Mycotoxin Identification and In Silico Toxicity Assessment Prediction in Atlantic Salmon

Antibacterial, antibiofilm, and chemical profiles of Ammi visnaga L. and Foeniculum vulgare mill. Essential oils, and ADMET, molecular docking investigation of essential oils major components

This study determined chemical profiles, antibacterial and antibiofilm activities of the essential oils (EOs) obtained by A. visnaga aerial parts and F. vulgare fruits. Butanoic acid, 2-methyl-, 3-methylbutyl ester (38.8%), linalyl propionate (34.7%) and limonene (8.5%) resulted as main constituents of A. visnaga EO. In F. vulgare EO trans-anethole (76.9%) and fenchone (14.1%) resulted as main components. The two EOs were active against five bacterial strains (Acinetobacter baumannii, Escherichia coli, Listeria monocytogenes, Pseudomonas aeruginosa, and Staphylococcus aureus) at different degrees. The MIC values ranged from 5 ± 2 to 10 ± 2 μL/mL except for S. aureus (MIC >20 μL/mL). EOs exhibited inhibitory effect on the formation of biofilm up to 53.56 and 48.04% against E. coli and A. baumannii, respectively and activity against bacterial metabolism against A. baumannii and E. coli, with biofilm-inhibition ranging from 61.73 to 73.55%. The binding affinity of the identified components was estimated by docking them into the binding site of S. aureus gyrase (PDB code 2XCT) and S. aureus tyrosyl-tRNA synthetase (PDB code 1JIJ). trans-Anethole and butanoic acid, 2-methyl-, 3-methylbutyl ester showed relatively moderate binding interactions with the amino acid residues of S. aureus tyrosyl-tRNA synthetase. In addition, almost all predicted compounds possess good pharmacokinetic properties with no toxicity, being inactive for cytotoxicity, carcinogenicity, hepatotoxicity, mutagenicity and immunotoxicity parameters. The results encourage the use of these EOs as natural antibacterial agents in food and pharmaceutical industries.

Suspect and nontarget screening of mycotoxins and their modified forms in wheat products based on ultrahigh-performance liquid chromatography-high resolution mass spectrometry

Various forms of mycotoxins commonly exist in food and pose a significant risk to human health. Here a comprehensive suspect and nontarget screening strategy for both parent and modified mycotoxins was developed using ultrahigh-performance liquid chromatography-high resolution mass spectrometry (UHPLCHRMS). We constructed an in-house MS/MS database containing 82 mycotoxins in 8 categories. Then fragmentation characteristics of different classes of mycotoxins were rapidly extracted by a Python program "Fragmentation pattern screener (FPScreener)" and nontarget screening rules were determined by analyzing the frequencies and average intensities of fragmentation characteristics. Using the suspect and nontarget screening strategy, we successfully identified six parent mycotoxins and eight modified mycotoxins with different confidence levels in contaminated wheat and flour samples. This strategy enables screening of unknown parents and modified mycotoxins in food matrices with corresponding fragmentation characteristics.

Diversity of Mycotoxins and Other Secondary Metabolites Recovered from Blood Oranges Infected by Colletotrichum, Alternaria, and Penicillium Species

This study identified secondary metabolites produced by Alternaria alternata, Colletotrichum gloeosporioides, and Penicillium digitatum in fruits of two blood orange cultivars before harvest. Analysis was performed by UHPLC-Q-TOF-MS. Three types of fruits were selected, asymptomatic, symptomatic showing necrotic lesions caused by hail, and mummified. Extracts from peel and juice were analyzed separately. Penicillium digitatum was the prevalent species recovered from mummified and hail-injured fruits. Among 47 secondary metabolites identified, 16, 18, and 13 were of A. alternata, C. gloeosporioides, and P. digitatum, respectively. Consistently with isolations, indicating the presence of these fungi also in asymptomatic fruits, the metabolic profiles of the peel of hail-injured and asymptomatic fruits did not differ substantially. Major differences were found in the profiles of juice from hail-injured and mummified fruits, such as a significant higher presence of 5,4-dihydroxy-3,7,8-trimethoxy-6C-methylflavone and Atrovenetin, particularly in the juice of mummified fruits of the Tarocco Lempso cultivar. Moreover, the mycotoxins patulin and Rubratoxin B were detected exclusively in mummified fruits. Patulin was detected in both the juice and peel, with a higher relative abundance in the juice, while Rubratoxin B was detected only in the juice. These findings provide basic information for evaluating and preventing the risk of contamination by mycotoxins in the citrus fresh fruit supply chain and juice industry.

