determine the HCA content in cooked meat products (beef, chicken, pork, fish) prepared by various cooking methods (pan frying, oven broiling, and oven baking at 170 to 230°C) that are preferred by U.S. meat consumers. The primary HCAs in these samples were PhIP (2-amino-1-methyl-6-phenylimidazo [4,5-b]pyridine) (1.49-10.89ng/g), MeIQx (2-amino-3,8-dimethylimidazo [4,5-f]quinoxaline) (not detected-4.0ng/g), and DiMeIQx (2-amino-3,4,8-trimethyl-imidazo [4,5-f]quinoxaline) (not detected-3.57ng/g). Type and content of HCAs in cooked meat samples were highly dependent on cooking conditions. The total HCA content in well-done meat was 3.5 times higher than that of medium-rare meat. Fried pork (13.91ng/g) had higher levels of total HCAs than fried beef (8.92ng/g) and fried chicken (7.00ng/g). Among the samples, fried bacon contained the highest total HCA content (17.59ng/g). Copyright © 2011 Elsevier Ltd. All rights reserved.

The protective effect of the flavonoids on food-mutagen-induced DNA damage in peripheral blood lymphocytes from colon cancer patients. <=SEP=> The food mutagens IQ (2-amino-3-methylimidazo[4,5-f]quinoline) and PhIP (2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine) are heterocyclic amines (HCA), generated when heating proteinaceous food. This study investigates the protective potential of the flavonoids quercetin (Q) and rutin (R) against oxidative stress induced in vitro by IQ and PhIP in lymphocytes from healthy individuals and untreated, newly diagnosed colon cancer patients using the Comet assay. In the presence of up to 500μM Q and R, the DNA damage resulting from a high dose of PhIP (75μM) or IQ (150μM) was significantly reduced (P<0.001) to levels comparable to six times lower IQ or 7.5 times lower PhIP doses. Lymphocytes from colon cancer patients had greater baseline DNA damage than those from healthy individuals (P<0.01) and this higher level of damage was also observed throughout in vitro treatment. Except for the >50years of age group and male gender, confounding factors such as smoking, drinking and/or dietary habits were not found to be significant. In conclusion, flavonoids reduced oxidative stress caused by food mutagens in vitro in lymphocytes of healthy individuals and colon cancer patients. Thus, dietary supplementation with flavonoid-rich vegetables and fruits may prove very effective in protecting against oxidative stress. Copyright © 2011 Elsevier Ltd. All rights reserved.

Dietary flavonoid intake and breast cancer survival among women on Long Island. <=SEP=> BACKGROUND: Laboratory research and a growing number of epidemiologic studies have provided evidence for a reduced risk of breast cancer associated with dietary intake of certain classes of flavonoids. However, the effects of flavonoids on survival are not known. In a population-based cohort of breast cancer patients, we investigated whether dietary flavonoid intake before diagnosis is associated with subsequent survival. METHODS: Women ages 25 to 98 years who were newly diagnosed with a first primary invasive breast cancer between August 1, 1996, and July 31, 1997, and participated in a population-based, case-control study (n=1,210) were followed for vital status through December 31, 2002. At the case-control interview conducted shortly after diagnosis, respondents completed a FFQ that assessed dietary intake in the previous 12 months. All-cause mortality (n=173 deaths) and breast cancer-specific mortality (n=113 deaths) were determined through the National Death Index. RESULTS: Reduced hazard ratios [age- and energy-adjusted hazard ratio (95% confidence interval)] for all-cause mortality were observed among premenopausal and postmenopausal women for the highest quintile of intake, compared with the lowest, for flavones [0.63 (0.41-0.96)], isoflavones [0.52 (0.33-0.82)], and anthocyanidins [0.64 (0.42-0.98)]. No significant trends in risk were observed. Results were similar for breast cancer-specific mortality only. CONCLUSION: Mortality may be reduced in association with high levels of dietary flavones and isoflavones among postmenopausal U.S. breast cancer patients. Larger studies are needed to confirm our findings.

