Luteolin protects against adipogenic and lipogenic potency induced by human relevant mixtures of persistent organic pollutants (POPs) in the 3T3-L1 model.

Human exposure to persistent organic pollutants (POPs) may contribute to obesogenic effects. We have previously shown that POP mixtures modelled on blood levels relevant to the Scandinavian population induces adipogenic effects in the mouse 3T3-L1 cell line. Luteolin is a flavone that has shown anti-lipogenic and anti-adipogenic effects on adipogenesis in in vitro models. In this study, luteolin has been applied to inhibit adipocyte formation and intracellular lipid content increase induced by a human relevant mixture of POPs. 3T3-L1 cells were exposed to a POP mixture consisting of 29 chemicals, including amongst others polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), perfluoroalkylated acids (PFAAs), and polybrominated diphenyl ethers (PBDEs). Rosiglitazone was applied as a positive lipogenic control. Luteolin was tested between 0.5 and 10 µM. High content analysis was used to assess changes in adipocyte formation and intracellular lipid content in the 3T3-L1 cell line. Luteolin significantly reduced POP-induced adipocyte formation at 2, 5 and 10 µM, and lipid accumulation at 10 µM. Interestingly, luteolin did not affect rosiglitazone induced adipo- and lipogenic effects, suggesting differences in mechanisms of action. In conclusion, this in vitro study shows that dietary polyphenols such as luteolin may protect against POP induced adipo- and lipogenic effects.

In vitro differential responses of rat and human aryl hydrocarbon receptor to two distinct ligands and to different polyphenols.

TCDD (2,3,7,8-tetrachlorodibenzo-p-dioxin) and several other environment/food-borne toxic compounds induce their toxicity via the aryl hydrocarbon receptor (AhR). AhR is also modulated by various endogenous ligands e.g. highly potent tryptophan (Trp)-derivative FICZ (6-formylindolo[3,2-b]carbazole) and natural ligands abundant in the human diet e.g. polyphenols. Therefore, evaluating AhR species-specific responses is crucial for understanding AhR physiological functions, establishing risk assessments, and exploring the applicability of AhR mediators in drug and food industry towards human-based usages. We studied AhR transactivation of FICZ/TCDD in vitro in a time-dependent and species-specific manner using dioxin responsive luciferase reporter gene assays derived from rat (DR-H4IIE) and human (DR-HepG2) hepatoma cells. We observed for the first time that FICZ potency was similar in both cell lines and was 40 times higher than TCDD in DR-HepG2 cells. Depleting Trp-derivative endogenously produced ligands by using culture medium without Trp, resulted in 3-fold higher AhR activation upon adding FICZ in DR-H4IIE cells, in contrast to DR-HepG2 cells which revealed a fast degradation of FICZ induction from 10 h post-exposure to complete disappearance after 24 h. Seven polyphenols and a mixture thereof, chosen based on commercially recommended doses and adjusted to human realistic exposure, caused rat and human species-specific AhR responses. Two isoflavones (daidzein and genistein) induced rat AhR synergistic effects with FICZ and/or TCDD, while quercetin, chrysin, curcumin, resveratrol, and the mixture exerted a strong inhibitory effect on the human AhR. Strikingly, resveratrol and quercetin at their realistic nanomolar concentrations acted additively in the mixture to abolish human AhR activation induced by various TCDD concentrations. Taken together, these results illustrate the species-specific complexity of AhR transcriptional activities modulated by various ligands and highlight the need for studies of human-based approaches.

A mixture of persistent organic pollutants relevant for human exposure inhibits the transactivation activity of the aryl hydrocarbon receptor in vitro.