Mineral Bioaccessibility and Antioxidant Capacity of Protein Hydrolysates from Salmon (Salmo salar) and Mackerel (Scomber scombrus) Backbones and Heads

Information on the bioaccessibility of minerals is essential to consider a food ingredient as a potential mineral fortifier. In this study, the mineral bioaccessibility of protein hydrolysates from salmon (Salmo salar) and mackerel (Scomber scombrus) backbones and heads was evaluated. For this purpose, the hydrolysates were submitted to simulated gastrointestinal digestion (INFOGEST method), and the mineral content was analyzed before and after the digestive process. Ca, Mg, P, Fe, Zn, and Se were then determined using an inductively coupled plasma spectrometer mass detector (ICP-MS). The highest bioaccessibility of minerals was found in salmon and mackerel head hydrolysates for Fe (≥100%), followed by Se in salmon backbone hydrolysates (95%). The antioxidant capacity of all protein hydrolysate samples, which was measured by Trolox Equivalent Antioxidant Capacity (TEAC), increased (10-46%) after in vitro digestion. The heavy metals As, Hg, Cd, and Pb were determined (ICP-MS) in the raw hydrolysates to confirm the harmlessness of these products. Except for Cd in mackerel hydrolysates, all toxic elements were below the legislation levels for fish commodities. These results suggest the possibility of using protein hydrolysates from salmon and mackerel backbones and heads for food mineral fortification, as well as the need to verify their safety.

Prioritization of mycotoxins based on mutagenicity and carcinogenicity evaluation using combined in silico QSAR methods

Mycotoxins and their metabolites are a family of compounds that contains a great diversity of both structure and biological properties. Information on their toxicity is spread within several databases and in scientific literature. Due to the number of molecules and their structure diversity, the cost and time required for hazard evaluation of each compound is unrealistic. In that purpose, new approach methodologies (NAMs) can be applied to evaluate such large set of molecules. Among them, quantitative structure-activity relationship (QSAR) in silico models could be useful to predict the mutagenic and carcinogenic properties of mycotoxins. First, a complete list of 904 mycotoxins and metabolites was built. Then, some known mycotoxins were used to determine the best QSAR tools for mutagenicity and carcinogenicity predictions. The best tool was further applied to the whole list of 904 mycotoxins. At the end, 95 mycotoxins were identified as both mutagen and carcinogen and should be prioritized for further evaluation.

Dietary beauvericin and enniatin B exposure cause different adverse health effects in farmed Atlantic salmon

The extensive use of plant ingredients in novel aquafeeds have introduced mycotoxins to the farming of seafood. The emerging enniatin B (ENNB) and beauvericin (BEA) mycotoxins have been found in the novel aquafeeds and farmed fish. Little is known about the potential toxicity of ENNs and BEA in farmed fish and their feed-to-organ transfer. Atlantic salmon (Salmo salar) pre-smolt (75.3 ± 8.10 g) were fed four graded levels of spiked chemical pure ENNB or BEA feeds for three months, in triplicate tanks. Organismal adverse health end-point assessment included intestinal function (protein digestibility), disturbed hematology (red blood cell formation), bone formation (spinal deformity), overall energy use (feed utilization), and lipid oxidative status (vitamin E). Both dietary BEA and ENNB had a low (<∼0.01%) transfer to organs (kidney > liver > brain > muscle), with a higher transfer for ENNB compared to BEA. BEA caused a growth reduction combined with a decreased protein digestion and feed conversion rate- ENNB caused a stunted growth, unrelated to feed utilization capacity. In addition, ENNB caused anemia while BEA gave an oxidative stress response. Lower bench-mark dose regression assessment showed that high background levels of ENNB in commercial salmon feed could pose a risk for animal health, but not in the case of BEA.

Mycotoxins in Seafood: Occurrence, Recent Development of Analytical Techniques and Future Challenges

The co-occurrence of mycotoxigenic fungi and mycotoxins in aquatic food commodities has recently become a source of severe worldwide food insecurity since these toxicants may damage human health. The consumption of aquatic food itself represents a relatively novel and non-negligible source of mycotoxins. Mycotoxins in seafood lead to important human genotoxins, carcinogens, and immunosuppressors. Consequently, it is crucial to quantify and characterize these contaminants in aquatic food products subject to extensive consumption and develop new regulations. The present paper provides an overview of recent advancements in liquid chromatography and mass spectrometry and the coupling of these techniques for identifying and characterizing mycotoxins in various fresh, comestible, and treated marine products. The disposable data display that a multiplicity of fungal species and further mycotoxins have been detected in seafood, comprising aflatoxins, ochratoxins, fumonisins, deoxynivalenol, zearalenone, and trichothecenes. In addition, a wider and up-to-date overview of global occurrence surveys of mycotoxin occurrence in seafood in 2017–2022 is explored. In this regard, the predominant occurrence of enniatins has been documented in seafood products. Likewise, special attention has been given to current EU seafood legal and existing national regulations of mycotoxins in seafood. In this way, rigorous national and international guidelines are needed for palpable and effective measures in the future. Nevertheless, controlling mycotoxins in aquatic foods is an ambitious aim for scientists and industry stakeholders to ensure sustainable global food safety.

