A Newly Developed HPLC-UV/Vis Method Using Chemical Derivatization with 2-Naphthalenethiol for Quantitation of Sulforaphane in Rat Plasma.

Sulforaphane (SFN), a naturally occurring isothiocyanate, has received significant attention because of its ability to modulate multiple biological functions, including anti-carcinogenic properties. However, currently available analytical methods based on high-performance liquid chromatography (HPLC)-UV/Vis for the quantification of SFN have a number of limitations, e.g., low UV absorbance, sensitivity, or accuracy, due to the lack of a chromophore for spectrometric detection. Therefore, we here employed the analytical derivatization procedure using 2-naphthalenethiol (2-NT) to improve the detectability of SFN, followed by HPLC separation and quantification with UV/Vis detection. The optimal derivatization conditions were carried out with 0.3 M of 2-NT in acetonitrile with phosphate buffer (pH 7.4) by incubation at 37 °C for 60 min. Separation was performed in reverse phase mode using a Kinetex C18 column (150 mm × 4.6 mm, 5 µm) at a flow rate of 1 mL/min, with 0.1% formic acid as a mobile phase A, and acetonitrile/0.1% formic acid solution as a mobile phase B with a gradient elution, with a detection wavelength of 234 nm. The method was validated over a linear range of 10-2000 ng/mL with a correlation of determination (R2) > 0.999 using weighted linear regression analysis. The intra- and inter-assay accuracy (% of nominal value) and precision (% of relative standard deviation) were within ±10 and <15%, respectively. Moreover, the specificity, recovery, matrix effect, process efficiency, and short-term and long-term stabilities of this method were within acceptable limits. Finally, we applied this method for studying in vivo pharmacokinetics (PK) following oral administration of SFN at doses of 10 or 20 mg/kg. The Cmax (µg/mL), Tmax (hour), and AUC0-12h (µg·h/mL) of each oral dose were 0.92, 1.99, and 4.88 and 1.67, 1.00, and 9.85, respectively. Overall, the proposed analytical method proved to be reliable and applicable for quantification of SFN in biological samples.

Development and validation of a high throughput bioanalytical UPLC-MS/MS method for simultaneous determination of tamoxifen and sulphoraphane in rat plasma: Application to an oral pharmacokinetic study.

Tamoxifen (TAM) is the choice of a drug approved by the Food and Drug Administration (FDA) for the treatment of estrogen-positive receptor (ER+) breast cancer. Sulphoraphane (SFN), a natural plant antioxidant compound, also acts on estrogen-positive breast cancer receptor. Thus, a combination of TAM with SFN is preferred as it helps to minimize the drug-related toxicity and increases the therapeutic efficacy by providing synergistic anticancer effects of both drugs. In the present study, a new simple, sensitive, precise, and selective UPLC-MS/MS method was developed for the simultaneous quantification of tamoxifen and sulphoraphane using propranolol as an internal standard (IS) in rat plasma. Chromatographic separation was achieved on reverse phase Acquity UPLC BEH C18 column (50 mm × 2.1 mm, i.d., 1.7 µm) with an isocratic mobile phase composed of solvent A (0.1% formic acid in acetonitrile) and B (0.1% formic acid in water) (80:20, v/v) at a flow-rate of 0.4 mL/min. The detection and quantification of analytes was performed on Waters ZsprayTM Xevo TQD using selected-ion monitoring operated under a positive electrospray ionization mode. The transitions were m/z = 372.0 [M+H]+ → 71.92 for tamoxifen, m/z = 177.9 [M+H]+ → 113.9 for sulphoraphane and m/z = 260.3 [M+H]+ → 116.1 for propranolol. The method was linear over the concentration range of 8-500 ng/mL (r2 = 0.9996) for tamoxifen, 30-2000 ng/mL (r2 = 0.9998) for sulphoraphane with insignificant matrix effect and high extraction recovery on spiked quality control (QC) samples. The intra- and inter-batch precisions and accuracy were within the acceptable limits, and both the analytes were found to be stable throughout the short term, long term and freeze thaw stability studies. The validated method was successfully applied for the simultaneous estimation of TAM and SFN in an oral pharmacokinetic study in female Wistar rats. This developed UPLC-MS/MS method could be a valuable tool for future pharmacokinetic interaction, therapeutic drug monitoring and pharmacokinetic characterization of novel formulations.

