Citrinin in Foods and Supplements: A Review of Occurrence and Analytical Methodologies

Development and validation of an analytical method for determination of citrinin in red rice and red yeast rice-based food supplements by ultra-high performance liquid chromatography tandem mass spectrometry

Citrinin is a hepato-nephrotoxic mycotoxin produced by fungal species. The Monascus purpureus fungus plays a crucial role in the fermentation of red rice to produce red yeast rice-based food supplements, which represent the primary source of human exposure to citrinin. In this study, a simple and sensitive analytical method was successfully developed and validated for the citrinin determination in these products. The extraction process involved a QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) step and citrinin determination by ultra high-performance liquid chromatography coupled with tandem mass spectrometry (UHPLC-MS/MS). The proposed method provided satisfactory linearity, percentage of recovery from 82 to 104% with relative standard deviations (RSD) lower than 14%, and limits of detection and quantification of 0.07 μg/Kg and 0.24 μg/kg, respectively. Among the 14 samples analyzed, citrinin was found in two red rice samples (0.24 and 0.46 μg/kg) and in six food supplements (from 0.44 to 87 μg/kg).

Apoptosis mediated by crosstalk between mitochondria and endoplasmic reticulum: A possible cause of citrinin disruption of the intestinal barrier

Citrinin (CTN) is a mycotoxin commonly found in contaminated foods and feed, posing health risks to both humans and animals. However, the mechanism by which CTN damages the intestine remains unclear. In this study, a model of intestinal injury was induced by administering 1.25 mg/kg and 5 mg/kg of CTN via gavage for 28 consecutive days in 6-week-old Kunming mice, aiming to explore the potential mechanisms underlying intestinal injury. The results demonstrate that CTN can cause structural damage to the mouse jejunum. Additionally, CTN reduces the protein expression of Claudin-1, Occludin, ZO-1, and MUC2, thereby disrupting the physical and chemical barriers of the intestine. Furthermore, exposure to CTN alters the structure of the intestinal microbiota in mice, thus compromising the intestinal microbial barrier. Meanwhile, the results showed that CTN exposure could induce excessive apoptosis in intestinal cells by altering the expression of proteins such as CHOP and GRP78 in the endoplasmic reticulum and Bax and Cyt c in mitochondria. The mitochondria and endoplasmic reticulum are connected through the mitochondria-associated endoplasmic reticulum membrane (MAM), which regulates the membrane. We found that the expression of bridging proteins Fis1 and BAP31 on the membrane was increased after CTN treatment, which would exacerbate the endoplasmic reticulum dysfunction, and could activate proteins such as Caspase-8 and Bid, thus further inducing apoptosis via the mitochondrial pathway. Taken together, these results suggest that CTN exposure can cause intestinal damage by disrupting the intestinal barrier and inducing excessive apoptosis in intestinal cells.

Visual detection of ochratoxin a based on GPE-PET bipolar electrode-electrochemiluminescence platform

A GPE-PET (graphene-polyethylene terephthalate) bipolar electrode-electrochemiluminescence (BPE-ECL) platform was developed for ochratoxin A (OTA) detection. PET served as the electrode sheet substrate, and GPE was drop-coated onto the surface of PET to form a conductive line. On the functional sensing interface, the thiol (-SH) modified OTA aptamer (OTA-Aptamer) are fixed on the surface of the gold-plated cathode through AuS bonds. The efficient electron transfer ability of methylene blue (MB) made the anode ECL signal strong. Due to competition between OTA and MB with OTA-Aptamer, leading to a decrease in ECL intensity of the [Ru(bpy)3]2+/TPA system on the BPE anode. Under optimized conditions, the GPE-PET BPE-ECL biosensor displayed superior sensitivity for OTA with a detection limit of 2 ng mL-1 and a wide linear concentration range of 5-100 ng mL-1. This method could be further applied to detect various toxins and had broad application prospects.

Citrinin Provoke DNA Damage and Cell-Cycle Arrest Related to Chk2 and FANCD2 Checkpoint Proteins in Hepatocellular and Adenocarcinoma Cell Lines

Citrinin (CIT), a polyketide mycotoxin produced by Penicillium, Aspergillus, and Monascus species, is a contaminant that has been found in various food commodities and was also detected in house dust. Several studies showed that CIT can impair the kidney, liver, heart, immune, and reproductive systems in animals by mechanisms so far not completely elucidated. In this study, we investigated the CIT mode of action on two human tumor cell lines, HepG2 (hepatocellular carcinoma) and A549 (lung adenocarcinoma). Cytotoxic concentrations were determined using an MTT proliferation assay. The genotoxic effect of sub-IC50 concentrations was investigated using the alkaline comet assay and the impact on the cell cycle using flow cytometry. Additionally, the CIT effect on the total amount and phosphorylation of two cell-cycle-checkpoint proteins, the serine/threonine kinase Chk2 and Fanconi anemia (FA) group D2 (FANCD2), was determined by the cell-based ELISA. The data were analyzed using GraphPad Prism statistical software. The CIT IC50 for HepG2 was 107.3 µM, and for A549, it was >250 µM. The results showed that sensitivity to CIT is cell-type dependent and that CIT in sub-IC50 and near IC50 induces significant DNA damage and cell-cycle arrest in the G2/M phase, which is related to the increase in total and phosphorylated Chk2 and FANCD2 checkpoint proteins in HepG2 and A549 cells.

Evaluation of PLA-Based Composite Films Filled with Cu2(OH)3NO3 Nanoparticles as an Active Material for the Food Industry: Biocidal Properties and Environmental Sustainability

The globalization of markets has diversified the food supply, but it has also made the distribution chain more difficult, increasing the risk of microbial contamination. One strategy to obtain safer food and extend its shelf life is to develop active packaging with antimicrobial properties that prevent the growth of pathogenic microorganisms or spoilage in food products. In this context, and in line with the growing social awareness about the environmental impact generated by plastic waste, this work evaluated the effectiveness of polylactic acid (PLA) films loaded with different concentrations of copper (II) hydroxynitrate nanoparticles (CuHS) against the microbiota of fresh foods (chicken, fish and cheese). The results showed that the developed films containing 1, 3 and 5% w/w of CuHS in the polymeric matrix caused a decrease in the microbial abundance equal to or higher than 3 logarithmic units in all foods tested. Moreover, the mechanical and thermal properties of the formulated composites showed that the added CuHS concentrations did not substantially modify these properties compared to the PLA films. Taking into account the results obtained for antimicrobial activity, Cu (II) migration levels and the cytotoxicity of the films formulated, the PLA composite loaded with 1% CuHS (w/w) was the most suitable for its potential use as food packaging material. In addition, the biodegradation of this composite film was studied under conditions simulating intensive aerobic composting, demonstrating that almost 100% disintegration after 14 days of testing was achieved. Therefore, the innovative PLA-based films developed represent a promising strategy for the fabrication of packaging and active surfaces to increase food shelf life while maintaining food safety. Moreover, their biodegradable character will contribute to efficient waste management, turning plastic residues into a valuable resource.

