The Association between Plasma Concentration of Phytoestrogens and Hypertension within the Korean Multicenter Cancer Cohort.

In order to examine the association between plasma phytoestrogen concentration (genistein, daidzein, equol and enterolactone) and hypertension, we conducted a nested case-control study for 229 hypertension cases including 112 prehypertension and 159 healthy controls derived from the Korean Multi-center Cancer Cohort (KMCC). The concentration of plasma phytoestrogens was measured using time-resolved fluoroimmunoassay. We assessed the association between plasma phytoestrogens and hypertension using logistic regression models using odds ratio (OR) and 95% confidence interval (95%CI). The highest tertile of plasma equol and enterolactone concentration exhibited a significantly decreased risk of hypertension (equol, OR = 0.34, 95%CI 0.20-0.57; enterolactone, OR = 0.32, 95%CI 0.18-0.57), compared with the lowest tertile. Equol and enterolactone showed reduced ORs for prehypertension (the highest tertile relative to the lowest tertile, OR = 0.50, 95%CI 0.26-0.96; OR = 0.38, 95%CI 0.19-0.75, respectively) and hypertension (OR = 0.42, 95%CI 0.22-0.81; OR = 0.28, 95%CI 0.14-0.54, respectively). There was a stronger association in hypertension (the highest tertile relative to the lowest tertile in obesity vs. non-obesity; equol, OR = 0.06 vs. 0.63; enterolactone, OR = 0.07 vs. 0.46; both p-heterogeneity < 0.01). This study suggests that equol and enterolactone may contribute to prevent primarily prehypertension and hypertension, and control cardiovascular disease (CVD) based on the continuum of hypertension and CVD. Further study to assess hypertension risk based on useful biomarkers, including phytoestrogens, may contribute to primary prevention of hypertension.

Simultaneous quantification of arctigenin and its glucuronide conjugate in mouse plasma using ultra-high performance liquid chromatography coupled to tandem mass spectrometry.

Arctigenin is a natural lignin and a main active component of Fructus arctii, the dried fruit of Arctium lappa. This compound was reported to have some biological activities such as anti-inflammatory, antioxidant, antiviral, renoprotective, and antitumor effects. Arctigenin is mainly metabolized to arctigenin-4'-O-glucuronide by UDP-glucuronosyltransferase. In this study, a simultaneous quantification method was established and validated for measuring arctigenin and arctigenin-4'-O-glucuronide in mouse plasma using ultra-high performance liquid chromatography with tandem mass spectrometry. The assay fulfilled the requirements of the United States Food and Drug Administration guideline for assay validation, with a lower limit of quantification of 2.00 ng/mL for arctigenin and 50.0 ng/mL for arctigenin-4'-O-glucuronide. The recovery rate and matrix effect ranged from 78.4 to 102.8% and 92.5 to 106.3%, respectively, for arctigenin, and 74.3 to 109.2% and 94.9 to 110.2% for arctigenin-4'-O-glucuronide. The method was applied to the measurement of plasma concentrations of arctigenin and arctigenin-4'-O-glucuronide in the plasma of mice after administration of arctigenin. All measured concentrations were within the calibration ranges. Our novel method may be useful to measure plasma arctigenin and arctigenin-4'-O-glucuronide concentrations, and contribute to evaluate the pharmacokinetics of arctigenin and arctigenin-4'-O-glucuronide in mice.

Dietary phytoestrogens and biomarkers of their intake in relation to cancer survival and recurrence: a comprehensive systematic review with meta-analysis.

