Lipidome Alterations with Exercise Among People With and Without HIV: An Exploratory Study

Age-related comorbidities and physical function impairments in aging people with HIV (PWH) can be improved through exercise interventions. The mechanisms underlying these improvements, including lipidomic changes, are unknown. Sedentary adults (50-75 years old) with or without HIV participated in supervised endurance/resistance exercise for 24 weeks. Plasma lipid concentrations (∼1,200 lipid species from 13 lipid classes) at baseline and week 24 were measured by mass spectrometry. Given multiple comparisons, unadjusted and Benjamini-Hochberg corrected p values are reported. Analyses are considered exploratory. Twenty-five PWH and 24 controls had paired samples at baseline and week 24. The change in total triacylglycerol (TAG) concentrations after exercise intervention differed between groups (unadj-p = 0.006, adj-p = 0.078) with concentrations increasing among controls, but not among PWH. Changes in concentrations of TAG species composed of long-chain fatty acids differed between groups (unadj-p < 0.04) with increases among controls, but not among PWH. Changes in total diacylglycerol (DAG) concentration from baseline to week 24 differed between groups (unadj-p = 0.03, adj-p = 0.2) with an increase in PWH and a nonsignificant decrease in controls. Baseline to week 24 changes in DAGs composed of palmitic acid (16:0), palmitoleic acid (16:1), and stearic acid (18:0) differed by serostatus (unadj-p = 0.009-0.03; adj-p 0.10-0.12), with nonsignificant increases and decreases in concentrations in PWH and controls, respectively. Concentrations of individual lysophosphatidylcholine (LPC) and ceramide (CER) species also differed by HIV serostatus (unadj-p < = 0.05). Although exploratory, the effects of exercise on the lipidome may differ among people with and without HIV, potentially due to underlying alterations in lipid processing and fatty acid oxidation in PWH. Clinical Trials NCT02404792.

Modulation of the oral glucocorticoid system during black raspberry mediated oral cancer chemoprevention

Recent reports suggest that glucocorticoids (GCs), which can be synthesized in the oral mucosa, play an important role in cancer development. Therefore, the objectives of this study were to characterize the role of the oral GC system in oral cancer, and determine the effect of black raspberry (BRB) administration on GC modulation during oral cancer chemoprevention. We determined the expression of GC enzymes in various oral cancer cell lines, and investigated the role of the GC inactivating enzyme HSD11B2 on CAL27 oral cancer cells using siRNA mediated knockdown approaches. Using two in vivo models of oral carcinogenesis with 4-nitroquinoline-1-oxide (4NQO) carcinogen on C57Bl/6 mice and F344 rats, we determined the effect of BRB on GC modulation during HNSCC chemoprevention. Our results demonstrate that HSD11B2, which inactivates cortisol to cortisone, is downregulated during oral carcinogenesis in clinical and experimental models. Knockdown of HSD11B2 in oral cancer cells promotes cellular proliferation, invasion and expression of angiogenic biomarkers EGFR and VEGFA. An ethanol extract of BRB increased HSD11B2 expression on oral cancer cells. Dietary administration of 5% BRB increased Hsd11b2 gene and protein expression and reduced the active GC, corticosterone, in cancer-induced mouse tongues. Our results demonstrate that the oral GC system is modulated during oral carcinogenesis, and black raspberry administration upregulates Hsd11b2 during oral cancer chemoprevention. In conclusion, our findings challenge the use of synthetic glucocorticoids in head and neck cancer, and support the use of natural product alternatives that potentially modulate GC metabolism in a manner that supports oral cancer chemoprevention.

Macrophage maturation from blood monocytes is altered in people with HIV, and is linked to serum lipid profiles and activation indices: A model for studying atherogenic mechanisms

People with HIV (PWH) are at increased risk for atherosclerotic cardiovascular disease (ASCVD). Proportions of vascular homing monocytes are enriched in PWH; however, little is known regarding monocyte-derived macrophages (MDMs) that may drive atherosclerosis in this population. We isolated PBMCs from people with and without HIV, and cultured these cells for 5 days in medium containing autologous serum to generate MDMs. Differential gene expression (DGE) analysis of MDMs from PWH identified broad alterations in innate immune signaling (IL-1β, TLR expression, PPAR βδ) and lipid processing (LXR/RXR, ACPP, SREBP1). Transcriptional changes aligned with the functional capabilities of these cells. Expression of activation markers and innate immune receptors (CD163, TLR4, and CD300e) was altered on MDMs from PWH, and these cells produced more TNFα, reactive oxygen species (ROS), and matrix metalloproteinases (MMPs) than did cells from people without HIV. MDMs from PWH also had greater lipid accumulation and uptake of oxidized LDL. PWH had increased serum levels of free fatty acids (FFAs) and ceramides, with enrichment of saturated FAs and a reduction in polyunsaturated FAs. Levels of lipid classes and species that are associated with CVD correlated with unique DGE signatures and altered metabolic pathway activation in MDMs from PWH. Here, we show that MDMs from PWH display a pro-atherogenic phenotype; they readily form foam cells, have altered transcriptional profiles, and produce mediators that likely contribute to accelerated ASCVD.

People with HIV (PWH) are at greater risk for developing cardiovascular disease (CVD) than the general public, but the mechanisms underlying this increased risk are poorly understood. Macrophages play key roles in the pathogenesis of atherosclerosis, and are potential targets for therapeutic intervention. Here, we investigate phenotypic and functional abnormalities in monocyte-derived macrophages (MDMs) isolated from PWH that may drive CVD risk in this population. MDMs were differentiated in the presence of autologous serum, enabling us to explore the contributions of serum components (lipids, inflammatory cytokines, microbial products) as drivers of altered MDM function. We link serum levels of inflammatory biomarkers and CVD-associated lipid species to MDM activation. Our study provides new insight into drivers of pro-atherogenic MDM phenotype in PWH, and identifies directions for future study and potential intervention strategies to mitigate CVD risk.

Dietary Black Raspberries Impact the Colonic Microbiome and Phytochemical Metabolites in Mice

SCOPE

Black raspberries (BRB) are a rich source of bioactive phytochemicals, including anthocyanins and ellagitannins. These phytochemicals are poorly absorbed and may be transformed by gut microbiota into various metabolites that may impact the colonic mucosa or upon absorption have systemic bioactivity. The objective of this study is to define the impact of a BRB-containing diet on the colon microbiome in mice and quantify the phytochemical metabolites in the colon contents and circulation.

METHODS AND RESULTS

Male mice were fed 10% w/w freeze-dried BRB powder for 6 weeks. The colonic microbiota was evaluated by 16S rRNA gene sequencing. Anthocyanin and ellagitannin metabolites, protocatechuic acid, and urolithins were analyzed by HPLC-MS/MS. The BRB diet impacted colon mucosal microbial composition with a more robust effect observed on the luminal microflora. BRB-derived protocatechuic acid and urolithins were quantified in the colon, luminal contents, plasma, liver, and prostate with protocatechuic acid present in higher concentrations compared to urolithins.

CONCLUSION

This study highlights the complex interactions between dietary phytochemicals, the host microbiome, and metabolism. It is demonstrated that microbially produced phytochemical metabolites are present in the colon and systemic circulation where they may exert biological activity.

