Disruption of normal adipocyte development and function by methyl- and propyl- paraben exposure.

Methyl- and propyl- parabens are generally regarded as safe by the U.S Food and Drug Administration and as such are commonly used in personal care products. These parabens have been associated with increased white adipogenesis in vitro and methyl paraben also increased the white adipose mass of mice. Given brown adipose also plays a role in energy balance, we sought to evaluate whether the effects of methyl- and propyl- parabens on white adipocytes extended to brown adipocytes. We challenged white and brown pre-adipocytes at low doses of both parabens (up to 1 µM) during the differentiation process and examined adipogenesis with the ORO assay. The impact of each paraben on glucose uptake and lipolytic activity of adipocytes were measured with a fluorescent glucose analog and enzymatically, respectively. Methyl- and propyl- parabens increased adipogenesis of 3T3-L1 white adipocytes but not brown adipocytes. In white adipocytes, methyl paraben increased glucose uptake and both parabens reduced basal lipolysis. However, in brown adipocytes, parabens had no effect on basal lipolysis and instead attenuated isoproterenol induced lipolysis. These data indicate that methyl- and propyl- parabens target the differentiation and metabolic processes of multiple types of adipocytes in a cell autonomous manner.

Cytotoxicity of the mycotoxins deoxynivalenol and ochratoxin A on Caco-2 cell line in presence of resveratrol.

Exposure to mycotoxins through dietary food intake involves a highly complex scenario where co-contamination of different mycotoxins has been frequently demonstrated. On the other hand, the effect of the interaction of mycotoxins with other generally considered beneficial food components, as the antioxidants, has been scarcely studied. The main goal of the present work was to assess the cytotoxic effects on Caco-2 cells of the mycotoxins deoxynivalenol (DON) and ochratoxin A (OTA), alone or combined, and to explore potential protective effects of resveratrol (RES), an antioxidant frequently found in wine. In parallel, reactive oxygen species (ROS) production has also been studied as a first approach to understand the underlying mechanism of cytotoxicity. Results indicate a higher toxic effect of the mycotoxins when they are co-exposed. This increase in cytotoxicity was not accompanied by an increase in ROS production. The co-exposure of OTA or DON with RES did not result in a decrease in cytotoxicity; on the contrary, it resulted in increased cytotoxicity not associated with an increase in ROS production.

Co-occurrence of musk fragrances and UV-filters in seafood and macroalgae collected in European hotspots.

In the last decades, awareness regarding personal care products (PCP), i.e. synthetic organic chemicals frequently used in cosmetic and hygienic products, has become a forward-looking issue, due to their persistency in the environment and their potential multi-organ toxicity in both human and wildlife. Seafood is one of the most significant food commodities in the world and, certainly, one of the most prone to bioaccumulation of PCP, what can consequently lead to human exposure, especially for coastal population, where its consumption is more marked. The aim of this work was to evaluate the co-occurrence of musk fragrances and UV-filters in both seafood and macroalgae collected in different European hotspots (areas with high levels of pollution, highly populated and near wastewater treatment plants). Despite the fact that UV-filters were detected in three different kind of samples (mussel, mullet, and clam), in all cases they were below the limit of quantification. Galaxolide (HHCB) and tonalide (AHTN) were the musk fragrances most frequently detected and quantified in samples from the European hotspots. Cashmeran (DPMI) was also detected in most samples but only quantified in two of them (flounder/herring and mullet). The highest levels of HHCB and AHTN were found in mussels from Po estuary.

Mycotoxins: occurrence, toxicology, and exposure assessment.

Mycotoxins are abiotic hazards produced by certain fungi that can grow on a variety of crops. Consequently, their prevalence in plant raw materials may be relatively high. The concentration of mycotoxins in finished products is usually lower than in raw materials. In this review, occurrence and toxicology of the main mycotoxins are summarised. Furthermore, methodological approaches for exposure assessment are described. Existing exposure assessments, both through contamination and consumption data and biomarkers of exposure, for the main mycotoxins are also discussed.

Occurrence and exposure assessment of aflatoxins in Catalonia (Spain).