While humans are exposed to mixtures of persistent organic pollutants (POPs), their risk assessment is usually based on a chemical-by-chemical approach. To assess the health effects associated with mixed exposures, knowledge on mixture toxicity is required. Several POPs are potential ligands of the Aryl hydrocarbon receptor (AhR), which involves in xenobiotic metabolism and controls many biological pathways. This study assesses AhR agonistic and antagonistic activities of 29 POPs individually and in mixtures by using Chemical-Activated LUciferase gene eXpression bioassays with 3 transgenic cell lines (rat hepatoma DR-H4IIE, human hepatoma DR-Hep G2 and human mammary gland carcinoma DR-T47-D). Among the 29 POPs, which were selected based on their abundance in Scandinavian human blood, only 4 exerted AhR agonistic activities, while 16 were AhR antagonists in DR-H4IIE, 5 in DR-Hep G2 and 7 in DR-T47-D when tested individually. The total POP mixture revealed to be AhR antagonistic. It antagonized EC50 TCDD inducing AhR transactivation at a concentration of 125 and 250 and 500 fold blood levels in DR-H4IIE, DR-T47-D and DR-Hep G2, respectively, although each compound was present at these concentrations lower than their LOEC values. Such values could occur in real-life in food contamination incidents or in exposed populations. In DR-H4IIE, the antagonism of the total POP mixture was due to chlorinated compounds and, in particular, to PCB-118 and PCB-138 which caused 90% of the antagonistic activity in the POP mixture. The 16 active AhR antagonists acted additively. Their mixed effect was predicted successfully by concentration addition or generalized concentration addition models, rather than independent action, with only two-fold IC50 underestimation. We also attained good predictions for the full dose-response curve of the antagonistic activity of the total POP mixture.

Human blood-based exposure levels of persistent organic pollutant (POP) mixtures antagonise androgen receptor transactivation and translocation.

INTRODUCTION: Human exposure to persistent organic pollutants (POPs) has been linked to genitourinary health-related conditions such as decreased sperm quality, hypospadias, and prostate cancer (PCa). Conventional risk assessment of POPs focuses on individual compounds. However, in real life, individuals are exposed to many compounds simultaneously. This might lead to combinatorial effects whereby the global effect of the mixture is different from the effect of the single elements or subgroups. POP mixtures may act as endocrine disruptors via the androgen receptor (AR) and potentially contribute to PCa development. AIM: To determine the endocrine disrupting activity of a POP mixture and sub-mixtures based upon exposure levels detected in a human Scandinavian population, on AR transactivation and translocation in vitro. MATERIALS AND METHODS: The Total POP mixture combined 29 chemicals modelled on the exposure profile of a Scandinavian population and 6 sub-mixtures: brominated (Br), chlorinated (Cl), Cl + Br, perfluorinated (PFAA), PFAA + Br, PFAA + Cl, ranging from 1/10× to 500× relative to what is found in human blood. Transactivation was measured by reporter gene assay (RGA) and translocation activity was measured by high content analysis (HCA), each using stably transfected AR model cell lines. RESULTS: No agonist activity in terms of transactivation and translocation was detected for any POP mixtures. In the presence of testosterone the Cl + Br mixture at 100× and 500× blood level antagonised AR transactivation, whereas the PFAA mixture at blood level increased AR transactivation (P < 0.05). In the presence of testosterone the Cl and PFAA + Br mixtures at 1/10×, 1×, and 50× blood level antagonised AR translocation (P < 0.05). CONCLUSION: Taken together, some combinations of POP mixtures can interfere with AR translocation. However, in the transactivation assay, these combinations did not affect gene transactivation. Other POP combinations were identified here as modulators of AR-induced gene transactivation without affecting AR translocation. Thus, to fully evaluate the effect of environmental toxins on AR signalling, both types of assays need to be applied.

Impact of a Transplantation Critical Care Model on Short-Term Outcomes Following Liver Transplantation in High Acuity Patients: A Single-Center Experience.