CONTEXT: Recent studies have outlined the potential role of dietary factors in patients who have survived cancer. OBJECTIVE: The aim of this study was to summarize the evidence of the relation between dietary intake of phytoestrogens and their blood biomarkers and, overall, cancer-specific mortality and recurrence in patients with cancer. DATA SOURCES: A systematic search of PubMed, EMBASE, and Web of Science databases of studies published up to September 2019 was performed. Databases were searched for prospective and retrospective cohort studies reporting on dietary phytoestrogen intake and/or blood biomarkers and the outcomes investigated. DATA EXTRACTION: Data were extracted from each identified study using a standardized form. DATA ANALYSIS: Twenty-eight articles on breast, lung, prostate, and colorectal cancer, and glioma were included for systematic review. Given the availability of studies, a quantitative meta-analysis was performed solely for breast cancer outcomes. A significant inverse association among higher dietary isoflavone intake, higher serum/plasma enterolactone concentrations, and overall mortality and cancer recurrence was found. Among other cancer types, 2 studies reported that higher serum enterolactone and higher intake of lignans were associated with cancer-specific survival for colorectal cancer and glioma, respectively. CONCLUSIONS: Dietary phytoestrogens may play a role in survival from breast cancer ; evidence regarding other cancers is too limited to draw any conclusions.

Simultaneous determination of eight bioactive constituents of Zhi-Zi-Hou-Po decoction in rat plasma by ultra high performance liquid chromatography with tandem mass spectrometry and its application to a pharmacokinetic study.

Zhi-Zi-Hou-Po Decoction, consisting of Gardenia jasminoides Ellis, Magnolia officinalis Rehd. et Wils., and Citrus aurantium L, is a classical Traditional Chinese Medicine formula for the treatment of depression. In order to make good and rational use of this formula in the future, a sensitive, selective, and reliable ultra high performance liquid chromatography with tandem mass spectrometry method was developed for simultaneous determination of two iridoid glycosides (geniposide and genipin gentiobioside), two lignans (honokiol and magnolol), four flavonoid glycosides (isonaringin, naringin, hesperidin, and neohesperidin), the major bioactive constituents of Zhi-Zi-Hou-Po Decoction, in rat plasma using paeoniflorin as internal standard. Plasma samples were pretreated by a simple protein precipitation with acetonitrile. Chromatographic separation was performed on a shim-pack XR-ODS C18 column (75 × 3.0 mm, 2.2 µm) using gradient elution with mobile phase consisting of 0.1% formic acid aqueous solution and acetonitrile at a flow rate of 0.5 mL/min. Mass spectrometric detection was conducted on a 3200 QTRAP mass spectrometry equipped with electrospray ionization source in negative ionization mode. Quantification was performed using multiple reactions monitoring mode. Calibration curves exhibited good linearity (r > 0.9947) over a wide concentration range for all analytes, and the lower limits of quantification were 10, 5, 1, 5, 1, 5, 1, and 5 ng/mL for geniposide, genipin gentiobioside, honokiol, magnolol, isonaringin, naringin, hesperidin, and neohesperidin, respectively. The intraday and interday precisions at three quality control levels were less than 12.3% and the accuracies ranged from -11.2 to 10.7%. Extraction recovery, matrix effect, and stability were satisfactory in rat plasma. The validated method was successfully applied to a pharmacokinetic study of the eight analytes after oral administration of Zhi-Zi-Hou-Po decoction to rats.

Prognostic associations of circulating phytoestrogens and biomarker changes in long-term survivors of postmenopausal breast cancer.

Lignans are associated with improved postmenopausal breast cancer (BC) survival, but whether these associations, particularly with enterolactone (major lignan metabolite), persist over time is unclear. Little is known about other phytoestrogens on prognosis in long-term survivors. The study examines associations of prognosis with 1) circulating postdiagnosis enterolactone, 2) eight circulating phytoestrogen metabolites, and 3) changes in enterolactone and genistein. In a German cohort of 2,105 postmenopausal BC patients with blood samples collected at recruitment 2002-2005 (baseline) and re-interview in 2009 (follow-up), delay-entry Cox proportional hazards regression was used. Landmark analysis showed that circulating enterolactone (log2) associations with 5-year survival changed over time, with strongest hazard ratios of 0.89 (95% CI, 0.80-0.99) at blood draw (BD) and 0.86 (0.77-0.97) at 2 years post-BD for BC mortality, and 0.87 (0.80-0.95) at BD and 0.84 (0.76-0.92) at 3 years post-BD for all-cause mortality, which attenuated thereafter. In long-term survivors, increasing concentrations of genistein (1.17, 1.01-1.36), resveratrol (1.19, 1.02-1.40), and luteolin (1.96, 1.07-3.58) measured in follow-up blood samples were associated with poorer subsequent prognosis. Neither enterolactone at follow-up nor changes in enterolactone/genistein were associated with prognosis. Large long-term longitudinal studies with multiple phytoestrogen measurements are required to understand long-term effects of phytoestrogens after BC.