The main objective of this study was to assess the exposure of Catalonian (Spain) population to AFs. Thus, two sub-objectives were considered: (1) to assess the occurrence of AFs in food marketed in Catalonia, and (2) to assess the consumption of those foods susceptible to AFs contamination by Catalonian population. AFs were analysed in a total of 603 samples considering special commodities as free-gluten, ethnic or baby foods. Analytical method consisted of an extraction and clean-up of aflatoxins step using immunoaffinity columns, and determination by HPLC with post-column photochemical derivatization and fluorescence detection. Food dietary intake was assessed using a food frequency questionnaire, administered to 1387 individuals by trained interviewers. Contamination and consumption raw datasets were combined by means of a direct method and a stochastic method, building the pseudo-parametric bootstrap confidence intervals of the main outputs. Margins of exposure (MoE) and cancer incidence were estimated for the different collectives. The highest percentages of positive samples were found in red pepper, pistachios and peanuts. Considering our results, the most exposed group was the celiac sufferer collective followed by the adolescents; however health concern should not be expected in the population groups.

Exposure assessment to ochratoxin A in Catalonia (Spain) based on the consumption of cereals, nuts, coffee, wine, and beer.

Ochratoxin A (OTA) was analysed in composite samples of cereal-based baby foods, beer, breakfast cereals (corn- and rice and wheat-based), loaf bread, peanuts and pistachios. Foodstuffs were collected in hypermarkets and supermarkets from 12 cities in the Spanish region of Catalonia, and composite samples were prepared for analysis involving liquid-liquid extraction, followed by immunoaffinity column clean-up and HPLC with fluorescence detection. Consumption data for the selected foodstuffs were collected by means of a food-frequency questionnaire. The studied population was grouped by age in infants, children, adolescents and adults; and exposure to OTA through the specified foodstuffs, and through wine and coffee, was assessed. Exposure assessment was done through deterministic and probabilistic modelling of the contamination and consumption data. OTA occurrence and mean of positive samples (ng g(-1) or ng ml(-1), for beer) were the following: 8.7% and 0.233 in baby foods; 88.7% and 0.022 in beer; 2.8% and 0.728 in corn-based breakfast cereals; 25% and 0.293 in wheat-based breakfast cereals; 12.9% and 0.283 in loaf bread; 41.7% and 0.241 in peanuts; and 2.9% and 0.228 in pistachios. The median estimated daily intake of OTA through the foodstuffs by each age group were below the latest provisional tolerable daily intakes (PTDIs) of 17 and 14 ng kg(-1) bw day(-1) recommended by the European Food Safety Authority (EFSA) in 2006 and the Joint FAO/WHO Expert Committee on Food Additives (JECFA) in 2007, respectively, ranging from 1% and 2% of those values in adolescents and children, to 3% and 11% in adults and infants.

Exposure assessment of T2 and HT2 toxins in Catalonia (Spain).

HT-2 toxin (HT2) and T-2 toxin (T2) are mycotoxins produced in several cereals by species of Fusarium. The aim of the present study was to assess the exposure of Catalonian population to the combined mycotoxins T2 and HT2. Three different approaches were considered to handle the left censored data: (1) a substitution method, (2) a parametric method using the maximum likelihood estimation (MLE) and (3) a non-parametric method using the Kaplan-Meier (KM) estimator. Raw contamination data was provided by a large survey conducted in this region, in addition to the raw consumption data from a nutritional study specifically designed to assess the dietary intake of the main foodstuffs related to T2 and HT2 contamination for all population age groups. Contamination and consumption data were combined by simulation using a stochastic method. Accuracy and reliability of the statistic estimates were assessed building the related confidence intervals using a pseudo-parametric bootstrap method. Considering the results from the present study, the most exposed group population to the toxin T2 and HT2 should be expected to be the children.

Occurrence of fumonisins in Catalonia (Spain) and an exposure assessment of specific population groups.

Fumonisin B1 (FB1) and B2 (FB2) are mycotoxins produced by Fusarium verticillioides and F. proliferatum and common contaminants of cereal crops. The objectives of this study were to (1) study the occurrence of fumonisins in Catalonia (north-eastern region of Spain) and (2) assess the exposure of the Catalonian population to these mycotoxins. Contamination data was provided by a wide survey where 928 individual samples were pooled to analyse 370 composite samples. Fumonisins were extracted and purified using immunoaffinity columns and determined by HPLC with fluorescence detection. The raw consumption data came from a nutritional study specifically designed to assess the dietary intake of the main foodstuffs related to fumonisin contamination for all population age groups. In addition, two specific groups were selected with respect to maize consumption: immigrants and celiac sufferers. Contamination and consumption data were combined by simulation using an essentially parametric-parametric (P-P) method. The P-P method draws sampling values from distribution functions fitted to consumption and contamination datasets. Moreover, to quantify the accuracy and reliability of the statistical estimates, we built related confidence intervals using a Pseudo-Parametric bootstrap method. The results of this study show that fumonisins are commonly found in some commodities on the Catalonian market, such as beer, corn snacks and ethnic foods; however, the values were well below the permitted maximum EU levels. The most exposed group were infants followed by immigrants but, in all cases, they were below the TDI of 2 µg/kg bw/day.