BACKGROUND: Orthotopic liver transplantation (OLT) is the definitive treatment for end-stage liver disease (ESLD). Patients with high acuity ESLD are frequently denied life-saving OLT by transplant centers due to reported inferior outcomes. We sought to analyze the impact of a specialized transplant critical care model (TCCM) on patient access to OLT and survival outcomes in high acuity patients. METHODS: From January 2009 to December 2016, 122 adults were wait-listed at our transplant center with laboratory Model for ESLD ≥35 or Status I. Outcomes in Era I (prior to TCCM) were compared to Era II (TCCM established October 1, 2012). RESULTS: Era II (TCCM) led to a significant increase in patients' access to OLT. Frequency and need to seek OLT at another center dropped 4-fold in Era II. Compared to Era I, the majority of patients in Era II required intensive care unit management (22% vs 83%, P < .01) and renal replacement therapy (11% vs 70%, P < .01) prior to OLT. Despite a higher acuity of illness in Era II, 1-year patient survival was comparable (89% Era I, 80% Era II, P = .35). CONCLUSION: Implementation of a specialized TCCM expanded OLT access to high acuity patients, reduced the need to seek higher level of care elsewhere, and achieved excellent short-term post-transplant survival outcomes.

Football training improves metabolic and cardiovascular health status in 55- to 70-year-old women and men with prediabetes.

We examined the effects of 16 weeks of football training and dietary advice on blood glucose control and health status in 55- to 70-year-old women and men with prediabetes. Fifty participants with prediabetes (age; 61 ± 6 years, BMI; 29.6 ± 4.7; VO2max 22.3 ± 5.7 mL·min-1 ·kg-1 ) were randomized into a football and dietary advice group (F+D; n = 27) and a dietary advice group (D; n = 23). F+D performed football training (twice weekly 30- to 60-minutes sessions) and received dietary advice, while D only received dietary advice. An oral glucose tolerance test (OGTT) was completed pre and post the 16-week period. Body composition, blood pressure, and maximal oxygen uptake (VO2max ) were additionally measured. Both groups demonstrated a decrement (P < .05) in fasting blood glucose (-0.4 ± 0.5 mmol·L-1 ) and lowered blood glucose throughout OGTT. F+D displayed lower values than D (P < .05) after 60 minutes (9.0 ± 2.7 vs 10.6 ± 2.9 mmol·L-1 ) and 120 minutes (5.7 ± 1.6 vs 7.5 ± 2.4 mmol·L-1 ). VO2max increased by 14% in F+D, with a higher (P < .05) change score than in D (2%). Mean arterial pressure declined more (P < .05) in F+D than in D (-8 ± 9 vs -4 ± 11 mm Hg). Fat loss was greater (P < .05) in F+D than in D (-3.4 ± 2.8 vs -1.2 ± 2.0 kg), and the increase in lean body mass was also greater (P < .05) in F+D than in D (0.7 ± 1.5 vs -0.3 ± 1.6 kg). In conclusion, football training combined with dietary advice has broad-spectrum effects on metabolic and cardiovascular health profile with greater overall effects than professional dietary advice per se for 55- to 70-year-old women and men with prediabetes.

Long-term follow-up of the incidence of Helicobacter pylori.

OBJECTIVES: Helicobacter pylori causes peptic ulcer disease and gastric cancer. Understanding the incidence of H. pylori could help guide research on potential infection prevention strategies. Previous studies indicate infection occurs in young children, but the risk of infection in older children and adolescents is unclear. Our hypothesis was that H. pylori infection is rare in adolescence or adulthood. Our aim was to determine the incidence of H. pylori over a prolonged follow-up in a cohort of 626 noninfected individuals. METHODS: Participants, including index children, mothers, fathers and siblings, from a previous study (1997-2002) were traced, and 883 of 946 participated in this extended follow-up. We used the 13C urea breath test (13C-UBT) to determine the incidence of H. pylori among 626 family members not infected in 2002, including 75 younger siblings who were not born or too young for testing in 2002. RESULTS: Eight (3.8%) of 210 index participants (mean ± standard deviation age 17.92 ± 0.77 years) became infected during 11.07 ± 0.56 years of follow-up (incidence, 3.42 per 1000 person-years; 95% confidence interval (CI), 1.48-6.74). Only one (0.6%) of 165 older siblings became infected (incidence, 0.57 per 1000 person-years; 95% CI, 0.007-3.16) and one of 176 parents became infected (incidence, 0.63 per 1000 person-years; 95% CI, 0.01-3.5). Of 75 younger siblings (age 10.9 ± 2.85 years) who were too young for testing or not yet born in 2002, nine (12%) became infected (incidence, 11.32 per 1000 person-years; 95% CI, 5.27-21.49). The highest incidence of H. pylori infection was in those born after 2005. CONCLUSIONS: The incidence of H. pylori was extremely low in older children and adults in developed countries. Spontaneous clearance of infection was uncommon in our study population.

