Grape Seed Waste Counteracts Aflatoxin B1 Toxicity in Piglet Mesenteric Lymph Nodes

Promising Phytogenic Feed Additives Used as Anti-Mycotoxin Solutions in Animal Nutrition

Mycotoxins are a major threat to animal and human health, as well as to the global feed supply chain. Among them, aflatoxins, fumonisins, zearalenone, T-2 toxins, deoxynivalenol, and Alternaria toxins are the most common mycotoxins found in animal feed, with genotoxic, cytotoxic, carcinogenic, and mutagenic effects that concern the animal industry. The chronic negative effects of mycotoxins on animal health and production and the negative economic impact on the livestock industry make it crucial to develop and implement solutions to mitigate mycotoxins. In this review, we summarize the current knowledge of the mycotoxicosis effect in livestock animals as a result of their contaminated diet. In addition, we discuss the potential of five promising phytogenics (curcumin, silymarin, grape pomace, olive pomace, and orange peel extracts) with demonstrated positive effects on animal performance and health, to present them as potential anti-mycotoxin solutions. We describe the composition and the main promising characteristics of these bioactive compounds that can exert beneficial effects on animal health and performance, and how these phytogenic feed additives can help to alleviate mycotoxins' deleterious effects.

In vitro and in vivo assessment of AFB1 and OTA toxic effects and the beneficial role of bioactive compounds. A systematic review

The purpose of this review was to investigate the current knowledge about aflatoxin B1 (AFB1) and ochratoxin A (OTA) toxicity and the possible beneficial role of bioactive compounds by using in vitro and in vivo models. Although AFB1 and OTA were tested in a similar percentage, the majority of studies focused on nephrotoxicity, hepatotoxicity, immune toxicity and neurotoxicity in which oxidative stress, inflammation, structural damage and apoptosis were the main mechanisms of action reported. Conversely, several biological compounds were assayed in order to modulate mycotoxins damage mainly in the liver, brain, kidney and immune system. Among them, pumpkin, curcumin and fermented whey were the most employed. Although a clear progress has been made by using in vivo models, further research is needed to assess not only the toxicity of multiple mycotoxins contamination but also the effect of functional compounds mixture, thereby reproducing more realistic situations for human health risk assessment.

Grape pomace as a novel functional ingredient: Mitigating ochratoxin A bioaccessibility and unraveling cytoprotective mechanisms in vitro

Mycotoxins, secondary metabolites produced by molds, pose significant health risk through contamination of globally consumed cereals. Ochratoxin A (OTA), a prevalent mycotoxin in cereals, is associated with various health hazards, including immunotoxicity. This study explores the bioaccessibility of OTA in bread and its impact on the gastrointestinal barrier. A focus is placed on grape pomace (GP), a by-product of the wine industry, as a potential mitigator of OTA toxicity. Results demonstrate that GP reduces OTA bioaccessibility in the human gastrointestinal system from 94% to 81% at intestinal level, showing promise in limiting the absorption of the harmful toxin. Additionally, GP exhibits cytoprotective effects, enhancing cell viability and mitigating OTA-induced toxicity in both Caco-2 and Jurkat T cells. In view of the above, to understand the mechanisms by which OTA exhibits its toxic effects, flow cytometry was chosen as the main technique for the analysis of cell cycle, reactive oxygen species levels and mitochondrial parameters. Cytofluorimetric evaluation indicates GP's potential in limiting OTA-induced damage at cellular level. The study suggests that GP could serve as functional ingredient to reduce mycotoxin bioaccessibility and toxicity in cereal-based foods, offering a novel and promising approach to enhance food safety and protect public health. The finding highlights the potential of utilizing grape pomace in food formulations to mitigate mycotoxin contamination, providing a valuable contribution to the ongoing efforts to ensure the safety of globally consumed cereal products.