The use of machine learning modeling, virtual screening, molecular docking, and molecular dynamics simulations to identify potential VEGFR2 kinase inhibitors

Targeting the signaling pathway of the Vascular endothelial growth factor receptor-2 is a promising approach that has drawn attention in the quest to develop novel anti-cancer drugs and cardiovascular disease treatments. We construct a screening pipeline using machine learning classification integrated with similarity checks of approved drugs to find new inhibitors. The statistical metrics reveal that the random forest approach has slightly better performance. By further similarity screening against several approved drugs, two candidates are selected. Analysis of absorption, distribution, metabolism, excretion, and toxicity, along with molecular docking and dynamics are performed for the two candidates with regorafenib as a reference. The binding energies of molecule1, molecule2, and regorafenib are - 89.1, - 95.3, and - 87.4 (kJ/mol), respectively which suggest candidate compounds have strong binding to the target. Meanwhile, the median lethal dose and maximum tolerated dose for regorafenib, molecule1, and molecule2 are predicted to be 800, 1600, and 393 mg/kg, and 0.257, 0.527, and 0.428 log mg/kg/day, respectively. Also, the inhibitory activity of these compounds is predicted to be 7.23 and 7.31, which is comparable with the activity of pazopanib and sorafenib drugs. In light of these findings, the two compounds could be further investigated as potential candidates for anti-angiogenesis therapy.

Underreported Human Exposure to Mycotoxins: The Case of South Africa

South Africa (SA) is a leading exporter of maize in Africa. The commercial maize farming sector contributes to about 85% of the overall maize produced. More than 33% of South Africa’s population live in rural settlements, and their livelihoods depend entirely on subsistence farming. The subsistence farming system promotes fungal growth and mycotoxin production. This review aims to investigate the exposure levels of the rural population of South Africa to dietary mycotoxins contrary to several reports issued concerning the safety of South African maize. A systematic search was conducted using Google Scholar. Maize is a staple food in South Africa and consumption rates in rural and urban communities are different, for instance, intake may be 1–2 kg/person/day and 400 g/person/day, respectively. Commercial and subsistence maize farming techniques are different. There exist differences influencing the composition of mycotoxins in food commodities from both sectors. Depending on the levels of contamination, dietary exposure of South Africans to mycotoxins is evident in the high levels of fumonisins (FBs) that have been detected in SA home-grown maize. Other potential sources of exposure to mycotoxins, such as carryover effects from animal products and processed foods, were reviewed. The combined effects between FBs and aflatoxins (AFs) have been reported in humans/animals and should not be ignored, as sporadic breakouts of aflatoxicosis have been reported in South Africa. These reports are not a true representation of the entire country as reports from the subsistence-farming rural communities show high incidence of maize contaminated with both AFs and FBs. While commercial farmers and exporters have all the resources needed to perform laboratory analyses of maize products, the greater challenge in combatting mycotoxin exposure is encountered in rural communities with predominantly subsistence farming systems, where conventional food surveillance is lacking.

Evaluation of the Safety and Ochratoxin A Degradation Capacity of Pediococcus pentosaceus as a Dietary Probiotic with Molecular Docking Approach and Pharmacokinetic Toxicity Assessment

The present study evaluated the properties and ochratoxin A (OTA) degradation capacity of the dietary probiotic Pediococcus pentosaceus BalaMMB-P3, isolated from a milk coagulant. The acidic tolerance of the isolate at pH 2–3 was checked with bile salts. No hemolytic activity was noted, which confirmed the nonpathogenicity of the strain. The isolate was tested in vitro for antibiotic susceptibility, enzymatic activity, bile salts hydrolase activity and antifungal activity against Penicillium verrucosum, Fusarium graminearum and Aspergillus ochraceus. A molecular docking-based OTA toxicity assessment was carried out for multitargeted proteins. The 16S rRNA gene-based phylogenetic assessment identified the strain as P. pentosaceus, and was authenticated in GenBank. The carboxylesterase and glutathione s-transferase enzymes showed active and strong interactions with esters and amide bonds, respectively. The compound exhibited carcinogenic and cytotoxicity effects at an LD₅₀ value of 20 mg/kg. Furthermore, the strain showed a potent ability to reduce OTA and suggested the prospects for utilization in nutritional aspects of food.