The effect of the GLP-1 analogue Exenatide on functional connectivity within an NTS-based network in women with and without obesity.

Objective: The differential effect of GLP-1 agonist Exenatide on functional connectivity of the nucleus tractus solitaries (NTS), a key region associated with homeostasis, and on appetite-related behaviours was investigated in women with normal weight compared with women with obesity. Methods: Following an 8-h fast, 19 female subjects (11 lean, 8 obese) participated in a 2-d double blind crossover study. Subjects underwent functional magnetic resonance imaging at fast and 30-min post subcutaneous injection of 5 µg of Exenatide or placebo. Functional connectivity was examined with the NTS. Drug-induced functional connectivity changes within and between groups and correlations with appetite measures were examined in a region of interest approach focusing on the thalamus and hypothalamus. Results: Women with obesity reported less hunger after drug injection. Exenatide administration increased functional connectivity of the left NTS with the left thalamus and hypothalamus in the obese group only and increased the correlation between NTS functional connectivity and hunger scores in all subjects, but more so in the obese. Conclusions: Obesity can impact the effects of Exenatide on brain connectivity, specifically in the NTS and is linked to changes in appetite control. This has implications for the use of GLP-1 analogues in therapeutic interventions.

Short Duration Small Sided Football and to a Lesser Extent Whole Body Vibration Exercise Induce Acute Changes in Markers of Bone Turnover.

We aimed to study whether short-duration vibration exercise or football sessions of two different durations acutely changed plasma markers of bone turnover and muscle strain. Inactive premenopausal women (n = 56) were randomized to complete a single bout of short (FG15) or long duration (FG60) small sided football or low magnitude whole body vibration training (VIB). Procollagen type 1 amino-terminal propeptide (P1NP) was increased during exercise for FG15 (51.6 ± 23.0 to 56.5 ± 22.5 µg·L-1, mean ± SD, P < 0.05) and FG60 (42.6 ± 11.8 to 50.2 ± 12.8 µg·L-1, P < 0.05) but not for VIB (38.8 ± 15.1 to 36.6 ± 14.7 µg·L-1, P > 0.05). An increase in osteocalcin was observed 48 h after exercise (P < 0.05), which did not differ between exercise groups. C-terminal telopeptide of type 1 collagen was not affected by exercise. Blood lactate concentration increased during exercise for FG15 (0.6 ± 0.2 to 3.4 ± 1.2 mM) and FG60 (0.6 ± 0.2 to 3.3 ± 2.0 mM), but not for VIB (0.6 ± 0.2 to 0.8 ± 0.4 mM) (P < 0.05). Plasma creatine kinase increased by 55 ± 63% and 137 ± 119% 48 h after FG15 and FG60 (P < 0.05), but not after VIB (26 ± 54%, NS). In contrast to the minor elevation in osteocalcin in response to a single session of vibration exercise, both short and longer durations of small sided football acutely increased plasma P1NP, osteocalcin, and creatine kinase. This may contribute to favorable effects of chronic training on musculoskeletal health.

Peer volunteer perspectives following a complex social cognitive intervention: a qualitative investigation.