Effect of Spirulina and Fish Processing By-Products Extracts on Citrinin-Induced Cytotoxicity in SH-SY5Y Cells

Citrinin (CIT) is a mycotoxin commonly found in grains, fruits, herbs, and spices. Its toxicity primarily affects the kidney and liver. Meanwhile, food industry by-products, particularly from fishing and aquaculture, contribute significantly to environmental concerns but can also serve as valuable sources of nutrients and bioactive compounds. Additionally, microalgae like spirulina (Arthrospira platensis) offer interesting high-added-value compounds with potential biological and cytoprotective properties. This study aims to reduce CIT's toxicity on SH-SY5Y cells using natural extracts from the microalgae spirulina and fish processing by-products (sea bass head). The combination of these extracts with CIT has shown increased cell viability up to 15% for fish by-products extract and about 10% for spirulina extract compared to CIT alone. Furthermore, a notable reduction of up to 63.2% in apoptosis has been observed when fish by-products extracts were combined with CIT, counteracting the effects of CIT alone. However, the extracts' effectiveness in preventing CIT toxicity in the cell cycle remains unclear. Overall, considering these nutrient and bioactive compound sources is crucial for enhancing food safety and mitigating the harmful effects of contaminants such as mycotoxins. Nevertheless, further studies are needed to investigate their mechanisms of action and better understand their protective effects more comprehensively.

Quality Control and Safety Assessment of Online-Purchased Food Supplements Containing Red Yeast Rice (RYR)

Dietary supplements containing red yeast rice (RYR), a fermentation product of the fungus Monascus purpureus grown on white rice, remain popular in Europe as proclaimed cholesterol-lowering aids. The cholesterol-lowering effects are due to the occurrence of monacolin K, which is often present as a mixture of monacolin K lactone (MK) and as monacolin K hydroxy acid (MKA). MK is structurally similar to the cholesterol-lowering medicine lovastatin. Recently, due to safety concerns linked to the use of statins, the European Commission prohibited RYR supplements with a maximum serving exceeding 3 mg of total monacolins per day. Moreover, the amount of the mycotoxin citrinin, potentially produced by M. purpureus, was also reduced to 100 µg/kg. Evidently, manufacturers that offer their products on the European market, including the online market, must also be compliant with these limits in order to guarantee the safety of their products. Therefore, thirty-five different RYR supplements, purchased from an EU-bound e-commerce platform or from registered online pharmacies, were screened for their compliance to the European legislation for citrinin content and the amount of total monacolin K. This was conducted by means of a newly developed LC-MS/MS methodology that was validated according to ISO 17025. Moreover, these supplements were also screened for possible adulteration and any contamination by micro-organisms and/or mycotoxins. It was found that at least four of the thirty-five RYR supplements (≈11%) might have reason for concern for the safety of the consumer either due to high total monacolin K concentrations exceeding the European predefined limits for total monacolins or severe bacterial contamination. Moreover, three samples (≈9%) were likely adulterated, and the labeling of six of the seventeen samples (≈35%) originating from an EU-based e-commerce platform was not compliant, as either the mandatory warning was missing or incomplete or the total amount of monacolins was not mentioned.

Successful treatment of acute tubulointerstitial nephritis probably due to Benikoji CholesteHelp®, a supplement containing red yeast rice

Red yeast rice has been used to produce alcoholic beverages and various fermented foods especially in East Asia. Since around March 2024, there have been many cases of kidney dysfunction in people who have taken certain supplements containing red yeast rice in Japan. We experienced a case of acute kidney injuries induced after taking a supplement containing red yeast rice. A 58-year-old woman was admitted to our hospital due to renal dysfunction suspected to be caused by taking the supplement Benikoji CholesteHelp®, which contains red yeast rice. With elevations of urinary tubular injury markers such as urinary β2-microglobulin and N-acetyl-β-D-glucosaminidase, serum creatinine levels were elevated up to 2.75 mg/dL. A kidney biopsy revealed a diagnosis of tubulointerstitial nephritis with lymphocytic infiltration of the interstitium, tubular atrophy, and interstitial fibrotic changes. After discontinuation of the supplement and initiation of the prednisolone treatment, renal dysfunction rapidly improved. The course of this case suggests tubular damage caused by the supplements containing red yeast rice. For early diagnosis and treatment, it should be noted that even what are regarded as nutritional health supplements can cause renal dysfunction.

Fasting-Induced Molting Impacts the Intestinal Health by Altering the Gut Microbiota

Fasting-induced molting (FIM) is a common method used to improve the laying performance of aged laying hens. Nevertheless, this approach may impose various stresses on chickens, such as disruptions in intestinal flora and inflammation issues within the intestines. However, the impact of an imbalance in intestinal flora on intestinal health during the FIM process remains elusive. Therefore, intestinal injury, the microbiome, and the metabolome were analyzed individually and integrated to elucidate the impact of the intestinal flora on intestinal health during the FIM process. The findings indicated that fasting resulted in a notable reduction in villus height and villus/crypt ratio, coupled with elevated levels of intestinal inflammation and permeability. During the fasting period, microbiota compositions changed. The abundance of Escherichia_Shigella increased, while the abundance of Ruminococcaceae_UCG-013 and Lactobacillus decreased. Escherichia_Shigella was positively correlated with Citrinin and Sterobilin, which lead to intestinal inflammation. Ruminococcaceae_UCG-013 and Lactobacillus exhibited positive correlations with Lanthionine and reduced Glutathione, thereby reducing intestinal inflammation. This study screened the intestinal probiotics, Ruminococcaceae UCG-013 and Lactobacillus, that influence gut health during the fasting period, providing an experimental basis for improving gut microbiota and reducing intestinal inflammation during the FIM process.

Application of Biosensors for the Detection of Mycotoxins for the Improvement of Food Safety

Mycotoxins, secondary metabolites synthesized by various filamentous fungi genera such as Aspergillus, Penicillium, Fusarium, Claviceps, and Alternaria, are potent toxic compounds. Their production is contingent upon specific environmental conditions during fungal growth. Arising as byproducts of fungal metabolic processes, mycotoxins exhibit significant toxicity, posing risks of acute or chronic health complications. Recognized as highly hazardous food contaminants, mycotoxins present a pervasive threat throughout the agricultural and food processing continuum, from plant cultivation to post-harvest stages. The imperative to adhere to principles of good agricultural and industrial practice is underscored to mitigate the risk of mycotoxin contamination in food production. In the domain of food safety, the rapid and efficient detection of mycotoxins holds paramount significance. This paper delineates conventional and commercial methodologies for mycotoxin detection in ensuring food safety, encompassing techniques like liquid chromatography, immunoassays, and test strips, with a significant emphasis on the role of electrochemiluminescence (ECL) biosensors, which are known for their high sensitivity and specificity. These are categorized into antibody-, and aptamer-based, as well as molecular imprinting methods. This paper examines the latest advancements in biosensors for mycotoxin testing, with a particular focus on their amplification strategies and operating mechanisms.

Screening Antibacterial Photodynamic Effect of Monascus Red Yeast Rice (Hong-Qu) and Mycelium Extracts

The fungus Monascus is a well-known source of secondary metabolites with interesting pharmaceutical and nutraceutical applications. In particular, Monascus pigments possess a wide range of biological activities (e.g. antimicrobial, antioxidant, anti-inflammatory or antitumoral). To broaden the scope of their possible application, this study focused on testing Monascus pigment extracts as potential photosensitizing agents efficient in antimicrobial photodynamic therapy (aPDT) against bacteria. For this purpose, eight different extracts of secondary metabolites from the liquid- and solid-state fermentation of Monascus purpureus DBM 4360 and Monascus sp. DBM 4361 were tested against Gram-positive and Gram-negative model bacteria, Bacillus subtilis and Escherichia coli and further screened for ESKAPE pathogens, Staphylococcus aureus and Pseudomonas aeruginosa. To the bacterial culture, increasing concentration of extracts was added and it was found that all extracts showed varying antimicrobial activity against Gram-positive bacteria in dark, which was further increased after irradiation. Gram-negative bacteria were tolerant to the extracts' exposure in the dark but sensitivity to almost all extracts that occurred after irradiation. The Monascus sp. DBM 4361 extracts seemed to be the best potential candidate for aPDT against Gram-positive bacteria, being efficient at low doses, i.e. the lowest total concentration of Monascus pigments exhibiting aPDT effect was 3.92 ± 1.36 mg/L for E. coli. Our results indicate that Monascus spp., forming monascuspiloin as the major yellow pigment and not-forming mycotoxin citrinin, is a promising source of antimicrobials and photoantimicrobials.