Uptake and metabolism of β-apo-8'-carotenal, β-apo-10'-carotenal, and β-apo-13-carotenone in Caco-2 cells

β-Apocarotenoids are eccentric cleavage products of carotenoids formed by chemical and enzymatic oxidations. They occur in foods containing carotenoids and thus might be directly absorbed from the diet. However, there is limited information about their intestinal absorption. The present research examined the kinetics of uptake and metabolism of β-apocarotenoids. Caco-2 cells were grown on 6-well plastic plates until a differentiated cell monolayer was achieved. β-Apocarotenoids were prepared in Tween 40 micelles, delivered to differentiated cells in serum-free medium, and incubated at 37°C for up to 8 h. There was rapid uptake of β-apo-8'-carotenal into cells, and β-apo-8'-carotenal was largely converted to β-apo-8'-carotenoic acid and a minor metabolite that we identified as 5,6-epoxy-β-apo-8'-carotenol. There was also rapid uptake of β-apo-10'-carotenal into cells, and β-apo-10'-carotenal was converted into a major metabolite identified as 5,6-epoxy-β-apo-10'-carotenol and a minor metabolite that is likely a dihydro-β-apo-10'-carotenol. Finally, there was rapid cellular uptake of β-apo-13-carotenone, and this compound was extensively degraded. These results suggest that dietary β-apocarotenals are extensively metabolized in intestinal cells via pathways similar to the metabolism of retinal. Thus, they are likely not absorbed directly from the diet.

Optimization of extraction methods for quantification of microcystin-LR and microcystin-RR in fish, vegetable, and soil matrices using UPLC-MS/MS

Human-driven environmental change has increased the occurrence of harmful cyanobacteria blooms in aquatic ecosystems. Concomitantly, exposure to microcystin (MC), a cyanobacterial toxin that can accumulate in animals, edible plants, and agricultural soils, has become a growing public health concern. For accurate estimation of health risks and timely monitoring, availability of reliable detection methods is imperative. Nonetheless, quantitative analysis of MCs in many types of biological and environmental samples has proven challenging because matrix interferences can hinder sample preparation and extraction procedures, leading to poor MC recovery. Herein, controlled experiments were conducted to enhance the use of ultra-performance liquid-chromatography tandem-mass spectrometry (UPLC-MS/MS) to recover MC-LR and MC-RR at a range of concentrations in seafood (fish), vegetables (lettuce), and environmental (soil) matrices. Although these experiments offer insight into detailed technical aspects of the MC homogenization and extraction process (i.e., sonication duration and centrifugation speed during homogenization; elution solvent to use during the final extraction), they centered on identifying the best (1) solvent system to use during homogenization (2-3 tested per matrix) and (2) single-phase extraction (SPE) column type (3 tested) to use for the final extraction. The best procedure consisted of the following, regardless of sample type: centrifugation speed = 4200 × g; elution volume = 8 mL; elution solvent = 80% methanol; and SPE column type = hydrophilic-lipophilic balance (HLB), with carbon also being satisfactory for fish. For sonication, 2 min, 5 min, and 10 min were optimal for fish, lettuce, and soil matrices, respectively. Using the recommended HLB column, the solvent systems that led to the highest recovery of MCs were methanol:water:butanol for fish, methanol:water for lettuce, and EDTA-Na₄P₂O₇ for soils. Given that the recommended procedures resulted in average MC-LR and MC-RR recoveries that ranged 93 to 98%, their adoption for the preparation of samples with complex matrices before UPLC-MS/MS analysis is encouraged.

High-Pressure Processing of Broccoli Sprouts: Influence on Bioactivation of Glucosinolates to Isothiocyanates

Effects of high-pressure processing (HPP, 100-600 MPa for 3 min at 30 °C) on the glucosinolate content, conversion to isothiocyanates, and color changes during storage in fresh broccoli sprouts were investigated. A mild heat treatment (60 °C) and boiling (100 °C) were used as positive and negative controls, respectively. Glucosinolates were quantified using liquid chromatography-mass spectrometry, and isothiocyanates were quantified using high-performance liquid chromatography-photodiode array detection. A formation of isothiocyanates was observed in all high-pressure-treated sprouts. The highest degree of conversion (85%) was observed after the 600 MPa treatment. Increased isothiocyanate formation at 400-600 MPa suggests an inactivation of the epithiospecifier protein. During storage, color changed from green to brownish, reflected by increasing a* values and decreasing L* values. This effect was less pronounced for sprouts treated at 100 and 600 MPa, indicating an influence on the responsible enzymes. In summary, HPP had no negative effects on the glucosinolate-myrosinase system in broccoli sprouts.

Application of a low polyphenol or low ellagitannin dietary intervention and its impact on ellagitannin metabolism in men

SCOPE

Plant polyphenols are widespread in the American diet, yet estimated intake is uncertain. We examine the application of the Polyphenol Explorer® (PED) database to quantify polyphenol and ellagitannin (ET) intake of men with prostate cancer and tested the implementation of diets restricted in polyphenols or ETs.

METHODS AND RESULTS

Twenty-four men enrolled in a 4-week trial were randomized to usual, low-polyphenol or low-ET diet. Estimated polyphenol and ET intakes were calculated from 3-day diet records utilizing the PED. Urine and plasma metabolites were quantified by UPLC-MS. Adherence to the restricted diets was 95% for the low polyphenol and 98% for low-ET diet. In the usual diet, estimated dietary polyphenol intake was 1568 ± 939 mg/day, with coffee/tea beverages (1112 ± 1028 mg/day) being the largest contributors and estimated dietary ET intake was 12 ± 13 mg/day. The low-polyphenol and low-ET groups resulted in a reduction of total polyphenols by 45% and 85%, respectively, and omission of dietary ETs. UPLC analysis of urinary host and microbial metabolites reflect ET intake.

CONCLUSION

PED is a useful database for assessing exposure to polyphenols. Diets restricted in total polyphenol or ET intake are feasible and UPLC assessment of ET metabolites is reflective of dietary intake.

Abstract 4317: Black raspberries show potent activity in prevention of experimental squamous cell esophageal cancer compared to a combination of selective COX-2 and iNOS inhibitors

Esophageal squamous cell carcinoma (SCC) remains a major health threat worldwide and preventive strategies are needed. We previously reported that overexpression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) are correlated with nitrosamine-induced squamous carcinogenesis of the esophagus and the selective iNOS and COX-2 inhibitors significantly inhibit incidence and progression. We also demonstrated anti-cancer activity of black raspberries (BRB) in a rodent model of esophageal SCC. The objective of the current study was to compare the impact of BRB versus the combination of celecoxib, a selective COX-2 inhibitor, and S,S’-1,4-phenylene-bis(1,2-ethanediyl)bis-isothiourea (PBIT), a selective iNOS inhibitor, in inhibition of SCC of the esophagus, and to elucidate molecular mechanism of an effective cancer prevention. We found that BRB is superior to the combination of two drugs in suppression of premalignant tissue growth in the rat esophagi. Moreover, rats fed BRB have lower tumor multiplicity than those fed celcecoxib + PBIT. Our data indicated that BRB also shows a potent inhibitory effect on esophageal iNOS and COX-2, in addition to modulating several associated oncogenic cell signaling pathways. We further conducted parallel mechanistic studies in vitro using BRB anthocyanins and the above two drugs. Our findings demonstrated that dietary BRB is superior to the combination of two chemopreventive pharmaceutical agents in prevention of experimental squamous cell esophageal cancer, suggesting the potential value of additional translational studies in developing food-based products using BRB for the prevention of esophageal SCC carcinogenesis in humans (Supported by NIH/NCI R01 CA131073).