BACKGROUND: Peer volunteers can be key to delivering effective social cognitive interventions due to increased potential for social modeling. We consulted peer volunteers who had just taken part in an 8-week social and nutritional mealtime intervention with older adults living alone, to seek their evaluation of the intervention. METHODS: Semi-structured focus groups were used with a total of 21 volunteers (17 female) and two facilitators. Thematic analysis was used to interrogate the data. RESULTS: Six themes (16 sub-themes) are discussed. Peer volunteers described the importance of the socializing aspect of the intervention, of pairing considerations and compatibility in peer interventions, of considering the needs of the participant, of benefits to the volunteers, and of the practical considerations of conducting an intervention. Volunteers also discussed considerations for future research and services for older adults living alone. CONCLUSIONS: Volunteers found their involvement in the intervention to be personally beneficial, and revealed some valuable considerations for the researchers to take forward to future research. Results are pertinent to intervention design and could inform future social cognitive and other peer-oriented interventions for older adults living alone.

Challenging conventional risk assessment with respect to human exposure to multiple food contaminants in food: A case study using maize.

Mycotoxins and heavy metals are ubiquitous in the environment and contaminate many foods. The widespread use of pesticides in crop production to control disease contributes further to the chemical contamination of foods. Thus multiple chemical contaminants threaten the safety of many food commodities; hence the present study used maize as a model crop to identify the severity in terms of human exposure when multiple contaminants are present. High Content Analysis (HCA) measuring multiple endpoints was used to determine cytotoxicity of complex mixtures of mycotoxins, heavy metals and pesticides. Endpoints included nuclear intensity (NI), nuclear area (NA), plasma membrane permeability (PMP), mitochondrial membrane potential (MMP) and mitochondrial mass (MM). At concentrations representing legal limits of each individual contaminant in maize (3ng/ml ochratoxin A (OTA), 1µg/ml fumonisin B1 (FB1), 2ng/ml aflatoxin B1 (AFB1), 100ng/ml cadmium (Cd), 150ng/ml arsenic (As), 50ng/ml chlorpyrifos (CP) and 5µg/ml pirimiphos methyl (PM), the mixtures (tertiary mycotoxins plus Cd/As) and (tertiary mycotoxins plus Cd/As/CP/PM) were cytotoxic for NA and MM endpoints with a difference of up to 13.6% (p≤0.0001) and 12% (p≤0.0001) respectively from control values. The most cytotoxic mixture was (tertiary mycotoxins plus Cd/As/CP/PM) across all 4 endpoints (NA, NI, MM and MMP) with increases up to 61.3%, 23.0%, 61.4% and 36.3% (p≤0.0001) respectively. Synergy was evident for two endpoints (NI and MM) at concentrations contaminating maize above legal limits, with differences between expected and measured values of (6.2-12.4% (p≤0.05-p≤0.001) and 4.5-12.3% (p≤0.05-p≤0.001) for NI and MM, respectively. The study introduces for the first time, a holistic approach to identify the impact in terms of toxicity to humans when multiple chemical contaminants are present in foodstuffs. Governmental regulatory bodies must begin to contemplate how to safeguard the population when such mixtures of contaminants are found in foods and this study starts to address this critical issue.

High content analysis: a sensitive tool to detect and quantify the cytotoxic, synergistic and antagonistic effects of chemical contaminants in foods.