Study of cytotoxicity in neuroblastoma cell line exposed to patulin and citrinin

Mycotoxins can be found in food and feed storage as well as in several kinds of foodstuff and are capable of harming mammals and some of them even in small doses. This study investigated on the undifferentiated neuronal cell line SH-SY5Y the effects of two mycotoxins: patulin (PAT) and citrinin (CTN), which are predominantly produced by fungi species Penicillium and Aspergillus. Here, the individual and combined cytotoxicity of PAT and CTN was investigated using the cytotoxic assay MTT. Our findings indicate that after 24 h of treatment, the IC50 value for PAT is 2.01 μM, which decreases at 1.5 μM after 48 h. In contrast, CTN did not attain an IC50 value at the tested concentration. Therefore, we found PAT to be the more toxic compared to CTN. However, the combined treatment suggests an additive toxic effect. With 2,7-dichlorodihydrofluorescin diacetate (DCFH-DA) DCFH-DA assay, ROS generation was demonstrated after CTN treatment, but PAT showed only small changes. The mixture presented a very constant behavior over time. Finally, the median-effect/combination index (CI-) isobologram equation demonstrated an additive effect after 24 h, but an antagonistic effect after 48 h for the interaction of the two mycotoxins.

Exposure to Mycotoxin Citrinin Promotes Carcinogenic Potential of Human Renal Cells

Mycotoxin citrinin (CTN), commonly found in food and health supplements, may induce chromosomal instability. In this study, human renal proximal tubule epithelial cells (hRPTECs) that were exposed to CTN (10 and 20 μM) over 3 days exhibited numerical chromosomal aberrations. Short-term (3 days) and long-term (30 days) exposures to CTN significantly promoted mitotic spindle abnormalities, wound healing, cell migration, and anchorage-independent growth in human embryonic kidney 293 (HEK293) cells. Short-term exposure to 10 and 20 μM CTN increased the number of migrated cells on day 10 by 1.7 and 1.9 times, respectively. The number of anchorage-independent colonies increased from 2.2 ± 1.3 to 7.8 ± 0.6 after short-term exposure to 20 μM CTN and from 2.0 ± 1.0 to 12.0 ± 1.2 after long-term exposure. The transcriptomic profiles of CTN-treated HEK293 were subjected to over-representative analysis (ORA), gene set enrichment analysis (GSEA), and Ingenuity pathway analysis (IPA). Short-term exposure to CTN promoted the RTK/KRAS/RAF/MAPK cascade, while long-term exposure altered the extracellular matrix organization. Both short- and long-term CTN exposure activated cancer and cell cycle-related signaling pathways. These results demonstrate the carcinogenic potential of CTN in human cells and provide valuable insights into the cancer risk associated with CTN.

Traditional Meat Products-A Mycotoxicological Review

Traditional meat products are commonly produced in small family businesses. However, big industries are also involved in the production of this kind of product, especially since a growing number of consumers crave the traditional taste and aromas. The popularization of original and organic products has resulted in a return to traditional production methods. Traditional meat products are produced worldwide. However, in such (domesticated) conditions there is a potential danger for mycotoxin contamination. This review aims to present the sources of mycotoxins in traditional meat products, the most common mycotoxins related to such meat products, and future prospects regarding the suppression of their occurrence. Special attention should be paid to reducing the transfer of mycotoxins via the food chain from animal feed to animals to humans (stable-to-table principle), which is also described in this review. Other sources of mycotoxins (spices, environment, etc.) should also be monitored for mycotoxins in traditional production. The importance of monitoring and regulating mycotoxins in meat products, especially in traditional meat products, is slowly being recognized by the institutions and hopefully, in the future, can deliver legally regulated limits for such products. This is especially important since meat products are available to the general population and can seriously affect human health.

A comparative review on methods of detection and quantification of mycotoxins in solid food and feed: a focus on cereals and nuts

Many emerging factors and circumstances urge the need to develop and optimize the detection and quantification techniques of mycotoxins in solid food and feed. The diversity of mycotoxins, which have different properties and affinities, makes the standardization of the analytical procedures and the adoption of a single protocol that covers the attributes of all mycotoxins a tedious or even an impossible mission. Several modifications and improvements have been undergone in order to optimize the performance of these methods including the extraction solvents, the extraction methods, the clean-up procedures, and the analytical techniques. The techniques range from the rapid screening methods, which lack sensitivity and specificity such as TLC, to a spectrum of more advanced protocols, namely, ELISA, HPLC, and GC-MS and LC-MS/MS. This review aims at assessing the current studies related to these analytical techniques of mycotoxins in solid food and feed. It discusses and evaluates, through a critical approach, various sample treatment techniques, and provides an in-depth examination of different mycotoxin detection methods. Furthermore, it includes a comparison of their actual accuracy and a thorough analysis of the observed benefits and drawbacks.

Machine Learning-Mediated Ultrasensitive Detection of Citrinin and Associated Mycotoxins in Real Food Samples Discerned from a Photoluminescent Carbon Dot Barcode Array

Economically viable remote sensing of foodborne contaminants using minimalistic chemical reagents and simultaneous automation calls for a concrete integration of a chemical detection strategy with artificial intelligence. In a first of its kind, we report the ultrasensitive detection of citrinin and associated mycotoxins like aflatoxin B1 and ochratoxin A using an Alizarin Red S (ARS) and cystamine-derived carbon dot (CD) that aptly amalgamate with machine learning algorithms for automation. The photoluminescence response of the CD as a function of various solvents and pH is used to generate array channels that are further modulated in the presence of the mycotoxins whose digital images were acquired to determine pixelation, essentially creating a barcode. The barcode was fed to machine learning algorithms that actualize and intertwine convoluted databases, demonstrating Extreme Gradient Boosting (XGBoost) as the optimized model out of eight algorithms tested. Spiked samples of wheat, rice, gram, maize, coffee, and milk were used to evaluate the testing model where an exemplary accuracy of 100% even at 10 pmol of mycotoxin concentration was achieved. Most importantly, the coexistence of mycotoxins could also be detected through the CD array and XGBoost synergy hinting toward a broader scope of the developed methodology for smart detection of foodborne contaminants.

The potential of citrus by-products in the development of functional food and active packaging

Food by-product valorization has become an important research area for promoting the sustainability of the food chain. Citrus fruits are among the most widely cultivated fruit crops worldwide. Citrus by-products, including pomace, seeds, and peels (flavedo and albedo), are produced in large amounts each year. Those by-products have an important economic value due to the high content on bioactive compounds, namely phenolic compounds and carotenoids, and are considered a valuable bio-resource for potential applications in the food industry. However, green extraction techniques are required to ensure their sustainability. This chapter addresses the main components of citrus by-products and their recent applications in food products and active food packaging, towards a circular economy. In addition, the concern regarding citrus by-products contamination (e.g. with pesticides residues and mycotoxins) is also discussed.