Citation Format: Ni Shi, Kenneth M. Riedl, Steven J. Schwartz, Xiaoli Zhang, Steven K. Steven, Tong Chen. Black raspberries show potent activity in prevention of experimental squamous cell esophageal cancer compared to a combination of selective COX-2 and iNOS inhibitors. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 4317.

Abstract LB-295: Food-based approach to cancer prevention: A phase I assessment of amorphous confections in modulating exposure and metabolism of black raspberry compounds in the oral cavity

Background: Oral cancer remains a major global malignancy, largely due to persistence of tobacco use worldwide. Preventive strategies focusing upon high risk individuals due to long term tobacco use or presence of pre-malignancy are needed. Based upon strong epidemiologic and laboratory evidence we have developed a black raspberry food-based product targeting this population and have tested variations in a phase I trial.

Objective:

1. To test three amorphous solids (glassy, elastic, and viscous) containing a bioactive rich black raspberry (BRB) fraction in a confectionary system for compliance.

2. To investigate the impact of amorphous structure in modulating oral exposure and metabolism of black raspberry compounds in the oral cavity as measured by differences in duration of black raspberry exposure and profile of black raspberry metabolites from saliva.

Methods: A four week, phase I, randomized, parallel study design with 60 non-smoking adults was used to investigate three amorphous forms having different release rates (prolonged, intermediate, and rapid), each at two doses (4 or 8 g BRB/day). Salivary kinetics and changes in black raspberry composition among and within individuals were assessed. HPLC with Tandem MS/MS was used to quantify and characterize black raspberry compounds from the confections and profile them in the saliva.

Results: All confections were well accepted having excellent adherence (94 ± 2%). Toxicities were limited to a grade I toxicity (NIH criteria). Oral residence time was 74% longer and saliva volume was 42% greater with glassy than the other two amorphous forms. Anthocyanin (cyanidin-3-glucoside) and ellagitannins were prevalent compounds in the saliva.

Conclusions: Three amorphous confectionary forms of a BRB food-based delivery vehicle demonstrated excellent compliance, with the glassy form showing potential for greater oral distribution, suggesting the potential for greater bioactivity. Food science and technology provides many strategies to develop novel and fully characterized food products for cancer prevention trials.

Citation Format: Jennifer H. Ahn-Jarvis, Steven K. Clinton, Elizabeth M. Grainger, Christina Simpson, Junnan Gu, Matthew D. Teegarden, Kenneth M. Riedl, Thomas J. Knobloch, Christopher M. Weghorst, Steven J. Schwartz, Yael Vodovotz. Food-based approach to cancer prevention: A phase I assessment of amorphous confections in modulating exposure and metabolism of black raspberry compounds in the oral cavity. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr LB-295.

Substrate Specificity of Purified Recombinant Chicken β-Carotene 9',10'-Oxygenase (BCO2)

Provitamin A carotenoids are oxidatively cleaved by β-carotene 15,15'-dioxygenase (BCO1) at the central 15-15' double bond to form retinal (vitamin A aldehyde). Another carotenoid oxygenase, β-carotene 9',10'-oxygenase (BCO2) catalyzes the oxidative cleavage of carotenoids at the 9'-10' bond to yield an ionone and an apo-10'-carotenoid. Previously published substrate specificity studies of BCO2 were conducted using crude lysates from bacteria or insect cells expressing recombinant BCO2. Our attempts to obtain active recombinant human BCO2 expressed in Escherichia coli were unsuccessful. We have expressed recombinant chicken BCO2 in the strain E. coli BL21-Gold (DE3) and purified the enzyme by cobalt ion affinity chromatography. Like BCO1, purified recombinant chicken BCO2 catalyzes the oxidative cleavage of the provitamin A carotenoids β-carotene, α-carotene, and β-cryptoxanthin. Its catalytic activity with β-carotene as substrate is at least 10-fold lower than that of BCO1. In further contrast to BCO1, purified recombinant chicken BCO2 also catalyzes the oxidative cleavage of 9-cis-β-carotene and the non-provitamin A carotenoids zeaxanthin and lutein, and is inactive with all-trans-lycopene and β-apocarotenoids. Apo-10'-carotenoids were detected as enzymatic products by HPLC, and the identities were confirmed by LC-MS. Small amounts of 3-hydroxy-β-apo-8'-carotenal were also consistently detected in BCO2-β-cryptoxanthin reaction mixtures. With the exception of this activity with β-cryptoxanthin, BCO2 cleaves specifically at the 9'-10' bond to produce apo-10'-carotenoids. BCO2 has been shown to function in preventing the excessive accumulation of carotenoids, and its broad substrate specificity is consistent with this.

Absorption and Distribution Kinetics of the 13C-Labeled Tomato Carotenoid Phytoene in Healthy Adults

BACKGROUND

Phytoene is a tomato carotenoid that may contribute to the apparent health benefits of tomato consumption. Although phytoene is a less prominent tomato carotenoid than lycopene, it is a major carotenoid in various human tissues. Phytoene distribution to plasma lipoproteins and tissues differs from lycopene, suggesting the kinetics of phytoene and lycopene differ.

OBJECTIVE

The objective of this study was to characterize the kinetic parameters of phytoene absorption, distribution, and excretion in adults, to better understand why biodistribution of phytoene differs from lycopene.

METHODS

Four adults (2 males, 2 females) maintained a controlled phytoene diet (1-5 mg/d) for 42 d. On day 14, each consumed 3.2 mg (13)C-phytoene, produced using tomato cell suspension culture technology. Blood samples were collected at 0, 1-15, 17, 21, and 24 h and 2, 3, 4, 7, 10, 14, 17, 21, and 28 d after (13)C-phytoene consumption. Plasma-unlabeled and plasma-labeled phytoene concentrations were determined using ultra-HPLC-quadrupole time-of-flight-mass spectrometry, and data were fit to a 7-compartment carotenoid kinetic model using WinSAAM 3.0.7 software.

RESULTS

Subjects were compliant with a controlled phytoene diet, consuming a mean ± SE of 2.5 ± 0.6 mg/d, resulting in a plasma unlabeled phytoene concentration of 71 ± 14 nmol/L. A maximal plasma (13)C-phytoene concentration of 55.6 ± 5.9 nM was achieved 19.8 ± 9.2 h after consumption, and the plasma half-life was 2.3 ± 0.2 d. Compared with previous results for lycopene, phytoene bioavailability was nearly double at 58% ± 19%, the clearance rate from chylomicrons was slower, and the rates of deposition into and utilization by the slow turnover tissue compartment were nearly 3 times greater.

CONCLUSIONS

Although only differing from lycopene by 4 double bonds, phytoene exhibits markedly different kinetic characteristics in human plasma, providing insight into metabolic processes contributing to phytoene enrichment in plasma and tissues compared with lycopene. This trial was registered at clinicaltrials.gov as NCT01692340.

Compartmental and noncompartmental modeling of ¹³C-lycopene absorption, isomerization, and distribution kinetics in healthy adults

BACKGROUND

Lycopene, which is a red carotenoid in tomatoes, has been hypothesized to mediate disease-preventive effects associated with tomato consumption. Lycopene is consumed primarily as the all-trans geometric isomer in foods, whereas human plasma and tissues show greater proportions of cis isomers.

OBJECTIVE

With the use of compartmental modeling and stable isotope technology, we determined whether endogenous all-trans-to-cis-lycopene isomerization or isomeric-bioavailability differences underlie the greater proportion of lycopene cis isomers in human tissues than in tomato foods.