Determination of total phenolic content and antioxidant activity of garlic (Allium sativum) and elephant garlic (Allium ampeloprasum) by attenuated... <=SEP=> The total phenolic contents and antioxidant activities of garlics from California, Oregon, Washington, and New York were determined by Fourier transform infrared (FT-IR) spectroscopy (400-4000 cm(-1)). The total phenolic content was quantified [Folin-Ciocalteu assay (FC)] and three antioxidant activity assays, 2,2-diphenyl-picrylhydrazyl (DPPH) assay, Trolox equivalent antioxidant capacity (TEAC) assay, and ferric reducing antioxidant power (FRAP), were employed for reference measurements. Four independent partial least-squares regression (PLSR) models were constructed with spectra from 25 extracts and their corresponding FC, DPPH, TEAC, and FRAP with values for 20 additional extracts predicted (R > 0.95). The standard errors of calibration and standard error of cross-validation were <1.45 (TEAC), 0.36 (FRAP), and 0.33 μmol Trolox/g FW (DPPH) and 0.55 mg gallic acid/g FW (FC). Cluster and dendrogram analyses could segregate garlic grown at different locations. Hydroxyl and phenolic functional groups most closely correlated with garlic antioxidant activity.

Diallyl sulfide inhibits PhIP-induced DNA strand breaks in normal human breast epithelial cells. <=SEP=> Heterocyclic amines (HCAs) are formed when meat products such as beef, chicken, pork and fish are cooked at high temperatures. The most abundant HCA found in the human diet is 2-amino-1-methyl-6-phenylimidazo[4,5-b] pyridine (PhIP). PhIP causes mammary carcinomas in female rats and mice, and is associated with an increased risk of developing colon, breast, and prostate cancer in humans. PhIP is metabolized by cytochrome P-450s producing N-OH-PhIP. The N-OH-PhIP can be esterified by phase II enzymes forming an arylnitrenium ion that binds to DNA causing adducts. Furthermore, N-OH-PhIP may be reduced by cytochrome b5 reductase producing superoxide anions and hydroxyl radicals causing DNA strand breaks. Diallyl sulfide (DAS) has been shown to prevent cancer in several animal models, presumably by metabolic modulation. We hypothesize that PhIP produces reactive oxygen species causing DNA strand breaks and that DAS will inhibit the formation of PhIP induced DNA strand breaks. To test this hypothesis we treated normal breast epithelial (MCF-10A) cells with PhIP, DAS and a combination of PhIP and DAS. The detection of lipid peroxides was used as a surrogate for ROS. Lipid peroxides were detected using a PeroxiDetect kit (Sigma). PhIP increased the production of lipid peroxides and DAS decreased the PhIP-induced peroxidation by 47%. To determine if PhIP causes DNA strand breaks in MCF-10A cells, cells were treated for 3, 6, 9, and 24 h with PhIP (100 microM), DAS (100 microM) and a combination of PhIP (100 microM) and DAS (100 microM). DNA strand breaks were evaluated using the Comet assay. PhIP produced DNA strand breaks in a dose- and time-dependent fashion. We have shown that DAS inhibits PhIP-induced DNA strand breaks by inhibiting the production of reactive oxygen species. Therefore, we propose that DAS can prevent PhIP-induced breast cancer.

Green tea consumption and breast cancer risk or recurrence: a meta-analysis. <=SEP=> Green tea is a commonly consumed beverage in Asia and has been suggested to have anti-inflammatory and possible anti-carcinogenic properties in laboratory studies. We sought to examine the association between green tea consumption and risk of breast cancer incidence or recurrence, using all available epidemiologic evidence to date. We conducted a systematic search of five databases and performed a meta-analysis of studies of breast cancer risk and recurrence published between 1998 and 2009, encompassing 5,617 cases of breast cancer. Summary relative risks (RR) were calculated using a fixed effects model, and tests of heterogeneity across combined studies were conducted. We identified two studies of breast cancer recurrence and seven studies of breast cancer incidence. Increased green tea consumption (more than three cups a day) was inversely associated with breast cancer recurrence (Pooled RR = 0.73, 95% CI: 0.56-0.96). An analysis of case-control studies of breast cancer incidence suggested an inverse association with a pooled RR of 0.81 (95% CI: 0.75, 0.88) while no association was found among cohort studies of breast cancer incidence. Combining all studies of breast cancer incidence resulted in significant heterogeneity. Available epidemiologic evidence supports the hypothesis that increased green tea consumption may be inversely associated with risk of breast cancer recurrence. The association between green tea consumption and breast cancer incidence remains unclear based on the current evidence.