High-pressure acidified steaming with varied citric acid dosing can successfully detoxify mycotoxins

Mycotoxins are toxic fungal metabolites that exert various toxicities, including leading to death in lethal doses. This study developed a novel high-pressure acidified steaming (HPAS) for detoxification of mycotoxins in foods and feed. The raw materials, maize and peanut/groundnut, were used for the study. The samples were separated into raw and processed categories. Processed samples were treated using HPAS at different citric acid concentrations (CCC) adjusted to pH 4.0, 4.5, and 5.0. The enzyme-linked immunosorbent assay (ELISA) kit method for mycotoxins analysis was used to determine the levels of mycotoxins in the grains, with specific focus on total aflatoxins (AT), aflatoxins B1 (AFB1), aflatoxin G1 (AFG1), ochratoxin A (OTA), and citrinin. The mean values of the AT, AFB1, AFG1, OTA, and citrinin in the raw samples were 10.06 ± 0.02, 8.21 ± 0.01, 6.79 ± 0.00, 8.11 ± 0.02, and 7.39 ± 0.01 μg/kg for maize, respectively (p ≤ .05); and for groundnut (peanut), they were 8.11 ± 0.01, 4.88 ± 0.01, 7.04 ± 0.02, 6.75 ± 0.01, and 4.71 ± 0.00 μg/kg, respectively. At CCC adjusted to pH 5.0, the AT, AFB1, AFG1, OTA, and citrinin in the samples significantly reduced by 30%-51% and 17%-38% for maize and groundnut, respectively, and were reduced to 28%-100% when CCC was adjusted to pH 4.5 and 4.0 (p ≤ .05). The HPAS process either completely detoxified the mycotoxins or at least reduced them to levels below the maximum limits of 4.00-6.00, 2.00, 2.00, 5.00, and 100 μg/kg for AT, AFB1, AFG1, OTA, and citrinin, respectively, set by the European Union, WHO/FAO, and USDA. The study clearly demonstrates that mycotoxins can be completely detoxified using HPAS at CCC adjusted to pH 4.0 or below. This can be widely applied or integrated into many agricultural and production processes in the food, pharmaceutical, medical, chemical, and nutraceutical industries where pressurized steaming can be applied for the successful detoxification of mycotoxins.

The Questionable Quality Profile of Food Supplements: The Case of Red Yeast Rice Marketed Products

Food supplements (FS) containing red yeast rice (RYR) are largely employed to reduce lipid levels in the blood. The main ingredient responsible for biological activity is monacolin K (MoK), a natural compound with the same chemical structure as lovastatin. Concentrated sources of substances with a nutritional or physiological effect are marketed in "dose" form as food supplements (FS). The quality profile of the "dosage form" of FS is not defined in Europe, whereas some quality criteria are provided in the United States. Here, we evaluate the quality profile of FS containing RYR marketed in Italy as tablets or capsules running two tests reported in The European Pharmacopoeia 11 Ed. and very close to those reported in the USP. The results highlighted variations in dosage form uniformity (mass and MoK content) compliant with The European Pharmacopoeia 11 Ed. specifications, whereas the time needed for disintegrating tablets was longer for 44% of the tested samples. The bioaccessibility of MoK was also investigated to obtain valuable data on the biological behaviour of the tested FS. In addition, a method for citrinin (CIT) determination was optimized and applied to real samples. None of the analyzed samples demonstrated CIT contamination (LOQ set at 6.25 ng/mL). Considering the widespread use of FS, our data suggest that greater attention should be paid by fabricants and regulatory authorities to ensure the quality profile and the safe consumption of marketed products.

Citrinin Exposure Induced Testicular Damage and Spermatogenesis Disorder by Triggering Endoplasmic Reticulum Stress

Damage to the reproductive system is the key factor leading to male infertility. Citrinin (CTN) is produced by Penicillium and Aspergillus in nature, and is definitely found in food and animal feed. Studies have revealed that CTN can cause damage to male reproductive organs and reduce fertility, but the mechanism of toxicity has not been revealed. In the present study, male Kunming mice were given different doses of CTN (0, 1.25, 5 or 20 mg/kg BW) by intragastric administration. The results demonstrated that CTN exposure caused disorder of androgen, a decline in sperm quality, and histopathological damage of testis. The inhibition of the expression of ZO-1, claudin-1 and occludin suggests that the blood-testis barrier (BTB) was damaged. Simultaneously, CTN inhibited the activity of antioxidant enzymes such as CAT and SOD, and promoted the production of MDA and ROS, resulting in oxidative damage of testis. Additionally, apoptotic cells were detected and the ratio of Bax/Bcl-2 was increased. Not only that, CTN activated the expression of endoplasmic reticulum stress (ERS)-related proteins IRE1, ATF6, CHOP, and GRP78. Interestingly, 4-Phenylbutyric Acid (4-PBA, an ERS inhibitor) treatment blocked the adverse effects of CTN exposure on male reproduction. In short, the findings suggested that CTN exposure can cause damage to mouse testis tissue, in which ERS exhibited an important regulatory role.

Food Toxicity of Mycotoxin Citrinin and Molecular Mechanisms of Its Potential Toxicity Effects through the Implicated Targets Predicted by Computer-Aided Multidimensional Data Analysis

The mycotoxin citrinin, which can contaminate food, is a major global concern. Citrinin is regarded as an inevitable pollutant in foods and feed since fungi are widely present in the environment. To identify contentious toxicity and lessen its severity by understanding the targets of citrinin in the human body and the impacted biosynthetic pathways, we analyzed the production of citrinin from Aspergillus flavus and Penicillium notatum and used a thorough bioinformatics analysis to characterize the toxicity and predict genes and protein targets for it. The predicted median fatal dosage (LD50) for citrinin was 105 mg/kg weight, and it belonged to toxicity class 3 (toxic if swallowed). Citrinin was found to be well absorbed by human intestinal epithelium and was a Pgp nonsubstrate (permeability glycoprotein), which means that once it is absorbed, it cannot be pumped out, hence leading to bioconcentration or biomagnification in the human body. The main targets of toxicity were casp3, TNF, IL10, IL1B, BAG3, CCNB1, CCNE1, and CDC25A, and the biological pathways implicated were signal transduction involved in DNA damage checkpoints, cellular and chemical responses to oxidative stress, DNA damage response signal transduction by P53, stress-activated protein kinase signaling cascade, netrin–UNC5B signaling, PTEN gene regulation, and immune response. Citrinin was linked to neutrophilia, squamous cell carcinoma, Fanconi anemia, leukemia, hepatoblastoma, and fatty liver diseases. The transcription factors E2F1, HSF1, SIRT1, RELA, NFKB, JUN, and MYC were found to be responsible. When data mining was performed on citrinin targets, the top five functional descriptions were a cell’s response to an organic cyclic compound, the netrin–UNC5B signaling pathway, lipids and atherosclerosis, thyroid cancer, and controlling the transcription of the PTEN gene.

