Determination of ochratoxin A in tissues of wild boar (Sus scrofa L.) by enzymatic digestion (ED) coupled to high-performance liquid chromatography with a fluorescence detector (HPLC-FLD)

Differential Immunomodulatory Effects of Head and Neck Cancer-Derived Exosomes on B Cells in the Presence of ATP

Head and neck squamous cell carcinoma (HNSCC) is an aggressive malignancy. Tumor-derived exosomes (TEX) have immunoregulatory properties. Adenosine triphosphate (ATP) and its immunosuppressive precursor adenosine (ADO) have been found in cancerous tissue. We investigated the effect of TEX on B cells in the presence of ATP. TEX were isolated from human HNSCC cell line (PCI-13) cultures and co-cultured with peripheral blood B cells of healthy donors, with or without TEX in different concentrations and with or without a low (20 µM) or high (2000 µM) ATP dose. We were able to demonstrate that TEX inhibit B-cell proliferation. The addition of TEX to either ATP concentration showed a decreasing trend in CD39 expression on B cells in a dose-dependent manner. High ATP levels (2000 µM) increased apoptosis and necrosis, and analysis of apoptosis-associated proteins revealed dose-dependent effects of ATP, which were modified by TEX. Altogether, TEX exhibited dual immunomodulatory effects on B cells. TEX were immunosuppressive by inhibiting B-cell proliferation; they were immunostimulatory by downregulating CD39 expression. Furthermore, TEX were able to modulate the expression of pro- and anti-apoptotic proteins. In conclusion, our data indicate that TEX play an important, but complex, role in the tumor microenvironment.

Toolbox for the Extraction and Quantification of Ochratoxin A and Ochratoxin Alpha Applicable for Different Pig and Poultry Matrices

Ochratoxin A (OTA) is one of the major mycotoxins causing severe effects on the health of humans and animals. Ochratoxin alpha (OTα) is a metabolite of OTA, which is produced through microbial or enzymatic hydrolysis, and one of the preferred routes of OTA detoxification. The methods described here are applicable for the extraction and quantification of OTA and OTα in several pig and poultry matrices such as feed, feces/excreta, urine, plasma, dried blood spots, and tissue samples such as liver, kidney, muscle, skin, and fat. The samples are homogenized and extracted. Extraction is either based on a stepwise extraction using ethyl acetate/sodium hydrogencarbonate/ethyl acetate or an acetonitrile/water mixture. Quantitative analysis is based on reversed-phase liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). Method validation was successfully performed and the linearity, limit of quantification, accuracy, precision as well as the stability of the samples, were evaluated. The analyte recovery of the spiked samples was between 80 and 120% (80–150% for spiked concentrations ≤ 1 ng/g or ng/mL) and the relative standard deviation was ≤ 15%. Therefore, we provide a toolbox for the extraction and quantification of OTA and OTα in all relevant pig and poultry matrices.

Ochratoxin A in Slaughtered Pigs and Pork Products

Ochratoxin A (OTA) is a mycotoxin that is produced after the growth of several Aspergillus and Penicillium spp. in feeds or foods. OTA has been proved to possess nephrotoxic, hepatotoxic, teratogenic, neurotoxic, genotoxic, carcinogenic and immunotoxic effects in animals and humans. OTA has been classified as possibly carcinogenic to humans (Group 2B) by the IARC in 2016. OTA can be mainly found in animals as a result of indirect transmission from naturally contaminated feed. OTA found in feed can also contaminate pigs and produced pork products. Additionally, the presence of OTA in pork meat products could be derived from the direct growth of OTA-producing fungi or the addition of contaminated materials such as contaminated spices. Studies accomplished in various countries have revealed that pork meat and pork meat products are important sources of chronic dietary exposure to OTA in humans. Various levels of OTA have been found in pork meat from slaughtered pigs in many countries, while OTA levels were particularly high in the blood serum and kidneys of pigs. Pork products made from pig blood or organs such as the kidney or liver have been often found to becontaminated with OTA. The European Union (EU) has established maximum levels (ML) for OTA in a variety of foods since 2006, but not for meat or pork products. However, the establishement of an ML for OTA in pork meat and meat by-products is necessary to protect human health.

The Occurrence and Contamination Level of Ochratoxin A in Plant and Animal-Derived Food Commodities

Ochratoxin A (OTA) is a highly toxic mycotoxin and poses great threat to human health. Due to its serious toxicity and widespread contamination, great efforts have been made to evaluate its human exposure. This review focuses on the OTA occurrence and contamination level in nine plant and animal derived food commodities: cereal, wine, coffee, beer, cocoa, dried fruit, spice, meat, and milk. The occurrence and contamination level varied greatly in food commodities and were affected by many factors, including spices, geography, climate, and storage conditions. Therefore, risk monitoring must be routinely implemented to ensure minimal OTA intake and food safety.