The cooked meat-derived mammary carcinogen 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine promotes invasive behaviour of breast cancer cells. <=SEP=> The cooked meat derived genotoxic carcinogen 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) induces cancer of the colon, prostate and mammary gland when fed to rats. Epidemiology studies link these tumours to a Western diet and exposure to heterocyclic amines such as PhIP. We have shown that PhIP is also potently estrogenic and have proposed that this hormonal activity contributes to its target site carcinogenicity. We now postulate that the estrogenic properties of PhIP influence metastatic potential. We have used an in vitro assay for cell invasion based upon digestion and migration through a reconstituted basement membrane model. Zymography and immunoblotting were used to confirm PhIP-mediated changes associated with induction of the invasive phenotype. Treatment of the mammary cancer cell lines MCF-7 and T47D with PhIP induces cells to digest and migrate through a reconstituted basement membrane. The response was dose dependent, observed at sub-nanomolar concentrations of PhIP and was inhibited by the antiestrogen ICI 182,780. The PhIP-induced invasive phenotype was associated with expression of cathepsin D, cyclooxygenase-2 and matrix metalloproteinase activity. These findings emphasise the range and potency of the biological activities associated with this cooked meat product and mechanistically support the tissue-specific carcinogenicity of the chemical. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Meat, fat and risk of breast cancer: a case-control study from Uruguay. <=SEP=> To examine whether meat intake modifies breast-cancer risk, a case-control study was conducted in Uruguay. Dietary patterns were assessed in detail (for cases, before diagnosis or symptoms occurred) using a food frequency questionnaire involving 64 food items, which allowed total energy intake to be calculated. Nutrient residuals were calculated through regression analysis. After adjustment for potential confounders (which included family history of breast cancer, menopausal status, body-mass index, total energy and total alcohol intake), an increased risk associated with consumption of total meat intake, red meat intake, total fat and saturated fat intake was observed. The strongest effect was observed for red meat intake (OR 4.2, 95% CL 2.3-7.7) for consumption in the upper quartile, after controlling for protein and fat intake. This suggests an independent effect for meat. Since experimental studies have shown a strong effect of heterocyclic amines in rat mammary carcinogenesis, further studies should be performed in human epidemiology, perhaps using biomarkers of heterocyclic amine exposure.

Intake of fried meat and risk of cancer: a follow-up study in Finland. <=SEP=> It has been suggested that mutagens in fried meat may be involved in the cancer process. Therefore the relationships between intake of fried meat and subsequent risk of cancers at different sites were studied among 9,990 Finnish men and women, 15-99 years of age and initially free of cancer. The baseline study was carried out in 1966-1972, and cases of cancer were identified through data linkage with the Finnish Cancer Registry. During a 24-year follow-up, 853 cancer cases were diagnosed. The intake of fried meat was estimated from a dietary history interview covering the total diet of the participants during the previous year. There was a positive association between fried meat intake and the risk of female-hormone-related cancers, i.e., cancer of the breast, endometrium and ovary combined. The relative risk of these cancers combined between persons in the highest and lowest tertiles of daily intake of fried meat adjusted for age, personal characteristics and intake of other main food groups was 1.77 (95% confidence interval = 1.11-2.84). Pancreatic and nervous system cancers also presented non-significant suggestive associations. No associations were observed with respect to other single cancer sites studied or to all sites of cancer combined. Further epidemiological efforts are needed to ascertain the potential link between fried-food mutagens and cancer risk.

Detection of PhIP (2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine) in the milk of healthy women. <=SEP=> An increased risk of breast cancer has been observed in women who consume "very well-done" meats. Heterocyclic amines are mutagenic and carcinogenic pyrolysis products formed during high temperature cooking of meats. In the present study, human milk samples were analyzed for PhIP, one of the most abundant dietary heterocyclic amine. A protocol was developed with a mixed-mode cation exchange sorbent for the extraction of heterocyclic amines from milk. Milk samples were acquired from healthy Canadian women. With LC/MS analysis and the method of isotope dilution for quantification, levels of PhIP were determined in human milk samples. PhIP was detected in 9 of the 11 milk samples, at levels as high as 59 pg/mL (ppt). No PhIP was detected in the milk of the vegetarian donor. Detection of PhIP in milk indicates that ductal mammary epithelial cells are directly exposed to this carcinogen, suggesting that heterocyclic amines are possible human mammary carcinogens.