Aflatoxin B1 (AFB1), ochratoxin A (OTA) and fumonisin B1 (FB1) are important mycotoxins in terms of human exposure via food, their toxicity and regulatory limits that exist worldwide. Mixtures of toxins can frequently be present in foods, however due to the complications of determining their combined toxicity, legal limits of exposure are determined for single compounds, based on long standing toxicological techniques. High content analysis (HCA) may be a useful tool to determine total toxicity of complex mixtures of mycotoxins. Endpoints including cell number (CN), nuclear intensity (NI), nuclear area (NA), plasma membrane permeability (PMP), mitochondrial membrane potential (MMP) and mitochondrial mass (MM) were compared to the conventional 3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyltetrazolium bromide (MTT) and neutral red (NR) endpoints in MDBK cells. Individual concentrations of each mycotoxin (OTA 3 µg/ml, FB1 8 µg/ml and AFB1 1.28 µg/ml) revealed no cytotoxicity with MTT or NR but HCA showed significant cytotoxic effects up to 41.6% (p≤0.001) and 10.1% (p≤0.05) for OTA and AFB1, respectively. The tertiary mixture (OTA 3 µg/ml, FB1 8 µg/ml and AFB1 1.28 µg/ml) detected up to 37.3% and 49.8% more cytotoxicity using HCA over MTT and NR, respectively. Whilst binary combinations of OTA (3 µg/ml) and FB1 (8 µg/ml) revealed synergistic interactions using HCA (MMP, MM, NI endpoints) not detected using MTT or NR. HCA is a highly novel and sensitive tool that could substantially help determine future regulatory limits, for single and combined toxins present in food, ensuring legislation is based on true risks to human health exposure.

Endocrine disruptor activity of multiple environmental food chain contaminants.

Industrial chemicals, antimicrobials, drugs and personal care products have been reported as global pollutants which enter the food chain. Some of them have also been classified as endocrine disruptors based on results of various studies employing a number of in vitro/vivo tests. The present study employed a mammalian reporter gene assay to assess the effects of known and emerging contaminants on estrogen nuclear receptor transactivation. Out of fifty-nine compounds assessed, estrogen receptor agonistic activity was observed for parabens( n = 3), UV filters (n = 6), phthalates (n = 4) and a metabolite, pyrethroids (n = 9) and their metabolites (n = 3). Two compounds were estrogen receptor antagonists while some of the agonists enhanced 17b-estradiol mediated response.This study reports five new compounds (pyrethroids and their metabolites) possessing estrogen agonist activity and highlights for the first time that pyrethroid metabolites are of particular concern showing much greater estrogenic activity than their parent compounds.

Validation and application of a reporter gene assay for the determination of estrogenic endocrine disruptor activity in milk.

Endocrine disruptors (EDs) are compounds known to interfere with the endocrine system by disturbing the action or pathways of natural hormones which may lead to infertility or cancer. Our diet is considered to be one of the main exposure routes to EDs. Since milk and dairy products are major components of our diet they should be monitored for ED contamination. Most assays developed to date utilise targeted, chromatography based methods which lack information on the biological activity and mixture effects of the monitored compounds. A biological reporter gene assay (RGA) was developed to assess the total estrogen hormonal load in milk. It has been validated according to EU decision 2002/657/EC. Analytes were extracted by liquid-liquid extraction with acetonitrile followed by clean up on a HLB column which yielded good recovery and small matrix effects. The method has been shown to be estrogen specific, repeatable and reproducible, with covariance values below 20%. In conclusion, this method enables the detection of low levels of estrogen hormonal activity in milk with a detection capability of 36 pg g(-)(1) EEQ and has been successfully applied in testing a range of milk samples.

Two histone deacetylases, FfHda1 and FfHda2, are important for Fusarium fujikuroi secondary metabolism and virulence.