Alternariol Monomethyl-Ether Induces Toxicity via Cell Death and Oxidative Stress in Swine Intestinal Epithelial Cells

Alternariol monomethyl-ether (AME), together with altenuene and alternariol, belongs to the Alternaria mycotoxins group, which can contaminate different substrates, including cereals. The aim of the present study was to obtain a deeper understanding concerning the effects of AME on pig intestinal health using epithelial intestinal cell lines as the data concerning the possible effects of Alternaria toxins on swine are scarce and insufficient for assessing the risk represented by Alternaria toxins for animal health. Our results have shown a dose-related effect on IPEC-1 cell viability, with an IC50 value of 10.5 μM. Exposure to the toxin induced an increase in total apoptotic cells, suggesting that AME induces programmed cell death through apoptosis based on caspase-3/7 activation in IPEC-1 cells. DNA and protein oxidative damage triggered by AME were associated with an alteration of the antioxidant response, as shown by a decrease in the enzymatic activity of catalase and superoxide dismutase. These effects on the oxidative response can be related to an inhibition of the Akt/Nrf2/HO-1 signaling pathway; however, further studies are needed in order to validate these in vitro data using in vivo trials in swine.

Accurate models and nutritional strategies for specific oxidative stress factors: Does the dose matter in swine production?

Oxidative stress has been associated with a number of physiological problems in swine, including reduced production efficiency. Recently, although there has been increased research into regulatory mechanisms and antioxidant strategies in relation to oxidative stress-induced pig production, it remains so far largely unsuccessful to develop accurate models and nutritional strategies for specific oxidative stress factors. Here, we discuss the dose and dose intensity of the causes of oxidative stress involving physiological, environmental and dietary factors, recent research models and the antioxidant strategies to provide theoretical guidance for future oxidative stress research in swine.

Performance, blood biochemistry, carcass fatty acids, antioxidant status, and HSP70 gene expressions in Japanese quails reared under high stocking density: the effects of grape seed powder and meal

Japanese quails reared under high stocking density (SD) were evaluated for the effects of grape seed powder (GSP) and meal (GSM) supplementation on performance, blood biochemistry, thigh and breast muscle fatty acids, antioxidant status, and HSP70 gene expression. We randomly assigned 288 (15-day-old) quail chicks to six treatment groups in a factorial design (2 × 3) with four replicates, involving two density levels [160 cm²/bird (LD) and 80 cm²/bird (HD)] and three feed forms (FFs) [no supplementation, grape seed powder (3% GSP), grape seed meal (3% GSM)]. SD had a significant effect on live weight, but not on weekly feed intake, daily weight gain, and feed conversion ratio. Serum creatinine and aspartate aminotransferase levels were significantly affected by FF and SD × FF (p < 0.05). A high SD reduced the n-3/n-6 ratio of breast muscle and a significant interaction was found between FF (p < 0.001). The SD × FF interaction reduced the Σn-6 ratio in HDM's thigh muscle, whereas in LDM, the ratio increased (p < 0.01). At high SD, neither GSP nor GSM reduced biological markers of oxidative stress (p > 0.05). Compared to GSP, GSM had higher efficacy at reducing HSP70 levels related to high SD levels. Despite this, at high SD, a diet containing 3% of GSP and GSM was not effective in overcoming oxidative stress. Therefore, more studies using different doses of GSM and GSP in quail diets would be beneficial.

Waste By-Product of Grape Seed Oil Production: Chemical Characterization for Use as a Food and Feed Supplement

Among the waste materials of wine production, grape seeds constitute an important fraction of the pomace, from which the precious edible oil is extracted. The residual mass from oil extraction, the defatted grape seeds (DGS), can be destined for composting or valorized according to the circular economy rules to produce pyrolytic biochar by gasification or pellets for integral energy recovery. Only a small quantity is used for subsequent extraction of polyphenols and tannins. In this study, we performed a chemical characterization of the DGS, by applying spectroscopic techniques (ICP-OES) to determine the metal content, separation techniques (HS-SPME-GC-MS) to evaluate the volatile fraction, and thermal methods of analysis (TGA-MS-EGA) to identify different matrix constituents. Our main goal is to obtain information about the composition of DGS and identify some bioactive compounds constituting the matrix in view of possible future applications. The results suggest that DGS can be further exploited as a dietary supplement, or as an enriching ingredient in foods, for example, in baked goods. Defatted grape seed flour can be used for both human and animal consumption, as it is a source of functional macro- and micronutrients that help in maintaining optimal health and well-being conditions.