Oral exposure to citrinin significantly exacerbates the pathophysiology of a mouse model of imiquimod-induced psoriasis via direct activation of dendritic cell

Citrinin, a mycotoxin produced by Penicillium citrinum and Penicillium verrucosum, mainly contaminates cereals. The aim of study was to investigate the novel immunoreactive effect of citrinin using a mouse model of psoriasis. A mouse model of psoriasis was generated by topical application of 5% imiquimod in female BALB/c mice. Standard rodent diet and rice samples with 3 ppm of citrinin were mixed to obtain a final citrinin concentration of 0.3 ppm, and a citrinin-contaminated diet was fed to mice daily. Skin thickness, scratching behavior, and trans epidermal water loss (TEWL) were monitored continuously during the imiquimod application. Immediately after the final imiquimod application, ear skin and auricular lymph node (LN) were sampled for further analysis. Only a slight increase was observed in skin thickness in the citrinin exposure group; however, citrinin exposure significantly exacerbated hyperkeratinization and inflammatory cell infiltration in histological evaluation. TEWL, which is representative of cutaneous barrier function, was significantly increased by citrinin exposure. In terms of immune function, the number of immune cells in LN (T cells and dendritic cells) and gene expression of interleukin (IL)-17 in skin tissue were significantly increased by citrinin exposure. Direct interaction of dendritic cells (DCs) in citrinin-induced psoriasis development was further examined by proinflammatory cytokine determination in THP-1 cells and murine bone marrow derived DCs. IL-6 and/or tumor necrosis factor α were significantly increased by citrinin exposure. Taken together, our results imply that oral exposure to citrinin exacerbates the symptoms of a mouse model of psoriasis via direct activation of DCs.

Citrinin inhibits the function of Leydig cells in male rats in prepuberty

Citrinin, a mycotoxin existing in fruits, has nephrotoxicity, hepatotoxicity and embryotoxicity. The effects of citrinin on Leydig cell development in prepuberty remains unclear. Male Sprague-Dawley rats were gavaged with 0, 1, 2.5, and 5 mg/kg citrinin from postnatal days 21-28. Citrinin at 5 mg/kg significantly decreased serum testosterone levels, while increasing serum LH and FSH levels. Citrinin at 1-5 mg/kg markedly downregulated Hsd17b3 and HSD17B3 expression, while upregulating Srd5a1 (SRD5A1) and Akr1c14 (AKR1C14) expression at 2.5 and/or 5 mg/kg. Citrinin at 5 mg/kg also significantly increased PCNA-labeling index in Leydig cells. Citrinin at 5 mg/kg significantly raised testicular MDA amount, whiling at 2.5 and 5 mg/kg downregulating SOD1 and SOD2 expression. Citrinin at 5 mg/kg markedly decreased the ratio of Bcl2 to Bax, in consistent with the increased apoptosis in Leydig cells judged by TUNEL assay. Enzymatic assay revealed that citrinin inhibited rat testicular HSD3B1 activity at 100 µM and HSD17B3 activity at 10-100 μM. Citrinin at 50 μM and higher also induced reactive oxygen species (ROS) and apoptosis of R2C cell line. In conclusion, citrinin inhibits Leydig cell development at multiple levels via different mechanisms and oxidative stress partially plays a role.

Comparative Transcriptomic Analysis of Key Genes Involved in Citrinin Biosynthesis in Monascus purpureus

Monascus pigments (MPs) display many beneficial biological activities and have been widely utilized as natural food-grade colorants in the food processing industry. The presence of the mycotoxin citrinin (CIT) seriously restricts the application of MPs, but the gene regulation mechanisms governing CIT biosynthesis remain unclear. We performed a RNA-Seq-based comparative transcriptomic analysis of representative high MPs-producing Monascus purpureus strains with extremely high vs. low CIT yields. In addition, we performed qRT-PCR to detect the expression of genes related to CIT biosynthesis, confirming the reliability of the RNA-Seq data. The results revealed that there were 2518 differentially expressed genes (DEGs; 1141 downregulated and 1377 upregulated in the low CIT producer strain). Many upregulated DEGs were associated with energy metabolism and carbohydrate metabolism, with these changes potentially making more biosynthetic precursors available for MPs biosynthesis. Several potentially interesting genes that encode transcription factors were also identified amongst the DEGs. The transcriptomic results also showed that citB, citD, citE, citC and perhaps MpigI were key candidate genes to limit CIT biosynthesis. Our studies provide useful information on metabolic adaptations to MPs and CIT biosynthesis in M. purpureus, and provide targets for the fermentation industry towards the engineering of safer MPs production.

Reviews of fungi and mycotoxins in Chinese dark tea

The fermentation is the main process to form the unique flavor and health benefits of dark tea. Numerous studies have indicated that the microorganisms play a significant part in the fermentation process of dark tea. Dark tea has the quality of "The unique flavor grows over time," but unscientific storage of dark tea might cause infestation of harmful microorganisms, thereby resulting in the remaining of fungi toxins. Mycotoxins are regarded as the main contributor to the quality of dark tea, and its potential mycotoxin risk has attracted people's attention. This study reviews common and potential mycotoxins in dark tea and discusses the possible types of masked mycotoxins in dark tea. A summary of the potential risks of mycotoxins and masked mycotoxins in dark tea is presented, intending to provide a reference for the prevention and risk assessment of harmful fungi in dark tea.

Citrinin Exposure in Germany: Urine Biomarker Analysis in Children and Adults

Citrinin (CIT), a mycotoxin known to exert nephrotoxicity, is a contaminant in food and feed. Since CIT contamination is not regularly analyzed, data on its occurrence and especially levels in food commodities are insufficient for conducting a conventional exposure assessment. Yet, human biomonitoring, i.e., an analysis of CIT and its metabolite dihydrocitrinone (DH-CIT) in urine samples allows to estimate exposure. This study investigated CIT exposure in young (2-14 years) and adult (24-61 years) residents of three federal states in Germany. A total of 179 urine samples from children and 142 from adults were collected and analyzed by a targeted LC-MS/MS based method for presence of CIT and DH-CIT. At least one of the biomarkers was detected and quantified in all urines, which indicated a widespread dietary exposure to the mycotoxin in Germany. Interestingly, the biomarker concentrations of CITtotal (sum of CIT and DH-CIT) were higher in children's urine (range 0.05-7.62 ng/mL; median of 0.54 ng/mL) than in urines from adults (range 0.04-3.5 ng/mL; median 0.3 ng/mL). The biomarker levels (CITtotal) of individual urines served to calculate the probable daily CIT intake, for comparison to a value of 0.2 µg/kg bw/day defined as 'level of no concern for nephrotoxicity' by the European Food Safety Authority. The median exposure of German adults was 0.013 µg/kg b.w., with only one urine donor exceeding this provisional tolerable daily intake (pTDI) for CIT. The median exposure of children was 0.05 µg/kg bw per day (i.e., 25% of the pTDI); however, CIT exposure in 12 individuals (6.3% of our study group) exceeded the limit value, with a maximum intake of 0.46 µg/kg b.w. per day. In conclusion, these results show evidence for non-negligible exposure to CIT in some individuals in Germany, mainly in children. Therefore, further biomonitoring studies and investigations aimed to identify the major sources of CIT exposure in food commodities are required.

