The protective role of liver X receptor (LXR) during fumonisin B1-induced hepatotoxicity

Fumonisin distorts the cellular membrane lipid profile: A mechanistic insight

Monitoring modifications in membrane lipids in association with external stimuli/agents, including fumonisins (FUMs), is a widely employed approach to assess cellular metabolic response/status. FUMs are prevalent fusariotoxins worldwide that have diverse structures with varying toxicity across species; nevertheless, they can induce metabolic disturbances and disease, including cancer. The capacity of FUMs to disrupt membrane lipids, demonstrated across numerous species and organs/tissues, is ascribed to a multitude of factors/events, which range from direct to indirect effects. Certain events are well established, whereas the potential consequences of others remain speculative. The most notable effect is their resemblance to sphingoid bases, which impacts the synthesis of ceramides leading to numerous changes in lipids' composition that are not limited to sphingolipids' composition of the membranes. The next plausible scenario involves the induction of oxidative stress, which is considered an indirect/secondary effect of FUMs. Additional modes of action include modifications of enzyme activities and nuclear signals related to lipid metabolism, although these are likely not yet fully comprehended. This review provides in-depth insight into the current state of these events and their potential mechanistic actions in modifying membrane lipids, with a focus on long-chain fatty acids. This paper also presents a detailed description of the reported modifications to membrane lipids by FUMs.

A review of the mechanisms of abnormal ceramide metabolism in type 2 diabetes mellitus, Alzheimer's disease, and their co-morbidities

The global prevalence of type 2 diabetes mellitus (T2DM) and Alzheimer's disease (AD) is rapidly increasing, revealing a strong association between these two diseases. Currently, there are no curative medication available for the comorbidity of T2DM and AD. Ceramides are structural components of cell membrane lipids and act as signal molecules regulating cell homeostasis. Their synthesis and degradation play crucial roles in maintaining metabolic balance in vivo, serving as important mediators in the development of neurodegenerative and metabolic disorders. Abnormal ceramide metabolism disrupts intracellular signaling, induces oxidative stress, activates inflammatory factors, and impacts glucose and lipid homeostasis in metabolism-related tissues like the liver, skeletal muscle, and adipose tissue, driving the occurrence and progression of T2DM. The connection between changes in ceramide levels in the brain, amyloid β accumulation, and tau hyper-phosphorylation is evident. Additionally, ceramide regulates cell survival and apoptosis through related signaling pathways, actively participating in the occurrence and progression of AD. Regulatory enzymes, their metabolites, and signaling pathways impact core pathological molecular mechanisms shared by T2DM and AD, such as insulin resistance and inflammatory response. Consequently, regulating ceramide metabolism may become a potential therapeutic target and intervention for the comorbidity of T2DM and AD. The paper comprehensively summarizes and discusses the role of ceramide and its metabolites in the pathogenesis of T2DM and AD, as well as the latest progress in the treatment of T2DM with AD.

Vitamin D inhibits tamoxifen-induced non-alcoholic fatty liver disease through a nonclassical estrogen receptor/liver X receptor pathway

Non-alcoholic Fatty Liver Disease (NAFLD) is one of the common side effects of tamoxifen treatment for estrogen receptor-positive breast cancer, and is representative of disorders of energy metabolism. Fatty liver is induced after tamoxifen (TAM) inhibition of estrogen receptor activity, but the exact mechanism is not clear. This study investigated the effects and mechanisms of TAM-induced steatosis in the liver. The effects and mechanisms of TAM on hepatocyte lipid metabolism were assessed using C57BL/6 female mice and human hepatoma cells. TAM promoted fat accumulation in the liver by upregulation of Srebp-1c expression. Regarding the molecular mechanism, TAM promoted the recruitment of the auxiliary transcriptional activator, p300, and dissociated the auxiliary transcriptional repressor, nuclear receptor corepressor (NCOR), of the complexes, which led to enhancement of Srebp-1c transcription and an increase of triglyceride (TG) synthesis. Vitamin D (VD), a common fat-soluble vitamin, can decrease TAM-induced NAFLD by promoting p300 dissociation and NCOR recruitment. Tamoxifen promoted the recruitment and dissociation of co-transcription factors on the LXR/ER/RXR receptor complex, leading to a disorder of liver lipid metabolism. VD interfered with TAM-induced liver lipid metabolism disorders by reversing this process.

