Computational Applications: Beauvericin from a Mycotoxin into a Humanized Drug

Drug discovery was initially attributed to coincidence or experimental research. Historically, the traditional approaches were complex, lengthy, and expensive, entailing costly random screening of synthesized compounds or natural products coupled with in vivo validation largely depending on the availability of appropriate animal models. Currently, in silico modeling has become a vital tool for drug discovery and repurposing. Molecular docking and dynamic simulations are being used to find the best match between a ligand and a molecule, an approach that could help predict the biomolecular interactions between the drug and the target host. Beauvericin (BEA) is an emerging mycotoxin produced by the entomopathogenic fungus Beauveria bassiana, being originally studied for its potential use as a pesticide. BEA is now considered a molecule of interest for its possible use in diverse biotechnological applications in the pharmaceutical industry and medicine. In this manuscript, we provide an overview of the repurposing of BEA as a potential therapeutic agent for multiple diseases. Furthermore, considerable emphasis is given to the fundamental role of in silico techniques to (i) further investigate the activity spectrum of BEA, a secondary metabolite, and (ii) elucidate its mode of action.

Cytotoxic Effects of Major and Emerging Mycotoxins on HepaRG Cells and Transcriptomic Response after Exposure of Spheroids to Enniatins B and B1

Mycotoxins, produced by fungi, frequently occur at different stages in the food supply chain between pre- and postharvest. Globally produced cereal crops are known to be highly susceptible to contamination, thus constituting a major public health concern. Among the encountered mycotoxigenic fungi in cereals, Fusarium spp. are the most frequent and produce both regulated (i.e., T-2 toxin, deoxynivalenol -DON-, zearalenone -ZEA-) and emerging (i.e., enniatins -ENNs-, beauvericin -BEA-) mycotoxins. In this study, we investigated the in vitro cytotoxic effects of regulated and emerging fusariotoxins on HepaRG cells in 2D and 3D models using undifferentiated and differentiated cells. We also studied the impact of ENN B1 and ENN B exposure on gene expression of HepaRG spheroids. Gene expression profiling pinpointed the differentially expressed genes (DEGs) and overall similar pathways were involved in responses to mycotoxin exposure. Complement cascades, metabolism, steroid hormones, bile secretion, and cholesterol pathways were all negatively impacted by both ENNs. For cholesterol biosynthesis, 23/27 genes were significantly down-regulated and could be correlated to a 30% reduction in cholesterol levels. Our results show the impact of ENNs on the cholesterol biosynthesis pathway for the first time. This finding suggests a potential negative effect on human health due to the essential role this pathway plays.

[Determination of beauvercin and enniatins in rice flour and wheat flour by solid phase extraction-ultra performance liquid chromatography-tandem mass spectrometry]

OBJECTIVE

To develop a method for the determination of beauvercin(BEA), enniatin A(ENNA), enniatin A1(ENNA1), enniatin B(ENNB) and enniatin B1(ENNB1) in rice flour and wheat flour by ultra performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS).

METHODS

Samples were extracted by acetonitrile-water, purified by Oasis Prime HLB solid-phase extraction column. The sample solution was separated by waters BEH C_(18) column(2.1 mm×100 mm, 1.8 μm). The detection was performed in the electrospray positive ionization(ESI+) under multiple reaction monitoring(MRM) mode. The internal standard method and the matrix-matched calibrations were used for quantification.

RESULTS

The linear relationships of BEA and 4 kinds of enniatins(ENNs) were good in the range of 0.1-50.0 ng/mL(r>0.999). The average recoveries of BEA and ENNs in rice flour and wheat flour were 96.4%-105.4% and 99.1%-109.2%, with the relative standard deviations(RSD) of 1.01%-7.42% and 1.09%-9.69%(n=6). The detection limits(LOD) of BEA and ENNs were 0.03 μg/kg. The quantitative limits(LOQ) of BEA and ENNs were 0.1μg/kg. The matrix induced suppression or enhancement effect were 72.7%-99.3% and 60.8%-100.4%, respectively. The levels of emerging BEA and ENNs in wheat flour were higher than rice flour. The detection rate of enniatin B was highest in wheat flour and rice flour, the contents were 0.03-9.57 μg/kg and 0.03-0.56 μg/kg, the positive percentage were 98.5% and 36.4%.

CONCLUSION

The method is quick, easy, accurate and sensitive, which is suitable for the determination of BEA and 4 kinds of ENNs in rice flour and wheat flour.

Beauvericin suppresses the proliferation and pulmonary metastasis of osteosarcoma by selectively inhibiting TGFBR2 pathway

Osteosarcoma (OS) patients, particularly those with distant metastasis, experience rapid progression and derive poor survival benefits from traditional therapies. Currently, effective drugs for treating patients with metastatic OS remain scarce. Here, we found that the cyclic hexadepsipeptide beauvericin (BEA) functioned as a new selective TGFBR2 inhibitor with potent antiproliferative and antimetastatic activities against OS cells. Functionally, BEA inhibited TGF-β signaling-mediated proliferation, invasiveness, mesenchymal phenotype, and extracellular matrix remodeling of OS cells, and suppressed tumor growth and reduced pulmonary metastasis in vivo. Mechanistic investigation revealed that BEA selectively and directly bound to Asn 332 of TGFBR2 and inhibited its kinase activity, thereby suppressing the aggressive progression of OS cells. Together, our study identifies an innovative and natural selective TGFBR2 inhibitor with effective antineoplastic activity against metastatic OS and demonstrates that targeting TGFBR2 could be a potential therapeutic strategy for metastatic OS.

Application of feature-based molecular networking and MassQL for the MS/MS fragmentation study of depsipeptides

The Feature-based Molecular Networking (FBMN) is a well-known approach for mapping and identifying structures and analogues. However, in the absence of prior knowledge about the molecular class, assessing specific fragments and clusters requires time-consuming manual validation. This study demonstrates that combining FBMN and Mass Spec Query Language (MassQL) is an effective strategy for accelerating the decoding mass fragmentation pathways and identifying molecules with comparable fragmentation patterns, such as beauvericin and its analogues. To accomplish this objective, a spectral similarity network was built from ESI-MS/MS experiments of Fusarium oxysporum at various collision energies (CIDs) and paired with a MassQL search query for conserved beauvericin ions. FBMN analysis revealed that sodiated and protonated ions clustered differently, with sodiated adducts needing more collision energy and exhibiting a distinct fragmentation pattern. Based on this distinction, two sets of particular fragments were discovered for the identification of these hexadepsipeptides: ([M + H]+) m/z 134, 244, 262, and 362 and ([M + Na]+) m/z 266, 284 and 384. By using these fragments, MassQL accurately found other analogues of the same molecular class and annotated beauvericins that were not classified by FBMN alone. Furthermore, FBMN analysis of sodiated beauvericins at 70 eV revealed subclasses with distinct amino acid residues, allowing distinction between beauvericins (beauvericin and beauvericin D) and two previously unknown structural isomers with an unusual methionine sulfoxide residue. In summary, our integrated method revealed correlations between adduct types and fragmentation patterns, facilitated the detection of beauvericin clusters, including known and novel analogues, and allowed for the differentiation between structural isomers.

[Quality status of Bombyx Batryticatus and suggestions for Chinese Pharmacopoeia (2025)]

To understand the current quality status and rearing situation of Bombyx Batryticatus, the authors collected 102 batches of Bombyx Batryticatus from different main producing areas and five major Chinese medicine markets from 2016 to 2018, and measured the properties and quality of the silk gland, to clarify the quality status of Bombyx Batryticatus from different producing areas and markets. In addition, 35 batches of Bombyx Batryticatus from 2019 to 2022 were used to verify the silk gland after revision. Moreover, Beauveria Bassiana was inoculated in the silkworm of 4-5 instars, and standardized rearing was carried out until they die. The death rate and the quality of Bombyx Batryticatus were measured to determine the differences in Bombyx Batryticatus of different instars, and explore the rationality of the infection age of Bombyx Batryticatus in Chinese Pharmacopoeia(2020). The results revealed that in the 102 batches of Bombyx Batryticatus, the qualification rate of silk gland was low; the content of total ash far exceeded the standard; the content of beauvericin varied greatly. The qualification rate of the silk gland of the 35 batches of Bombyx Batryticatus was only 47.49%, which could be increased to 73.00% if the number of silk gland was 2 to 4. The death rate of Bombyx Batryticatus at different infection ages was quite different, with uneven quality. Generally, the yield of Bombyx Batryticatus inoculated on the first day of the fifth instar was high with good quality. Therefore, in combination with the quality and actual production of Bombyx Batryticatus, the following suggestions were proposed for revision of Bombyx Batryticatus in Chinese Pharmacopoeia(2025): The number of silk gland should be revised as 2-4 bright brown or bright black silk glands, after which, the quality of Bombyx Batryticatus could be guaranteed, and the "quality identification based on character" could also be reflected scientifically; the content determination index that the content of beauvericin shall not be less than 0.017% should be added to better control the quality of Bombyx Batryticatus; the infection age should be revised as the first day of the fifth instar to narrow the age span, which could better fit the actual production and ensure the quality of Bombyx Batryticatus.