Histone modifications are crucial for the regulation of secondary metabolism in various filamentous fungi. Here we studied the involvement of histone deacetylases (HDACs) in secondary metabolism in the phytopathogenic fungus Fusarium fujikuroi, a known producer of several secondary metabolites, including phytohormones, pigments, and mycotoxins. Deletion of three Zn(2+)-dependent HDAC-encoding genes, ffhda1, ffhda2, and ffhda4, indicated that FfHda1 and FfHda2 regulate secondary metabolism, whereas FfHda4 is involved in developmental processes but is dispensable for secondary-metabolite production in F. fujikuroi. Single deletions of ffhda1 and ffhda2 resulted not only in an increase or decrease but also in derepression of metabolite biosynthesis under normally repressing conditions. Moreover, double deletion of both the ffhda1 and ffhda2 genes showed additive but also distinct phenotypes with regard to secondary-metabolite biosynthesis, and both genes are required for gibberellic acid (GA)-induced bakanae disease on the preferred host plant rice, as Δffhda1 Δffhda2 mutants resemble the uninfected control plant. Microarray analysis with a Δffhda1 mutant that has lost the major HDAC revealed differential expression of secondary-metabolite gene clusters, which was subsequently verified by a combination of chemical and biological approaches. These results indicate that HDACs are involved not only in gene silencing but also in the activation of some genes. Chromatin immunoprecipitation with the Δffhda1 mutant revealed significant alterations in the acetylation state of secondary-metabolite gene clusters compared to the wild type, thereby providing insights into the regulatory mechanism at the chromatin level. Altogether, manipulation of HDAC-encoding genes constitutes a powerful tool to control secondary metabolism in filamentous fungi.

Differences in brain responses between lean and obese women to a sweetened drink.

BACKGROUND: Ingestion of sweet food is driven by central reward circuits and restrained by endocrine and neurocrine satiety signals. The specific influence of sucrose intake on central affective and reward circuitry and alterations of these mechanisms in the obese are incompletely understood. For this, we hypothesized that (i) similar brain regions are engaged by the stimulation of sweet taste receptors by sucrose and by non-nutrient sweeteners and (ii) during visual food-related cues, obese subjects show greater brain responses to sucrose compared with lean controls. METHODS: In a double-blind, crossover design, 10 obese and 10 lean healthy females received a sucrose or a non-nutrient sweetened beverage prior to viewing food or neutral images. BOLD signal was measured using a 1.5 Tesla MRI scanner. KEY RESULTS: Viewing food images after ingestion of either drink was associated with engagement of similar brain regions (amygdala, hippocampus, thalamus, anterior insula). Obese differed from lean subjects in behavioral and brain responses rating both beverages as less tasteful and satisfying, yet demonstrating greater brain responses. Obese subjects also showed engagement of an additional brain network (including anterior insula, anterior cingulate, hippocampus, and amygdala) only after sucrose ingestion. CONCLUSIONS & INFERENCES: Obese subjects had a reduced behavioral hedonic response, yet a greater engagement of affective brain networks, particularly after sucrose ingestion, suggesting that in obese subjects, lingual and gut-derived signaling generate less central hedonic effects than food-related memories in response to visual cues, analogous to response patterns implicated in food addiction.

Endocrine disrupting effects of ochratoxin A at the level of nuclear receptor activation and steroidogenesis.

Ochratoxin A (OTA) is a mycotoxin and extrolite of fungi which has been reported in a range of foods. This study uses mammalian reporter gene assays (RGAs) with natural steroid receptors and the H295R steroidogenesis assay to assess the endocrine disrupting activity of OTA. At the receptor level, OTA (within a concentration range of 0.25-2500 ng/ml) did not induce an agonistic response in an oestrogen, androgen, progestagen or glucocorticoid RGA. An antagonistic effect was observed in all of the RGAs at the highest concentration tested (2500 ng/ml). However, while there was no significant cytotoxic effect observed in the MTT (thiazolyl blue tetrazolium bromide) cell viability assay at this concentration, there was a corresponding change in cell morphology which may be related to the resulting antagonistic effect. At the hormone production level, H295R cells were used as a steroidogenesis model and exposed to OTA (within a concentration range of 0.1-1000 ng/ml). Treatment of the cells with 1000 ng/ml OTA increased the production of estradiol (117±14 ng/ml) over 3 times that of the solvent control (36±9 pg/ml). Western blotting confirmed an increase in aromatase protein. Overall the results indicate that OTA does not appear to interact with steroid receptors but has the potential to cause endocrine disruption by interfering with steroidogenesis. This is the first study identifying the effect OTA may have on production of the steroid hormone estradiol.