Inhibition of Aflatoxin Production by Citrinin and Non-Enzymatic Formation of a Novel Citrinin-Kojic Acid Adduct

Screening for microorganisms that inhibit aflatoxin production from environments showed that Penicillium citrinum inhibited aflatoxin production by Aspergillus parasiticus. The inhibitory substance in the culture medium of P. citrinum was confirmed to be citrinin (CTN). RT-PCR analyses showed that CTN did not inhibit expressions of aflatoxin biosynthetic genes (aflR, pksL1, and fas-1) of A. parasiticus, whereas feeding experiments using A. parasiticus showed that CTN inhibited the in vivo conversion of dihydrosterigmatocystin to AFB₂·AFG₂. These results suggest that CTN inhibits a certain post-transcriptional step in aflatoxin biosynthesis. CTN in the culture medium of A. parasiticus was found to be decreased or lost with time, suggesting that a certain metabolite produced by A. parasiticus is the cause of the CTN decrease; we then purified, characterized, and then analyzed the substance. Physico-chemical analyses confirmed that the metabolite causing a decrease in CTN fluorescence was kojic acid (KA) and the resulting product was identified as a novel substance: (1R,3S,4R)-3,4-dihydro-6,8-dihydroxy-1-(3-hydroxy-6-(hydroxymethyl)-4-oxo-4H-pyran-2-yl)-3,4,5-trimethyl-1H-isochromene-7-carboxylic acid, which was named "CTN-KA adduct". Our examination of the metabolites' toxicities revealed that unlike CTN, the CTN-KA adduct did not inhibit aflatoxin production by A. parasiticus. These results indicate that CTN's toxicity was alleviated with KA by converting CTN to the CTN-KA adduct.

Neurotoxicity of mycotoxin citrinin: Novel evidence in developing zebrafish and underlying mechanisms in human neuron cells

Citrinin (CTN) is a mycotoxin that is found as a contaminant in various types of food/feed grains and fermented food supplements. Previous studies have already established the nephrotoxicity and hepatotoxicity of CTN, but the neurotoxicity of CTN has not been clearly examined. In this study, CTN at 2-20 μM was first found to interfere with the neural ganglia formation and locomotive behavior of embryonic zebrafish, a vertebrate animal model, at 24 hpf and 6 dpf, respectively. Further exposure of human neuroblastoma SH-SY5Y cells to 10 and 20 μM CTN for 72 h indicated that pathways responsible for neuron differentiation and projection guidance were down-regulated while oxidative stress and electron transport chain pathways were up-regulated based on the enrichment results of GSEA in the transcriptomic profiling. PCR analysis verified that CTN significantly down-regulated the expression of marker genes involved in neuron differentiation and synaptic signaling. CTN at the doses impairing cellular neurite outgrowth did not trigger mitochondrial oxidative stress and dysfunction. The neurotoxic mechanisms of CTN provide new information that is valuable in the assessment of CTN-related health risk for the general public.

Microbial detoxification of mycotoxins in food

Mycotoxins are toxic secondary metabolites produced by certain genera of fungi including but not limited to Fusarium, Aspergillus, and Penicillium. Their persistence in agricultural commodities poses a significant food safety issue owing to their carcinogenic, teratogenic, and immunosuppressive effects. Due to their inherent stability, mycotoxin levels in contaminated food often exceed the prescribed regulatory thresholds posing a risk to both humans and livestock. Although physical and chemical methods have been applied to remove mycotoxins, these approaches may reduce the nutrient quality and organoleptic properties of food. Microbial transformation of mycotoxins is a promising alternative for mycotoxin detoxification as it is more specific and environmentally friendly compared to physical/chemical methods. Here we review the biological detoxification of the major mycotoxins with a focus on microbial enzymes.

Detoxification of the Mycotoxin Citrinin by a Manganese Peroxidase from Moniliophthora roreri

Citrinin (CIT) is a mycotoxin found in foods and feeds and most commonly discovered in red yeast rice, a food additive made from ordinary rice by fermentation with Monascus. Currently, no enzyme is known to be able to degrade CIT effectively. In this study, it was discovered that manganese peroxidase (MrMnP) from Moniliophthora roreri could degrade CIT. The degradation appeared to be fulfilled by a combination of direct and indirect actions of the MrMnP with the CIT. Pure CIT, at a final concentration of 10 mg/L, was completely degraded by MrMnP within 72 h. One degradation product was identified to be dihydrocitrinone. The toxicity of the CIT-degradation product decreased, as monitored by the increased survival rate of the Caco-2 cells incubated with MrMnP-treated CIT. In addition, MrMnP could degrade CIT (with a starting concentration of up to 4.6 mg/L) completely contaminated in red yeast rice. MrMnP serves as an excellent candidate enzyme for CIT detoxification.

Mycotoxins and Essential Oils-From a Meat Industry Hazard to a Possible Solution: A Brief Review

The preservation of food supplies has been humankind's priority since ancient times, and it is arguably more relevant today than ever before. Food sustainability and safety have been heavily prioritized by consumers, producers, and government entities alike. In this regard, filamentous fungi have always been a health hazard due to their contamination of the food substrate with mycotoxins. Additionally, mycotoxins are proven resilient to technological processing. This study aims to identify the main mycotoxins that may occur in the meat and meat products "Farm to Fork" chain, along with their effect on the consumers' health, and also to identify effective methods of prevention through the use of essential oils (EO). At the same time, the antifungal and antimycotoxigenic potential of essential oils was considered in order to provide an overview of the subject. Targeting the main ways of meat products' contamination, the use of essential oils with proven in vitro or in situ efficacy against certain fungal species can be an effective alternative if all the associated challenges are addressed (e.g., application methods, suitability for certain products, toxicity).

Metabolite Production in Alkanna tinctoria Links Plant Development with the Recruitment of Individual Members of Microbiome Thriving at the Root-Soil Interface

Plants are naturally associated with diverse microbial communities, which play significant roles in plant performance, such as growth promotion or fending off pathogens. The roots of Alkanna tinctoria L. are rich in naphthoquinones, particularly the medicinally used enantiomers alkannin and shikonin and their derivatives. Former studies already have shown that microorganisms may modulate plant metabolism. To further investigate the potential interaction between A. tinctoria and associated microorganisms, we performed a greenhouse experiment in which A. tinctoria plants were grown in the presence of three distinct soil microbiomes. At four defined plant developmental stages, we made an in-depth assessment of bacterial and fungal root-associated microbiomes as well as all extracted primary and secondary metabolite content of root material. Our results showed that the plant developmental stage was the most important driver influencing the plant metabolite content, revealing peak contents of alkannin/shikonin derivatives at the fruiting stage. Plant root microbial diversity was influenced both by bulk soil origin and to a small extent by the developmental stage. The performed correlation analyses and cooccurrence networks on the measured metabolite content and the abundance of individual bacterial and fungal taxa suggested a dynamic and at times positive or negative relationship between root-associated microorganisms and root metabolism. In particular, the bacterial genera Labrys and Allorhizobium-Neorhizobium-Pararhizobium-Rhizobium as well as four species of the fungal genus Penicillium were found to be positively correlated with higher content of alkannins. IMPORTANCE Previous studies have shown that individual, isolated microorganisms may influence secondary metabolism of plants and induce or stimulate the production of medicinally relevant secondary metabolism. Here, we analyzed the microbiome-metabolome linkage of the medicinal plant Alkanna tinctoria, which is known to produce valuable compounds, particularly the naphthoquinones alkannin and shikonin and their derivatives. A detailed bacterial and fungal microbiome and metabolome analysis of A. tinctoria roots revealed that the plant developmental stage influenced root metabolite production, whereas soil inoculants from three different geographical origins in which plants were grown shaped root-associated microbiota. Metabolomes of plant roots of the same developmental stage across different soils were highly similar, pinpointing to plant maturity as the primary driver of secondary metabolite production. Correlation and network analyses identified bacterial and fungal taxa showing a positive relationship between root-associated microorganisms and root metabolism. In particular, the bacterial genera Allorhizobium-Neorhizobium-Pararhizobium-Rhizobium and Labrys as well as the fungal species of genus Penicillium were found to be positively correlated with higher content of alkannins.