Survey of the enniatins and beauvericin in raw and UHT cow's milk in Poland

Introduction

The enniatins A, A1, B and B1 (ENNs) and beauvericin (BEA) are structurally related compounds produced by Fusarium species. They occur as contaminants in cereals, such as wheat, barley and maize. They are called "emerging mycotoxins", because they have been reported in feed and food and their toxic effects are not fully known. Data on their levels in food (especially in milk) are limited. The study aimed to evaluate the occurrence of ENNs and BEA in milk.

Material and Methods

A total of 103 bovine milk samples (76 of raw milk and 27 of UHT milk) were collected from different parts of Poland and analysed using liquid chromatography-tandem mass spectrometry.

Results

Among the 76 raw milk samples, 31 (41%) and 15 (20%) samples were contaminated with ENN B and with BEA, respectively. No contamination with other enniatins was found. The highest concentration of BEA was found in raw milk and was 6.17 μg kg-1. Out of the 27 samples of UHT milk, 16 (59%) were contaminated with ENN B at concentrations ranging from 0.157 μg kg-1 to 0.587 μg kg-1 (limit of quantification (LOQ) 0.098 μg kg-1). Beauvericin was detected in 9 UHT milk samples (33%) at concentrations ranging from 0.101 μg kg-1 to 1.934 μg kg-1 (LOQ 0.095 μg kg-1).

Conclusion

This study demonstrated constant but low milk contamination in Poland with ENN B and BEA. The analysis of milk samples revealed that the emerging mycotoxins ENN B and BEA were measured in trace amounts. It does not suggest any immediate risk to milk consumers; however, it is unknown whether long-term exposure to low levels of toxins may be harmful.

Study on In Vitro Metabolism and In Vivo Pharmacokinetics of Beauvericin

Beauvericin (BEA) is a well-known mycotoxin produced by many fungi, including Beaveria bassiana. The purpose of this study was to evaluate the in vitro distribution and metabolism characteristics as well as the in vivo pharmacokinetic (PK) profile of BEA. The in vitro metabolism studies of BEA were performed using rat, dog, mouse, monkey and human liver microsomes, cryopreserved hepatocytes and plasma under conditions of linear kinetics to estimate the respective elimination rates. Additionally, LC-UV-MSn (n = 1~2) was used to identify metabolites in human, rat, mouse, dog and monkey liver microsomes. Furthermore, cytochrome P450 (CYP) reaction phenotyping was carried out. Finally, the absolute bioavailability of BEA was evaluated by intravenous and oral administration in rats. BEA was metabolically stable in the liver microsomes and hepatocytes of humans and rats; however, it was a strong inhibitor of midazolam 1′-hydroxylase (CYP3A4) and mephenytoin 4′-hydroxylase (CYP2C19) activities in human liver microsomes. The protein binding fraction values of BEA were >90% and the half-life (T1/2) values of BEA were approximately 5 h in the plasma of the five species. The absolute bioavailability was calculated to be 29.5%. Altogether, these data indicate that BEA has great potential for further development as a drug candidate. Metabolic studies of different species can provide important reference values for further safety evaluation.

Ecophysiology of Fusarium chaquense a Novel Type A Trichothecene Producer Species Isolated from Natural Grasses

Fusarium chaquense, a recently formally described novel species, has been identified as an T-2 toxin (T-2), HT-2 toxin (HT-2) and other toxins producer in natural grasses (Poaceae) from Argentina. The major objective of this study was to describe the effect of water activity (aW, 0.995, 0.98, 0.95, 0.93 and 0.91), temperature (15, 25 and 30 °C) and incubation time (5, 15 and 25 days) on growth and to evaluate the production of T-2, HT-2 toxins and beauvericin (BEA) by two F. chaquense strains in a grass-based media. The results showed a wide range of conditions for F. chaquense growth and mycotoxin production. Both strains had a maximum growth rate at the highest aW (0.995) and 25 °C. Regarding mycotoxin production, more T-2 than the other analysed mycotoxins were produced by the two strains. T-2 production was favoured at 0.995 aW and 30 °C, while HT-2 production at 0.98-0.95 aW and 15 °C. The maximum levels of BEA were produced at 0.995 aW and 25-30 °C. Two-dimensional profiles of aW by temperature interactions were obtained from these data in order to identify areas where conditions indicate a significant risk of mycotoxins accumulation on grass. For its versatility on growth and mycotoxin production in a wide range of aW and temperatures, F. chaquense would have an adaptive advantage over other Fusarium species, and this would explain its high frequency of isolation in natural grasses grown up in the Chaco wetlands.

[Simultaneous determination of beauvericin and four enniatins in eggs by ultra-performance liquid chromatography-tandem mass spectrometry coupled with cold-induced liquid-liquid extraction and dispersive solid phase extraction]

新型生物毒素白僵菌素(BEA)和恩镰孢菌素(ENNs)是由镰刀菌种产生的有毒代谢产物,主要污染谷物及其制品,会威胁人类健康,因此受到人们越来越多的关注。该工作建立了冷诱导液液萃取-分散固相萃取净化-超高效液相色谱-串联质谱法(CI-LLE-DSPE-UPLC-MS/MS)同时测定鸡蛋中白僵菌素和4种恩镰孢菌素残留的分析方法。以乙腈-水-乙酸(79:20:1, v/v/v)为提取溶剂,采用冷诱导液液萃取与分散固相萃取净化相结合的方法进行样品处理,同时,对影响待测物提取与净化效率的提取溶剂、冷冻萃取温度与时间、净化剂用量等因素和色谱条件进行了优化。样品经20 mL提取液涡旋提取20 min,放入-40 ℃冰箱静置30 min后,取2 mL上层溶液经70 mg C18粉末净化,离心,上清液于40 ℃浓缩至近干,残留物用1 mL 80%(v/v)乙腈水溶液溶解,进样分析。以乙腈与5 mmol/L甲酸铵溶液作为流动相进行梯度洗脱,经ACQUITY UPLC BEH C18色谱柱(100 mm×2.1 mm, 1.7 μm)分离,采用ESI⁺电离,在多反应监测模式下采集,白僵菌素采用稳定同位素内标法定量,4种恩镰孢菌素采用基质匹配曲线外标法定量。结果表明,5种待测物在0.1~50.0 μg/L范围内线性关系良好,相关系数(r²)为0.9983~0.9997,该方法的检出限(LOD)为0.05~0.15 μg/kg,定量限(LOQ)为0.20~0.50 μg/kg。以阴性鸡蛋样品为基质,在低、中、高3个浓度水平(0.5、5.0、25.0 μg/kg)下进行加标试验考察方法的准确度与精密度,各待测物的平均回收率为81.1%~106%,相对标准偏差(RSD)为0.27%~9.79%。采用所建立的方法对农村散养鸡蛋与市售鸡蛋进行检测,结果表明,BEA在散养鸡蛋的检出率为30.4%, 4种ENNs均未被检出。该方法灵敏度高,稳定性好,回收率高,定量准确,简单易操作,适用于禽蛋食品中白僵菌素与恩镰孢菌素的同时快速测定。

The role of pumpkin pulp extract carotenoids against mycotoxin damage in the blood brain barrier in vitro