Effects of FB1 and HFB1 on Autonomous Exploratory and Spatial Memory and Learning Abilities in Mice

Fumonisin B1 (FB1) is a representative form of fumonisin and is widely present in food and feed. Hydrolyzed fumonisin B1 (HFB1) emerges as a breakdown product of FB1, which is accompanied by FB1 alterations. While previous studies have primarily focused on the liver or kidney toxicity of FB1, with limited studies existing on its neurotoxicity and even fewer on the toxicity of HFB1, this study focuses on the neurotoxicity of FB1 and HFB1 exposure in mice investigated by the open field test, Morris water maze test, histopathological analysis, and nontargeted metabolomics. Further, the levels of oxidative stress-related indices, neurotransmitters, and sphingolipids in the brain were measured to analyze their correlation with behavioral outcomes. The results showed that both FB1 (5 mg/kg) and HFB1 (2.8 mg/kg) reduced autonomous exploratory behavior in mice, impaired spatial learning and memory, and caused mild abnormalities in the brain structure. Quantitative analysis further indicated that exposure to FB1 and HFB1 disrupted neurotransmitter homeostasis, exacerbated oxidative stress, and significantly increased the sphinganine/sphingosine (Sa/So) ratio. Moreover, HFB1 exhibited neurotoxic effects similar to those of FB1, emphasizing the need to pay attention to the neurotoxicity effect of HFB1. These findings underscore the importance of understanding the risks and potential neurological damage associated with FB1 and HFB1 exposure, highlighting the necessity for further research in this crucial field.

The role of chromatin-modifying enzymes and histone modifications in the modulation of p16 gene in fumonisin B1-induced toxicity in human kidney cells

Fumonisin B₁ (FB₁) poses a risk to animal and human health. Although the effects of FB₁ on sphingolipid metabolism are well documented, there are limited studies covering the epigenetic modifications and early molecular alterations associated with carcinogenesis pathways caused by FB₁ nephrotoxicity. The present study investigates the effects of FB₁ on global DNA methylation, chromatin-modifying enzymes, and histone modification levels of the p16 gene in human kidney cells (HK-2) after 24 h exposure. An increase (2.23-fold) in the levels of 5-methylcytosine (5-mC) at 100 µmol/L was observed, a change independent from the decrease in gene expression levels of DNA methyltransferase 1 (DNMT1) at 50 and 100 µmol/L; however, DNMT3a and DNMT3b were significantly upregulated at 100 µmol/L of FB₁. Dose-dependent downregulation of chromatin-modifying genes was observed after FB₁ exposure. In addition, chromatin immunoprecipitation results showed that 10 µmol/L of FB₁ induced a significant decrease in H3K9ac, H3K9me3 and H3K27me3 modifications of p16, while 100 µmol/L of FB₁ caused a significant increase in H3K27me3 levels of p16. Taken together, the results suggest that epigenetic mechanisms might play a role in FB₁ carcinogenesis through DNA methylation, and histone and chromatin modifications.

Mycotoxins on edible insects: Should we be worried?

Edible insects are a solid alternative to meet the growing demand for animal protein. However, there are doubts regarding the safety of insect consumption. Mycotoxins are substances of concern for food safety, as they may cause harmful effects on the human organism and accumulate in the tissues of some animals. This study focuses on the characteristics of the main mycotoxins, the mitigation of human consumption of contaminated insects, and the effects of mycotoxins on insect metabolism. To date, studies reported the interaction of the mycotoxins aflatoxin B1, ochratoxin A, zearalenone, deoxynivalenol, fumonisin B1, and T-2, isolated or combined, in three insect species from Coleoptera and one from Diptera order. The use of rearing substrates with low mycotoxin contamination did not reduce the survival and development of insects. Fasting practices and replacing contaminated substrate with a decontaminated one decreased the concentration of mycotoxins in insects. There is no evidence that mycotoxins accumulate in the tissues of the insects' larvae. Coleoptera species showed high excretion capacity, while Hermetia illucens had a lower excretion capacity of ochratoxin A, zearalenone, and deoxynivalenol. Thus, a substrate with low mycotoxin contamination could be used for raising edible insects, particularly from the Coleoptera order.