Serum enterolactone concentrations are low in colon but not in rectal cancer patients.

The dietary lignan metabolite, enterolactone, has been suggested to have anti-cancer functions, and high serum enterolactone concentrations have been associated with decreased risk of breast and prostate cancers. We hypothesized that serum enterolactone concentrations as a marker of plant-based foods are associated with decreased risk in colorectal cancer (CRC). We measured serum enterolactone glucuronide and sulfate concentrations by liquid chromatography-tandem mass spectrometry in 115 CRC patients and 76 sex- and age-matched controls and analyzed the results with respect to tumor parameters, clinical parameters, and systemic inflammatory markers. Patients with colon cancer had significant lower serum enterolactone glucuronide and sulfate concentrations than controls (glucuronide: median 3.14 nM vs. 6.32 nM, P < 0.001; sulfate: median 0.13 nM vs. 0.17 nM, P = 0.002), whereas rectal cancer patients had similar enterolactone levels as controls (glucuronide: median 5.39 nM vs. 6.32 nM, P = 0.357; sulfate: median 0.19 nM vs. 0.17 nM, P = 0.452). High serum enterolactone concentrations were associated with low tumor grade, high serum creatinine levels, and concomitant diabetes. In summary, our results suggest that serum enterolactone concentrations are decreased in colon but not in rectal cancer. Further investigations are required to assess whether this reflects an altered lignan metabolism by the colon microbiome.

A validated ultra-HPLC-MS/MS method for determination of honokiol in human plasma and its application to a clinical pharmacokinetic study.

Aim: To investigate pharmacokinetics of honokiol after administration of honokiol liposome injection (HKLI) and support the clinical studies of HKLI; it is crucial to determine the concentration of honokiol in human biological samples. Experimental method & results: Human plasma samples were extracted by protein precipitation and analyzed by a new ultra-HPLC-MS/MS (UPLC-MS/MS) method with LLOQ of 0.5 ng/ml. The method was validated according to bioanalytical guidelines from the US FDA and EMA. Successful method validation proved that the method was sensitive and selective, and was suitable for determination of honokiol in clinical plasma samples. Conclusion: The method was successfully applied to evaluate the pharmacokinetics of honokiol after administration of HKLI to Chinese subjects with advanced non-small-cell lung cancer in a first in-human study.

Pre-diagnostic plasma enterolactone concentrations are associated with lower mortality among individuals with type 2 diabetes: a case-cohort study in the Danish Diet, Cancer and Health cohort.

AIMS/HYPOTHESIS: The phytoestrogen enterolactone is a gut microbiota-derived metabolite of plant lignans with suggested beneficial properties for health. In the current study, we investigated the association between pre-diagnostic plasma enterolactone concentrations and mortality among individuals diagnosed with type 2 diabetes. METHODS: In a population of people diagnosed with diabetes, nested within the Danish Diet, Cancer and Health cohort, we conducted a case-cohort study including a random sample of n = 450 cases (deceased) and a randomly selected subcohort of n = 850 (in total n = 617 deaths). Information on diagnosis, vital status and cause of death was obtained from Danish registers. Cox proportional hazard models with special weighting were applied to assess all-cause and cause-specific mortality. RESULTS: The median enterolactone concentration of the current population was low, 10.9 nmol/l (5th percentile to 95th percentile: 1.3-59.6), compared with previously reported concentrations from the Diet, Cancer and Health cohort. Pre-diagnostic enterolactone concentrations were associated with lower all-cause mortality when assessed linearly per doubling in concentration (log2) (HR 0.91 [95% CI 0.85, 0.96]) and according to quartiles (HR 0.63 [95% CI 0.48, 0.84]) for the highest quartile of enterolactone compared with the lowest quartile. For cause-specific mortality, only death from diabetes (registered as underlying cause of death) reached statistical significance. CONCLUSIONS/INTERPRETATION: Based on this large cohort of people with diabetes with detailed and complete baseline and follow-up information, pre-diagnostic enterolactone concentrations were inversely associated with mortality. To our knowledge, this is the first study on enterolactone and type 2 diabetes mortality. Our findings call for further exploration of enterolactone in type 2 diabetes management.