Some mycotoxins such as beauvericin (BEA), ochratoxin A (OTA), and zearalenone (ZEA) can cross the blood brain barrier, which is why we tested the anti-inflammatory action of a pumpkin carotenoid extract (from the pulp) against these mycotoxins and their combinations (OTA+ZEA and OTA+ZEA+BEA) on a blood brain barrier model with co-cultured ECV304 and C6 cells using an untargeted metabolomic approach. The cells were added with mycotoxins at a concentration of 100 nmol/L per mycotoxin and pumpkin carotenoid extract at 500 nmol/L. For control we used only vehicle solvent (cell control) or vehicle solvent with pumpkin extract (extract control). After two hours of exposure, samples were analysed with HPLC-ESI-QTOF-MS. Metabolites were identified against the Metlin database. The proinflammatory arachidonic acid metabolite eoxin (14,15-LTE4) showed lower abundance in ZEA and BEA+OTA+ZEA-treated cultures that also received the pumpkin extract than in cultures that were not treated with the extract. Another marker of inflammation, prostaglandin D2-glycerol ester, was only found in cultures treated with OTA+ZEA and BEA+OTA+ZEA but not in the ones that were also treated with the pumpkin extract. Furthermore, the concentration of the pumpkin extract metabolite dihydromorelloflavone significantly decreased in the presence of mycotoxins. In conclusion, the pumpkin extract showed protective activity against cellular inflammation triggered by mycotoxins thanks to the properties pertinent to flavonoids contained in the pulp.

Pilot Study: Does Contamination with Enniatin B and Beauvericin Affect the Antioxidant Capacity of Cereals Commonly Used in Animal Feeding?

Increasing consumption of cereals has been associated with reduced risk of several chronic diseases, as they contain phytochemicals that combat oxidative stress. Cereal contamination by the “emerging mycotoxins” beauvericin (BEA) and enniatins (ENs) is a worldwide health problem that has not yet received adequate scientific attention. Their presence in feeds represents a risk for animals and a potential risk for humans because of their carry-over to animal-derived products. This preliminary study aimed to investigate if the total antioxidant capacity (TAC) of corn, barley, and wheat flours could be influenced by contamination with increasing levels of BEA and ENN B. The highest TAC value was observed in barley compared with wheat and corn (p < 0.001) before and after contamination. No effect of mycotoxin or mycotoxin level was found, whereas cereal x mycotoxin exhibited a significant effect (p < 0.001), showing a lower TAC value in wheat contaminated by ENN B and in barley contaminated by BEA. In conclusion, barley is confirmed as a source of natural antioxidants with antiradical potentials. Additional studies with a larger sample size are necessary to confirm the obtained results, and investigations of the toxic effects of these emergent mycotoxins on animals and humans should be deepened.

Phytotoxic Metabolites Produce by Fusarium oxysporum f. sp. cubense Race 2

Banana is a major tropical fruit crop but banana production worldwide is seriously threatened due to Fusarium wilt. Fusarium oxysporum f. sp. cubense (Foc), the causal agent of Fusarium wilt of banana (also referred as Panama disease) is an asexual, soil inhabiting facultative parasite. Foc isolates can be classified into three races that are not defined genetically, but for their pathogenicity to different banana cultivars. Despite mycotoxins being some of the best studied virulence factors of phytopathogenic fungi and these have been useful for the prediction of Foc virulence on banana plants, toxins produced by Foc race 2 strains have not been previously identified. The aim of this contribution was to identify the phytotoxic metabolites closely related to banana wilt caused by a Foc race 2 strain. We used an in vitro bioassay on detached banana leaves to evaluate the specificity of the microbial culture filtrates before a partial purification and further identification of Foc race 2 phytotoxins. A 29-day-old host-specific culture filtrate was obtained but specificity of culture filtrate was unrecovered after partial purification. The non-specific phytotoxins were characterized as fusaric acid, beauvericin, and enniatin A. Whereas some, if not all, of these phytotoxins are important virulence factors, a proteinaceous fraction from the specific 29-day-old culture filtrate protected the leaves of the resistant banana cultivar from damage caused by such phytotoxic metabolites.

Further data on the levels of emerging Fusarium mycotoxins in cereals collected from Tianjin, China

A number of 344 samples were collected from Tianjin, China and were analysed for the occurrence of emerging Fusarium mycotoxins including enniatin A (ENN A), enniatin A₁ (ENN A₁), enniatin B (ENN B), enniatin B₁ (ENN B₁) and beauvericin (BEA) by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The frequencies of mycotoxins studied were 69.0% (40/58), 69.8% (37/53), 85.9% (67/78), 78.9% (75/95), and 30.0% (18/60) for rice, wheat, corn, wheat flour, and corn flour, respectively. BEA was the predominant toxin in rice (average = 37.2 μg/kg) and wheat (average = 58.4 μg/kg), followed by ENN B and ENN B₁, while less ENN A and ENN A₁ were detected. ENN A was most common in corns with an average level of 28.1 μg/kg, while BEA had a higher average of 62.8 μg/kg. The levels of ENNs and BEA significantly decreased in wheat flours and corn flours, presumably due to the production process. The co-occurrences of ENNs and BEA in cereal samples were common in the combination of two and three mycotoxins and the significant positive correlations in concentrations were also obtained among them. Besides, agroclimate was considered as an important factor for Fusarium production and the mycotoxin contamination was found more serious in Jizhou district, which had more rainfall and less sunshine, than the other agriculture regions. These results suggested the necessity of carrying out in-depth and large-scale monitoring of mycotoxins in cereals and their products nationwide.

Coffee Silverskin and Spent Coffee Suitable as Neuroprotectors against Cell Death by Beauvericin and α-Zearalenol: Evaluating Strategies of Treatment

Coffee silverskin and spent coffee have been evaluated in a neuroblastoma cell line (SH-SY5Y cells) against beauvericin (BEA) and α-zearalenol (α-ZEL)-induced cytotoxicity with different strategies of treatment. First, the direct treatment of mycotoxins and coffee by-products extracts in SH-SY5Y cells was assayed. IC₅₀ values for α-ZEL were 20.8 and 14.0 µM for 48 h and 72 h, respectively and, for BEA only at 72 h, it was 2.5 µM. Afterwards, the pre-treatment with spent coffee obtained by boiling water increased cell viability for α-ZEL at 24 h and 48 h from 10% to 16% and from 25% to 30%, respectively; while with silverskin coffee, a decrease was observed. Opposite effects were observed for BEA where an increase for silverskin coffee was observed at 24 h and 48 h, from 14% to 23% and from 25% to 44%, respectively; however, a decrease below 50% was observed for spent coffee. Finally, the simultaneous treatment strategy for the highest concentration assayed in SH-SY5Y cells provided higher cytoprotection for α-ZEL (from 44% to 56% for 24 h and 48 h, respectively) than BEA (30% for 24 h and 48 h). Considering the high viability of coffee silverskin extracts for SH-SY5Y cells, there is a forthcoming promising use of these unexploited residues in the near future against mycotoxins effects.

Feedborne Mycotoxins Beauvericin and Enniatins and Livestock Animals

Mycotoxins are secondary metabolites produced by several species of fungi, including the Fusarium, Aspergillus, and Penicillium species. Currently, more than 300 structurally diverse mycotoxins are known, including a group called minor mycotoxins, namely enniatins, beauvericin, and fusaproliferin. Beauvericin and enniatins possess a variety of biological activities. Their antimicrobial, antibiotic, or ionoforic activities have been proven and according to various bioassays, they are believed to be toxic. They are mainly found in cereal grains and their products, but they have also been detected in forage feedstuff. Mycotoxins in feedstuffs of livestock animals are of dual concern. First one relates to the safety of animal-derived food. Based on the available data, the carry-over of minor mycotoxins from feed to edible animal tissues is possible. The second concern relates to detrimental effects of mycotoxins on animal health and performance. This review aims to summarize current knowledge on the relation of minor mycotoxins to livestock animals.