The ameliorative effect of Lactobacillus paracasei BEJ01 against FB1 induced spermatogenesis disturbance, testicular oxidative stress and histopathological damage

Fumonisin B1 (FB1) is a possible carcinogenic molecule for humans as classified by the International Agency for Research on Cancer (IARC) in 2B group. In livestock, it is responsible for several mycotoxicoses and economic losses. Lactobacillus strains, inhabitants of a wide range of foodstuffs and the gastrointestinal tract, are generally recognized as safe (GRAS). Thus, the aim of this work was to evaluate the protective effect of Lactobacillus paracasei (LP) against FB1-induced reprotoxicities including testicular histopathology, sperm quality disturbance, and testosterone level reduction.Pubescent mice were divided randomly into four groups and treated for 10 days. Group 1: Control; Group 2: FB1 (100 μg/kg b.w); Group 3: LP (2 × 109 CFU/kg b.w); Group 4: LP (2 × 109 CFU/kg b.w) and FB1 (100 μg/kg b.w). After the end of the treatment, animals were sacrificed. Plasma, epididymis, and testis were collected for reproductive system studies.Our results showed that FB1 altered epididymal sperm quality, generated oxidative stress, and induced histological alterations. Interestingly, these deleterious effects have been counteracted by the LP administration in mice.In conclusion, LP was able to prevent FB1-reproductive system damage in BALB/c mice and could be validated as an anti-caking agent in an animal FB1-contaminated diet.

Mitochondrial calcium uniporter involved in foodborne mycotoxin-induced hepatotoxicity

Foodborne mycotoxins are toxic metabolites that are produced by fungi. The widespread contamination of food and its by-products by mycotoxins is a global food safety problem that potentially threatens public health and other exposed animals. Most foodborne mycotoxins induce hepatotoxicity. However, only few studies have investigated the regulatory mechanisms of mitochondrial calcium transport monomers in mycotoxin-induced hepatotoxicity. Therefore, according to relevant studies and reports, this review suggests that intracellular Ca(2 +) homeostasis and mitochondrial Ca(2 +) uniporter are involved in the regulation of mycotoxin-induced hepatotoxicity. This review provides some ideas for future research involving mitochondrial Ca(2 +) uniporter in the molecular targets of mycotoxin-induced hepatotoxicity, as well as a reference for the research and development of related drugs and the treatment of related diseases.

Tissular Genomic Responses to Oral FB1 Exposure in Pigs

Fumonisin B1 (FB1) is a widespread mycotoxin produced by fungal Fusarium species—mainly in maize, one of the plants most commonly used for food and feed. Pigs and horses are the animal species most susceptible to this mycotoxin. FB1 exposure can cause highly diverse clinical symptoms, including hepatotoxicity, immunotoxicity, and intestinal barrier function disturbance. Inhibition of ceramide synthetase is a well-understood ubiquitous molecular mechanism of FB1 toxicity, but other more tissue-specific effects remain to be elucidated. To investigate the effects of FB1 in different exposed tissues, we cross-analyzed the transcriptomes of fours organs: liver, jejunum, jejunal Peyer’s patches, and spleen. During a four-week study period, pigs were fed a control diet or a FB1-contaminated diet (10 mg/kg feed). In response to oral FB1 exposure, we observed common biological processes in the four organs, including predominant and recurrent processes (extracellular matrix organization, integrin activation, granulocyte chemotaxis, neutrophil migration, and lipid and sterol homeostasis), as well as more tissue-specific processes that appeared to be related to lipid outcomes (cell cycle regulation in jejunum, and gluconeogenesis in liver).