Unveiling ochratoxin a controlling and biodetoxification molecular mechanisms: Opportunities to secure foodstuffs from OTA contamination

Anarchic growth of ochratoxin A (OTA) producing fungi during crop production, prolonged storage, and processing results in OTA contamination in foodstuffs. OTA in food exacerbates the risk of health and economic problems for consumers and farmers worldwide. Although the toxic effects of OTA on human health have not been well established, comprehensive preventive and remedial measures will be essential to eliminate OTA from foodstuffs. Strict regulations, controlling OTA at pre- or post-harvest stage, and decontamination of OTA have been adopted to prevent human and animal OTA exposure. Biological control of OTA and bio-decontamination are the most promising strategies due to their safety, specificity and nutritional value. This review addresses the current understanding of OTA biodegradation mechanisms and recent developments in OTA control and bio-decontamination strategies. Additionally, this review analyses the strength and weaknesses of different OTA control methods and the contemporary approaches to enhance the efficiency of biocontrol agents. Overall, this review will support the implementation of new strategies to effectively control OTA in food sectors. Further studies on efficacy-related issues, production issues and cost-effectiveness of OTA biocontrol are to be carried out to improve the knowledge, develop improved delivery technologies and safeguard the durability of OTA biocontrol approaches.

Citrinin Mycotoxin Contamination in Food and Feed: Impact on Agriculture, Human Health, and Detection and Management Strategies

Citrinin (CIT) is a mycotoxin produced by different species of Aspergillus, Penicillium, and Monascus. CIT can contaminate a wide range of foods and feeds at any time during the pre-harvest, harvest, and post-harvest stages. CIT can be usually found in beans, fruits, fruit and vegetable juices, herbs and spices, and dairy products, as well as red mold rice. CIT exerts nephrotoxic and genotoxic effects in both humans and animals, thereby raising concerns regarding the consumption of CIT-contaminated food and feed. Hence, to minimize the risk of CIT contamination in food and feed, understanding the incidence of CIT occurrence, its sources, and biosynthetic pathways could assist in the effective implementation of detection and mitigation measures. Therefore, this review aims to shed light on sources of CIT, its prevalence in food and feed, biosynthetic pathways, and genes involved, with a major focus on detection and management strategies to ensure the safety and security of food and feed.

Recent Progress in Rapid Determination of Mycotoxins Based on Emerging Biorecognition Molecules: A Review

Mycotoxins are secondary metabolites produced by fungal species, which pose significant risk to humans and livestock. The mycotoxins which are produced from Aspergillus, Penicillium, and Fusarium are considered most important and therefore regulated in food- and feedstuffs. Analyses are predominantly performed by official laboratory methods in centralized labs by expert technicians. There is an urgent demand for new low-cost, easy-to-use, and portable analytical devices for rapid on-site determination. Most significant advances were realized in the field bioanalytical techniques based on molecular recognition. This review aims to discuss recent progress in the generation of native biomolecules and new bioinspired materials towards mycotoxins for the development of reliable bioreceptor-based analytical methods. After brief presentation of basic knowledge regarding characteristics of most important mycotoxins, the generation, benefits, and limitations of present and emerging biorecognition molecules, such as polyclonal (pAb), monoclonal (mAb), recombinant antibodies (rAb), aptamers, short peptides, and molecularly imprinted polymers (MIPs), are discussed. Hereinafter, the use of binders in different areas of application, including sample preparation, microplate- and tube-based assays, lateral flow devices, and biosensors, is highlighted. Special focus, on a global scale, is placed on commercial availability of single receptor molecules, test-kits, and biosensor platforms using multiplexed bead-based suspension assays and planar biochip arrays. Future outlook is given with special emphasis on new challenges, such as increasing use of rAb based on synthetic and naïve antibody libraries to renounce animal immunization, multiple-analyte test-kits and high-throughput multiplexing, and determination of masked mycotoxins, including stereoisomeric degradation products.

Biological Detoxification of Mycotoxins: Current Status and Future Advances

Mycotoxins are highly toxic metabolites produced by fungi that pose a huge threat to human and animal health. Contamination of food and feed with mycotoxins is a worldwide issue, which leads to huge financial losses, annually. Decades of research have developed various approaches to degrade mycotoxins, among which the biological methods have been proved to have great potential and advantages. This review provides an overview on the important advances in the biological removal of mycotoxins over the last decade. Here, we provided further insight into the chemical structures and the toxicity of the main mycotoxins. The innovative strategies including mycotoxin degradation by novel probiotics are summarized in an in-depth discussion on potentialities and limitations. We prospected the promising future for the development of multifunctional approaches using recombinant enzymes and microbial consortia for the simultaneous removal of multiple mycotoxins.

Subchronic exposure of individual and combined ochratoxin A and citrinin selectively affects the expression of rat renal organic cation transporters

Ochratoxin A (OTA) and citrinin (CIT) are nephrotoxins found co-occurring in various human/animal food/feed and recognized as a health threat. However, most studies investigate individual effects and neglect their combined nephrotoxic effects in mammals. Previous studies have indicated that organic anion/cation transporters (OATs/OCTs) localized in renal proximal tubules mediate the transport of OTA and CIT. Still, little is known about the in vivo effects of individual/combined OTA and CIT on protein localization/expression of OCTs, physiologically/pharmacologically important renal transporters. Here, we used Western blot and immunofluorescence microscopy to study the effects of subchronic (21-day) exposure to individual/combined OTA (0.125 and 0.250 mg kg^-1 b.w.) and CIT (20 mg kg^-1 b.w.) on protein localization/expression of organic cation transporters (rOct1/Slc22a1 and rOct2/Slc22a2) in kidneys of Wistar rats. Since the antioxidant resveratrol (RSV) has shown measurable protective effects against OTA- and CIT-related oxidative stress toxicity in vitro, we investigated the effects of an OTA + CIT + RSV combination on rOct1/2 localization/expression in the same model. Individual OTA induced a dose-dependent decrease of rOct1 but not rOct2 protein expression, whereas their localization pattern remained unchanged. Individual CIT did not affect the renal rOct1/2 protein localization/expression. Combined OTA + CIT exposure induced a significant decrease of rOct1 protein expression by an OTA250 dose, whereas oral co-administration of OTA + CIT + RSV resulted in a significant decrease of rOct1/2 protein expression. Thus, we revealed an OTA-related selective effect on the rOct1/2 protein expression and a non-specific adverse effect of RSV in the OTA + CIT + RSV combination on the renal organic cation transport system in rat.

Risk Assessment of RYR Food Supplements: Perception vs. Reality

Thirty-seven red yeast rice (RYR) food supplements were screened for their mycotoxin and natural statin content. Products included pure RYR capsules and multi-ingredient formulations with standardized amounts of monacolin K (MK), marketed both online and retail in the European Union. In terms of mycotoxins, citrinin (CIT) was found in all the monitored products. As CIT content ranged from 100 to 25100 μg/kg, only four products were compliant with maximum EU levels in force until April 2020, while a single product was compliant with the limit of 100 μg/kg introduced after that date. Four contaminated products were labeled as "citrinin free". In terms of natural statins, nine products had a lower content vs. label statements (from -30 to -83%), while for 24 a larger MK amount (from 10 to 266%) was noticed. Three products had a negligible MK content and only 19 offered a daily dosage exceeding 10 mg as dictated by the health claim granted by EFSA in the EU. No sample had label values compliant with pharmaceutical Good Manufacturing Practices requirements (95-105% content of active constituent). Variable, but small amounts of simvastatin (0.1-7.5 μg per daily dose) were found in 30 samples. These results suggest that limited efficacy and reported safety issues may stem from an under-regulated and undercontrolled market, weakening both effectiveness and risk assessment evaluations.