DESIGN

Healthy men (n = 4) and women (n = 4) consumed (13)C-lycopene (10.2 mg; 82% all-trans and 18% cis), and plasma was collected over 28 d. Unlabeled and (13)C-labeled total lycopene and lycopene-isomer plasma concentrations, which were measured with the use of high-performance liquid chromatography-mass spectrometry, were fit to a 7-compartment model.

RESULTS

Subjects absorbed a mean ± SEM of 23% ± 6% of the lycopene. The proportion of plasma cis-(13)C-lycopene isomers increased over time, and all-trans had a shorter half-life than that of cis isomers (5.3 ± 0.3 and 8.8 ± 0.6 d, respectively; P < 0.001) and an earlier time to reach maximal plasma concentration than that of cis isomers (28 ± 7 and 48 ± 9 h, respectively). A compartmental model that allowed for interindividual differences in cis- and all-trans-lycopene bioavailability and endogenous trans-to-cis-lycopene isomerization was predictive of plasma (13)C and unlabeled cis- and all-trans-lycopene concentrations. Although the bioavailability of cis (24.5% ± 6%) and all-trans (23.2% ± 8%) isomers did not differ, endogenous isomerization (0.97 ± 0.25 μmol/d in the fast-turnover tissue lycopene pool) drove tissue and plasma isomeric profiles.

CONCLUSION

(13)C-Lycopene combined with physiologic compartmental modeling provides a strategy for following complex in vivo metabolic processes in humans and reveals that postabsorptive trans-to-cis-lycopene isomerization, and not the differential bioavailability of isomers, drives tissue and plasma enrichment of cis-lycopene. This trial was registered at clinicaltrials.gov as NCT01692340.

Isoflavone pharmacokinetics and metabolism after consumption of a standardized soy and soy-almond bread in men with asymptomatic prostate cancer

Epidemiologic associations suggest that populations consuming substantial amounts of dietary soy exhibit a lower risk of prostate cancer. A 20-week randomized, phase II, crossover trial was conducted in 32 men with asymptomatic prostate cancer. The crossover involved 8 weeks each of soy bread (SB) and soy-almond bread (SAB). The primary objective was to investigate isoflavone bioavailability and metabolite profile. Secondary objectives include safety, compliance, and assessment of biomarkers linked to prostate carcinogenesis. Two distinct SBs were formulated to deliver approximately 60 mg aglycone equivalents of isoflavones per day. The isoflavones were present as aglycones (∼78% as aglycones) in the SAB whereas in the standard SB predominantly as glucosides (18% total isoflavones as aglycones). Compliance to SB (97% ± 4%) and SAB (92% ± 18%) was excellent; toxicity was rare and limited to grade 1 gastrointestinal complaints. Pharmacokinetic studies between SB and SAB showed modest differences. Peak serum concentration time (Tmax) was significantly faster with SAB meal compared with SB in some isoflavonoids, and AUC0 to 24 h of dihydrodaidzein and O-desmethylangolensin was significantly greater after an SB meal. An exploratory cluster analysis was used to identify four isoflavone-metabolizing phenotypes. Insulin-like growth factor-binding protein increased significantly by 41% (P = 0.024) with soy intervention. Findings from this study provide the necessary framework to study isoflavone-metabolizing phenotypes as a strategy for identification of individuals that might benefit or show resistance to cancer preventive strategies using dietary soy. A standardized SB used for future large-scale randomized clinical trials to affect human prostate carcinogenesis is feasible.

Abstract 4278: Soy isoflavones and their metabolites modulate IL-12-induced NK cell IFN-γ production

Soybeans and foods derived from them are a rich source of phytochemcials that have gained attention due to their ability to affect obesity, metabolism, cancer, and inflammation. Soy isoflavones (genistein and daidzein) have also been shown to be differentially metabolized between individuals. This is presumably due to differences in gut microbiota, and can lead to production of terminal isoflavone metabolites such as O-desmethylangolensin (ODMA) and equol. In a prior phase-I clinical study conducted by our group, patients with prostate cancer received a novel soy-enriched bread product. Analysis of blood and urine following soy intervention revealed that men clustered into distinct groups based on their ability to metabolize daidizein into either ODMA or equol. Reduced pro-inflammatory cytokines and percentages of Tregs and MDSC were also observed in the blood of patients after 8 weeks of soy bread intervention as compared to baseline. Given these differences, we hypothesized that individual isoflavones and metabolites would have unique immunomodulatory effects upon human natural killer (NK) cell function. Although a limited number of prior studies have evaluated how soy isoflavones or their metabolites modulate inflammation and different immune subsets (monocytes, macrophages, DCs), their role in NK cell biology remains poorly defined. Understanding the role of soy isoflavones and their metabolites in regulating NK cell activity is critical due to NK cells’ importance in the anti-tumor response and immunosurveillance. We found that the soy isoflavones and their metabolites did not affect the viability of healthy donor PBMC (n = 3) at concentrations as high as 25μM. However, pre-treatment of healthy donor PBMC (n = 3) with genistein (mean 7.1 ng/ml ±1.3) or equol (mean 6.7 ng/ml ±1.8) for 4 hours and then stimulated with IL-12/18 for 72 hours decreased IFN-γ production compared to unstimulated controls (mean 26.7 ng/ml ±16.1). In contrast, daidzein and ODMA had no effect. We next utilized intracellular flow cytometry to determine the cellular subset(s) that were modulated by soy isoflavones or their metabolites. These data revealed that only genistein and equol decreased the percentage of IL-12/18 induced IFN-γ producing NK cells (CD56+CD3-) by 30% and 53%, respectively. There was no observed difference in other IFN-γ producing immune subsets (T and NKT cells) when cultured with the soy isoflavones or metabolites. Furthermore, we found soy isoflavones and metabolites altered in vitro cytotoxicity of human IL-12 stimulated NK cells. Ongoing studies in our laboratory are elucidating the precise signaling pathways downstream of IL-12 in human NK cells that are modulated in response to soy isoflavones and their bioactive metabolites. This study provides critical insight regarding the impact of dietary soy on NK cell mediated responses potentially informing the use of soy during chemopreventive or immune based therapies.

Citation Format: Thomas A. Mace, Samantha King, Matthew Farren, Elizabeth McMichael, Steven Scoville, William E. Carson, Gregory Young, Jennifer Thomas-Ahner, Kenneth M. Riedl, Steven Schwartz, Steven K. Clinton, Gregory Lesinski. Soy isoflavones and their metabolites modulate IL-12-induced NK cell IFN-γ production. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4278. doi:10.1158/1538-7445.AM2015-4278

Abstract 1902: Experimental investigations on the effects of specific berry phytochemicals and metabolites in esophageal cancer prevention in vitro