HepG2 liver cells treated with fumonisin B1 in galactose supplemented media have altered expression of genes and proteins known to regulate cholesterol flux

Fumonisin B1 (FB1) contributes to mycotoxicosis in animals and has been associated with the incidence of some cancers in humans. The effect of FB1 on lipidomic profiles, sphingolipids and cholesterol levels have been demonstrated in experimental models, however, the events leading to altered cholesterol levels are unclear. This study investigates the molecular mechanisms that regulate the effect of FB1 on cholesterol homeostasis in galactose supplemented HepG2 liver cells. Galactose supplementation is a proven method utilised to circumvent the Crabtree effect exhibited by cancer cells, which forces cancer cells to activate the mitochondria. HepG2 cells were cultured in galactose supplemented media and treated with FB1 (IC50 = 25 μM) for 6 h. Cell viability was determined using the MTT assay. Metabolic status was evaluated using ATP luciferase assay, and cholesterol regulatory transcription factors (SIRT1, SREBP-1C, LXR, LDLR, PCSK9, and ABCA1) were investigated using western blotting and qPCR. FB1 in galactose supplemented HepG2 cells increased gene expression of SIRT1 (P<0.05), SREBP-1C, LXR, and LDLR; however, PCSK9 (P<0.05) was decreased. Furthermore, protein expression of SIRT1, LXR, and LDLR was elevated upon FB1 treatment, while SREBP-1C and PCSK9 were reduced. The data provides evidence that SIRT1 reduced the expression of PCSK9 and deacetylated LXR to prevent degradation of LDLR. This could result in a dysregulated cholesterol flux, which may contribute to FB1 mediated toxicity.

Grape Seed Proanthocyanidin Ameliorates FB1-Induced Meiotic Defects in Porcine Oocytes

Fumonisin B₁ (FB₁), as the most prevalent and toxic fumonisin, poses a health threat to humans and animals. The cytotoxicity of FB₁ is closely related to oxidative stress and apoptosis. The purpose of this study is to explore whether Grape seed proanthocyanidin (GSP), a natural antioxidant, could alleviate the meiotic maturation defects of oocytes caused by FB₁ exposure. Porcine cumulus oocyte complexes (COCs) were treated with 30 μM FB₁ alone or cotreated with 100, 200 and 300 μM GSP during in vitro maturation for 44 h. The results show that 200 μM GSP cotreatment observably ameliorated the toxic effects of FB₁ exposure, showing to be promoting first polar body extrusion and improving the subsequent cleavage rate and blastocyst development rate. Moreover, 200 μM GSP cotreatment restored cell cycle progression, reduced the proportion of aberrant spindles, improved actin distribution and protected mitochondrial function in FB₁-exposed oocytes. Furthermore, reactive oxygen species (ROS) generation was significantly decreased and the mRNA levels of CAT, SOD2 and GSH-PX were obviously increased in the 200 μM GSP cotreatment group. Notably, the incidence of early apoptosis and autophagy level were also significantly decreased after GSP cotreatment and the mRNA expression levels of BAX, CASPASE3, LC3 and ATG5 were markedly decreased, whereas BCL2 and mTOR were observably increased in the oocytes after GSP cotreatment. Together, these results indicate that GSP could exert significant preventive effects on FB₁-induced oocyte defects by ameliorating oxidative stress through repairing mitochondrial dysfunction.

Fumonisin B1 triggers carcinogenesis via HDAC/PI3K/Akt signalling pathway in human esophageal epithelial cells