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.

Assessment of Citrinin in Spices and Infant Cereals Using Immunoaffinity Column Clean-Up with HPLC-Fluorescence Detection

Historically, the analysis of citrinin has mainly been performed on cereals such as red yeast rice; however, in recent years, more complex and abnormal commodities such as spices and infant foods are becoming more widely assessed. The aim of this study was to develop and validate clean-up methods for spices and cereal-based infant foods using a citrinin immunoaffinity column before HPLC analysis with fluorescence detection. Each method developed was validated with a representative matrix, spiked at various citrinin concentrations, based around European Union (EU) regulations set for ochratoxin A (OTA), with recoveries >80% and % RSD < 9% in all cases. The limit of detection (LOD) and the limit of quantification (LOQ) were established at 1 and 3 µg/kg for spices and 0.1 and 0.25 µg/kg for infant cereals, respectively. These methods were then tested across a variety of spices and infant food products to establish efficacy with high recoveries >75% and % RSD < 5% across all matrices assessed. Therefore, these methods proved suitable for providing effective clean-up of spices and infant cereals, enabling reliable quantification of citrinin detected. Samples such as nutmeg and infant multigrain porridge had higher levels of citrinin contamination than anticipated, indicating that citrinin could be a concern for public health. This highlighted the need for close monitoring of citrinin contamination in these commodities, which may become regulated in the future.

Fungal quinones: diversity, producers, and applications of quinones from Aspergillus, Penicillium, Talaromyces, Fusarium, and Arthrinium

Quinones represent an important group of highly structurally diverse, mainly polyketide-derived secondary metabolites widely distributed among filamentous fungi. Many quinones have been reported to have important biological functions such as inhibition of bacteria or repression of the immune response in insects. Other quinones, such as ubiquinones are known to be essential molecules in cellular respiration, and many quinones are known to protect their producing organisms from exposure to sunlight. Most recently, quinones have also attracted a lot of industrial interest since their electron-donating and -accepting properties make them good candidates as electrolytes in redox flow batteries, like their often highly conjugated double bond systems make them attractive as pigments. On an industrial level, quinones are mainly synthesized from raw components in coal tar. However, the possibility of producing quinones by fungal cultivation has great prospects since fungi can often be grown in industrially scaled bioreactors, producing valuable metabolites on cheap substrates. In order to give a better overview of the secondary metabolite quinones produced by and shared between various fungi, mainly belonging to the genera Aspergillus, Penicillium, Talaromyces, Fusarium, and Arthrinium, this review categorizes quinones into families such as emodins, fumigatins, sorbicillinoids, yanuthones, and xanthomegnins, depending on structural similarities and information about the biosynthetic pathway from which they are derived, whenever applicable. The production of these quinone families is compared between the different genera, based on recently revised taxonomy. KEY POINTS: • Quinones represent an important group of secondary metabolites widely distributed in important fungal genera such as Aspergillus, Penicillium, Talaromyces, Fusarium, and Arthrinium. • Quinones are of industrial interest and can be used in pharmacology, as colorants and pigments, and as electrolytes in redox flow batteries. • Quinones are grouped into families and compared between genera according to the revised taxonomy.

Dietary Supplements Based on Red Yeast Rice-A Source of Citrinin?

Citrinin (CIT) is secondary metabolite of filamentous molds. This mycotoxin has nephrotoxic, hepatotoxic, embryocidal, and fetotoxic properties. It is also produced by several species of the three genera Penicillium spp., Aspergillus spp., and Monascus spp., which are used to make red yeast rice (RYR). The material for this study consisted of 15 dietary supplements containing an extract of fermented red rice, available on the Polish market. Samples were extracted using a MeOH-H2O mixture, cleaned-up with an immunoaffinity CitriTest HPLC column, and quantified by HPLC-FLD. None of the analyzed samples contained CIT above the established limit of detection (LOD). Studies on the presence of toxic metabolites in red yeast rice show the importance of regulating this product and of clear information on the label regarding the standardized amounts of monacolin.

Natural Bioactive Compounds from Food Waste: Toxicity and Safety Concerns

Although synthetic bioactive compounds are approved in many countries for food applications, they are becoming less and less welcome by consumers. Therefore, there has been an increasing interest in replacing these synthetic compounds by natural bioactive compounds. These natural compounds can be used as food additives to maintain the food quality, food safety and appeal, and as food supplements or nutraceuticals to correct nutritional deficiencies, maintain a suitable intake of nutrients, or to support physiological functions, respectively. Recent studies reveal that numerous food wastes, particularly fruit and vegetables byproducts, are a good source of bioactive compounds that can be extracted and reintroduced into the food chain as natural food additives or in food matrices for obtaining nutraceuticals and functional foods. This review addresses general questions concerning the use of fruit and vegetables byproducts as new sources of natural bioactive compounds that are being addressed to foods as natural additives and supplements. Those bioactive compounds must follow the legal requirements and evaluations to assess the risks for human health and their toxicity must be considered before being launched into the market. To overcome the potential health risk while increasing the biological activity, stability and biodistribution of the supplements' technological alternatives have been studied such as encapsulation of bioactive compounds into micro or nanoparticles or nanoemulsions. This will allow enhancing the stability and release along the gastrointestinal tract in a controlled manner into the specific tissues. This review summarizes the valorization path that a bioactive compound recovered from an agro-food waste can face from the moment their potentialities are exhibited until it reaches the final consumer and the safety and toxicity challenges, they may overcome.

Citrinin Determination in Food and Food Supplements by LC-MS/MS: Development and Use of Reference Materials in an International Collaborative Study

The development of incurred reference materials containing citrinin (CIT) and their successful application in a method validation study (MVS) in order to harmonize CIT determination in food and food supplements are demonstrated. CIT-contaminated materials made of red yeast rice (RYR), wheat flour, and Ginkgo biloba leaves (GBL), as well as food supplements made of red yeast rice (FS-RYR) and Ginkgo biloba leaves (FS-GBL), were manufactured in-house via fungal cultivation on collected raw materials. The homogeneity and stability from randomly selected containers were verified according to the ISO 13528. CIT was found to be homogenously distributed and stable in all contaminated materials, with no significant degradation during the timescale of the MVS when storage was performed up to +4 °C. Next, an MVS was organized with eighteen international laboratories using the provided standard operating procedure and 12 test materials, including three RYRs (blank, <50 µg/kg, <2000 µg/kg), two wheat flours (blank, <50 µg/kg), two GBL powders (blank, <50 µg/kg), three FS-RYRs (blank, <50 µg/kg, <2000 µg/kg), and two FS-GBLs (blank, <50 µg/kg). The results of seven CIT-incurred materials showed acceptable within-laboratory precision (RSDr) varying from 6.4% to 14.6% and between-laboratory precision (RSDR) varying from 10.2% to 37.3%. Evidenced by HorRat values < 2.0, the results of the collaborative trial demonstrated that the applied analytical method could be standardized. Furthermore, the appropriateness of producing CIT reference materials is an important step towards food and feed quality control systems and the organization of proficiency tests.