Measuring Sulforaphane and Its Metabolites in Human Plasma: A High Throughput Method.

(1) Background: There is increasing understanding of the potential health benefits of cruciferous vegetables. In particular sulforaphane (SFN), found in broccoli, and its metabolites sulforaphane-glutathione (SFN-GSH), sulforaphane-cysteine (SFN-Cys), sulforaphane cysteine-glycine (SFN-CG) and sulforaphane-N-acetyl-cysteine (SFN-NAC) have potent antioxidant effects that may offer therapeutic value. Clinical investigation of sulforaphane as a therapeutic antioxidant requires a sensitive and high throughput process for quantification of sulforaphane and metabolites; (2) Methods: We collected plasma samples from healthy human volunteers before and for eight hours after consumption of a commercial broccoli extract supplement rich in sulforaphane. A rapid and sensitive method for quantification of sulforaphane and its metabolites in human plasma using Liquid Chromatography-Mass Spectrometry (LC-MS) has been developed; (3) Results: The LC-MS analytical method was validated at concentrations ranging between 3.9 nM and 1000 nM for SFN-GSH, SFN-CG, SFN-Cys and SFN-NAC and between 7.8 nM and 1000 nM in human plasma for SFN. The method displayed good accuracy (1.85%-14.8% bias) and reproducibility (below 9.53 %RSD) including low concentrations 3.9 nM and 7.8 nM. Four SFN metabolites quantitation was achieved using external standard calibration and in SFN quantitation, SFN-d8 internal standardization was used. The reported method can accurately quantify sulforaphane and its metabolites at low concentrations in plasma; (4) Conclusions: We have established a time- and cost-efficient method of measuring sulforaphane and its metabolites in human plasma suitable for high throughput application to clinical trials.

Effects of long-term consumption of broccoli sprouts on inflammatory markers in overweight subjects.

BACKGROUND & AIMS: Broccoli sprouts represent an interesting choice of healthy food product as they are rich in glucosinolates and their cognate bioactive metabolites, isothiocyanates able to counteract the negative effects of diverse pathologies. As obesity is linked to an inflammatory component, the aim of the study was to evaluate the anti-inflammatory action of broccoli sprouts in overweight adult subjects. METHODS: An in vivo controlled study was performed in 40 healthy overweight subjects (ClinicalTrials.gov ID NCT 03390855). Treatment phase consisted on the consumption of broccoli sprouts (30 g/day) during 10 weeks and the follow-up phase of 10 weeks of normal diet without consumption of these broccoli sprouts. Anthropometric parameters as body fat mass, body weight, and BMI were determined. Inflammation status was assessed by measuring levels of TNF-α, IL-6, IL-1ß and C-reactive protein. RESULTS: IL-6 levels significantly decreased (mean values from 4.76 pg/mL to 2.11 pg/mL with 70 days of broccoli consumption, p < 0.001) and during control phase the inflammatory levels were maintained at low grade (mean values from 1.20 pg/mL to 2.66 pg/mL, p < 0.001). C-reactive protein significantly decreased as well. CONCLUSIONS: This study represents an advance in intervention studies as the broccoli sprouts were included in a daily dietary pattern in quantities that reflect a real consumption. Further studies are necessary to elucidate the role of this healthy rich and nutritious food product, but these promising results support the current evidence on the healthy properties of Brassica varieties.

Absorption and metabolism of isothiocyanates formed from broccoli glucosinolates: effects of BMI and daily consumption in a randomised clinical trial.