Dietary intake of meat and meat-derived heterocyclic aromatic amines and their correlation with DNA adducts in female breast tissue. <=SEP=> It was the aim of this study to examine the association of the consumption of meat in general, meat prepared by different cooking methods and the dietary intake of heterocyclic aromatic amines (HCA) with the level of DNA adducts in the breast tissue of women undergoing reduction mammoplasty. Dietary intake of meat and HCA were assessed via questionnaire in 44 women undergoing reduction mammoplasty. DNA adduct analysis in breast tissue was performed by (32)P-postlabelling analysis. Spearman rank correlation coefficients (r) were calculated to examine the association of meat consumption and dietary HCA intake with tissue DNA adduct levels. A median DNA adduct level of 18.45 (interquartile range 12.81-25.65) per 10(9) nucleotides in breast tissue was observed; median HCA intake was 40.43 ng/day (interquartile range 19.55-102.33 ng/day). Total HCA intake (r = 0.33, P = 0.03), consumption of fried meat (r = 0.39, P = 0.01), beef (r = 0.32, P = 0.03) and processed meat (r = 0.51, P = 0.0004) were statistically significantly correlated with the level of DNA adducts in breast tissue. The detected DNA adducts could not be confirmed to be specific HCA-derived DNA adducts by comparison with external standards, using the (32)P-postlabelling assay. We observed strong correlations of dietary HCA intake and consumption of fried and processed meat with DNA adduct levels in breast tissue of 44 women. Since the detected DNA adducts were not necessarily specific only for HCA, it is possible that HCA intake is a surrogate of other genotoxic substances, such as polycyclic aromatic hydrocarbons, in meat prepared at high temperatures.

The cooked food derived carcinogen 2-amino-1-methyl-6-phenylimidazo[4,5-b] pyridine is a potent oestrogen: a mechanistic basis for its tissue-speci... <=SEP=> The cooked meat carcinogen 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) induces tumours of the breast, colon and prostate in rats. Here we show that in addition to its well-established genotoxicity, which can be detected at concentrations >10(-6) M, PhIP is also oestrogenic. In COS-1 cells transiently transfected with an oestrogen-responsive reporter gene, PhIP (10(-10)-10(-6) M) mediated transcription through oestrogen receptor (ER) alpha, but not ER-beta, and inhibition by the pure ER antagonist ICI 182 780 demonstrated a requirement for a functional ER. In contrast, the structurally related food-derived carcinogen 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) failed to induce reporter gene transcription. Additionally, we show that in a hormonally responsive breast cancer cell line (MCF-7 cells), PhIP induced transcriptional activation using endogenously expressed ER. Examination of the genotoxic potential of PhIP using a model mammalian cell mutation assay (hprt(-) locus) demonstrated that the genetic toxicology of PhIP was readily detectable, but separate, in terms of effective concentration, from its oestrogenic activity. To determine whether the oestrogenicity of PhIP could mediate oestrogen-dependent responses such as cell growth, we examined the growth of hormonally responsive cells (MCF-7 cells). We show that PhIP can stimulate cell proliferation and, again, this was dependent upon a functional ER. Using ligand blotting, we further show that PhIP can stimulate the expression of progesterone receptor (PR-A and PR-B) and c-MYC and activate the MAPK signal transduction pathway. These responses were similar to that produced by oestradiol, in terms of temporal aspects, potency and a requirement for a functional ER. Each of these dose-dependent mitogenic responses occurred at concentrations of PhIP ( approximately 10(-9)-10(-11)M) that are likely to be equivalent to systemic human exposure via consumption of cooked meat. Thus PhIP can induce cellular responses that encompass altered gene expression and mitogenesis. We suggest that the combination of genetic toxicology and oestrogen-like promotion of genomic and cellular events provide a mechanism for the tissue-specific tumorigenicity of this compound.