Using Turmeric Oil as a Solvent Improves the Distribution of Sesamin-Sesamolin in the Serum and Brain of Mice.

Accumulation of amyloid-ß peptide is associated with Alzheimer's dementia. Previously, we reported that sesamin and sesamolin inhibited ß-secretase activity in vitro, and each was transported to the serum and brain in mice after oral administration. However, the bioavailability of sesamin and sesamolin was poor in mice. In this study, we aimed to improve the bioavailability of sesamin and sesamolin. We found that the levels of sesamin and sesamolin in mouse serum and brain were higher after the administration of a mixture of sesame extract and turmeric oil (MST) than those after administering sesame extract alone. Serum sesamin and sesamolin contents in the MST-treated group were 23-fold and 15-fold higher, respectively, than those in the sesame extract-treated group. Brain sesamin and sesamolin contents in the MST-treated group were 14-fold and 11-fold higher, respectively, than those in the sesame extract-treated group. These results suggest that turmeric oil is an effective solvent to enhance the bioavailability of sesamin and sesamolin.

Factors Explaining Interpersonal Variation in Plasma Enterolactone Concentrations in Humans.

Lignans are diphenolic plant compounds with potential health modulating properties that are absorbed to the circulation and metabolized to the enterolignans enterodiol (END) and enterolactone (ENL) by gut microbiota. Epidemiological studies have inconsistently shown that a high lignan intake and circulating ENL are associated with reduced risk of breast-, prostate-, and colorectal cancer as well as cardiovascular disease and total and cause-specific mortality. Inconsistencies can be due to interpersonal variation of ENL formation or responses. The aim of this review is to identify and evaluate the impact of factors influencing variability in plasma concentrations of the main enterolignan, ENL. The main determinants of plasma ENL concentrations are intake of lignan and lignan-rich foods, composition and activity of intestinal microflora, antimicrobial use, nutrient intake, BMI, smoking, sex, and age. Composition and activity of the intestinal microbiota appear to be the most critical factor governing interpersonal variability in plasma ENL concentration followed by the use of antibiotics. Future studies with combined data from gut microbiota and metabolomics with food intake and life style data can be used to estimate the relative contribution of the different factors to ENL concentration in quantitative terms.

Dietary flaxseed and tamoxifen affect the inflammatory microenvironment in vivo in normal human breast tissue of postmenopausal women.

BACKGROUND: Anti-oestrogens such as tamoxifen, decrease the risk of breast cancer but are unsuitable for prevention because of their side-effects. Diet modifications may be a breast cancer prevention strategy. Here, we investigated if a diet addition of flaxseed, which can be converted to the phytoestrogen enterolactone by the gut microbiota, exhibited similar effects as tamoxifen on normal human breast tissue in vivo, with special emphasis on inflammatory mediators implicated in cancer progression. SUBJECTS: A total of 28 postmenopausal women were included. Thirteen women added 25 g of ground flaxseed per day and 15 were treated with tamoxifen as an adjuvant for early breast cancer for 6 weeks. Microdialysis of normal breast tissue and, as a control, in subcutaneous abdominal fat was performed for sampling of extracellular proteins in vivo before and after exposures. RESULTS: Enterolactone levels increased significantly after flaxseed. IL-1Ra and IL-1Ra/IL-1ß ratio in the breast increased in a similar fashion after the two different treatments. Flaxseed also increased breast specific levels of IL-1RT2, IL-18 and sST2 and an overall increase of MMP-9. These changes correlated significantly with enterolactone levels. Tamoxifen decreased breast tissue levels of IL-8 and IL-18. None of the treatments induced any changes of IL-1ß, IL-1RT1, IL-18BP, IL-33, IL-6, IL-6RA, MMP-1, MMP-2 and MMP-3. CONCLUSIONS: We conclude that dietary flaxseed and tamoxifen exert both similar and different effects, as listed above, on normal breast tissue in vivo and that a relatively modest diet change can induce significant effects on the breast microenvironment.