Sulphoraphane originates from glucoraphanin in broccoli and is associated with anti-cancer effects. A preclinical study suggested that daily consumption of broccoli may increase the production of sulphoraphane and sulphoraphane metabolites available for absorption. The objective of this study was to determine whether daily broccoli consumption alters the absorption and metabolism of isothiocyanates derived from broccoli glucosinolates. We conducted a randomised cross-over human study (n 18) balanced for BMI and glutathione S-transferase µ 1 (GSTM1) genotype in which subjects consumed a control diet with no broccoli (NB) for 16 d or the same diet with 200 g of cooked broccoli and 20 g of raw daikon radish daily for 15 d (daily broccoli, DB) and 100 g of broccoli and 10 g of daikon radish on day 16. On day 17, all subjects consumed a meal of 200 g of broccoli and 20 g of daikon radish. Plasma and urine were collected for 24 h and analysed for sulphoraphane and metabolites of sulphoraphane and erucin by triple quadrupole tandem MS. For subjects with BMI >26 kg/m2 (median), plasma AUC and urinary excretion rates of total metabolites were higher on the NB diet than on the DB diet, whereas for subjects with BMI <26 kg/m2, plasma AUC and urinary excretion rates were higher on the DB diet than on the NB diet. Daily consumption of broccoli interacted with BMI but not GSTM1 genotype to affect plasma concentrations and urinary excretion of glucosinolate-derived compounds believed to confer protection against cancer. This trial was registered as NCT02346812.

Are Raw Brassica Vegetables Healthier Than Cooked Ones? A Randomized, Controlled Crossover Intervention Trial on the Health-Promoting Potential of Ethiopian Kale.

The present human intervention trial investigated the health-promoting potential of B. carinata, with a focus on effects of thermal processing on bioactivity. Twenty-two healthy subjects consumed a B. carinata preparation from raw (allyl isothiocyanate-containing) or cooked (no allyl isothiocyanate) leaves for five days in a randomized crossover design. Peripheral blood mononuclear cells were exposed to aflatoxin B1 (AFB1), with or without metabolic activation using human S9 mix, and subsequently analyzed for DNA damage using the comet assay. Plasma was analyzed for total antioxidant capacity and prostaglandin E2 (PGE2) levels. Cooked B. carinata significantly reduced DNA damage induced by AFB1 as compared to baseline levels (+S9 mix: 35%, -S9 mix: 33%, p ≤ 0.01, respectively). Raw B. carinata only reduced DNA damage by S9-activated AFB1 by 21% (p = 0.08). PGE2 plasma levels were significantly reduced in subjects after consuming raw B. carinata. No changes in plasma antioxidant capacity were detectable. A balanced diet, including raw and cooked Brassica vegetables, might be suited to fully exploit the health-promoting potential. These results also advocate the promotion of B. carinata cultivation in Eastern Africa as a measure to combat effects of unavoidable aflatoxin exposure.

Untargeted Metabolomic Screen Reveals Changes in Human Plasma Metabolite Profiles Following Consumption of Fresh Broccoli Sprouts.

SCOPE: Several lines of evidence suggest that the consumption of cruciferous vegetables is beneficial to human health. Yet, underlying mechanisms and key molecular targets that are involved with achieving these benefits in humans are still not fully understood. To accelerate this research, we conduct a human study to identify potential molecular targets of crucifers for further study. This study aims to characterize plasma metabolite profiles in humans before and after consuming fresh broccoli sprouts (a rich dietary source of bioactive sulforaphane). METHODS AND RESULTS: Ten healthy adults consume fresh broccoli sprouts (containing 200 µmol sulforaphane equivalents) at time 0 and provide blood samples at 0, 3, 6, 12, 24, and 48 h. An untargeted metabolomics screen reveals that levels of several plasma metabolites are significantly different before and after sprout intake, including fatty acids (14:0, 14:1, 16:0, 16:1, 18:0, and 18:1), glutathione, glutamine, cysteine, dehydroepiandrosterone, and deoxyuridine monophosphate. Evaluation of all time points is conducted using paired t-test (R software) and repeated measures analysis of variance for a within-subject design (Progenesis QI). CONCLUSION: This investigation identifies several potential molecular targets of crucifers that may aid in studying established and emerging health benefits of consuming cruciferous vegetables and related bioactive compounds.