Formation of a mutagenic heterocyclic aromatic amine from creatinine in urine of meat eaters and vegetarians. <=SEP=> Liquid chromatography electrospray ionization mass spectrometry (MS) with a triple quadrupole MS was used to identify known and novel heterocyclic aromatic amines (HAAs) in human urine. The identities of 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (8-MeIQx) and 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) were confirmed by their product ion spectra. The constant neutral loss scan mode was employed to probe for other analytes in urine that display the transition [M+H]+-->[M+H-CH3*]+*, which is common to HAAs containing an N-methylimidazo moiety, and led to the detection of a previously unreported isomer of 8-MeIQx [Holland, R., et al. (2004) Chem. Res. Toxicol. 17, 1121-1136]. We now report the identification of another novel HAA, 2-amino-1-methylimidazo[4,5-b]quinoline (IQ[4,5-b]), an isomer of the powerful animal carcinogen 2-amino-3-methylimidazo[4,5-f]quinoline (IQ). The amounts of IQ[4,5-b] measured in the urine of human volunteers who consumed grilled beef ranged from 15 to 135% of the ingested dose, while the amounts of 8-MeIQx and PhIP excreted in urine were on average <2% of the ingested dose. Base treatment of urine at 70 degrees C increased the concentrations of 8-MeIQx and PhIP by as much as 6-fold, indicating the presence of phase II conjugates; however, the amount of IQ[4,5-b] increased by more than 100-fold. IQ[4,5-b] was also detected in the urine of vegetarians following base hydrolysis. The formation of IQ[4,5-b], but not IQ, 8-MeIQx, or PhIP, also occurred in urine incubated at 37 degrees C. Creatinine and 2-aminobenzaldehyde are likely precursors of IQ[4,5-b]. The detection of IQ[4,5-b] in the urine of both meat eaters and vegetarians suggests that this HAA may be present in nonmeat staples or that IQ[4,5-b] formation may occur endogenously within the urinary bladder or other biological fluids.

Caffeine-Not just a stimulant. <=SEP=> OBJECTIVE: The beneficial effects of human caffeine consumption deserve clarification. METHODS: A detailed literature review was conducted and summarized. RESULTS: A large body of scientific evidence describes the beneficial effects of human caffeine consumption on a number of physiologic systems. CONCLUSION: The consumption of moderate amounts of caffeine 1) increases energy availability, 2) increases daily energy expenditure, 3) decreases fatigue, 4) decreases the sense of effort associated with physical activity, 5) enhances physical performance, 6) enhances motor performance, 7) enhances cognitive performance, 8) increases alertness, wakefulness, and feelings of "energy," 9) decreases mental fatigue, 10) quickens reactions, 11) increases the accuracy of reactions, 12) increases the ability to concentrate and focus attention, 13) enhances short-term memory, 14) increases the ability to solve problems requiring reasoning, 15) increases the ability to make correct decisions, 16) enhances cognitive functioning capabilities and neuromuscular coordination, and 17) in otherwise healthy non-pregnant adults is safe. Copyright © 2010 Elsevier Inc. All rights reserved.

A case of fatal caffeine poisoning. <=SEP=> Caffeine is a natural alkaloid methylxanthine that is found in various plants such as coffee or tea. Symptoms of a severe overdose may present with hypokalemia, hyponatremia, ventricular arrhythmias, hypertension followed by hypotension, respiratory failure, seizures, rhabdomyolysis, ventricular fibrillation and finally circulatory collapse. A 21-year-old woman called for the ambulance herself soon after the ingestion of about 10,000 mg of caffeine. At the arrival of the ambulance, the patient went into cardiac arrest almost immediately. After a total resuscitation period of 34 min including seven counter-shocks and 2 mg epinephrine, the patient was stable enough to be transferred to the hospital. The patient soon went into VF again and received two more counter-shocks and 1 mg epinephrine and finally an intravenous bolus dose of 300 mg amiodarone. The initial arterial blood gas showed pH at 6.47, lactate at 33 mmol/l and potassium level at 2.3 mmol/l. Unfortunately, no blood samples for caffeine analysis were taken. Three days after hospital admission, the patient developed myoclonus, which did not respond to medical treatment. Excessive intake of caffeine may produce arrhythmias and pronounced hypokalemia and ensuing ventricular fibrillation. In case of counter-shock-resistant VF, it can be necessary to give an early loading dose of amiodarone. Furthermore, it may be beneficial to replace the potassium as early as possible. Epinephrine and buffer solutions used during resuscitation may further decrease blood potassium levels and should be administrated cautiously. Epinephrine can be replaced by other vasopressor drugs, such as vasopressin without effects on beta-receptors.