Mass Spectrometry-Based Metabolomics Reveals a Concurrent Action of Several Chemical Mechanisms in Arabidopsis-Fusarium oxysporum Compatible and Incompatible Interactions

Fusarium oxysporum is a destructive root-infecting plant pathogen that causes significant yield losses in many economically important crop species. Hence, a deeper understanding of pathogen infection strategies is needed. With liquid chromatography-tandem mass spectrometry and gas chromatography-time of flight mass spectrometry platforms, we analyzed the metabolic changes in a time-course experiment with Arabidopsis accessions either resistant (Col-0) or susceptible (Ler-0) to isolates of Fusarium oxysporum forma specialis matthioli infection. We showed a concurrent effect of Fusarium-derived polyols and the mycotoxin beauvericin in the suppression of the immune response of susceptible hosts. A significant increase in oxidized glutathione in the resistant host was probably associated with effective reactive oxygen species-mediated resistance responses. Through a combination of targeted and untargeted metabolomics, we demonstrated the concurrent action of several Arabidopsis defense systems as well as the concurrent action of several virulence systems in the fungal attack of susceptible Arabidopsis.

Fusarium Cyclodepsipeptide Mycotoxins: Chemistry, Biosynthesis, and Occurrence

Most of the fungi from the Fusarium genus are pathogenic to cereals, vegetables, and fruits and the products of their secondary metabolism mycotoxins may accumulate in foods and feeds. Non-ribosomal cyclodepsipeptides are one of the main mycotoxin groups and include beauvericins (BEAs), enniatins (ENNs), and beauvenniatins (BEAEs). When ingested, even small amounts of these metabolites significantly affect human and animal health. On the other hand, in view of their antimicrobial activities and cytotoxicity, they may be used as components in drug discovery and processing and are considered as suitable candidates for anti-cancer drugs. Therefore, it is crucial to expand the existing knowledge about cyclodepsipeptides and to search for new analogues of these compounds. The present manuscript aimed to highlight the extensive variability of cyclodepsipeptides by describing chemistry, biosynthesis, and occurrence of BEAs, ENNs, and BEAEs in foods and feeds. Moreover, the co-occurrence of Fusarium species was compared to the amounts of toxins in crops, vegetables, and fruits from different regions of the world.

Divergence of Beauvericin Synthase Gene among Fusarium and Trichoderma Species

Beauvericin (BEA) is a cyclodepsipeptide mycotoxin, showing insecticidal, antibiotic and antimicrobial activities, as well as inducing apoptosis of cancer cell lines. BEA can be produced by multiple fungal species, including saprotrophs, plant, insect and human pathogens, particularly belonging to Fusarium, Beauveria and Isaria genera. The ability of Trichoderma species to produce BEA was until now uncertain. Biosynthesis of BEA is governed by a non-ribosomal peptide synthase (NRPS), known as beauvericin synthase (BEAS), which appears to present considerable divergence among different fungal species. In the present study we compared the production of beauvericin among Fusarium and Trichoderma strains using UPLC methods. BEAS fragments were sequenced and analyzed to examine the level of the gene’s divergence between these two genera and confirm the presence of active BEAS copy in Trichoderma. Seventeen strains of twelve species were studied and phylogenetic analysis showed distinctive grouping of Fusarium and Trichoderma strains. The highest producers of beauvericin were F. proliferatum and F. nygamai. Trichoderma strains of three species (T. atroviride, T. viride, T. koningiopsis) were minor BEA producers. The study showed beauvericin production by Fusarium and Trichoderma species and high variance of the non-ribosomal peptide synthase gene among fungal species from the Hypocreales order.

Beauvericin and Enniatins: In Vitro Intestinal Effects

Food and feed contamination by emerging mycotoxins beauvericin and enniatins is a worldwide health problem and a matter of great concern nowadays, and data on their toxicological behavior are still scarce. As ingestion is the major route of exposure to mycotoxins in food and feed, the gastrointestinal tract represents the first barrier encountered by these natural contaminants and the first structure that could be affected by their potential detrimental effects. In order to perform a complete and reliable toxicological evaluation, this fundamental site cannot be disregarded. Several in vitro intestinal models able to recreate the different traits of the intestinal environment have been applied to investigate the various aspects related to the intestinal toxicity of emerging mycotoxins. This review aims to depict an overall and comprehensive representation of the in vitro intestinal effects of beauvericin and enniatins in humans from a species-specific perspective. Moreover, information on the occurrence in food and feed and notions on the regulatory aspects will be provided.

Occurrence, Pathogenicity, and Mycotoxin Production of Fusarium temperatum in Relation to Other Fusarium Species on Maize in Germany

Fusarium subglutinans is a plant pathogenic fungus infecting cereal grain crops. In 2011, the species was divided in Fusarium temperatumsp. nov. and F. subglutinans sensu stricto. In order to determine the occurrence and significance of F. temperatum and F. subglutinans on maize, a monitoring of maize ears and stalks was carried out in Germany in 2017 and 2018. Species identification was conducted by analysis of the translation elongation factor 1α (TEF-1α) gene. Ninety-four isolates of F. temperatum and eight isolates of F. subglutinans were obtained during two years of monitoring from 60 sampling sites in nine federal states of Germany. Inoculation of maize ears revealed a superior aggressiveness for F. temperatum, followed by Fusarium graminearum, Fusarium verticillioides, and F. subglutinans. On maize stalks, F. graminearum was the most aggressive species while F. temperatum and F. subglutinans caused only small lesions. The optimal temperature for infection of maize ears with F. temperatum was 24 °C and 21 °C for F. subglutinans. All strains of F. temperatum and F. subglutinans were pathogenic on wheat and capable to cause moderate to severe head blight symptoms. The assessment of mycotoxin production of 60 strains of F. temperatum cultivated on rice revealed that all strains produced beauvericin, moniliformin, fusaric acid, and fusaproliferin. The results demonstrate a higher prevalence and aggressiveness of F. temperatum compared to F. subglutinans in German maize cultivation areas.

Isolation of Beauveria bassiana from the Chagas Disease Vector Triatoma infestans in the Gran Chaco Region of Argentina: Assessment of Gene Expression during Host-Pathogen Interaction

A native strain of the entomopathogenic fungus Beauveria bassiana (Bb-C001) was isolated from a naturally infected Triatoma infestans, Klug (Hemiptera: Reduviidae) adult cadaver in the Gran Chaco region, Salta province, Argentina. The isolate was both phenotypic and molecularly characterized in a context of fungus-insect interaction, by measuring the expression pattern of toxin genes during infection and immune response of T. infestans. The commercial strain GHA of B. bassiana, which was previously used in field interventions to control these vectors, was used as reference in this study. The phylogenetic trees based on both ribosomal internal transcribed spacer (ITS) and elongation factor 1-alpha (EF1-α) indicated that Bb-C001 fits into a B. bassiana cluster, and the sequence-characterized amplified regions (SCAR) showed that Bb-C001 is different from the GHA strain. There were no differences between both strains regarding viability, radial growth, and conidia production, either in the median survival time or insect mortality. However, Bb-C001 showed a higher expression than GHA of the bassianolide synthetase gene (BbbslS) during infection, and similar levels of the beauvericin synthetase gene (BbbeaS). Immune-related genes of T. infestans nymphs (limpet-2 and defensin-1, -2, and -6) were later expressed and thus insects failed to stop the infection process. These results showed that B. bassiana Bb-C001 is a promised fungal strain to be incorporated in the current biological control programs of T. infestans in Salta province, Argentina.

on Pancreatic Cancer Cells

This study describes the antiproliferative and antimigration effects of beauvericin from a culture broth of Isaria sp. in human pancreatic cancer cells (PANC-1). Activity-guided fractionation of the EtOAc extract of cultured broth of Isaria sp. RD055140 afforded beauvericin (1), a new isariotin derivative, 7-O-methylisariotin C (2), together with the known isariotin analogs, TK-57-164A (3) and B (4). As a result of the measurement of the cell viability, 1 inhibited cell growth (IC50 = 4.8 µM) of PANC-1 cells. Furthermore, 1 was found to inhibit the migration activity of PANC-1 cells by upregulating the expression of the E-cadherin gene and reducing N-cadherin and Snail genes in a dose-dependent manner (0.1-1 µM). These activities of 1 had lower concentrations than the cytotoxic activity. These findings suggest that 1 can be used as an anticancer agent against human pancreatic carcinoma.