Fumonisin B1 (FB1) is a contaminant that commonly present in the global environment, especially in food and feed. Epidemiologic studies have shown that esophageal cancer is associated with fumonisin toxicity. However, the molecular mechanism of FB1-induced esophageal cancer is unclear. In this research, the molecular mechanism of FB1-induced cell carcinogenesis in human esophageal epithelial cells line (HEEC) was explored. We found that FB1 (0.3125-5 μM) could promote cell proliferation, and the same phenomenon was found in a 3D cell model. FB1 could also accelerate cell migration. The expression levels of DNA damage markers were significantly increased after FB1 exposure. Meanwhile, the expression levels of cell cycle-regulated proteins and cancer-related genes were abnormal. Furthermore, FB1 significantly upregulated the histone deacetylase (HDAC) expression and activated the phosphoinositide 3 kinase (PI3K)/protein kinase B (Akt) signalling pathway. The HDAC inhibitor trichostatin A (TSA) could repressed FB1-promoted cell proliferation and abnormal phenomenon induced by FB1. Moreover, myriocin (ISP-1) could relieve FB1-enhanced HDAC expression and cell proliferation, which implied that ISP-1 may be used to block the fumonisin toxicity in the future. Our findings suggested that the HDAC/PI3K/Akt signalling pathway is a novel mechanism for FB1-induced cell carcinogenesis in HEEC and provided new ideas for the prevention and control of fumonisin toxicity, subsequently avoiding adverse effects on the ecosystem and human health.

Hepatotoxicity of food-borne mycotoxins: molecular mechanism, anti-hepatotoxic medicines and target prediction

Mycotoxins are metabolites produced by fungi. The widespread contamination of food and feed by mycotoxins is a global food safety problem and a serious threat to people's health. Most food-borne mycotoxins have strong hepatotoxicity. However, no effective methods have been found to prevent or treat Mycotoxin- Induced Liver Injury (MILI) in clinical and animal husbandry. In this paper, the molecular mechanisms and potential anti-MILI medicines of six food-borne MILI are reviewed, and their targets are predicted by network toxicology, which provides a theoretical basis for further study of the toxicity mechanism of MILI and the development of effective strategies to manage MILI-related health problems in the future and accelerate the development of food safety.

LXR-Mediated Regulation of Marine-Derived Piericidins Aggravates High-Cholesterol Diet-Induced Cholesterol Metabolism Disorder in Mice

Reported as two antirenal cell carcinoma (RCC) drug candidates, marine-derived compounds piericidin A (PA) and glucopiericidin A (GPA) exhibit hepatotoxicity in renal carcinoma xenograft mice. Proteomics and transcriptomics reveal the hepatotoxicity related with cholesterol disposition since RCC is characterized by cholesterol accumulation. PA/GPA aggravate hepatotoxicity in high-cholesterol diet (HCD)-fed mice while exhibiting no toxicity in chow diet-fed mice. High cholesterol accumulation in liver is liver X receptor (LXR)-mediated cytochrome P450 family 7 subfamily a member 1 (CYP7A1) depression and low-density lipoprotein receptor (LDLR) activation. The farnesoid X nuclear receptor (FXR) is also depressed with a downregulated target gene OSTα. Different from PA directly combined with LXRα as an inhibitor, GPA exists as a prodrug in the liver and exerts toxic effects due to transformation into PA. Surface plasmon resonance (SPR) and docking results of 17 piericidins illustrate that glycosides exert no LXRα binding activity. A longer survival time of GPA-treated mice indicates that further exploration in anti-RCC drug research should focus on reducing glycosides transformed into PA and concentrating in the kidney tumor rather than the liver for lowering the risk of hepatotoxicity.

The Effects of Mixed Fusarium Mycotoxins at EU-Permitted Feed Levels on Weaned Piglets' Tissue Lipids

At exactly the individual permitted EU-tolerance dietary limits, fumonisins (FB: 5 mg/kg diet) and mixed fusariotoxins (DZ: 0.9 mg deoxynivalenol + 0.1 mg zearalenone/kg diet, and FDZ: 5 mg fumonisins + 0.9 mg deoxynivalenol + 0.1 mg zearalenone/kg diet) were administered to piglets (n = 6/group) for three weeks. Bodyweights of intoxicated piglets increased, while feed conversion ratios decreased. In FDZ, both the absolute and relative weight of the liver decreased. In the renal-cellular membrane, the most pronounced alterations were in FDZ treatment, followed by individual FB exposure. In both treatments, high proportions of C20:0 and C22:0 with low fatty acid (FA) unsaturation were found. In hepatocyte phospholipids, FDZ toxins exerted antagonistic interactions, and FB had the strongest increasing effect on FA monounsaturation. Among all investigated organs, the spleen lipids were the least responsive, in which FDZ expressed synergistic reactions on C20:0 (↑ FDZ vs. FB) and C22:0 (↓ FDZ vs. DZ). The antioxidant defense of the kidney was depleted (↓ glutathione concentration by FB-exposure). Blood plasma indicated renal injury (profound increase of urea and creatinine in FB vs. DZ and FDZ). FB strongly increased total-cholesterol and low density lipoprotein concentrations, whereas FDZ synergistically increased gamma-glutamyltransferase, alkaline-phosphatase, calcium and phosphorus levels. Summarized, individual and combined multiple fusariotoxins modified the membrane lipid profile and antioxidant defense of splanchnic organs, and serum biochemicals, without retarding growth in piglets.