Bioavailability and kinetics of sulforaphane in humans after consumption of cooked versus raw broccoli. <=SEP=> The aim of this study was to determine the bioavailability and kinetics of the supposed anticarcinogen sulforaphane, the hydrolysis product of glucoraphanin, from raw and cooked broccoli. Eight men consumed 200 g of crushed broccoli, raw or cooked, with a warm meal in a randomized, free-living, open cross-over trial. Higher amounts of sulforaphane were found in the blood and urine when broccoli was eaten raw (bioavailability of 37%) versus cooked (3.4%, p ) 0.002). Absorption of sulforaphane was delayed when cooked broccoli was consumed (peak plasma time ) 6 h) versus raw broccoli (1.6 h, p ) 0.001). Excretion half-lives were comparable, 2.6 and 2.4 h on average, for raw and cooked broccoli, respectively (p ) 0.5). This study gives complete kinetic data and shows that consumption of raw broccoli results in faster absorption, higher bioavailability, and higher peak plasma amounts of sulforaphane, compared to cooked broccoli.

Glucoraphanin and 4-hydroxyglucobrassicin contents in seeds of 59 cultivars of broccoli, raab, kohlrabi, radish, cauliflower, brussels sprouts, kal... <=SEP=> The importance of dietary sulforaphane in helping maintain good health continues to gain support within the health-care community and awareness among U.S. consumers. In addition to the traditional avenue for obtaining sulforaphane, namely, the consumption of appropriate cruciferous vegetables, other consumer products containing added glucoraphanin, the natural precursor to sulforaphane, are now appearing in the United States. Crucifer seeds are a likely source for obtaining glucoraphanin, owing to a higher concentration of glucoraphanin and the relative ease of processing seeds as compared to vegetative parts. Seeds of several commonly consumed crucifers were analyzed not only for glucoraphanin but also for components that might have negative health implications, such as certain indole-containing glucosinolates and erucic acid-containing lipids. Glucoraphanin, 4-hydroxyglucobrassicin, other glucosinolates, and lipid erucic acid were quantified in seeds of 33 commercially available cultivars of broccoli, 4 cultivars each of kohlrabi, radish, cauliflower, Brussels sprouts, kale, and cabbage, and 2 cultivars of raab.

Lung deposition of fine and ultrafine particles outdoors and indoors during a cooking event and a no activity period. <=SEP=> Some indoor activities increase the number concentration of small particles and, hence, enhance the dose delivered to the lungs. The received particle dose indoors may exceed noticeably the dose from ambient air under routine in-house activities like cooking. In the present work, the internal dose by inhalation of ultrafine and fine particles is assessed, using an appropriate mechanistic model of lung deposition, accommodating aerosol, and inhalation dynamics. The analysis is based on size distribution measurements (10-350 nm) of indoor and outdoor aerosol number concentrations in a typical residence in Athens, Greece. Four different cases are examined, namely, a cooking event, a no activity period indoors and the equivalent time periods outdoors. When the cooking event (frying of bacon-eggs with a gas fire) occurred, the amount of deposited particles deep into the lung of an individual indoors exceeded by up to 10 times the amount received by an individual at the same time period outdoors. The fine particle deposition depends on the level of physical exertion and the hygroscopic properties of the inhaled aerosol. The dose is not found linearly dependant on the indoor/outdoor concentrations during the cooking event, whereas it is during the no activity period. PRACTICAL IMPLICATIONS: The necessity for determining the dose in specific regions of the human lung, as well as the non-linear relationship between aerosol concentration and internal dose makes the application of dosimetry models important. Lung dose of fine and ultrafine particles, during a cooking event, is compared with the dose at no indoor activity and the dose received under outdoor exposure conditions. The dose is expressed in terms of number or surface of deposited particles. This permits to address the dosimetry of very small particles, which are released by many indoor sources but represent a slight fraction of the particulate matter mass. The enhancement of the internal dose resulting from fine and ultrafine particles generated during the cooking event vs. the dose when no indoor source is active is assessed. The results for those cases are also compared with the dose calculated for the measured aerosol outdoors.