Cyclodepsipeptide Biosynthesis in Hypocreales Fungi and Sequence Divergence of The

Fungi from the Hypocreales order synthesize a range of toxic non-ribosomal cyclic peptides with antimicrobial, insecticidal and cytotoxic activities. Entomopathogenic Beauveria, Isaria and Cordyceps as well as phytopathogenic Fusarium spp. are known producers of beauvericins (BEAs), beauvenniatins (BEAEs) or enniatins (ENNs). The compounds are synthesized by beauvericin/enniatin synthase (BEAS/ESYN1), which shows significant sequence divergence among Hypocreales members. We investigated ENN, BEA and BEAE production among entomopathogenic (Beauveria, Cordyceps, Isaria) and phytopathogenic (Fusarium) fungi; BEA and ENNs were quantified using an LC-MS/MS method. Phylogenetic analysis of partial sequences of putative BEAS/ESYN1 amplicons was also made. Nineteen fungal strains were identified based on sequence analysis of amplified ITS and tef-1α regions. BEA was produced by all investigated fungi, with F. proliferatum and F. concentricum being the most efficient producers. ENNs were synthesized mostly by F. acuminatum, F. avenaceum and C. confragosa. The phylogeny reconstruction suggests that ancestral BEA biosynthesis independently diverged into biosynthesis of other compounds. The divergent positioning of three Fusarium isolates raises the possibility of parallel acquisition of cyclic depsipeptide synthases in ancient complexes within Fusarium genus. Different fungi have independently evolved NRPS genes involved in depsipeptide biosynthesis, with functional adaptation towards biosynthesis of overlapping yet diversified metabolite profiles.

Fumonisin and Beauvericin Chemotypes and Genotypes of the Sister Species Fusarium subglutinans and Fusarium temperatum

Fusarium subglutinans and Fusarium temperatum are common maize pathogens that produce mycotoxins and cause plant disease. The ability of these species to produce beauvericin and fumonisin mycotoxins is not settled, as reports of toxin production are not concordant. Our objective was to clarify this situation by determining both the chemotypes and genotypes for strains from both species. We analyzed 25 strains from Argentina, 13 F. subglutinans and 12 F. temperatum strains, for toxin production by ultraperformance liquid chromatography mass spectrometry (UPLC-MS). We used new genome sequences from two strains of F. subglutinans and one strain of F. temperatum, plus genomes of other Fusarium species, to determine the presence of functional gene clusters for the synthesis of these toxins. None of the strains examined from either species produced fumonisins. These strains also lack Fum biosynthetic genes but retain homologs of some genes that flank the Fum cluster in Fusarium verticillioides None of the F. subglutinans strains we examined produced beauvericin although 9 of 12 F. temperatum strains did. A complete beauvericin (Bea) gene cluster was present in all three new genome sequences. The Bea1 gene was presumably functional in F. temperatum but was not functional in F. subglutinans due to a large insertion and multiple mutations that resulted in premature stop codons. The accumulation of only a few mutations expected to disrupt Bea1 suggests that the process of its inactivation is relatively recent. Thus, none of the strains of F. subglutinans or F. temperatum we examined produce fumonisins, and the strains of F. subglutinans examined also cannot produce beauvericin. Variation in the ability of strains of F. temperatum to produce beauvericin requires further study and could reflect the recent shared ancestry of these two species.IMPORTANCEFusarium subglutinans and F. temperatum are sister species and maize pathogens commonly isolated worldwide that can produce several mycotoxins and cause seedling disease, stalk rot, and ear rot. The ability of these species to produce beauvericin and fumonisin mycotoxins is not settled, as reports of toxin production are not concordant at the species level. Our results are consistent with previous reports that strains of F. subglutinans produce neither fumonisins nor beauvericin. The status of toxin production by F. temperatum needs further work. Our strains of F. temperatum did not produce fumonisins, while some strains produced beauvericin and others did not. These results enable more accurate risk assessments of potential mycotoxin contamination if strains of these species are present. The nature of the genetic inactivation of BEA1 is consistent with its relatively recent occurrence and the close phylogenetic relationship of the two sister species.

Diversity and Toxigenicity of Fungi that Cause Pineapple Fruitlet Core Rot

The identity of the fungi responsible for fruitlet core rot (FCR) disease in pineapple has been the subject of investigation for some time. This study describes the diversity and toxigenic potential of fungal species causing FCR in La Reunion, an island in the Indian Ocean. One-hundred-and-fifty fungal isolates were obtained from infected and healthy fruitlets on Reunion Island and exclusively correspond to two genera of fungi: Fusarium and Talaromyces. The genus Fusarium made up 79% of the isolates, including 108 F. ananatum, 10 F. oxysporum, and one F. proliferatum. The genus Talaromyces accounted for 21% of the isolated fungi, which were all Talaromyces stollii. As the isolated fungal strains are potentially mycotoxigenic, identification and quantification of mycotoxins were carried out on naturally or artificially infected diseased fruits and under in vitro cultures of potential toxigenic isolates. Fumonisins B₁ and B₂ (FB₁-FB₂) and beauvericin (BEA) were found in infected fruitlets of pineapple and in the culture media of Fusarium species. Regarding the induction of mycotoxin in vitro, F.proliferatum produced 182 mg kg⁻¹ of FB₁ and F. oxysporum produced 192 mg kg⁻¹ of BEA. These results provide a better understanding of the causal agents of FCR and their potential risk to pineapple consumers.

A Novel and Potentially MultifacetedDehydroascorbate Reductase Increasing theAntioxidant Systems Is Induced by Beauvericinin Tomato

Dehydroascorbate reductases (DHARs) are important enzymes that reconvert the dehydroascorbic acid (DHA) into ascorbic acid (ASC). They are involved in the plant response to oxidative stress, such as that induced by the mycotoxin beauvericin (BEA). Tomato plants were treated with 50 µM of BEA; the main antioxidant compounds and enzymes were evaluated. DHARs were analyzed in the presence of different electron donors by native and denaturing electrophoresis as well as by western blot and mass spectrometry to identify a novel induced protein with DHAR activity. Kinetic parameters for dehydroascorbate (DHA) and glutathione (GSH) were also determined. The novel DHAR was induced after BEA treatment. It was GSH-dependent and possessed lower affinity to DHA and GSH than the classical DHARs. Interestingly, the mass spectrometry analysis of the main band appearing on sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) revealed a chloroplast sedoheptulose 1,7-bisphosphatase, a key enzyme of the Calvin cycle, and a chloroplast mRNA-binding protein, suggesting that the DHA reducing capacity could be a side activity or the novel DHAR could be part of a protein complex. These results shed new light on the ascorbate-glutathione regulation network under oxidative stress and may represent a new way to increase the plant antioxidant defense system, plant nutraceutical value, and the health benefits of plant consumption.

Cytotoxic Activities and Molecular Mechanisms of the Beauvericin and Beauvericin G1 Microbial Products against Melanoma Cells

Melanoma is the most serious type of skin cancer and remains highly drug-resistant. Therefore, the discovery of novel effective agents against melanoma is in high demand. Herein, we investigated the cytotoxic activities in melanoma cells and underlying molecular mechanisms of beauvericin (BEA) and its analogue beauvericin G₁ (BEA G₁), which are cyclohexadepsipeptides isolated from fungi. BEA and BEA G₁ significantly suppressed the growth, clonogenicity, migration, and invasion of A375SM human melanoma cells and promoted caspase-dependent apoptosis through upregulation of death receptors, as well as modulation of pro- and anti-apoptotic Bcl-2 family members. Furthermore, the effects of BEA and BEA G₁ were associated with the suppression of multiple molecular targets that play crucial roles in melanoma oncogenesis, including ERK, JNK, p38, NF-κB, STAT3, and MITF. Notably, the cytotoxic efficacy of BEA G₁ against A375SM cells was stronger than that of BEA. These findings suggest that BEA and BEA G₁ can be further investigated as potent cytotoxic natural compounds for the suppression of melanoma progression.