Effect of Dietary Flaxseed Intake on Circulating Sex Hormone Levels among Postmenopausal Women: A Randomized Controlled Intervention Trial.

Lignan intake, and its richest food source, flaxseed, have been associated with reduced breast cancer risk. Endogenous sex hormones, such as estrogens, play a role in breast cancer development, and lignans may alter these sex hormone levels. To assess the effect of flaxseed on circulating sex hormones, a randomized controlled trial was conducted among 99 postmenopausal women in Toronto, Canada. The intervention arm consumed 2 tablespoons (15 g) of ground flaxseed daily for 7 weeks; the control arm maintained usual diet. Baseline and week 7 concentrations of 14 serum sex hormones were measured using liquid chromatography-tandem mass spectrometry (LC-MS/MS) and immunoassay, and serum enterolignans (lignan biomarker) using LC-MS/MS. Intervention effects on sex hormone levels were assessed using analysis of covariance. Serum enterolignans increased among the flaxseed arm (+516%). Women consuming flaxseed (vs. controls) had increased serum 2-hydroxyestrone [treatment effect ratio (TER) = 1.54; 95% CI: 1.18-2.00] and 2:16α-hydroxyestrone ratio (TER =1.54; 95% CI: 1.15-2.06); effects on other hormones were not statistically significant. Within the flaxseed arm, change in enterolignan level was positively correlated with changes in 2-hydroxyestrone and 2:16α-hydroxyestrone ratio, and negatively with prolactin. Findings suggest flaxseed affects certain circulating sex hormone levels with possible implications for future breast cancer prevention research.

The flaxseed lignan secoisolariciresinol diglucoside decreases local inflammation, suppresses NFκB signaling, and inhibits mammary tumor growth.

PURPOSE: Exposure to the polyphenolic plant lignan secoisolariciresinol diglucoside (SDG) and its metabolite enterolactone (ENL) has been associated with reduced breast cancer progression, particularly for estrogen receptor alpha (ERα)-negative disease, and decreased preclinical mammary tumor growth. However, while preclinical studies have established that SDG and ENL affect measures of progression in models of triple-negative breast cancer (TNBC, a subset of ERα-negative disease), the molecular mechanisms underlying these effects remain unclear. METHODS: C57BL/6 mice were fed a control diet (control, 10% kcal from fat) or control diet + SDG (SDG, 100 mg/kg diet) for 8 weeks, then orthotopically injected with syngeneic E0771 mammary tumor cells (a model of TNBC); tumor growth was monitored for 3 weeks. The role of reduced NF-κB signaling in SDG's anti-tumor effects was explored in vitro via treatment with the bioactive SDG metabolite ENL. In addition to the murine E0771 cells, the in vitro studies utilized MDA-MB-231 and MCF-7 cells, two human cell lines which model the triple-negative and luminal A breast cancer subtypes, respectively. RESULTS: SDG supplementation in the mice significantly reduced tumor volume and expression of phospho-p65 and NF-κB target genes (P < 0.05). Markers of macrophage infiltration were decreased in the distal-to-tumor mammary fat pad of mice supplemented with SDG relative to control mice (P < 0.05). In vitro, ENL treatment inhibited viability, survival, and NF-κB activity and target gene expression in E0771, MDA-MB-231, and MCF-7 cells (P < 0.05). Overexpression of Rela attenuated ENL's inhibition of E0771 cell viability and survival. CONCLUSIONS: SDG reduces tumor growth in the E0771 model of TNBC, likely via a mechanism involving inhibition of NF-κB activity. SDG could serve as a practical and effective adjuvant treatment to reduce recurrence, but greater understanding of its effects is needed to inform the development of more targeted recommendations for its use.