N-Nitroso compounds in the diet. <=SEP=> N-Nitroso compounds were known almost 40 years ago to be present in food treated with sodium nitrite, which made fish meal hepatotoxic to animals through formation of nitrosodimethylamine (NDMA). Since that time, N-nitroso compounds have been shown in animal experiments to be the most broadly acting and the most potent group of carcinogens. The key role of nitrite and nitrogen oxides in forming N-nitroso compounds by interaction with secondary and tertiary amino compounds has led to the examination worldwide of foods for the presence of N-nitroso compounds, which have been found almost exclusively in those foods containing nitrite or which have become exposed to nitrogen oxides. Among these are cured meats, especially bacon-and especially when cooked; concentrations of 100 micrograms kg(-1) have been found or, more usually, near 10 micrograms kg(-1). This would correspond to consumption of 1 microgram of NDMA in a 100-g portion. Much higher concentrations of NDMA (but lower ones of other nitrosamines) have been found in Japanese smoked and cured fish (more than 100 micrograms kg(-1)). Beer is one source of NDMA, in which as much as 70 micrograms l(-1) has been reported in some types of German beer, although usual levels are much lower (10 or 5 micrograms l(-1)); this could mean a considerable intake for a heavy beer drinker of several liters per day. Levels of nitrosamines have been declining during the past three decades, concurrent with a lowering of the nitrite used in food and greater control of exposure of malt to nitrogen oxides in beer making. There have been declines of N-nitroso compound concentrations in many foods during the past two decades. The small amounts of nitrosamines in food are nonetheless significant because of the possibility-even likelihood-that humans are more sensitive to these carcinogens than are laboratory rodents. Although it is probable that alkylnitrosamides (which induce brain tumors in rodents) are present in cured meats and other potentially nitrosated products in spite of much searching, there has been only limited indirect evidence of their presence. Copyright 1999 Elsevier Science B.V.

Fruit and vegetable intake and overall cancer risk in the European Prospective Investigation into Cancer and Nutrition (EPIC). <=SEP=> BACKGROUND: It is widely believed that cancer can be prevented by high intake of fruits and vegetables. However, inconsistent results from many studies have not been able to conclusively establish an inverse association between fruit and vegetable intake and overall cancer risk. METHODS: We conducted a prospective analysis of the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort to assess relationships between intake of total fruits, total vegetables, and total fruits and vegetables combined and cancer risk during 1992-2000. Detailed information on the dietary habit and lifestyle variables of the cohort was obtained. Cancer incidence and mortality data were ascertained, and hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using multivariable Cox regression models. Analyses were also conducted for cancers associated with tobacco and alcohol after stratification for tobacco smoking and alcohol drinking. RESULTS: Of the initial 142 605 men and 335 873 women included in the study, 9604 men and 21 000 women were identified with cancer after a median follow-up of 8.7 years. The crude cancer incidence rates were 7.9 per 1000 person-years in men and 7.1 per 1000 person-years in women. Associations between reduced cancer risk and increased intake of total fruits and vegetables combined and total vegetables for the entire cohort were similar (200 g/d increased intake of fruits and vegetables combined, HR = 0.97, 95% CI = 0.96 to 0.99; 100 g/d increased intake of total vegetables, HR = 0.98, 95% CI = 0.97 to 0.99); intake of fruits showed a weaker inverse association (100 g/d increased intake of total fruits, HR = 0.99, 95% CI = 0.98 to 1.00). The reduced risk of cancer associated with high vegetable intake was restricted to women (HR = 0.98, 95% CI = 0.97 to 0.99). Stratification by alcohol intake suggested a stronger reduction in risk in heavy drinkers and was confined to cancers caused by smoking and alcohol. CONCLUSIONS: A very small inverse association between intake of total fruits and vegetables and cancer risk was observed in this study. Given the small magnitude of the observed associations, caution should be applied in their interpretation.