In Vitro Activity of Beauvericin against All Developmental Stages of Sarcoptes scabiei

Scabies is a frequent cutaneous infection caused by the mite Sarcoptes scabiei in a large number of mammals, including humans. As the resistance of S. scabiei against several chemical acaricides has been previously documented, the establishment of alternative and effective control molecules is required. In this study, the potential acaricidal activity of beauvericin was assessed against different life stages of S. scabiei var. suis and in comparison with dimpylate and ivermectin, two commercially available molecules used for the treatment of S. scabiei infection in animals and/or humans. The toxicity of beauvericin against cultured human fibroblast skin cells was evaluated using an MTT proliferation assay. In our in vitro model, developmental stages of S. scabiei were placed in petri dishes filled with Columbia agar supplemented with pig serum and different concentrations of the drugs. Cell sensitivity assays demonstrated low toxicity of beauvericin against primary human fibroblast skin cells. At 0.5 and 5 mM, beauvericin showed higher activity against adults and eggs of S. scabiei compared to dimpylate and ivermectin. These results revealed that the use of beauvericin is promising and might be considered for the treatment of S. scabiei infection.

Individual and Combined Effect of Zearalenone Derivates and Beauvericin Mycotoxins on SH-SY5Y Cells

Beauvericin (BEA) and zearalenone derivatives, α-zearalenol (α-ZEL), and β-zearalenol (β-ZEL), are produced by several Fusarium species. Considering the impact of various mycotoxins on human's health, this study determined and evaluated the cytotoxic effect of individual, binary, and tertiary mycotoxin treatments consisting of α-ZEL, β-ZEL, and BEA at different concentrations over 24, 48, and 72 h on SH-SY5Y neuronal cells, by using the MTT assay (3-(4,5-dimethylthiazol-2-yl)-2,5diphenyltetrazoliumbromide). Subsequently, the isobologram method was applied to elucidate if the mixtures produced synergism, antagonism, or additive effects. Ultimately, we determined the amount of mycotoxin recovered from the media after treatment using liquid chromatography coupled with electrospray ionization-quadrupole time-of-flight mass spectrometry (LC-ESI-qTOF-MS). The IC50 values detected at all assayed times ranged from 95 to 0.2 μM for the individual treatments. The result indicated that β-ZEL was the most cytotoxic mycotoxin when tested individually. The major effect detected for all combinations assayed was synergism. Among the combinations assayed, α-ZEL + β-ZEL + BEA and α-ZEL + BEA presented the highest cytotoxic potential with respect to the IC value. At all assayed times, BEA was the mycotoxin recovered at the highest concentration in individual form, and β-ZEL + BEA was the combination recovered at the highest concentration.

A proposal for the control of enniatins and beauvericin using UHPLC-MS/MS

Mycotoxins have become one of the most common contaminants reported worldwide. Current legislation has established maximum levels only for some well-known mycotoxins; however, there are many other "emerging mycotoxins" for which there is no regulation, as enniatins and beauvericin. An analytical method based on salting-out assisted liquid-liquid extraction followed by ultra-high performance liquid chromatography tandem mass spectrometry is proposed for determination of enniatin A, A1, B, B1, and beauvericin in different plant-based milks, as a possible source of these contaminants, is proposed. The method showed good precision and trueness (RSD <8% and recoveries between 84-97%) with a moderate matrix effect. From a total of 32 samples of plant-based milks of different compositions (including 8 rice milks, 8 oat milks and 16 soy milks), 3 samples were contaminated with the five mycotoxins, while 5 samples were contaminated with four of them, being oat milk the most susceptible for contamination.

Comparative Structure-Activity Analysis of the Antimicrobial Activity, Cytotoxicity, and Mechanism of Action of the Fungal Cyclohexadepsipeptides Enniatins and Beauvericin

Filamentous fungi, although producing noxious molecules such as mycotoxins, have been used to produce numerous drugs active against human diseases such as paclitaxel, statins, and penicillin, saving millions of human lives. Cyclodepsipeptides are fungal molecules with potentially adverse and positive effects. Although these peptides are not novel, comparative studies of their antimicrobial activity, toxicity, and mechanism of action are still to be identified. In this study, the fungal cyclohexadepsipeptides enniatin (ENN) and beauvericin (BEA) were assessed to determine their antimicrobial activity and cytotoxicity against human cells. Results showed that these peptides were active against Gram-positive bacteria, Mycobacterium, and fungi, but not against Gram-negative bacteria. ENN and BEA had a limited hemolytic effect, yet were found to be toxic at low doses to nucleated human cells. Both peptides also interacted with bacterial lipids, causing low to no membrane permeabilization, but induced membrane depolarization and inhibition of macromolecules synthesis. The structure-activity analysis showed that the chemical nature of the side chains present on ENN and BEA (either iso-propyl, sec-butyl, or phenylmethyl) impacts their interaction with lipids, antimicrobial action, and toxicity.

Cytotoxicity, Genotoxicity and Disturbance of Cell Cycle in HepG2 Cells Exposed to OTA and BEA: Single and Combined Actions

Mycotoxins are produced by a number of fungal genera spp., for example, Aspergillus, Penicillium, Alternaria, Fusarium, and Claviceps. Beauvericin (BEA) and Ochratoxin A (OTA) are present in various cereal crops and processed grains. This goal of this study was to determine their combination effect in HepG2 cells, presented for the first time. In this study, the type of interaction among BEA and OTA through an isobologram method, cell cycle disturbance by flow cytometry, and genotoxic potential by in vitro micronucleus (MN) assay following the TG 487 (OECD, 2016) of BEA and OTA individually and combined in HepG2 cells are presented. Cytotoxic concentration ranges studied by the MTT assay over 24, 48, and 72 h were from 0 to 25 µM for BEA and from 0 to 100 µM for OTA, while BEA + OTA combinations were at a 1:10 ratio from 3.4 to 27.5 µM. The toxicity observed for BEA was higher than for OTA at all times assayed; additive and synergistic effects were detected for their mixtures. Cell cycle arrest in the G0/G1 phase was detected for OTA and BEA + OTA treatments in HepG2 cells. Genotoxicity revealed significant effects for BEA, OTA, and in combinations underlining the importance of studying real exposure scenarios of chronic exposure to mycotoxins.

Evidence for Naturally Produced Beauvericins Containing N-Methyl-Tyrosine in Hypocreales Fungi

Beauvericin is a depsipeptide mycotoxin. The production of several beauvericin analogues has previously been shown among various genera among Hypocreales fungi. This includes so-called beauvenniatins, in which one or more N-methyl-phenylalanine residues is exchanged with other amino acids. In addition, a range of "unnatural" beauvericins has been prepared by a precursor addition to growth medium. Our aim was to get insight into the natural production of beauvericin analogues among different Hypocreales fungi, such as Fusarium and Isaria spp. In addition to beauvericin, we tentatively identified six earlier described analogues in the extracts; these were beauvericin A and/or its structural isomer beauvericin F, beauvericin C, beauvericin J, beauvericin D, and beauvenniatin A. Other analogues contained at least one additional oxygen atom. We show that the additional oxygen atom(s) were due to the presence of one to three N-methyl-tyrosine moieties in the depsipeptide molecules by using different liquid chromatography⁻mass spectrometry-based approaches. In addition, we also tentatively identified a beauvenniatin that contained N-methyl-leucine, which we named beauvenniatin L. This compound has not been reported before. Our data show that N-methyl-tyrosine containing beauvericins may be among the major naturally produced analogues in certain fungal strains.

Identification and Quantification of Enniatins and Beauvericin in Animal Feeds and Their Ingredients by LC-QTRAP/MS/MS

Emerging fusariotoxins, mainly enniatins (ENNs) and beauvericin (BEA), are secondary toxic metabolites produced by Fusarium spp. and are widely distributed contaminants of cereals and by-products. Mycotoxin contamination in these products supposes an important risk to feed supply security in the feed industry due to the common use of cereals in feed formulations. Hence, continuous monitoring of both raw materials and feed mixtures is highly recommended as stated by sanitary authorities. Therefore, an analytical procedure based on liquid chromatography tandem mass spectrometry and an acetonitrile-based extraction followed by a d-SPE (QuEChERS) step for the simultaneous determination of emerging Fusarium mycotoxins was in-house validated and successfully applied to raw materials (n = 39) and feed manufactured with them (n = 48). The analytical method was validated following the European guidelines and satisfactory results were obtained. Both raw materials and complete feedstuffs showed mycotoxin contamination at incidences of 18% and 92%, respectively. ENN B was the most commonly found mycotoxin in the analyzed samples at concentrations up to several tens of µg/kg. On the other hand, the co-occurrence of mycotoxins was observed in 47% of samples, ENN B and BEA being the most common combination. These results highlight the necessity to take a vigilant attitude to monitor the occurrence of contaminants in raw materials and feedstuffs throughout the manufacturing chain and storage.