A Randomized Controlled Trial of the Effect of Broccoli Sprouts on Antioxidant Gene Expression and Airway Inflammation in Asthmatics.

BACKGROUND: Broccoli sprouts (BS) are the richest source of sulforaphane (SFN), which is a potent inducer of phase II enzymes, which play a critical role in preventing oxidative stress (OS) and inflammation. OBJECTIVES: The objective of this study was to determine if ingestion of whole BS improves airway inflammatory and physiologic outcomes, and OS in adults with asthma and allergic sensitization to an indoor allergen. METHODS: The study is a double-blind, placebo-controlled, randomized trial to compare the effects of BS with placebo (alfalfa sprouts [AS]) on airway inflammation and markers of OS. Forty adults (aged 18-50 years) were randomized to eat either (a) 100 g of BS daily or (b) 100 g of AS daily for 3 days. Fractional exhaled nitric oxide (FENO), forced expiratory volume 1, nasal epithelial and PBMC gene expression, inflammatory and OS biomarkers, and symptoms were assessed both before and after ingestion of the sprouts. The primary outcome variable was the change in FENO. Secondary outcome measures included rhinitis and asthma symptoms, lung function, and OS and inflammatory biomarkers. RESULTS: BS ingestion for 3 consecutive days did not reduce FENO, despite resulting in a marked increase in serum SFN concentrations (21 vs 22 parts per billion, P = .76). Furthermore, BS consumption did not induce cytoprotective antioxidant genes in either PBMCs or nasal epithelial cells, reduce OS and inflammatory markers, or improve lung function. CONCLUSIONS: Ingestion of whole BS for 3 days does not appear to improve eosinophilic pulmonary inflammation, inflammatory and OS biomarkers, or clinical features of asthma among atopic adults with asthma despite resulting in a marked increase in serum SFN levels.

Concentrations of thiocyanate and goitrin in human plasma, their precursor concentrations in brassica vegetables, and associated potential risk for hypothyroidism.

Brassica vegetables are common components of the diet and have beneficial as well as potentially adverse health effects. Following enzymatic breakdown, some glucosinolates in brassica vegetables produce sulforaphane, phenethyl, and indolylic isothiocyanates that possess anticarcinogenic activity. In contrast, progoitrin and indolylic glucosinolates degrade to goitrin and thiocyanate, respectively, and may decrease thyroid hormone production. Radioiodine uptake to the thyroid is inhibited by 194 µmol of goitrin, but not by 77 µmol of goitrin. Collards, Brussels sprouts, and some Russian kale (Brassica napus) contain sufficient goitrin to potentially decrease iodine uptake by the thyroid. However, turnip tops, commercial broccoli, broccoli rabe, and kale belonging to Brassica oleracae contain less than 10 µmol of goitrin per 100-g serving and can be considered of minimal risk. Using sulforaphane plasma levels following glucoraphanin ingestion as a surrogate for thiocyanate plasma concentrations after indole glucosinolate ingestion, the maximum thiocyanate contribution from indole glucosinolate degradation is estimated to be 10 µM, which is significantly lower than background plasma thiocyanate concentrations (40-69 µM). Thiocyanate generated from consumption of indole glucosinolate can be assumed to have minimal adverse risks for thyroid health.

Associations between cruciferous vegetable intake and selected biomarkers among women scheduled for breast biopsies.