Aptamer-based detection of fumonisin B1: A critical review

Mycotoxin contamination is a current issue affecting several crops and processed products worldwide. Among the diverse mycotoxin group, fumonisin B1 (FB1) has become a relevant compound because of its adverse effects in the food chain. Conventional analytical methods previously proposed to quantify FB1 comprise LC-MS, HPLC-FLD and ELISA, while novel approaches integrate different sensing platforms and fluorescently labelled agents in combination with antibodies. Nevertheless, such methods could be expensive, time-consuming and require experience. Aptamers (ssDNA) are promising alternatives to overcome some of the drawbacks of conventional analytical methods, their high affinity through specific aptamer-target binding has been exploited in various designs attaining favorable limits of detection (LOD). So far, two aptamers specific to FB1 have been reported, and their modified and shortened sequences have been explored for a successful target quantification. In this critical review spanning the last eight years, we have conducted a systematic comparison based on principal component analysis of the aptamer-based techniques for FB1, compared with chromatographic, immunological and other analytical methods. We have also conducted an in-silico prediction of the folded structure of both aptamers under their reported conditions. The potential of aptasensors for the future development of highly sensitive FB1 testing methods is emphasized.

Liver X Receptor α in Sciatic Nerve Exerts an Alleviating Effect on Neuropathic Pain Behaviors Induced by Crush Injury

Peripheral nerve injury often leads to neuropathic pain. In the present study, we assessed the role of liver x receptor alpha (LXRα), an oxysterol regulated nuclear transcription factor that promotes reverse cholesterol transport and alternative (M2) macrophage activation, in the development of neuropathic pain. We found that compared to WT mice, in LXRα knockout mice the development of mechanical allodynia following sciatic nerve crush was accelerated and the duration was prolonged. Furthermore, the expression of M1-like macrophage marker iNOS and M1-like macrophages inducer hydrogen peroxide (H2O2) was increased, whereas expression of M2 macrophage marker arginase-1 (Arg-1) and interleukin-10 (IL-10) was reduced in the sciatic nerve of LXRα knockout mice. Moreover, peri-sciatic administration of LXRs agonist GW3965, immediately after the nerve crush, into wild type mice, suppressed the mechanical allodynia induced by crush injury. GW3965 also suppressed the expression of iNOS and production of H2O2 in the injured nerve and enhanced the expression of IL-10 and Arg-1. Importantly, peri-sciatic administration of IL-10 neutralization antibody prevented the alleviating effect of GW3965 on mechanical allodynia. Altogether, these results indicates that the lack of LXRα in the sciatic nerve results in an augmented inflammatory profile of macrophages, which ultimately speed up the development of neuropathic pain and dampen its recovery following nerve injury. Activation of LXRα by its agonist might rebalance the neuroprotective and neurotoxic macrophage phenotypes, and thus alleviate the neuropathic pain behavior.