Fusarium, an Entomopathogen-A Myth or Reality?

The Fusarium species has diverse ecological functions ranging from saprophytes, endophytes, and animal and plant pathogens. Occasionally, they are isolated from dead and alive insects. However, research on fusaria-insect associations is very limited as fusaria are generalized as opportunistic insect-pathogens. Additionally, their phytopathogenicity raises concerns in their use as commercial biopesticides. Insect biocontrol potential of Fusarium is favored by their excellent soil survivability as saprophytes, and sometimes, insect-pathogenic strains do not exhibit phytopathogenicity. In addition, a small group of fusaria, those belonging to the Fusarium solani species complex, act as insect mutualists assisting in host growth and fecundity. In this review, we summarize mutualism and pathogenicity among fusaria and insects. Furthermore, we assert on Fusarium entomopathogenicity by analyzing previous studies clearly demonstrating their natural insect-pathogenicity in fields, and their presence in soils. We also review the presence and/or production of a well-known insecticidal metabolite beauvericin by different Fusarium species. Lastly, some proof-of-concept studies are also summarized, which demonstrate the histological as well as immunological changes that a larva undergoes during Fusarium oxysporum pathogenesis. These reports highlight the insecticidal properties of some Fusarium spp., and emphasize the need of robust techniques, which can distinguish phytopathogenic, mutualistic and entomopathogenic fusaria.

A Review on the Synthesis and Bioactivity Aspects of Beauvericin, a Fusarium Mycotoxin

Beauvericin (BEA) is an emerging Fusarium mycotoxin that contaminates food and feeds globally. BEA biosynthesis is rapidly catalyzed by BEA synthetase through a nonribosomal, thiol-templated mechanism. This mycotoxin has cytotoxicity and is capable of increasing oxidative stress to induce cell apoptosis. Recently, large evidence further shows that this mycotoxin has a variety of biological activities and is being considered a potential candidate for medicinal and pesticide research. It is noteworthy that BEA is a potential anticancer agent since it can increase the intracellular Ca²⁺ levels and induce the cancer cell death through oxidative stress and apoptosis. BEA has exhibited effective antibacterial activities against both pathogenic Gram-positive and Gram-negative bacteria. Importantly, BEA exhibits an effective capacity to inhibit the human immunodeficiency virus type-1 integrase. Moreover, BEA can simultaneously target drug resistance and morphogenesis which provides a promising strategy to combat life-threatening fungal infections. Thus, in this review, the synthesis and the biological activities of BEA, as well as, the underlying mechanisms, are fully analyzed. The risk assessment of BEA in food and feed are also discussed. We hope this review will help to further understand the biological activities of BEA and cast some new light on drug discovery.

Fusarium Molds and Mycotoxins: Potential Species-Specific Effects

This review summarizes the information on biochemical and biological activity of the main Fusarium mycotoxins, focusing on toxicological aspects in terms of species-specific effects. Both in vitro and in vivo studies have centered on the peculiarity of the responses to mycotoxins, demonstrating that toxicokinetics, bioavailability and the mechanisms of action of these substances vary depending on the species involved, but additional studies are needed to better understand the specific responses. The aim of this review is to summarize the toxicological responses of the main species affected by Fusarium mycotoxins.

The Natural Fungal Metabolite Beauvericin Exerts Anticancer Activity In Vivo: A Pre-Clinical Pilot Study

Recently, in vitro anti-cancer properties of beauvericin, a fungal metabolite were shown in various cancer cell lines. In this study, we assessed the specificity of this effect by comparing beauvericin cytotoxicity in malignant versus non-malignant cells. Moreover, we tested in vivo anticancer effects of beauvericin by treating BALB/c and CB-17/SCID mice bearing murine CT-26 or human KB-3-1-grafted tumors, respectively. Tumor size and weight were measured and histological sections were evaluated by Ki-67 and H/E staining as well as TdT-mediated-dUTP-nick-end (TUNEL) labeling. Beauvericin levels were determined in various tissues and body fluids by LC-MS/MS. In addition to a more pronounced activity against malignant cells, we detected decreased tumor volumes and weights in beauvericin-treated mice compared to controls in both the allo- and the xenograft model without any adverse effects. No significant differences were detected concerning percentages of proliferating and mitotic cells in tumor sections from treated and untreated mice. However, a significant increase of necrotic areas within whole tumor sections of beauvericin-treated mice was found in both models corresponding to an enhanced number of TUNEL-positive, i.e., apoptotic, cells. Furthermore, moderate beauvericin accumulation was detected in tumor tissues. In conclusion, we suggest beauvericin as a promising novel natural compound for anticancer therapy.

Enniatin B and beauvericin are common in Danish cereals and show high hepatotoxicity on a high-content imaging platform

Mycotoxins are fungi-born metabolites that can contaminate foods through mould-infected crops. They are a significant food/feed-safety issue across the globe and represent a substantial financial burden for the world economy. Moreover, with a changing climate and fungal biota, there is now much discussion about emerging mycotoxins that are measurable at significant levels in crops world-wide. Unfortunately, we still know very little about the bioavailability and toxic potentials of many of these less characterized mycotoxins, including the large family of enniatins. In this study, we present new occurrence data for enniatin A, A1, B, B1 and beauvericin in four Danish crops: oat, wheat, and barley from the 2010 harvest, and rye from 2011 harvest. The occurrence of the four enniatins were B > B1 > A1 > A. Enniatin B was detected in 100% of tested samples regardless of crop type. In addition to occurrence data, we report a proof-of-concept study using a human-relevant high-content hepatotoxicity, or "quadroprobe," assay to screen mycotoxins for their cytotoxic potential. The assay was sensitive for most cytotoxic compounds in the 0.009-100 µM range. Among eight tested mycotoxins (enniatin B, beauvericin, altenariol, deoxynivalenol, aflatoxin B1, andrastin A, citrinin, and penicillic acid), enniatin B and beauvericin showed significant cytotoxicity at a concentration lower than that for aflatoxin B1, which is the archetypal acute hepatotoxic and liver-carcinogenic mycotoxin. Hence, the quadroprobe hepatotoxicity assay may become a valuable assessment tool for toxicity assessment of mycotoxins in the future. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 1658-1664, 2017.

Enniatin and Beauvericin Biosynthesis in Fusarium Species: Production Profiles and Structural Determinant Prediction

Members of the fungal genus Fusarium can produce numerous secondary metabolites, including the nonribosomal mycotoxins beauvericin (BEA) and enniatins (ENNs). Both mycotoxins are synthesized by the multifunctional enzyme enniatin synthetase (ESYN1) that contains both peptide synthetase and S-adenosyl-l-methionine-dependent N-methyltransferase activities. Several Fusarium species can produce ENNs, BEA or both, but the mechanism(s) enabling these differential metabolic profiles is unknown. In this study, we analyzed the primary structure of ESYN1 by sequencing esyn1 transcripts from different Fusarium species. We measured ENNs and BEA production by ultra-performance liquid chromatography coupled with photodiode array and Acquity QDa mass detector (UPLC-PDA-QDa) analyses. We predicted protein structures, compared the predictions by multivariate analysis methods and found a striking correlation between BEA/ENN-producing profiles and ESYN1 three-dimensional structures. Structural differences in the β strand's Asn789-Ala793 and His797-Asp802 portions of the amino acid adenylation domain can be used to distinguish BEA/ENN-producing Fusarium isolates from those that produce only ENN.

Beauvericin Inhibits Neuromuscular Transmission and Skeletal Muscle Contractility in Mouse Hemidiaphragm Preparation

The effects of Beauvericin (BEA) produced by the fungusBeauveria bassianaandFusariumsp. on neuromuscular transmission and contractility were determined in an isolated neuromuscular mouse hemidiaphragm preparation. BEA (5 µM) significantly inhibits indirectly elicited twitch amplitude. At higher concentrations (7.5 and 10 µM), BEA produces a significant reduction of directly elicited, or complete block of indirectly evoked, muscle contraction. BEA also appears to be myotoxic, as indicated by a slowly developing muscle contracture. Development of neuromuscular blockade and contracture is concentration dependent. BEA acted by presynaptically depressing spontaneous acetylcholine release as indicated by the reduction in the frequency of spontaneous miniature endplate potentials (MEPPs), while the membrane potential of muscle fibers remained unchanged. At higher concentrations (7.5 and 10 µM), BEA progressively reduces or completely blocks MEPPs and EPPs amplitudes. Changes in MEPPs and EPPs are associated with substantial depolarization of muscle fibers when exposed to 7.5 and 10 µM of BEA. These results indicate that BEA has neurotoxic and myotoxic effects, which overlap in a narrow range of concentrations.