OBJECTIVE: To examine the relationship between dietary cruciferous vegetable intake and selected tumour biomarkers for histone acetylation (H3K9ac, H3K18ac, HDAC3 and HDAC6), proliferation (Ki-67) and cell-cycle regulation (p21) from breast tissue. DESIGN: The study used baseline data of women recruited to participate in a clinical trial of sulforaphane supplement. Dietary cruciferous vegetable intake was collected through a validated Arizona Cruciferous Vegetable Intake Questionnaire. Breast tissue was obtained from biopsy samples. Spearman correlations were calculated between intake of specific cruciferous vegetables and biomarkers. Tissue biomarkers were log2-transformed to obtain approximate normality. Linear regression analyses were conducted to examine associations between cruciferous vegetable intake and biomarkers adjusting for age and use of non-steroidal anti-inflammatory drugs. False discovery rate (FDR) was used to account for multiple comparisons. SETTING: Clinical trial baseline. SUBJECTS: Fifty-four women who had abnormal mammogram findings and were scheduled for breast biopsy. RESULTS: Mean intake of total cruciferous vegetables from all food sources was 81·7 (sd 57·3) g/d. Mean urinary total sulforaphane metabolites was 0·08 (sd 0·07) µm/mm creatinine. Total cruciferous vegetable intake was inversely associated with Ki-67 protein expression in breast ductal carcinoma in situ (DCIS) tissue (ß=-0·004; se=0·001; FDR q value=0·03), but not in benign or invasive ductal carcinoma (IDC) tissue. No association was found for other biomarkers measured (HDAC3, HDAC6, H3K9, H3K18 and p21) in all tissues examined (benign, DCIS and IDC). CONCLUSIONS: The present study sought to provide additional evidence for the potential role of sulforaphane in histone acetylation and cell proliferation. Here, we report that total cruciferous vegetable intake is associated with decreased cell proliferation in breast DCIS tissue.

Isothiocyanate metabolism, distribution, and interconversion in mice following consumption of thermally processed broccoli sprouts or purified sulforaphane.

SCOPE: Broccoli sprouts are a rich source of glucosinolates, a group of phytochemicals that when hydrolyzed, are associated with cancer prevention. Our objectives were to investigate the metabolism, distribution, and interconversion of isothiocyanates (ITCs) in mice fed thermally processed broccoli sprout powders (BSPs) or the purified ITC sulforaphane. METHODS AND RESULTS: For 1 wk, mice were fed a control diet (n = 20) or one of four treatment diets (n = 10 each) containing nonheated BSP, 60°C mildly heated BSP, 5-min steamed BSP, or 3 mmol purified sulforaphane. Sulforaphane and erucin metabolite concentrations in skin, liver, kidney, bladder, lung, and plasma were quantified using HPLC-MS/MS. Thermal intensity of BSP processing had disparate effects on ITC metabolite concentrations upon consumption. Mild heating generally resulted in the greatest ITC metabolite concentrations in vivo, followed by the nonheated and steamed BSP diets. We observed interconversion between sulforaphane and erucin species or metabolites, and report that erucin is the favored form in liver, kidney, and bladder, even when only sulforaphane is consumed. CONCLUSION: ITC metabolites were distributed to all tissues analyzed, suggesting the potential for systemic benefits. We report for the first time tissue-dependent ratio of sulforaphane and erucin, though further investigation is warranted to assess biological activity of individual forms.

Kinetics of sulforaphane in mice after consumption of sulforaphane-enriched broccoli sprout preparation.

SCOPE: Sulforaphane (SF) is a natural isothiocyanate in broccoli sprouts with cancer chemopreventive activity. This study is aimed to use different methods to develop broccoli sprout preparations to compare their ability to deliver SF to the mice and to evaluate the kinetics and biodistribution of SF. METHODS AND RESULTS: The SF-enriched sprout preparation generated by two-step procedure (quick-steaming followed by myrosinase treatment) contained the highest level of SF, which was 11 and 5 times higher than the freeze-dried fresh broccoli sprouts and the quick-steamed, freeze-dried broccoli sprouts, respectively. After oral administration of 2.5 mg/g body weight of the broccoli sprout preparations, SF was quickly absorbed and distributed throughout the tissues. The SF-rich preparation resulted in the highest exposure, with peak plasma SF concentration of 337 ng/mL, which is 6.0 times and 2.6 times higher compared to the other two preparations. A whole body physiologically based pharmacokinetic model (developed with ADAPT 5 software) suggests that distribution of SF is perfusion-limited in all organs. CONCLUSION: This study provides a broccoli sprout preparation that can serve as a good source of SF, and the model can be utilized to guide the dose designed for the use of broccoli sprout preparation in chemoprevention.

Dietary fiber intake modifies the association between secondhand smoke exposure and coronary heart disease mortality among Chinese non-smokers in Singapore.