Occurrence of zearalenone, an oestrogenic mycotoxin, in Catalonia (Spain) and exposure assessment.

The objectives of this study were to assess the occurrence of zearalenone (ZEA) in food in Catalonia (Spain); to assess the consumption of the main food items contaminated with ZEA; and finally, to estimate the dietary exposure of the Catalonian population to the mycotoxin. Therefore 1187 samples were collected from the Catalonian market and pooled to obtain 485 analytical samples (composites) of the commodities most susceptible to ZEA contamination and commonly consumed in the region. Extraction and clean-up was performed using immunoaffinity columns and ZEA was detected and quantified by high performance liquid chromatography (HPLC) and fluorescence detection. A specific food frequency questionnaire (FFQ) was administered to 1264 individuals by trained interviewers to estimate the consumption of the relevant foods. The results showed that the occurrence of ZEA in food marketed in Catalonia was infrequent. Sliced bread, corn snacks and sweet corn were the commodities where it was most often present. In considering the contamination levels and food consumption estimates, the dietary intake of ZEA by the Catalonian population was estimated to be considerably lower than the temporary tolerable daily intake (TDI) of 200 ng ZEA kg(-1) bw day(-1).

Sphinganine and sphingosine levels and ratio in urine and blood samples from a Catalonian population, Spain.

Fumonisins occur mainly in maize and they produce alterations on sphingolipid metabolism, unbalancing the sphinganine (Sa)/sphingosine (So) ratio. This alteration has been proposed as a biomarker of fumonisin exposure. The objective of this study was to establish the urinary and plasmatic levels of Sa, So as well as the ratio Sa/So from a sample of the Catalonian (Spain) population exposed to fumonisins at low levels. Firstly, plasma and urinary Sa and So levels and the ratio Sa/So were compared between two population groups, and later urinary Sa and So levels from corn food consumers and a control group were monitored for 2 weeks under controlled intake of corn foods. Sa and So levels were determined in urine and blood samples using validated methods using HPLC with fluorescence detection. Significant differences were not found in urine samples when Sa/So ratios were compared from corn food consumers and non-consumers, while significant differences were found in urine and plasma samples, but evidence of the mechanism of action of fumonisins was not apparent. Through a time-course study we have narrowed down the day in which the maximum alteration of Sa/So ratio should be expected in humans. This paper reports some useful information to improve the design of studies to validate the ratio Sa/So as a possible biomarker of fumonisin exposure.

Quantitative dietary exposure assessment of the Catalonian population (Spain) to the mycotoxin deoxynivalenol.

The mycotoxin deoxynivalenol (DON) is one of the most common contaminants of cereals worldwide, and its occurrence has been widely reported in raw foods and foodstuffs, around the European region, including Catalonia. In the present work, a stochastic methodology has been applied to accurately assess the exposure of the Catalonian population (Spain) to DON through food consumption. Raw contamination data was provided by a large survey conducted in this region, in addition to the raw consumption data from a nutritional study specifically designed to assess the dietary intake of the main foodstuffs related to DON contamination for all population age groups. Contamination and consumption data were combined by simulation using an essentially parametric (P-P) method. The P-P method draws sampling values from distribution functions fitted to consumption and contamination data sets. Moreover, to quantify the accuracy and reliability of the statistics estimates, we built the related confidence intervals using a pseudo-parametric bootstrap method. Considering the results drawn from the P-P simulation method, the Catalonian population should be expected to be exposed at moderated levels of deoxynivalenol, the infants and individuals with ethnic dietary patterns being the most exposed population groups.

Ochratoxin A and its metabolite ochratoxin alpha in urine and assessment of the exposure of inhabitants of Lleida, Spain.