An in vitro investigation of endocrine disrupting effects of trichothecenes deoxynivalenol (DON), T-2 and HT-2 toxins.

Trichothecenes are a large family of chemically related mycotoxins. Deoxynivalenol (DON), T-2 and HT-2 toxins belong to this family and are produced by various species of Fusarium. The H295R steroidogenesis assay, regulation of steroidogenic gene expression and reporter gene assays (RGAs) for the detection of androgen, estrogen, progestagen and glucocorticoid (ant)agonist responses, have been used to assess the endocrine disrupting activity of DON, T-2 and HT-2 toxins. H295R cells were used as a model for steroidogenesis and gene expression studies and exposed with either DON (0.1-1000ng/ml), T-2 toxin (0.0005-5ng/ml) or HT-2 toxin (0.005-50ng/ml) for 48h. We observed a reduction in hormone levels in media of exposed cells following radioimmunoassay. Cell viability was determined by four colorimetric assays and we observed reduced cell viability with increasing toxin concentrations partly explaining the significant reduction in hormone levels at the highest toxin concentration of all three trichothecenes. Thirteen of the 16 steroidogenic genes analyzed by quantitative real time PCR (RT-qPCR) were significantly regulated (P<0.05) by DON (100ng/ml), T-2 toxin (0.5ng/ml) and HT-2 toxin (5ng/ml) compared to the control, with reference genes (B2M, ATP5B and ACTB). Whereas HMGR and CYP19 were down-regulated, CYP1A1 and CYP21 were up-regulated by all three trichothecenes. DON further up-regulated CYP17, HSD3B2, CYP11B2 and CYP11B1 and down-regulated NR5A1. T-2 toxin caused down-regulation of NR0B1 and NR5A1 whereas HT-2 toxin induced up-regulation of EPHX and HSD17B1 and down-regulation of CYP11A and CYP17. The expressions of MC2R, StAR and HSD17B4 genes were not significantly affected by any of the trichothecenes in the present study. Although the results indicate that there is no evidence to suggest that DON, T-2 and HT-2 toxins directly interact with the steroid hormone receptors to cause endocrine disruption, the present findings indicate that exposure to DON, T-2 toxin and HT-2 toxin have effects on cell viability, steroidogenesis and alteration in gene expression indicating their potential as endocrine disruptors.

Endocrine disrupting effects of zearalenone, alpha- and beta-zearalenol at the level of nuclear receptor binding and steroidogenesis.

The mycotoxin zearalenone (ZEN) is a secondary metabolite of fungi which is produced by certain species of the genus Fusarium and can occur in cereals and other plant products. Reporter gene assays incorporating natural steroid receptors and the H295R steroidogenesis assay have been implemented to assess the endocrine disrupting activity of ZEN and its metabolites α-zearalenol (α-ZOL) and ß-zearalenol (ß-ZOL). α-ZOL exhibited the strongest estrogenic potency (EC(50) 0.022±0.001 nM), slightly less potent than 17-ß estradiol (EC(50) 0.015±0.002 nM). ZEN was ~70 times less potent than α-ZOL and twice as potent as ß-ZOL. Binding of progesterone to the progestagen receptor was shown to be synergistically increased in the presence of ZEN, α-ZOL or ß-ZOL. ZEN, α-ZOL or ß-ZOL increased production of progesterone, estradiol, testosterone and cortisol hormones in the H295R steroidogenesis assay, with peak productions at 10 µM. At 100 µM, cell viability decreased and levels of hormones were significantly reduced except for progesterone. ß-ZOL increased estradiol concentrations more than α-ZOL or ZEN, with a maximum effect at 10 µM, with ß-ZOL (562±59 pg/ml)>α-ZOL (494±60 pg/ml)>ZEN (375±43 pg/ml). The results indicate that ZEN and its metabolites can act as potential endocrine disruptors at the level of nuclear receptor signalling and by altering hormone production.