OBJECTIVE: Secondhand smoke (SHS) exposure increases the risk for coronary heart disease (CHD) by an estimated 25% to 30% via oxidative stress and inflammatory mechanisms that may be ameliorated by dietary components. The aim of this study was to evaluate the hypothesized modifying role of nutrients with known antioxidant and/or anti-inflammatory properties on the relationship between SHS exposure and CHD mortality. METHODS: Detailed SHS exposure and dietary information was collected among 29,579 non-smokers in the Singapore Chinese Health Study, a prospective population-based cohort. The evaluation of whether or not dietary factors (ß-cryptoxanthin, lutein, ω-3 polyunsaturated fatty acids, fiber, isothiocyanates, and soy isoflavones) modified the relationship between SHS exposure and CHD mortality was conducted within multivariable Cox proportional hazards models by creating an interaction term between the potential dietary effect modifier (lowest quartile of intake versus the second through fourth quartiles of intake) and the SHS exposure (none versus living with at least one smoker[s]). RESULTS: Evidence for a main-effects association between SHS exposure and risk for CHD mortality was not observed. In stratified analyses by levels of selected dietary nutrient intake, fiber modified the effects of SHS exposure on risk for CHD mortality (P for interaction = 0.02). The adjusted hazards ratio for SHS exposure (living with at least one smoker[s] versus living with no smokers) and CHD mortality was 1.62 (95% confidence interval, 1.00-2.63) for those with low-fiber intake. In contrast, among those with high-fiber intake, there was no association with SHS exposure. CONCLUSION: We provide evidence that a diet high in fiber may ameliorate the harmful effects of SHS exposure on risk for CHD mortality.

Effects of bioactive-rich extracts of pomegranate, persimmon, nettle, dill, kale and Sideritis and isolated bioactives on arachidonic acid induced markers of platelet activation and aggregation.

BACKGROUND: The beneficial effect of fruit- and vegetable-rich diets on cardiovascular health is partly attributed to the effect of their bioactive compounds on platelet function. The aim of this study was to investigate the effects of bioactive-rich plant extracts and isolated bioactive metabolites on platelet function. Blood samples from healthy subjects (n = 4) and subjects with metabolic syndrome (n = 4) were treated with six extracts of bioactive-rich plants consumed as traditional foods in the Black Sea region, or with human metabolites of the bioactives quercetin and sulforaphane. Markers of arachidonic acid induced platelet activation and platelet-leucocyte aggregation were assessed using flow cytometry. RESULTS: In subjects with metabolic syndrome, kale extract significantly inhibited agonist induced P-selectin expression (P = 0.004). Sulforaphane-cysteine-glycine, a human plasma metabolite of the related glucosinolate, glucoraphanin, significantly inhibited P-selectin and GPIIb-IIIa expression (P = 0.020 and 0.024, respectively) and platelet-neutrophil aggregation (P = 0.027). Additionally, pomegranate extract significantly inhibited GPIIb-IIIa expression (P = 0.046) in subjects with metabolic syndrome. In healthy subjects only dill extract significantly inhibited agonist induced P-selectin expression (P = 0.025). CONCLUSION: These data show that bioactive-rich extracts of kale and pomegranate that are consumed as traditional plant foods of Black Sea area countries were effective in modulating platelet function.

Determination of benzyl isothiocyanate metabolites in human plasma and urine by LC-ESI-MS/MS after ingestion of nasturtium (Tropaeolum majus L.).