Fumonisin B1 regulates LDL receptor and ABCA1 expression in an LXR dependent mechanism in liver (HepG2) cells

The metabolic toxicity of Fumonisin B₁ (FB₁) converges at the accumulation of sphingoid bases and reduced ceramide levels. Several studies have alluded to a hypercholesterolemic endpoint after FB₁ exposure, yet the molecular mechanisms remain elusive. Cell surface receptors are important regulators of cholesterol metabolism by regulating influx of lipids and efflux of cholesterol. Western blot analysis showed that FB₁ elevates the expression of ABCA1 (a cholesterol efflux promoter) in an LXR dependent mechanism. We further highlight the potential role of PCSK9 in the degradation of LDL receptor. These data provide important evidence for the mechanism underlying hypercholesterolemia in FB₁ treated models. The disruption of lipid homeostasis by FB₁ is beginning to shift away from canonical ceramide synthase inhibition, and this changed perspective may shed light on diseases caused by dysregulated cholesterol metabolism such as cancer initiation and promotion.

Combination of Antimicrobial Starters for Feed Fermentation: Influence on Piglet Feces Microbiota and Health and Growth Performance, Including Mycotoxin Biotransformation in vivo

The aim of this study was to apply a combination of the microbial starters Lactobacillus uvarum LUHS245, Lactobacillus casei LUHS210, Pediococcus acidilactici LUHS29, and Pediococcus pentosaceus LUHS183 for feed fermentation and to evaluate the influence of fermentation on feed acidity and microbiological characteristics, as well as on the piglet feces microbiota, health, and growth performance. Additionally, mycotoxin biotransformation was analyzed, including masked mycotoxins, in feed and piglet feces samples. The 36-day experiment was conducted using 25-day-old Large White/Norwegian Landrace (LW/NL) piglets with an initial body weight of 6.9–7.0 kg, which were randomly distributed into two groups (in each 100 piglets): control group, fed with basal diet (based on barley, wheat, potato protein, soybean protein concentrate, and whey powder), and treated group, fed with fermented feed at 500 g kg⁻¹ of total feed. Compared to a commercially available lactic acid bacteria (LAB) combination, the novel LAB mixture effectively reduced feed pH (on average pH 3.65), produced a 2-fold higher content of L(+) lactic acid, increased viable LAB count [on average 8.8 log₁₀ colony-forming units (CFU) g⁻¹], and led to stable feed fermentation during the entire test period (36 days). Fecal microbiota analysis showed an increased number of probiotic bacteria in the treated group, particularly Lactobacillus, when compared with the control group at the end of experiment. This finding indicates that fermented feed can modify microbial profile change in the gut of pigs. In treated piglets' blood (at day 61), the serum high-density lipoprotein (HDL) cholesterol and triglycerides (TG) were significantly higher, but the levels of T4, glucose, K, alkaline phosphatase (AP), and urea were significantly decreased (p ≤ 0.05) compared with the control group. Mycotoxin analysis showed that alternariol monomethyl ether (AME) and altenuene were found in 61-day-old control piglets' feces and in fermented feed samples. However, AME was not found in treated piglets' feces. Feed fermentation with the novel LAB combination is a promising means to modulate piglets' microbiota, which is essential to improve nutrient absorption, growth performance, and health parameters. The new LAB composition suggests a novel dietary strategy to positively manipulate fermented feed chemicals and bio-safety and the piglet gut microbial ecology to reduce antimicrobials use in pig production and increase local feed stock uses and economical effectiveness of the process.

Evaluation of the Individual and Combined Toxicity of Fumonisin Mycotoxins in Human Gastric Epithelial Cells

Fumonisin contaminates food and feed extensively throughout the world, causing chronic and acute toxicity in human and animals. Currently, studies on the toxicology of fumonisins mainly focus on fumonisin B1 (FB1). Considering that FB1, fumonisin B2 (FB2) and fumonisin B3 (FB3) could coexist in food and feed, a study regarding a single toxin, FB1, may not completely reflect the toxicity of fumonisin. The gastrointestinal tract is usually exposed to these dietary toxins. In our study, the human gastric epithelial cell line (GES-1) was used as in vitro model to evaluate the toxicity of fumonisin. Firstly, we found that they could cause a decrease in cell viability, and increase in membrane leakage, cell death and the induction of expression of markers for endoplasmic reticulum (ER) stress. Their toxicity potency rank is FB1 > FB2 >> FB3. The results also showed that the synergistic effect appeared in the combinations of FB1 + FB2 and FB1 + FB3. Nevertheless, the combinations of FB2 + FB3 and FB1 + FB2 + FB3 showed a synergistic effect at low concentration and an antagonistic effect at high concentration. We also found that myriocin (ISP-1) could alleviate the cytotoxicity induced by fumonisin in GES-1 cells. Finally, this study may help to determine or optimize the legal limits and risk assessment method of mycotoxins in food and feed and provide a potential method to block the fumonisin toxicity.