Cytoprotective Effects of Fish Protein Hydrolysates against H2O2-Induced Oxidative Stress and Mycotoxins in Caco-2/TC7 Cells

Many studies report the potent antioxidant capacity for fish protein hydrolysates, including radical scavenging activity and inhibition ability on lipid peroxidation (LPO). In this study, the in vitro cytotoxicity of protein hydrolysates from different salmon, mackerel, and herring side streams fractions was evaluated in the concentration range from 1 to 1:32 dilution, using cloned human colon adenocarcinoma cells TC7 (Caco-2/TC7) by MTT and PT assays. The protein hydrolysates' antioxidant capacity and oxidative stress effects were evaluated by LPO and reactive oxygen species (ROS) generation, respectively. The antioxidant capacity for pure and bioavailable hydrolysate fraction was also evaluated and compared. Additionally, mycotoxin levels were determined in the fish protein hydrolysates, and their cytoprotective effect against T-2 toxin was evaluated. Both hydrolysates and their bioavailable fraction induced similar cell viability rates. The highest cytoprotective effect was obtained for the salmon viscera protein hydrolysate (HSV), which increased the cell viability by 51.2%. ROS accumulation induced by H₂O₂ and LPO was suppressed by all pure hydrolysates. The cytoprotective effect of hydrolysates was observed against T-2. Moreover, the different fish fraction protein hydrolysates contain variable nutrients and unique bioactive peptide composition showing variable bioactivity, which could be a useful tool in developing dietary supplements with different target functional properties.

Salmon (Salmo salar) Side Streams as a Bioresource to Obtain Potential Antioxidant Peptides after Applying Pressurized Liquid Extraction (PLE)

The pressurized liquid extraction (PLE) technique was used to obtain protein extracts with antioxidant capacity from salmon muscle remains, heads, viscera, skin, and tailfins. A protein recovery percentage ≈28% was obtained for all samples except for viscera, which was ≈92%. These values represented an increase of 1.5-4.8-fold compared to stirring extraction (control). Different SDS-PAGE profiles in control and PLE extracts revealed that extraction conditions affected the protein molecular weight distribution of the obtained extracts. Both TEAC (Trolox equivalent antioxidant capacity) and ORAC (oxygen radical antioxidant capacity) assays showed an outstanding antioxidant activity for viscera PLE extract. Through liquid chromatography coupled with electrospray ionization triple time-of-flight (nanoESI qQTOF) mass spectrometry, 137 and 67 peptides were identified in control and PLE extracts from salmon viscera, respectively None of these peptides was found among the antioxidant peptides inputted in the BIOPEP-UMP database. However, bioinformatics analysis showed several antioxidant small peptides encrypted in amino acid sequences of viscera extracts, especially GPP (glycine-proline-proline) and GAA (glycine-alanine-alanine) for PLE extracts. Further research on the relationship between antioxidant activity and specific peptides from salmon viscera PLE extracts is required. In addition, the salmon side streams studied presented non-toxic levels of As, Hg, Cd, and Pb, as well as the absence of mycotoxins or related metabolites. Overall, these results confirm the feasible use of farmed salmon processing side streams as alternative sources of protein and bioactive compounds for human consumption.

An Integrated Approach for the Valorization of Sea Bass (Dicentrarchus labrax) Side Streams: Evaluation of Contaminants and Development of Antioxidant Protein Extracts by Pressurized Liquid Extraction

In this study, the presence of As, Hg, Cd, Pb, and mycotoxins in sea bass side streams (muscle, head, viscera, skin, and tailfin) was evaluated as a preliminary step to assess the effect of an innovative extraction technique (Pressurized Liquid Extraction; PLE) to obtain antioxidant protein extracts. Then, a response surface methodology-central composite design was used to evaluate and optimize the PLE extraction factors (pH, temperature, and extraction time) in terms of total protein content and total antioxidant capacity (TEAC and ORAC). Heavy metals were found in all samples while DON mycotoxin only in viscera, both far below the safe limits established by authorities for fish muscle tissue and fish feed, respectively. The selected optimal PLE extraction conditions were pH 7, 20 °C, 5 min for muscle, pH 4, 60 °C, 15 min for heads, pH 7, 50 °C, 15 min for viscera, pH 7, 55 °C, 5 min for skin, and pH 7, 60 °C, 15 min for tailfins. Optimal PLE conditions allowed increasing protein content (1.2-4.5 fold) and antioxidant capacity (1-5 fold) of sea bass side stream extracts compared to controls (conventional extraction). The highest amount of protein was extracted from muscle while the highest protein recovery percentage was found in viscera. Muscle, head, and viscera extracts showed higher antioxidant capacity than skin and tailfin extracts. Moreover, different SDS-PAGE patterns were observed among samples and a greater quantity of protein fragments of lower molecular weight were found in optimal than control extracts.