Prediagnosis plasma concentrations of enterolactone and survival after colorectal cancer: the Danish Diet, Cancer and Health cohort.

The association between lifestyle and survival after colorectal cancer has received limited attention. The female sex hormone, oestrogen, has been associated with lower colorectal cancer risk and mortality after colorectal cancer. Phyto-oestrogens are plant compounds with structure similar to oestrogen, and the main sources in Western populations are plant lignans. We investigated the association between the main lignan metabolite, enterolactone and survival after colorectal cancer among participants in the Danish Diet, Cancer and Health cohort. Prediagnosis plasma samples and lifestyle data, and clinical data from time of diagnosis from 416 women and 537 men diagnosed with colorectal cancer were used. Enterolactone was measured in plasma using a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method. Participants were followed from date of diagnosis until death or end of follow-up. During this time, 210 women and 325 men died (170 women and 215 men died due to colorectal cancer). The Cox proportional hazards model was used to estimate hazard ratios (HR) and 95 % CI. Enterolactone concentrations were associated with lower colorectal cancer-specific mortality among women (HRper doubling: 0·88, 95 % CI 0·80, 0·97, P=0·0123). For men, on the contrary, enterolactone concentrations were associated with higher colorectal cancer-specific mortality (HRper doubling: 1·10, 95 % CI 1·01, 1·21, P=0·0379). The use of antibiotics affects enterolactone production, and the associations between higher enterolactone and lower colorectal cancer-specific mortality were more pronounced among women who did not use antibiotics (analysis on a subset). Our results suggest that enterolactone is associated with lower risk of mortality among women, but the opposite association was found among men.

Preparation of honokiol nanoparticles by liquid antisolvent precipitation technique, characterization, pharmacokinetics, and evaluation of inhibitory effect on HepG2 cells.

BACKGROUND: Honokiol is a bioactive lignanoid and has been utilized in traditional Chinese medicine for a long time. It exhibits several pharmacological properties, such as anticancer effects, anti-inflammatory effects, and antianxiety effects. However, the poor aqueous solubility of honokiol has impeded clinical applications. MATERIALS AND METHODS: In the present study, we adopted the liquid antisolvent precipitation (LAP) technique to prepare nanoparticles of honokiol for enhancement of solubility and bioavailability. Moreover, the honokiol nanoparticles obtained were investigated and evaluated in terms of morphology, physicochemical properties, saturation solubility, dissolution in vitro, bioavailability in vivo, toxicity, and the inhibitory effect on growth of HepG2 cells. RESULTS: The obtained honokiol nanoparticles existed nearly in spherical shape and could be turned into amorphous structure by the LAP method. Moreover, the solubility of the honokiol nanoparticles was extremely higher than that of free honokiol, and the nanoparticle dissolution rate was also higher than that of free honokiol, which was about 20.41 times and 26.2 times than that of free honokiol in artificial gastric juice and in artificial intestinal juice. The area under the curve [AUC(0-t)] value of honokiol nanoparticles was about 6.52 times greater than that of free honokiol; therefore, the honokiol nanoparticles had a higher bioavailability than free honokiol but were innoxious to the organs of rats. Additionally, the honokiol nanoparticles exhibited a higher inhibition of HepG2 cells due to their lower IC50 compared to free honokiol. CONCLUSION: Honokiol nanoparticles have high solubility and bioavailability, and can become a new oral drug formulation and produce a better response for its clinical applications.

Circulating isoflavone and lignan concentrations and prostate cancer risk: a meta-analysis of individual participant data from seven prospective studies including 2,828 cases and 5,593 controls.