In our previous studies, we found that both lyophilized strawberries and black raspberries exhibit significant and similar potential in prevention of esophageal squamous cell carcinoma (SCC). Berry phytochemicals are considered to be responsible, at least in part, for their health benefits that have been observed in other diseases. The current study was designed to provide leads for the development of specific phytochemicals or metabolites as chemopreventive agents using the principles of pharmacognosy. Lyophilized strawberries (Fragaria ananassa) were obtained from the California Strawberry Commission. Lyophilized black raspberries (Jewel variety) were obtained from the Stokes Raspberry Farm (Wilmington, OH). Sample (100 mg) of lyophilized berries was firstly extracted with acidified acetone. Berry phytochemicals were then identified with a combination of high performance liquid chromatography/tandem mass spectrometry (HPLC-MS/MS), accessible standards, UV-vis and reported mass. The identified compounds were classified into three main categories: anthocyanins (ACN), ellagitannin/ellagic acid/ellagic acid derivatives (EAs) and flavonols. By HPLC-MS/MS analysis, we found that ACN, EAs and flavonols account for 84.2%, 12.2% and 3.6% by dry weight in lyophilized black raspberries, respectively; and 58.4%, 32.8% and 8.8% by dry weight, respectively, in lyophilized strawberries. Cyanidin-3-rutinoside (58.2%) and cyaniding-3-xylorutinoside (18.2%) are the most and second abundant anthocyanins in black raspberries. While in strawberries, pelargonidin-3-glucoside accounts for 41.1%, most individual anthocyanin by dry weight. Pelargonidin-3-rutinoside is the only anthocyanin identified in both black raspberries and strawberries. There are more EAs in strawberries (32.8%) compared to them in black raspberries (12.2%). We also identified agrimoniin, a main ellagitannin, as the second most abundant phenolic by dry weight (16.2%) in strawberries. We treated esophageal SCC KYSE cell lines with cyanidin-3-rutinoside, pelargonidin-3-rutinoside and their metabolites including protocatechuic acid and 4-hydroxybenzoic acid. Our data showed that major berry anthocyanins and their metabolites can significantly inhibit esophageal SCC cell proliferation in vitro. Further research efforts are needed to test their abilities to modulate oncogenic signaling in esophageal SCC, many of which are currently underway.

Citation Format: Ni Shi, Kenneth M. Riedl, Steven J. Schwartz, Xiaoli Zhang, Zui Pan, Steven K. Clinton, Tong Chen. Experimental investigations on the effects of specific berry phytochemicals and metabolites in esophageal cancer prevention in vitro. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1902. doi:10.1158/1538-7445.AM2015-1902

Abstract LB-246: Dietary strawberry phytochemical metabolism in saliva, urine, and genetic biomarkers in smokers and non-smokers

Background: Epidemiological studies implicate tobacco smoke and alcohol consumption are critical risk factors for oral cancer. Yet diets rich in strawberries have shown in rodent and cell studies to have significant protective effects which lower the risk of oral cancer. A fully-characterized strawberry confection was evaluated for safety and adherence in a 6-week, randomized, placebo-controlled, crossover trial involving smokers (n=12) and non-smokers (n=13).

Methods: Using HPLC with tandem mass spectroscopy, strawberry phytochemicals in strawberry powder, confection and saliva collected during a 30 minute timed intervention were fully characterized. Buccal tissue was evaluated using pre-validated TaqMan Gene Expression assays corresponding to known smoke-altered oral transcriptome biomarkers used for RT-qPCR analysis. UPLC with mass spectroscopy quantified ellagic acid metabolites (dimethyl-, isourolithin A, urolithin A, B, and C) in 24hr urine collections.

Results: Adherence strawberry confections intervention (equivalent to 2 cups of whole strawberries) in smoker (91%) and nonsmokers (99%) was excellent. Toxicities to strawberry intervention was limited to a grade I toxicity (NIH criteria). Significantly less ellagic acid and ellagitannins were observed in saliva compared to confection (p&lt;0.001). Anthocyanin profiles in saliva of smokers differed significantly than non-smokers. One biomarker, Ankyrin Repeat Domain 37 (ANKRD37), was found to be significantly down-regulated in smokers following strawberry confection intervention (p=0.0484). Significant increase (p&lt;0.001) in urolithin A (4.29 ± 1.16 nmol/24hr) and C (0.13 ± 0.03 nmol/24hr) was observed in all participants after strawberry intervention compared to anthocyanin-free diet or placebo intervention. Isourolithin A and urolithin B was observed in 29% and 24% of participants, respectively.

Conclusions: A fully characterized strawberry confection was utilized and significant changes in biomarkers of strawberry exposure from saliva, urine and genomic materials were observed. Both ellagitannin metabolites, urolithin A and C would be reliable biomarkers of strawberry exposure. Moreover, differences in ellagitannin metabolite profiles and in ANKRD37 between smokers and non-smokers warrant further studies.

Citation Format: Jennifer H. Ahn-Jarvis, Steven K. Clinton, Kenneth M. Riedl, Marta T. Sears, Thomas J. Knobloch, Steven J. Schwartz, Christopher M. Weghorst, Yael Vodovotz. Dietary strawberry phytochemical metabolism in saliva, urine, and genetic biomarkers in smokers and non-smokers. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr LB-246. doi:10.1158/1538-7445.AM2014-LB-246

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.

The human enzyme that converts dietary provitamin A carotenoids to vitamin A is a dioxygenase

β-Carotene 15-15'-oxygenase (BCO1) catalyzes the oxidative cleavage of dietary provitamin A carotenoids to retinal (vitamin A aldehyde). Aldehydes readily exchange their carbonyl oxygen with water, making oxygen labeling experiments challenging. BCO1 has been thought to be a monooxygenase, incorporating oxygen from O2 and H2O into its cleavage products. This was based on a study that used conditions that favored oxygen exchange with water. We incubated purified recombinant human BCO1 and β-carotene in either (16)O2-H2(18)O or (18)O2-H2(16)O medium for 15 min at 37 °C, and the relative amounts of (18)O-retinal and (16)O-retinal were measured by liquid chromatography-tandem mass spectrometry. At least 79% of the retinal produced by the reaction has the same oxygen isotope as the O2 gas used. Together with the data from (18)O-retinal-H2(16)O and (16)O-retinal-H2(18)O incubations to account for nonenzymatic oxygen exchange, our results show that BCO1 incorporates only oxygen from O2 into retinal. Thus, BCO1 is a dioxygenase.

Characterization of black raspberry functional food products for cancer prevention human clinical trials

Our team is designing and fully characterizing black raspberry (BRB) food products suitable for long-term cancer prevention studies. The processing, scale-up, and storage effects on the consistency, quality, bioactive stability, and sensory acceptability of two BRB delivery systems of various matrices are presented. BRB dosage, pH, water activity, and texture were consistent in the scale-up production. Confections retained >90% of anthocyanins and ellagitannin after processing. Nectars had >69% of anthocyanins and >66% of ellagitannin retention, which varied with BRB dosage due to the processing difference. Texture remained unchanged during storage. BRB products consumed in a prostate cancer clinical trial were well accepted in sensory tests. Thus, this study demonstrates that two different BRB foods can be formulated to meet quality standards with a consistent bioactive pattern and successfully scaled up for a large human clinical trial focusing on cancer risk and other health outcomes.

Nonanthocyanin secondary metabolites of black raspberry (Rubus occidentalis L.) fruits: identification by HPLC-DAD, NMR, HPLC-ESI-MS, and ESI-MS/MS analyses

Nonanthocyanin secondary metabolites potentially contributing to the antiproliferative bioactivity of black raspberry ( Rubus occidentalis L.) fruits were extracted in ethyl acetate and isolated by semipreparative and analytical HPLC and analyzed by NMR, HPLC-ESI-MS, and ESI-MS/MS techniques. Here we present complete and partial structures of a variety of the chemical entities such as quercetin 3-glucoside, quercetin 3-rutinoside, myricetin glucoside, dihydrokaempferol glucoside, benzoic acid β-d-glucopyranosyl ester, 3,4-dihydroxybenzoic acid, epicatechin, caffeic acid, p-coumaric acid, p-coumaryl glucoside, p-coumaryl sugar ester, ellagic acid, methyl ellagic acid acetylpentose, methyl ellagic acid valerylpentose, trans-piceid, phloretin glucoside (phloridzin), dihydrosinapic acid, salicylic acid β-d-glucopyranosyl ester, a salicylic acid derivative without attached sugar, p-alkylphenyl glucoside, and a citric acid derivative. To our knowledge, 15 of these compounds were not previously reported in black raspberry fruits.