Determination of Mitotane (DDD) and Principal Metabolite by a Simple HPLC-UV Method and Its Validation in Human Plasma Samples

Mitotane (DDD) is prescribed in adrenocortical renal carcinoma. Its principal metabolite, dichlorodiphenylethene (DDE), can accumulate in fat tissues and from a toxicological point of view, is probably more interesting than the other metabolite dichlorodiphenylacetate (DDA). Therapeutic Drug Monitoring (TDM) of DDD plasma concentrations is required to combine therapeutic efficacy with acceptable toxicity. Therefore, we developed a simple and fast HPLC-UV method to monitor plasma concentrations after a liquid–liquid extraction of plasma calibration samples, quality controls, and anonymous plasma samples with unknown DDD and DDE concentrations. Samples were injected into an HPLC instrument and peaks of mitotane (DDD), DDE and aldrin (internal standard, IS) were resolved by a stationary phase C18 column (250 mm × 4.6 mm, 5 μm), maintained at 35 °C. Mobile phase, made by water/acetonitrile (10/90, v/v), was pumped at a flow of 1.0 mL/min, and absorbance was monitored at a wavelength of 226 nm. Average recovery was 95% for all analytes, and the method was linear for both DDD (r2 = 0.9988, range 1–50 mg/L) and DDE (r2 = 0.9964, range 1–40 mg/L). The values of limit of detection and quantitation were 0.102 and 0.310 mg/L for DDD and 0.036 and 0.108 mg/L for DDE, respectively. The retention time values of DDD, DDE and IS were 7.06, 9.42 and 12.60 min, respectively. The method was successfully validated according to FDA guidelines and finally adopted for routine TDM.

Ochratoxin A Levels in Tissues of Wild Boars (Sus scrofa) from Northern Italy

Ochratoxin A (OTA) is a mycotoxin produced by Aspergillus and Penicillium, capable of contaminating several foodstuffs. OTA damages primarily the kidneys, and is suspected to be a carcinogenic substance, thus maximum levels for OTA in foodstuffs have been established in the EU. Italian Ministry of Health suggested a maximum level of 1 μg/kg OTA in pork meat and derived products. In this study, OTA concentrations in liver, kidney, and muscle of 64 wild boars (Sus scrofa) killed in two areas (area A and B) of Parma province (northern Italy), characterized by different habitat types, were assessed by HPLC-FLD technique. OTA was detected in 54% liver, 52% kidney, and 16% muscle samples. OTA levels were significantly higher in liver and kidney compared with muscle, and were above 1 μg/kg in 19 liver, 17 kidney, and 4 muscle samples. OTA levels in wild boars from area A resulted significantly higher with respect to those from area B, suggesting an environmental influence on OTA contamination in wild boars. This study seems to confirm that wild boar meat is a potential source of OTA, thus monitoring the presence of this mycotoxin in game meat might be recommended to prevent risks for human health.

A rapid HPLC-FLD method for Ochratoxin A detection in pig muscle, kidney, liver by using enzymatic digestion with MISPE extraction

Ochratoxin A (OTA) is a mycotoxin produced as a secondary metabolite by various Aspergillus and Penicillium species with nephrotoxic, carcinogenic, immunotoxic and teratogenic effects. OTA has been found in several food commodities, including cereals, beer, wine and spices. OTA can also be present in animal products (especially in pig derived products) as a result of carryover from contaminated feed. Permitted level of 1 µg/kg OTA in pig meat or pig-derived products was set in Italy, as in other countries. Key parameters which affected MISPE, should be described such as extraction efficiency and were optimized, analyzed by an isocratic HPLC-FLD method. Under the optimized conditions, for all analyzed matrices mean recovery was > 89%. Method can be applied as alternative routine procedure to detect OTA presence in pig products. Points:  *Aim of the study was to develop and validate a quantitative HPLC-FLD method based on MISPE with complex solid matrices (edible tissues) followed by chromatographic analysis.  *The new method was developed and validated in pig complex matrix and is very sensitive LOD and LOQ respectively 0.001 and 0.003 µg/kg.  *This method is relatively simple to use and with good performances. Was possible to reuse MISPE column with a "regeneration" solution, until to 7 times.