Phytoestrogens may influence prostate cancer development. This study aimed to examine the association between prediagnostic circulating concentrations of isoflavones (genistein, daidzein, equol) and lignans (enterolactone and enterodiol) and the risk of prostate cancer. Individual participant data were available from seven prospective studies (two studies from Japan with 241 cases and 503 controls and five studies from Europe with 2,828 cases and 5,593 controls). Because of the large difference in circulating isoflavone concentrations between Japan and Europe, analyses of the associations of isoflavone concentrations and prostate cancer risk were evaluated separately. Prostate cancer risk by study-specific fourths of circulating concentrations of each phytoestrogen was estimated using multivariable-adjusted conditional logistic regression. In men from Japan, those with high compared to low circulating equol concentrations had a lower risk of prostate cancer (multivariable-adjusted OR for upper quartile [Q4] vs. Q1 = 0.61, 95% confidence interval [CI] = 0.39-0.97), although there was no significant trend (OR per 75 percentile increase = 0.69, 95 CI = 0.46-1.05, ptrend = 0.085); Genistein and daidzein concentrations were not significantly associated with risk (ORs for Q4 vs. Q1 = 0.70, 0.45-1.10 and 0.71, 0.45-1.12, respectively). In men from Europe, circulating concentrations of genistein, daidzein and equol were not associated with risk. Circulating lignan concentrations were not associated with the risk of prostate cancer, overall or by disease aggressiveness or time to diagnosis. There was no strong evidence that prediagnostic circulating concentrations of isoflavones or lignans are associated with prostate cancer risk, although further research is warranted in populations where isoflavone intakes are high.

Circulating enterolactone concentrations and prognosis of postmenopausal breast cancer: assessment of mediation by inflammatory markers.

Higher lignan exposure has been associated with lower all-cause mortality (ACM) and breast cancer-specific mortality (BCSM) for postmenopausal breast cancer patients. However, the biological mechanisms underpinning these associations are still unclear. We investigated for the first time whether and to what extent the association between enterolactone (ENL), the major lignan metabolite, and postmenopausal breast cancer prognosis is mediated by inflammatory biomarkers. Circulating concentrations of ENL and inflammatory markers were measured in a population-based prospective cohort of 1,743 breast cancer patients recruited between 2002 and 2005 and followed-up until 2009. Hazard ratios (HR) and 95% CIs were estimated using multivariable Cox regression. Mediation analysis was performed to estimate the percentage association between ENL (log2) and ACM, BCSM and distant disease-free survival (DDFS), which is mediated by C-reactive protein (CRP) (log2), as the strongest potential mediator, and also interleukin (IL)-10. Median serum/plasma ENL and CRP concentrations for all patients, including 180 deceased patients, were 23.2 and 17.5 nmol/L, and 3.2 and 6.5 mg/l, respectively. ENL concentrations were significantly inversely associated with ACM, BCSM and DDFS (per doubling of ENL concentrations: HRs 0.93 [0.87, 0.99], 0.91 [0.84, 0.99] and 0.92 [0.87, 0.99]), after adjusting for prognostic factors and BMI. Estimated 18, 14 and 12% of the effects of ENL on ACM, BCSM and DDFS, respectively, were mediated through CRP. No mediational effect of IL-10 was found. We provide first evidence that the proinflammatory marker CRP may partially mediate the association of ENL with postmenopausal breast cancer survival, which supports hormone-independent mechanisms.

Investigation of potential toxic components based on the identification of Genkwa Flos chemical constituents and their metabolites by high-performance liquid chromatography coupled with a Q Exactive high-resolution benchtop quadrupole Orbitrap mass spectrometer.