Porcine Hepatic Response to Fumonisin B1 in a Short Exposure Period: Fatty Acid Profile and Clinical Investigations

Scarce studies have investigated the impact of fumonisin B1 (FB1) on the hepatic tissue fatty acid (FA) profile, and no study is available on piglets. A 10-day in vivo experiment was performed on seven piglets/group: control and FB1-fed animals (diet was contaminated with fungal culture: 20 mg FB1/kg diet). Independent sample t-test was carried out at p < 0.05 as the significance level. Neither growth, nor feed efficiency, was affected. The hepatic phospholipid (PL) fatty acids (FAs) were more susceptible for FB1, while triglyceride (TG) was less responsive. The impact of FB1 on hepatic PL polyunsaturated fatty acids (PUFAs) was more pronounced than on saturated fatty acids. Among all PUFAs, predominant ones in response were docosapentaenoicacid (DPA) (↓), docosahexaenoic DHA (↓) and arachidonic acids (↑). This led to a higher omega-6:omega-3 ratio, whereas a similar finding was noted in TGs. Neither total saturation (SFA) nor total monousaturation (MUFA) were affected by the FB1 administration. The liver showed an increase in malondialdehyde, as well as antioxidant capacity (reduced glutathione and glutathione peroxidase). The plasma enzymatic assessment revealed an increase in alkaline phosphatase (ALP), while alanine transaminase (ALT), aspartate transaminase (AST), lactate dehydrogenase (LDH), and gamma-glutamyltransferase (GGT) were not influenced. The microscopic sections provided evidence of vacuolar degeneration of the hepatocytes' cytoplasm, but it was not severe. Furthermore, the lung edema was developed, while the kidney was not affected. In conclusion, regarding FB1-mediated hepatotoxicity in piglets, the potential effect of slight hepatotoxicity did not compromise growth performance, at least at the dose and exposure period applied.

Fumonisins at Doses below EU Regulatory Limits Induce Histological Alterations in Piglets

Fumonisins (FBs) are mycotoxins produced by Fusarium species that can contaminate human food and animal feed. Due to the harmful effects of FBs on animals, the European Union (EU) defined a recommendation of a maximum of 5 mg FBs (B1 + B2)/kg for complete feed for swine and 1 µg FBs/kg body weight per day as the tolerable daily intake for humans. The aim of this study was to evaluate the toxicity of dietary exposure to low doses of FBs, including a dose below the EU regulatory limits. Four groups of 24 weaned castrated male piglets were exposed to feed containing 0, 3.7, 8.1, and 12.2 mg/kg of FBs for 28 days; the impact was measured by biochemical analysis and histopathological observations. Dietary exposure to FBs at a low dose (3.7 mg/kg of feed) significantly increased the plasma sphinganine-to-sphingosine ratio. FBs-contaminated diets led to histological modifications in the intestine, heart, lung, lymphoid organs, kidney, and liver. The histological alterations in the heart and the intestine appeared at the lowest dose of FBs-contaminated diet (3.7 mg/kg feed) and in the kidney at the intermediate dose (8.1 mg/kg feed). At the highest dose tested (12.2 mg/kg feed), all the organs displayed histological alterations. This dose also induced biochemical modifications indicative of kidney and liver alterations. In conclusion, our data indicate that FBs-contaminated diets at doses below the EU regulatory limit cause histological lesions in several organs. This study suggests that EU recommendations for the concentration of FBs in animal feed, especially for swine, are not sufficiently protective and that regulatory doses should be modified for better protection of animal health.