A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated to determine the concentration of benzyl isothiocyanate (BITC) metabolites in human plasma and urine. In this study, the following BITC metabolites have been considered: BITC-glutathione, BITC-cysteinylglycine, BITC-cysteine, and BITC-N-acetyl-L-cysteine. The assay development included: (1) synthesis of BITC conjugates acting as reference substances; (2) sample preparation based on protein precipitation and solid-phase extraction; (3) development of a quantitative LC-MS/MS method working in the multiple-reaction monitoring mode; (4) validation of the assay; (5) investigation of the stability and the reactivity of BITC conjugates in vitro; (6) application of the method to samples from a human intervention study. The lower limits of quantification were in the range of 21-183 nM depending on analyte and matrix, whereas the average recovery rates from spiked plasma and urine were approximately 85 and 75 %, respectively. BITC conjugates were found to be not stable in alkaline buffered solutions. After consumption of nasturtium, containing 1,000 µM glucotropaeolin, the primary source of BITC, quantifiable levels of BITC-NAC, BITC-Cys, and BITC-CysGly were found in human urine samples. Maximum levels in urine were determined 4 h after the ingestion of nasturtium. With regard to the human plasma samples, all metabolites were determined including individual distributions. The work presented provides a validated LC-MS/MS method for the determination of BITC metabolites and its successful application for the analysis of samples collected in a human intervention study.

A derivatization method for the simultaneous detection of glucosinolates and isothiocyanates in biological samples.

Various analytical methods have been established to quantify isothiocyanates (ITCs) that derive from glucosinolate hydrolysis. However, to date there is no valid method applicable to pharmacokinetic studies that detects both glucosinolates and ITCs. A specific derivatization procedure was developed for the determination of ITCs based on the formation of a stable N-(tert-butoxycarbonyl)-L-cysteine methyl ester derivative, which can be measured by high-performance liquid chromatography with ultraviolet detection after extraction with ethylacetate. The novel method, which is also applicable to the indirect determination of glucosinolates after their hydrolysis by myrosinase, was established for the simultaneous determination of glucoraphanin and sulforaphane. By derivatization, the sensitivity of ITC detection was increased 2.5-fold. Analytical recoveries from urine and plasma were greater than 75% and from feces were approximately 50%. The method showed intra- and interday variations of less than 11 and 13%, respectively. Applicability of the method was demonstrated in mice that received various doses of glucoraphanin or that were fed a glucoraphanin-rich diet. Besides glucoraphanin and sulforaphane, glucoerucin and erucin were detected in urine and feces of mice. The novel method provides an essential tool for the analysis of bioactive glucosinolates and their hydrolysis products and, thus, will contribute to the elucidation of their bioavailability.

DTPA complexation of bismuth in human blood serum.

The in vivo(212)Pb/(212)Bi generator is promising for application in targeted alpha therapy (TAT) of cancer. One main limitation of its therapeutic application is due to potential release of (212)Bi from the radioconjugate upon radioactive decay of the mother nuclide (212)Pb, potentially leading to irradiation of healthy tissue. The objective of the present work is to assess whether the chelate CHX-A''-DTPA (N-(2-aminoethyl)-trans-1,2-diaminocyclohexane-N,N',N''-pentaacetic acid) bound to a biological carrier molecule may be able to re-complex released (212)Bi under in vivo conditions to limit its translocation from the target site. CHX-A''-DTPA was bound to bovine gamma globulin (BGG) to mimic a model conjugate and the stability of the Bi-CHX-A''-DTPA-BGG conjugate was studied in blood serum by ultrafiltration. TRLFS experiments using Cm(III) as a fluorescent probe demonstrated that linking CHX-A''-DTPA to BGG does not affect the coordination properties of the ligand. Furthermore, comparable stability constants were observed between Bi(III) and free CHX-A''-DTPA, BGG-bound CHX-A''-DTPA and DTPA. The complexation constants determined between Bi(III) and the chelate molecules are sufficiently high to allow ultra trace amounts of the ligand to efficiently compete with serum transferrin controlling Bi(III) speciation in blood plasma conditions. Nevertheless, CHX-A''-DTPA is not able to complex Bi(III) generated in blood serum because of the strong competition between Bi(III) and Fe(II) for the ligand. In other words, CHX-A''-DTPA is not "selective" enough to limit Bi(iii) release in the body when applying the (212)Pb/(212)Bi in vivo generator.

Enhancing sulforaphane absorption and excretion in healthy men through the combined consumption of fresh broccoli sprouts and a glucoraphanin-rich powder.