Genkwa Flos, a famous traditional Chinese medicine has been reported to have significant hepatotoxicity. A high-throughput and reliable method was established to explore potential toxic components by high-performance liquid chromatography coupled with a Q Exactive high-performance benchtop quadrupole-Orbitrap mass spectrometer. A total of 68 compounds including 22 chemical components and 46 metabolites were tentatively identified based on the accurately measured mass value, retention time, and fragmentation pattern. Besides, the metabolic pathways of main components in Genkwa Flos were also illustrated. The results indicated that hydroxylation, demethylation, methylation, glucuronidation, sulfation, cysteine conjugation, and glutathione conjugation participated in the metabolic reactions of Genkwa Flos. Moreover, 12 Genkwa Flos chemical components and 26 metabolites were detected in cell lysate, which were considered as the bound components to HL-7702 cells. In view of cell affinity theory, these compounds were preliminarily deduced to be potential toxic ingredients for the hepatotoxicity induced by Genkwa Flos. The results demonstrated that the developed method was a very feasible and efficient approach for the components identification even in the complex matrix. In conclusion, this study will provide a deep insight into the toxic substances of Genkwa Flos and lay a chemical basis for in-depth toxic studies on Genkwa Flos hepatotoxicity.

Plasma enterolactone and risk of prostate cancer in middle-aged Swedish men.

PURPOSE: Enterolactone (ENL) is formed in the human gut after consumption of lignans, has estrogenic properties, and has been associated with risk of prostate cancer. We examined the association between plasma ENL levels and prostate cancer in a nested case-control study within the population-based Malmö Diet and Cancer cohort. We also examined the association between plasma ENL and dietary and lifestyle factors. METHODS: The study population consisted of 1010 cases occurring during a mean follow-up of 14.6 years, and 1817 controls matched on age and study entry date. We used national registers (95%) and hospital records (5%) to ascertain cases. Diet was estimated by a modified diet history method. Plasma ENL concentrations were determined by a time-resolved fluoroimmunoassay. Odds ratios were calculated by unconditional logistic regression. RESULTS: There were no significant associations between plasma ENL and incidence of all prostate cancer (odds ratio 0.99 [95% confidence interval 0.77-1.280] for the highest ENL quintile versus lowest, p for trend 0.66). However, in certain subgroups of men, including men with abdominal obesity (p for interaction = 0.012), we observed associations between high ENL levels and lower odds of high-risk prostate cancer. Plasma ENL was positively associated with consumption of high-fibre bread, fruit, tea, and coffee; with age, and with height, while it was negatively associated with smoking and waist circumference; however, although significant, all associations were rather weak (r ≤ |0.14|). CONCLUSION: ENL concentration was not consistently associated with lower prostate cancer risk, although it was weakly associated with a healthy lifestyle.

Plasma phytoestrogens concentration and risk of colorectal cancer in two different Asian populations.

BACKGROUND & AIMS: To evaluate the relationship between phytoestrogen and colon cancer risk, we quantified plasma isoflavones (Genistein and Daidzein) and lignan (enterolactone) in a Korean nested case-control study and conducted replication study in a Vietnamese case-control study. METHODS: Study populations of 101 cases and 391 controls were selected from the Korean Multicenter Cancer Cohort which was constructed from 1993 to 2004. For replication study, Vietnamese hospital-based case-control subjects of 222 cases and 206 controls were selected from 2003 to 2007. The concentrations of plasma genistein, daidzein, and enterolactone were quantified by liquid chromatography-mass spectrometry. Logistic regression models were used to compute odds ratios (ORs) and 95% confidence intervals (CIs), and meta-analysis was conducted to estimate combined ORs (CORs) and 95% Cis of Korean and Vietnamese population in 2014. RESULTS: Genistein showed a continual decrease in colorectal cancer risk according to level up of the concentration categories in Korean and Vietnamese population (P for trend = 0.032, and 0.001, respectively) and a significantly decreased risk was found at the highest concentration of genistein and daidzein (for the highest category compared to the lowest: COR (95% CI) = 0.46 (0.30-0.69), and COR (95% CI) = 0.54 (0.36-0.82)). When the study population was stratified, the beneficial relationship of genistein with colorectal cancer was observed regardless of sex and anatomical subtype. However, enterolacton level was not associated with colorectal cancer risk. CONCLUSIONS: High plasma levels of isoflavones had relationship with a decreased risk of colorectal cancer, regardless of different ethnic background.