Substrate specificity of purified recombinant human β-carotene 15,15'-oxygenase (BCO1)

Humans cannot synthesize vitamin A and thus must obtain it from their diet. β-Carotene 15,15'-oxygenase (BCO1) catalyzes the oxidative cleavage of provitamin A carotenoids at the central 15-15' double bond to yield retinal (vitamin A). In this work, we quantitatively describe the substrate specificity of purified recombinant human BCO1 in terms of catalytic efficiency values (kcat/Km). The full-length open reading frame of human BCO1 was cloned into the pET-28b expression vector with a C-terminal polyhistidine tag, and the protein was expressed in the Escherichia coli strain BL21-Gold(DE3). The enzyme was purified using cobalt ion affinity chromatography. The purified enzyme preparation catalyzed the oxidative cleavage of β-carotene with a Vmax = 197.2 nmol retinal/mg BCO1 × h, Km = 17.2 μM and catalytic efficiency kcat/Km = 6098 M(-1) min(-1). The enzyme also catalyzed the oxidative cleavage of α-carotene, β-cryptoxanthin, and β-apo-8'-carotenal to yield retinal. The catalytic efficiency values of these substrates are lower than that of β-carotene. Surprisingly, BCO1 catalyzed the oxidative cleavage of lycopene to yield acycloretinal with a catalytic efficiency similar to that of β-carotene. The shorter β-apocarotenals (β-apo-10'-carotenal, β-apo-12'-carotenal, β-apo-14'-carotenal) do not show Michaelis-Menten behavior under the conditions tested. We did not detect any activity with lutein, zeaxanthin, and 9-cis-β-carotene. Our results show that BCO1 favors full-length provitamin A carotenoids as substrates, with the notable exception of lycopene. Lycopene has previously been reported to be unreactive with BCO1, and our findings warrant a fresh look at acycloretinal and its alcohol and acid forms as metabolites of lycopene in future studies.

Abstract LB-188: Isoflavone pharmacokinetics and metabolism after consumption of soy and soy-almond bread in men with asymptomatic prostate cancer

Background: Soy phytochemicals, particularly isoflavones, are hypothesized to have anti-prostate cancer activity. Soy isoflavones are present predominantly as glucosides but when combined with β-glucosidase activity in almond meal, a greater conversion to aglycones has been observed. We hypothesized that soy bread will serve as an excellent source of soy polyphenols and that an aglycone-rich soy-almond bread (SAB) compared to a glycoside-rich soy bread (SB) will demonstrate greater bioavailability of soy isoflavones.

Methods: SB and SAB were fed in a 20 week randomized phase II cross-over trial involving 32 men with asymptomatic metastatic prostate cancer and escalating prostate specific antigen (PSA). Isoflavones were quantitated by HPLC in soy breads and isoflavone metabolites in 24h urine. HPLC-tandem mass spectrometry evaluated isoflavone pharmacokinetics in plasma. Biomarkers were determined by chemiluminescence-based assays.

Results: The aglycone composition in the SB and SAB was 18% and 78%, respectively. Compliance was 95±14%, toxicity rare and limited to grade I GI complaints (NIH_NCI criteria). Urinary isoflavone patterns over 24hours revealed that isoflavonoid metabolites were significantly greater with soy bread consumption. Plasma pharmacokinetics following a test meal showed that daidzein (p=0.028) and genistein (p=0.010) absorption was significantly faster from the aglycone-rich SAB. Interestingly, PSA doubling time was prolonged compared to pre-enrollment, in 60% of men (n=30) with soy intervention.

Conclusions: Bread is an excellent vehicle for the delivery of soy phytochemicals with outstanding compliance. Modification of soy bread with a source of β-glucosidase may enhance the initial absorption rates of isoflavones. Food products, such as SAB, with consistent and stable composition of phytochemicals can be developed that are appropriate for long-term chemoprevention studies in humans or as an adjunct to therapy.

Citation Format: Jennifer H. Ahn-Jarvis, Steven K. Clinton, Elizabeth M. Grainger, Kenneth M. Riedl, Steven J. Schwartz, Yael Vodovotz. Isoflavone pharmacokinetics and metabolism after consumption of soy and soy-almond bread in men with asymptomatic prostate cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr LB-188. doi:10.1158/1538-7445.AM2013-LB-188

Design and selection of soy breads used for evaluating isoflavone bioavailability in clinical trials

To modulate isoflavone aglycone composition within a soy functional food, soy ingredients were processed and evaluated in a soy bread system intended for clinical trials. A soy flour/soy milk mixture (SM) was boiled, fermented, steamed, or roasted prior to dough preparation. The isoflavone compositions of five processed SM and their corresponding breads combined with and without β-glucosidase-rich almonds were examined using HPLC. Isoflavone malonyl-glucosides (>80%) were converted into acetyl and simple glucoside forms (substrates more favorable for β-glucosidase) in steamed and roasted SM. Their corresponding breads had isoflavones predominately as aglycones (∼75%) with soy-almond bread with steamed SM being more consumer acceptable than roasted. Isoflavone composition in soy bread was stable during frozen storage and toasting. A suitable glycoside-rich soy bread (31.6 ± 2.1 mg aglycone equiv/slice) using unprocessed SM and an aglycone-rich soy-almond bread (31.1 ± 1.9 mg aglycone equiv/slice) using steamed SM were developed to evaluate fundamental questions of isoflavone bioavailability in clinical trials.

Anti-tumorigenicity of dietary α-mangostin in an HT-29 colon cell xenograft model and the tissue distribution of xanthones and their phase II metabolites

SCOPE

This study investigated the in vivo and in vitro activity of α-mangostin (α-MG), the most abundant xanthone in mangosteen pericarp, on HT-29 cell tumorigenicity, proliferation, and several markers of tumor cell activity, as well as the profile and amounts of xanthones in serum, tumor, liver, and feces.

METHODS AND RESULTS

Balb/c nu/nu mice were fed either control diet or diet containing 900 mg α-MG/kg. After 1 week of acclimation to diet, mice were injected subcutaneously with HT-29 cells and fed the same diets ad libitum for an additional 2 or 4 weeks. After 2 and 4 weeks, tumor mass and the concentrations of BcL-2 and β-catenin in tumors of mice fed diet with α-MG were significantly less than in mice fed control diet. Xanthones and their metabolites were identified in serum, tumor, liver, and feces. In vitro treatment of HT-29 cells with α-MG also inhibited cell proliferation and decreased expression of BcL-2 and β-catenin.

CONCLUSION

Our data demonstrate that the anti-neoplastic effect of dietary α-MG is associated with the presence of xanthones in the tumor tissue. Further investigation of the impact of beverages and food products containing xanthones on the prevention of colon cancer or as complementary therapy is merited.