A new validated HPLC-UV method for therapeutic monitoring of daptomycin in comparison with reference mass spectrometry

Daptomycin, a cyclic lipopeptide antibiotic with a broad spectrum of activity against Gram-positive bacteria, is also active against multi-resistant bacterial strains, as well as methicillin-resistant S. aureus, vancomycin-resistant enterococci or penicillin-resistant S. pneumoniae. For these reasons it is a viable alternative for the treatment of persisting infections. However, the therapeutic drug monitoring of daptomycin is recommended because the known variability in drug disposition and the severe clinical conditions of patients. Therefore, we developed a simple and fast UV-HPLC method according to FDA guidelines to monitor plasma concentrations of the drug. Briefly, after a liquid-liquid extraction, plasma calibration samples, quality controls and patients' samples were injected in a HPLC instrument and peaks of daptomycin and gentamicin (internal standard) were resolved by a C₁₈ 250 × 4.6 mm, 5 μm stationary phase and peaks were monitored at UV = 262 nm. Mobile phase (isocratic flow of 1 mL/min) consisted of acetonitrile-buffer (KH₂PO₄ 20 mM pH = 3.2) 46:54, vol/vol. Under these conditions, IS and daptomycin peaked at 4.1 and 5.8 min after injection. Values of limits of detection and quantitation accounted for 1.65 and 5.00 (μg/ml), respectively. Values of method linearity (r²) in range 5-100 mg/L were 0.9975 and 0.9956 plasma samples and solvent standard, respectively. Inter- and intra-day variability coefficients were lower than 15 %. The comparison with a reference, commercially-available LC-MS/MS method on 122 patient plasma samples returned excellent correlation (r² = 0.9474). In conclusion, the present method demonstrated to be reliable and suitable for daptomycin TDM in clinical routine.

Simultaneous determination of 19 mycotoxins in lotus seed using a multimycotoxin UFLC-MS/MS method

Objectives

In relevance to the internal components and improper environmental conditions, lotus seeds are susceptible to fungal contamination and mycotoxins residue, leading to harmful impacts on the quality and safety, as well as their pharmaceutical efficacy and clinical use. It is necessary and urgent to assess various mycotoxins residue in lotus seeds. This study aimed to develop a sensitive method for accurate assessment of multimycotoxin residues in lotus seeds.

Methods

A simple and reliable modified ultrasonication-assisted extraction, QuEChERS purification based ultrafast liquid chromatography tandem mass spectrometry (UFLC-MS/MS) method was successfully developed for ultrasensitive determination of 19 multiclass mycotoxins in starch-rich lotus seeds. Four extraction modes and three clean-up sorbents for improving the recoveries of mycotoxins were optimized. Limits of detection (LODs) and quantification, linearity, precision, accuracy, and matrix effect were studied for method validation. For simultaneous qualitation and quantification, the 19 chemically diversified mycotoxins were well separated on a CAPCELL CORE C18 column (100 mm × 2.1 mm, 2.7 μm) and detected in positive/negative electrospray ionization mode within 7 min.

Key findings

The validated method exhibited satisfactory linearity (r > 0.995), ultragood selectivity (LODs of 0.1–15.0 μg/kg), excellent precision (RSDs <13.0%) and convincing accuracy (recoveries between 79.4% and 131.6% with RSDs <14.4%). Matrix effect, between 54.5% and 113.6%, appeared especially for aflatoxins B1 and B2, deoxynivalenol and T-2 toxins. Matrix-matched curve-based quantification showed that 26 (57.8%) out of 45 lotus seed samples were contaminated with one or more mycotoxins, and ochratoxin A, aflatoxin B2, aflatoxin B1 and citrinin were the most prevalent mycotoxins.

Conclusions

This study reports for the first time the incidence of a wide range of 19 mycotoxins in lotus seeds and the proposed method will get broad application for more trace components in other complex matrices.

Determination of Multi-Class Mycotoxins in Tartary Buckwheat by Ultra-Fast Liquid Chromatography Coupled with Triple Quadrupole Mass Spectrometry

Considering crops are susceptible to toxicogenic fungi during plantation, pre-processing and storage, an ultra-fast liquid chromatography coupled with triple quadrupole mass spectrometry (UFLC-QTrap-MS/MS) method was developed and validated for simultaneous determination of the 12 most frequent mycotoxins, including aflatoxin B₁, B₂, G₁, G₂, HT-2, T-2 toxin, ochratoxin A, fumonisin B₁, B₂, zearalanone, zearalenone, and deoxynivalenol, in 14 batches of Tartary buckwheat cultivar, collected from different origins in Sichuan Province, China. Differing from those complicated approaches, a simple and cost-efficient pretreatment method based on dilute-and-shoot was employed. Based on optimized chromatographic and mass spectrometry conditions, these 12 mycotoxins could be analyzed with high correlation coefficients (all over 0.995), high precision (RSD 0.47–9.26%), stability (RSD 0.72–11.36%), and recovery (79.52% to 108.92%, RSD 4.35–14.27%). Furthermore, this analysis method exhibited good determination performance with little disturbance of the matrix effect. Finally, this proposed method was applied for 14 batches of Tartary buckwheat seeds, in which aflatoxin B₁ (AFB₁) was detected in one moldy cultivar, Meigu No. 2, with its concentration exceeding the maximum residue limits set by EU regulations. The method thus established, which has significant advantages, could provide a preferred determination approach candidate for measurement of multiple mycotoxins measurement in Tartary buckwheat, even other kinds of foodstuffs.