Sulforaphane (SF) is a chemopreventive isothiocyanate (ITC) derived from glucoraphanin (GRP) hydrolysis by myrosinase, a thioglucoside present in broccoli. The ability of broccoli powders sold as supplements to provide dietary SF is often of concern as many supplements contain GRP, but lack myrosinase. In a previous study, biomarkers of SF bioavailability from a powder rich in GRP, but lacking myrosinase, were enhanced by co-consumption of a myrosinase-containing air-dried broccoli sprout powder. Here, we studied the absorption of SF from the GRP-rich powder used in the previous study, but in combination with fresh broccoli sprouts, which are commercially available and more applicable to the human diet than air-dried sprout powder. A total of four participants each consumed four meals (separated by 1 week) consisting of dry cereal and yogurt with sprouts equivalent to 70 µmol SF, GRP powder equivalent to 120 µmol SF, both or neither. Metabolites of SF were analysed in blood and urine. The 24 h urinary SF-N-acetylcysteine recovery was 65, 60 and 24 % of the dose ingested from combination, broccoli sprout and GRP powder meals, respectively. In urine and plasma, ITC appearance was delayed following the GRP powder meal compared with the sprout and combination meals. Compared with the GRP powder or sprouts alone, combining broccoli sprouts with the GRP powder synergistically enhanced the early appearance of SF, offering insight into the combination of foods for improved health benefits of foods that reduce the risk for cancer.

Development and validation of an LC-MS-MS method for the simultaneous determination of sulforaphane and its metabolites in rat plasma and its application in pharmacokinetic studies.

A highly sensitive and simple high-performance liquid chromatographic-tandem mass spectrometric (LC-MS-MS) assay is developed and validated for the quantification of sulforaphane and its metabolites in rat plasma. Sulforaphane (SFN) and its metabolites, sulforaphane glutathione (SFN-GSH) and sulforaphane N-acetyl cysteine (SFN-NAC) conjugates, are extracted from rat plasma by methanol-formic acid (100:0.1, v/v) and analyzed using a reversed-phase gradient elution on a Develosil 3 µm RP-Aqueous C(30) 140Å column. A 15-min linear gradient with acetonitrile-water (5:95, v/v), containing 10 mM ammonium acetate and 0.2% formic acid, as mobile phase A, and acetonitrile-water (95:5, v/v), containing 10 mM ammonium acetate and 0.2% formic acid as mobile phase B, is used. Sulforaphane and its metabolites are well separated. Sulforaphene is used as the internal standard. The lower limits of quantification are 1 ng/mL for SFN and 10 ng/mL for both SFN-NAC and SFN-GSH. The calibration curves are linear over the concentration range of 25-20,000 ng/mL of plasma for each analyte. This novel LC-MS-MS method shows satisfactory accuracy and precision and is sufficiently sensitive for the performance of pharmacokinetic studies in rats.

Sulforaphane absorption and excretion following ingestion of a semi-purified broccoli powder rich in glucoraphanin and broccoli sprouts in healthy men.

Sulforaphane (SF) is a chemopreventive isothiocyanate (ITC) derived from the myrosinase-catalyzed hydrolysis of glucoraphanin, a thioglucoside present in broccoli. Broccoli supplements often contain glucoraphanin but lack myrosinase, putting in question their ability to provide dietary SF. This study compared the relative absorption of SF from air-dried broccoli sprouts rich in myrosinase and a glucoraphanin-rich broccoli powder lacking myrosinase, individually and in combination. Subjects (n=4) each consumed 4 meals consisting of dry cereal and yogurt with 2 g sprouts, 2 g powder, both, or neither. Blood and urine were analyzed for SF metabolites. The 24 h urinary SF recovery was 74%, 49%, and 19% of the dose ingested from broccoli sprouts, combination, and broccoli powder meals, respectively. Urinary and plasma ITC appearance was delayed from the broccoli powder compared to the sprouts and combination. A liver function panel indicated no toxicity from any treatment at 24 h. These data indicate a delayed appearance in plasma and urine of SF from the broccoli powder relative to SF from myrosinase-rich sprouts. Combining broccoli sprouts with the broccoli powder enhanced SF absorption from broccoli powder, offering the potential for development of foods that modify the health impact of broccoli products.