Inhibition of bladder cancer by broccoli isothiocyanates sulforaphane and erucin: characterization, metabolism, and interconversion

SCOPE

Epidemiologic evidence suggests diets rich in cruciferous vegetables, particularly broccoli, are associated with lower bladder cancer risk. Our objectives are to investigate these observations and determine the role of isothiocyanates in primary or secondary bladder cancer prevention.

METHODS AND RESULTS

We initially investigate the mechanisms whereby broccoli and broccoli sprout extracts and pure isothiocyanates inhibit normal, noninvasive (RT4), and invasive (J82, UMUC3) human urothelial cell viability. Sulforaphane (IC(50) = 5.66 ± 1.2 μM) and erucin (IC(50) = 8.79 ± 1.3 μM) are found to be the most potent inhibitors and normal cells are least sensitive. This observation is associated with downregulation of survivin, epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor 2 (HER2/neu), G(2) /M cell cycle accumulation, and apoptosis. In a murine UMUC3 xenograft model, we fed semipurified diets containing 4% broccoli sprouts, or 2% broccoli sprout isothiocyanate extract; or gavaged pure sulforaphane or erucin (each at 295 μmol/kg, similar to dietary exposure); and report tumor weight reduction of 42% (p = 0.02), 42% (p = 0.04), 33% (p = 0.04), and 58% (p < 0.0001), respectively. Sulforaphane and erucin metabolites are present in mouse plasma (micromolar range) and tumor tissue, with N-acetylcysteine conjugates as the most abundant. Interconversion of sulforaphane and erucin metabolites was observed.

CONCLUSION

This work supports development of fully characterized, novel food products containing broccoli components for phase I/II human studies targeting bladder cancer prevention.

Impact of food matrix on isoflavone metabolism and cardiovascular biomarkers in adults with hypercholesterolemia

The role of food matrix and gender on soy isoflavone metabolism and biomarkers of activity were examined in twenty free-living adults (34.7 ± 11.5 years old) with hypercholesterolemia (221.9 ± 18.7mg dL(-1)). In a randomized crossover design study, participants consumed soy bread (3 wk) or a soy beverage (3 wk) containing 20 g soy protein with 99 and 93 mg isoflavones aglycone equivalents per day, respectively. During soy bread intervention, women had significantly greater microbial metabolite excretion (P = 0.05) of isoflavonoids than men. In men, isoflavone metabolite excretion was not discernibly different between the two matrices. Significant reductions (P≤ 0.05) in triglycerides (24.8%), LDL cholesterol (6.0%), apolipoprotein A-I (12.3%), and lipid oxidative stress capacity (25.5%), were observed after soy food intervention. Our findings suggest that the food matrix significantly impacts soy isoflavone metabolism, particularly microbial metabolites in women.

Determination of carotenoids, total phenolic content, and antioxidant activity of Arazá (Eugenia stipitata McVaugh), an Amazonian fruit

The fruit of Arazá (Eugenia stipitata McVaugh) native to the Colombian Amazon is considered a potentially economically valuable fruit for the Andean economy due to its novel and unique taste. The fruit has an intense yellow color, but its chemical composition and properties have not been well studied. Here we report the identification and quantitation of carotenoids in the ripe fruit using high performance liquid chromatography (HPLC) with photodiode array detector (PDA) and atmospheric pressure chemical ionization (APcI) mass spectrometry (MS/MS). The qualitative carotenoid profile of the fruit according to maturity stage was also observed. Furthermore, antioxidant activity of the peel and pulp were assessed using the ferric reducing ability of plasma (FRAP), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and 1,1-diphenyl-2-picrylhydrazyl (DPPH) methods, in addition to chemical indexes and total phenolic content. Multiple carotenoids were identified in the peel and pulp including four xanthophylls (free and esterified as their mono and diesters) and two carotenes. One of the xanthophylls was tentatively identified as zeinoxanthin, while the others were identified as lutein, zeaxanthin, and β-cryptoxanthin. Carotenes included α-carotene and β-carotene. The total carotenoid content was significantly higher in the peel (2484 ± 421 μg/100 g FW) than in the pulp (806 ± 348 μg/100 g FW) with lutein, β-cryptoxanthin, and zeinoxanthin as the major carotenoid components. The unique carotenoid composition of this fruit can differentiate it from other carotenoid-rich fruits and perhaps be useful in authentication procedures. Overall, results from this study suggest that Colombian Arazá may be a good edible source of carotenoids important in retinal health as well as carotenoids with provitamin A activity. Therefore, Arazá fruit can be used as a nutraceutical ingredient and in production of functional foods in the Colombian diet.

Xanthones in mangosteen juice are absorbed and partially conjugated by healthy adults

The proposed health-promoting effects of the pericarp from mangosteen fruit have been attributed to a family of polyphenols referred to as xanthones. The purpose of this study was to determine the bioavailability of xanthones from 100% mangosteen juice in healthy adult participants (n = 10). Pericarp particles accounted for 1% of the mass and 99% of the xanthone concentration in the juice. The juice provided 5.3 ± 0.1 mmol/L total xanthones with α-mangostin, garcinones (C, D, and E), γ-mangostin, gartanins, and other identified xanthones accounting for 58, 2, 6, 4, and 5%, respectively. Participants ingested 60 mL mangosteen juice with a high-fat breakfast. Free and conjugated (glucuronidated/sulfated) xanthones were detected in serum and urine. There was marked variation in the AUC (762-4030 nmol/L × h), maximum concentration (113 ± 107 nmol/L), and time to maximum concentration (3.7 ± 2.4 h) for α-mangostin in sera during the 24-h collection. Similarly, xanthones in 24-h urine ranged from 0.9 to 11.1 μmol and accounted for 2.0 ± 0.3% (range 0.3-3.4%) of the ingested dose. There were no significant differences between female and male participants in mean pharmacokinetic values of α-mangostin in serum and urinary xanthones. Only 15.4 ± 0.7% of total xanthones in pericarp particles in the juice partitioned into mixed micelles during in vitro digestion. These results show that xanthones in mangosteen juice are absorbed when ingested along with a high-fat meal, although release of xanthones from pericarp particles during digestion may be limited.

Drinking water with red beetroot food color antagonizes esophageal carcinogenesis in N-nitrosomethylbenzylamine-treated rats

This study was undertaken to determine if the oral consumption of red beetroot food color would result in an inhibition of N-nitrosomethylbenzylamine (NMBA)-induced tumors in the rat esophagus. Rats were treated with NMBA and given either regular water ad libitum or water containing 78 microg/mL commercial red beetroot dye, E162. The number of NMBA-induced esophageal papillomas was reduced by 45% (P < .001) in animals that received the food color compared to controls. The treatment also resulted in reduced rates of cell proliferation in both precancerous esophageal lesions and in papillomas of NMBA-treated rats, as measured by immunohistochemical staining of Ki-67 in esophageal tissue specimens. The effects of beetroot food color on angiogenesis (microvessel density by CD34 immunostaining), inflammation (by CD45 immunostaining), and apoptosis (by terminal deoxynucleotidyl transferase dUTP nick end-labeling staining) in esophageal tissue specimens were also determined. Compared to rats treated with NMBA only, the levels of angiogenesis and inflammation in the beetroot color-consuming animals were reduced, and the apoptotic rate was increased. Thus, the mechanism(s) of chemoprevention by the active constituents of red beetroot color include reducing cell proliferation, angiogenesis, and inflammation and stimulating apoptosis. Importantly, consumption of the dye in the drinking water for a period of 35 weeks did not appear to induce any overt toxicity. Based on the fact that red beetroot color contains betanins, which have strong antioxidant activity, it is postulated that these effects are mediated through inhibition of oxygen radical-induced signal transduction. However, the sum of constituents of E162 has not been determined, and other components with other mechanisms may also be involved in antagonizing cancer development.