Ochratoxin A (OTA) as well as its metabolite ochratoxin α (OTα) were detected in human urine in order to assess the exposure to OTA of a group of 72 adult inhabitants of the city of Lleida (Spain). Urine samples were enzymatically treated; OTA and OTα were separated by liquid-liquid extraction, and detected by HPLC-fluorescence. Exposure to OTA was also evaluated by the estimation of its daily intake from food contamination data from the literature and from food consumption data provided by the participants, who filled in a food frequency questionnaire (FFQ) and a three-day food consumption record (3DR). OTA occurrence (12.5%, limit of detection=0.034 ng/mL) was lower than OTα occurrence (61.1%, limit of detection=0.023 ng/mL). The range of concentrations was 0.057-0.562 ng/mL and 0.056-2.894 ng/mL for OTA and for OTα, respectively. It could be observed for positive samples that the FFQ data were related to the OTA concentration in urine, whereas the 3DR data were related to the OTα levels in urine. The OTA estimated daily intake of the participants was lower than 30% of the latest provisional tolerable daily intake of 14 ng/kg body weight/day in the worst cases of exposure.

Aflatoxins and ochratoxin A in pistachios sampled in Spain: occurrence and presence of mycotoxigenic fungi.

A survey of the fungal contamination and occurrence of aflatoxins and ochratoxin A (OTA) in 50 pistachio nut samples collected from commercial stores around Catalonia (Spain) was carried out. Aspergillus flavus was found in 30% of samples, whereas Aspergillus section Nigri, Aspergillus ochraceus, and Penicillium verrucosum were found in 40%, 2% and 26% of samples, respectively. A total of 204 fungal isolates were obtained; 70.8% of A. flavus isolates were able to produce aflatoxin B1 and B2, whereas OTA production capacity was detected in 54.4% of the A. section Nigri biseriate isolates. Aflatoxins were detected in five samples (10% of total), all exceeding the maximum legal limit set for aflatoxin B1 (2 µg kg(-1)) or for total aflatoxins (4 µg kg(-1)), with one sample having a very high level of contamination (1134.5 µg kg(-1)). Only one sample of pistachio showed OTA contamination at 0.67 µg kg(-1). Simultaneous contamination by aflatoxins and OTA was not observed in these samples. It was concluded that the frequency of aflatoxins and OTA contamination in pistachio samples available in the Spanish market is relatively low. Thus, no significant contribution to health risk should be expected from aflatoxin consumption through pistachios among healthy consumers. However, the existence of single samples with an extremely high aflatoxin concentration reinforces the need for effective prevention strategies in pistachio processing and commercialization.

Biomonitoring of Fusarium spp. mycotoxins: perspectives for an individual exposure assessment tool.

Fusarium species are probably the most prevalent toxin-producing fungi of the northern temperate regions and are commonly found on cereals grown in the temperate regions of America, Europe and Asia. Among the toxins formed by Fusarium we find trichothecenes of the A-type or B-type, zearalenone, fumonisins or nivalenol. The current exposure assessment consists of the qualitative and/or quantitative evaluation based on the knowledge of the mycotoxin occurrence in the food and the dietary habits of the population. This process permits quantifying the mycotoxin dietary intake through deterministic or probabilistic methods. Although these methods are suitable to assess the exposure of populations to contaminants and to identify risk groups, they are not recommended to evaluate the individual exposition, due to a low accuracy and sensitivity. On the contrary, the use of biochemical indicators has been proposed as a suitable method to assess individual exposure to contaminants. In this work, several techniques to biomonitor the exposure to fumonisins, deoxynivalenol, zearalenone or T-2 toxin have been reviewed.

Survey of patulin occurrence in apple juice and apple products in Catalonia, Spain, and an estimate of dietary intake.

This study was conducted to assess patulin exposure in the Catalonian population. Patulin levels were determined in 161 apple juice samples, 77 solid apple-based food samples and 146 apple-based baby food samples obtained from six hypermarkets and supermarkets from twelve main cities of Catalonia, Spain. Patulin was analysed by a well-established validated method involving ethyl acetate extraction and direct analysis by high-performance liquid chromatography (HPLC) with ultraviolet light detection. Mean patulin levels for positive samples in apple juice, solid apple-based food and apple-based baby food were 8.05, 13.54 and 7.12 µg kg(-1), respectively. No samples exceeded the maximum permitted levels established by European Union regulation. Dietary intake was separately assessed for babies, infants and adults through a Food Frequency Questionnaire developed from 1056 individuals from Catalonia. Babies were the main group exposed to patulin, however no risk was detected at these levels of contamination. Adults and infants consumers were far from risk levels. Another approach to determine estimated exposure was conducted through Monte Carlo simulation that distinguishes variability in exposures from uncertainty of distributional parameter estimates.