Ecophysiology of Fusarium temperatum isolated from maize in Argentina

The effect of water activity (aw = 0.95, 0.98 and 0.995), temperature (15, 25 and 30°C), incubation time (7, 14, 21 and 28 days), and their interactions on growth and moniliformin (MON), beauvericin (BEA), fusaproliferin (FUS) and fumonisin B1 (FB1) production by two strains of Fusarium temperatum isolated from Argentinean maize were determined in vitro on sterile layers of maize grains. The results showed that there was a wide range of conditions for growth and mycotoxins production by F. temperatum. Both strains were found to grow faster with increasing aw and at 30°C. In relation to mycotoxin production, the two strains produced more FUS than the other mycotoxins regardless of aw or temperature evaluated (maximum = 50,000 μg g(-1)). For FUS, MON and BEA, the maximum levels were observed at 0.98 aw and 30°C (50,000, 5000 and 2000 μg g(-1) respectively). The lowest levels for these three mycotoxins were detected at 15°C and 0.95 aw (1700 and 100 μg g(-1) for FUS and MON respectively), and at 0.98 aw (400 μg g(-1) for BEA). The maximum levels of FB1 were produced at 15°C and 0.98 aw (1000 μg g(-1)). At all aw and temperatures combinations evaluated there was an increase in toxin concentrations with time incubation. The maximum levels were detected at 21 days. Statistical analyses of aw, temperature, incubation time, and the two- and three-way interactions between them showed significant effects on mycotoxins production by F. temperatum. For its versatility on growth and mycotoxin production, F. temperatum represents a toxicological risk for maize in the field and also during grain storage.

Development of a Rapid LC-MS/MS Method for the Determination of Emerging Fusarium mycotoxins Enniatins and Beauvericin in Human Biological Fluids

A novel method for the simultaneous determination of enniatins A, A1, B and B1 and beauvericin, both in human urine and plasma samples, was developed and validated. The method consisted of a simple and easy pretreatment, specific for each matrix, followed by solid phase extraction (SPE) and detection by high performance liquid chromatography-tandem mass spectrometry with an electrospray ion source. The optimized SPE method was performed on graphitized carbon black cartridges after suitable dilution of the extracts, which allowed high mycotoxin absolute recoveries (76%–103%) and the removal of the major interferences from the matrix. The method was extensively evaluated for plasma and urine samples separately, providing satisfactory results in terms of linearity (R² of 0.991–0.999), process efficiency (>81%), trueness (recoveries between 85% and 120%), intra-day precision (relative standard deviation, RSD < 18%), inter-day precision (RSD < 21%) and method quantification limits (ranging between 20 ng·L⁻¹ and 40 ng·L⁻¹ in plasma and between 5 ng·L⁻¹ and 20 ng·L⁻¹ in urine). Finally, the highly sensitive validated method was applied to some urine and plasma samples from different donors.

Detection of inhibitors of Candida albicans Cdr transporters using a diS-C3(3) fluorescence

Candida albicans is a major cause of opportunistic and life-threatening, systemic fungal infections. Hence new antifungal agents, as well as new methods to treat fungal infections, are still needed. The application of inhibitors of drug-efflux pumps may increase the susceptibility of C. albicans to drugs. We developed a new fluorescence method that allows the in vivo activity evaluation of compounds inhibiting of C. albicans transporters. We show that the potentiometric dye 3,3′-dipropylthiacarbocyanine iodide diS-C₃(3) is pumped out by both Cdr1 and Cdr2 transporters. The fluorescence labeling with diS-C₃(3) enables a real-time observation of the activity of C. albicans Cdr1 and Cdr2 transporters. We demonstrate that enniatin A and beauvericin show different specificities toward these transporters. Enniatin A inhibits diS-C₃(3) efflux by Cdr1 while beauvericin inhibits both Cdr1p and Cdr2p.

Natural occurrence of emerging Fusarium mycotoxins in feed and fish from aquaculture

A new analytical method for the simultaneous determination of enniatins (ENs) and beauvericin (BEA) in fish feed and fish tissues by liquid chromatography coupled to mass spectrometry with linear ion trap (LC-MS/MS-LIT) was developed. Results showed that the developed method is precise and sensitive. The presence of emerging Fusarium mycotoxins, ENs and BEA, was determined in samples of aquaculture fish and feed for farmed fish, showing that all feed samples analyzed were contaminated with mycotoxins, with 100% coexistence. In aquacultured fish samples, the highest incidence was found in edible muscle and liver. As for the exposure assessment calculated, it was found that average consumer intake was lower than tolerable daily intake (TDI) values for other Fusarium mycotoxins.

Occurrence of enniatins and beauvericin in 60 Chinese medicinal herbs

A total of 60 Chinese medicinal herbs were examined for contamination of the emerging Fusarium mycotoxins enniatins (ENNs) A, A1, B, B1 and beauvericin (BEA). The herbs under study are commonly used in China as both medicines and food. The dried samples of herbs were randomly collected from traditional Chinese medicine stores in Zhejiang province, China. Sample preparation was achieved by methanol extraction, followed by a simple membrane filtration step; no tedious clean-ups were involved. ENNs A, A1, B, B1 and BEA were analysed by the recently developed stable isotope dilution assays, using liquid chromatography-tandem mass spectrometry (LC-MS/MS). With limits of detection ranging between 0.8 and 1.2 µg kg(-1) for the analytes under study, 25% of all analysed samples were contaminated with at least one of the ENNs and BEA. BEA was the most frequently detected toxin with a 20% incidence in all samples. The percentages of ENN-positive samples were lower: each single ENN was detected in 6.7-11.7% of all samples. Considering the total amounts of the five mycotoxins in single samples, values between 2.5 and 751 µg kg(-1) were found. The mean total amount in positive samples was 126 µg kg(-1). Regarding ginger, the frequent occurrence of ENNs and BEA in dried ginger could be confirmed in samples from Germany. However, in fresh ginger root the toxins were not detectable. This is the first report on the presence of ENNs and BEA in Chinese medicinal herbs.

Mycotoxins: occurrence, toxicology, and exposure assessment

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

Sequence divergence of the enniatin synthase gene in relation to production of beauvericin and enniatins in Fusarium species

Beauvericin (BEA) and enniatins (ENNs) are cyclic peptide mycotoxins produced by a wide range of fungal species, including pathogenic Fusaria. Amounts of BEA and ENNs were quantified in individual rice cultures of 58 Fusarium strains belonging to 20 species, originating from different host plant species and different geographical localities. The species identification of all strains was done on the basis of the tef-1α gene sequence. The main aim of this study was to analyze the variability of the esyn1 gene encoding the enniatin synthase, the essential enzyme of this metabolic pathway, among the BEA- and ENNs-producing genotypes. The phylogenetic analysis based on the partial sequence of the esyn1 gene clearly discriminates species producing exclusively BEA from those synthesizing mainly enniatin analogues.

Beauvericin production by the Lepidoptera pathogenic fungus Isaria tenuipes: Analysis of natural specimens, synnemata from cultivation, and mycelia from liquid-media fermentation

Beauvericin was analyzed in three forms of the Lepidoptra pathogenic fungus Isaria tenuipes (4 isolates): (a) natural specimen, (b) cultivated synnemata on rice media, and (c) mycelia from fermentation in liquid media. Beauvericin was detected in very low amounts in all tested natural specimens. Synnemata on rice contained much higher concentrations of beauvericin than the corresponding natural materials, although the concentrations were lower than mycelia from liquid fermentation. The results casted a caution that beauvericin concentration should be carefully checked, as a possible toxic constituent, upon mass production of a selected strain of Isaria tenuipes for health food purposes.