Black raspberry components inhibit proliferation, induce apoptosis, and modulate gene expression in rat esophageal epithelial cells

We have shown that a diet containing freeze-dried black raspberries (BRB) inhibits the development of chemically induced cancer in the rat esophagus. To provide insights into possible mechanisms by which BRB inhibit esophageal carcinogenesis, we evaluated an ethanol (EtOH) extract of BRB, and two component anthocyanins (cyanidin-3-O-glucoside and cyanidin-3-O-rutinoside) in BRB, for their effects on growth, apoptosis, and gene expression in rat esophageal epithelial cell lines. The EtOH extract and both anthocyanins selectively caused significant growth inhibition and induction of apoptosis in a highly tumorigenic cell line (RE-149 DHD) but not in a weakly tumorigenic line (RE-149). The uptake of anthocyanins from the EtOH extract into RE-149 DHD cells far exceeded their uptake into RE-149 cells, which may have accounted for the selective effects of the extract on growth and apoptosis of RE-149 DHD cells. The growth inhibitory and proapoptotic effects were enhanced by the daily addition of the EtOH extract and the anthocyanins to the medium. Interestingly, the EtOH extract did not alter cyclooxygenase-2 (COX-2) and nitric oxide synthase (i-NOS) expression in RE-149 DHD cells, whereas both anthocyanins downregulated the expressions of these genes. This differential effect may have been related to the relative amounts of anthocyanins in the extract vs. when they were added individually to the medium. We conclude that the selective effects of the EtOH extract on growth and apoptosis of highly tumorigenic rat esophageal epithelial cells in vitro may be due to preferential uptake and retention of its component anthocyanins, and this may also be responsible for the greater inhibitory effects of freeze-dried whole berries on tumor cells in vivo.

Abstract 1897: Isothiocyanates and their metabolites in the plasma of mice fed broccoli sprouts isothiocyanate extract, broccoli sprouts, sulforaphane or erucin: A potential role in bladder cancer prevention

Background: Epidemiologic evidence suggests that cruciferous vegetables, particularly broccoli, may reduce bladder cancer risk. Our objectives were to characterize glucosinolates (GLUs) and their metabolites, isothiocyanates (ITCs), found in broccoli and broccoli sprouts, define bioactivity in bladder cancer cell lines in vitro, and to determine absorption and bioavailability in mice.

Methods: Broccoli and broccoli sprouts GLUs and ITCs were characterized by HPLC-MS-MS and cyclocondensation assay. In vitro effects of non-hydrolyzed (GLUs) and hydrolyzed broccoli and broccoli sprouts (ITCs), and pure ITCs sulforaphane (SFN), erucin (ECN), iberin and allyl ITC, were studied on normal bladder urothelial cells (NBC) and a panel of human bladder cancer cell lines (BCC), representing the spectrum of bladder cancer biology (RT4: non-invasive; J82 and UMUC3: invasive). Cell viability (MTS and SRB assays), apoptosis (caspase-3/7 activity and PARP cleavage) and cell cycle analysis (flow cytometry) were performed. We defined absorption in control female mice and those fed diet containing 4% freeze-dried broccoli sprouts, or 2% freeze-dried broccoli sprouts extract; or gavaged daily with 295 µmol/kg sulforaphane or 295 µmol/kg erucin; for two weeks (n=16/group). Plasma mercapturic acid pathway metabolites of sulforaphane and erucin were extracted and then quantified by UPLC-MS/MS.

Results: We observed significant dose-dependent decreases in cell viability of bladder cancer cell lines by broccoli or broccoli sprouts extracts as well as by pure ITCs. Broccoli sprout ITCs and SFN (IC50 = 2.52 µM) followed by ECN (IC50 = 2.24 µM) were the most potent inhibitors. Normal bladder urothelial cells were less sensitive than cancer cells. SFN and ECN resulted in a dose-dependent induction of apoptosis and modulation of the cell cycle in BCC. Metabolites of sulforaphane and erucin were absent in control mice and present in plasma of all treated groups, with dietary and pure phytochemical treatments, resulting in similar plasma metabolite concentrations (micromolar range). N-acetyl cysteine conjugates were found at highest concentrations, followed by cysteinyl and glutathione conjugates and small amounts of detectable cysteinyl glycine conjugates and free SFN. Evidence of inter-conversion of sulforaphane and erucin was seen.

Conclusion: Broccoli extracts and pure ITCs inhibit cell viability, induce apoptosis and cell cycle arrest in non-invasive and invasive human bladder cancer cell lines. In vivo, dietary and gavaged ITCs are readily absorbed and metabolized to various conjugates. The distribution to bladder cancer xenografts will also be discussed.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1897.

Determination of anthocyanins, total phenolic content, and antioxidant activity in Andes Berry (Rubus glaucus Benth)

Anthocyanins, total phenolic content, ascorbic acid content, and the antioxidant activity were determined in extracts of Andes berry fruit (Rubus glaucus Benth). Anthocyanis (ACNs) were isolated and characterized by means of high-performance liquid chromatography (HPLC) with photodiode array detection and electro spray ionization/mass spectrometry (PDA-ESI/MS/MS) analysis. The anthocyanin (ACN) content was 45 mg/100 g FW. The isolated anthocyanins were characterized as cyanidin 3-sambubioside, cyanidin 3-glucoside, cyanidin 3-xylorutinoside, cyanidin 3-rutinoside, pelargonidin 3-glucoside, and pelargonidin 3-rutinoside. The ascorbic acid content was 10.1 mg/100 g FW. The total phenolic content as determined by the Folin-Ciocalteau method was 294 mg GAE/100 g FW while the antioxidant activity as measured by ABTS(.) (+) radical scavenging capacity and ferric reducing antioxidant power (FRAP) was 2.01 and 4.50 mmol TE/100 g FW or 8.22 mmoles ferric iron reduced/100 g FW, respectively. The high phenolic content and antioxidant capacity of Andes berry suggest that this fruit could be a rich source of natural pigments, nutraceuticals, and natural antioxidants.

Tannin-protein complexes as radical scavengers and radical sinks

The 2,2'-azinobis(3-ethylbenzothiazoline 6-sulfonic acid) radical cation (ABTS(*)(+)) decolorization assay has been used to determine the antioxidant activity of the polyphenol epicatechin(16) (4 --> 8) catechin (procyanidin, PC) alone or in complex with the model proteins bovine serum albumin (BSA) or gelatin. PC had a molar antioxidant capacity of approximately 54, 92, or 108 radicals at pH values of 3.0, 4.9, or 7.4, respectively. Radical scavenging occurred via a rapid step followed by a slow step. Interaction with gelatin reduced the rate of rapid scavenging by 50% (PC-BSA mixtures reduced by 15%). Inhibition paralleled formation of precipitable PC-protein complexes over a range of protein/PC ratios. However, inhibition was virtually overcome in 10 min. Reaction with ABTS(*)(+) converted the PC-protein complexes from a dissociable form to a form resistant to dissociation by strong denaturants such as SDS. This study demonstrates that PC is a potent ABTS(*)(+) scavenger even when bound to protein and that the complexes may act as a radical sink within the gastrointestinal tract.