Origanum vulgare Essential Oil Modulates the AFB1-Induced Oxidative Damages, Nephropathy, and Altered Inflammatory Responses in Growing Rabbits

The current study was performed to investigate the toxic effects of aflatoxin B1 (AFB1) through the evaluation of kidney function tests and histopathological examination of renal tissues, targeting the therapeutic role of Marjoram (Origanum vulgare essential oil-OEO) in improving health status. Forty-eight New Zealand Whites growing rabbits (four weeks old) weighing on average 660.5 ± 2.33 g were randomly and equally distributed into four groups, each of which had four replicas of three animals as the following: Control group (only basal diet), AFB1 group (0.3 mg AFB1/kg diet), OEO group (1 g OEO/kg diet) and co-exposed group (1 g OEO/kg + 0.3 mg AF/kg diet). Our study lasted eight weeks and was completed at 12 weeks of age. The results revealed that OEO decreased the toxic effects of AFB1 in rabbit kidneys by substantially reducing the cystatin C levels in the AFB1 group. Additionally, OEO decreased oxidative stress and lipid peroxidation levels in the co-exposed group. Moreover, OEO reduced DNA damage and inflammatory response in addition to the down-regulation of stress and inflammatory cytokines-encoding genes. Besides, OEO preserved the cytoarchitecture of rabbits' kidneys treated with AFB1. In conclusion, O. vulgare essential oil supplementation ameliorated the deleterious effects of AFB1 on the rabbits' kidneys by raising antioxidant levels, decreasing inflammation, and reversing oxidative DNA damage.

Grape seed meal by-product is able to counteract oxidative stress induced by lipopolysaccharide and dextran sulphate in IPEC cells and piglets after weaning

Oxidative stress is a pivotal factor in the pathogenesis of intestinal inflammation, leading to cellular damage and tissue injury. Natural antioxidants compounds found in agro-industrial by-products have proven their effectiveness in treatment of intestinal inflammation and oxidative stress, exhibiting many favourable effects. The aim of this study was to evaluate the capacity of a grape seed meal byproduct (GSM) to counteract the effects induced by E. coli lipopolysaccharide (LPS, 5μg/ml) in vitro on IPEC-1 cells and by dextran sulphate sodium (DSS, 1g/b.w./day) in vivo on piglets after weaning. Reactive oxygen species (ROS), pro-oxidant markers (malondialdehyde MDA, thiobarbituric acid reactive substances TBARS, protein carbonyl, DNA oxidative damage) antioxidant enzymes (catalase -CAT, superoxide dismutase -SOD, glutathione peroxidase -GPx, endothelial and inducible nitric oxide synthases -eNOS and iNOS) and several important components of Keap1/Nrf2 signalling pathway were analysed in IPEC-1 cells as well as in piglet's colon and lymph nodes. Our results demonstrated that GSM extract or 8% dietary GSM showed anti-oxidant properties counteracting the pro-oxidant response (ROS, MDA-TBARS, protein carbonyl, DNA/RNA damage) induced by LPS or DSS and restoring the levels of endogenous antioxidant enzymes, including CAT, SOD, GPx, eNOS and iNOS in colon and mesenteric lymph nodes. These beneficial effects were modulated via Nrf2 signalling pathway in both in vitro and in vivo studies.

Yeast-Fermented Rapeseed Meal Extract Is Able to Reduce Inflammation and Oxidative Stress Caused by Escherichia coli Lipopolysaccharides and to Replace ZnO in Caco-2/HTX29 Co-Culture Cells

(1) The present study tested in vitro the capacity of a fermented rapeseed meal extract to reduce medicinal ZnO, which will be banned at the EU level from 2023 onwards because of its potential to cause environmental pollution and the development of Zn resistance in gut bacteria. Rapeseed meal could be an important ZnO substitute as it has antioxidant/radical scavenging properties due to its content of bioactive compounds (e.g., polyphenols). (2) Protein array and flow cytometry were used to detect apoptosis, oxidative stress production, and inflammatory and signaling-related molecules in Caco-2 and goblet HT29-MTX co-culture cells challenged with Escherichia coli lipopolysaccharides and treated with ZnO and FRSM. (3) LPS induced cell death (21.1% vs. 12.7% in control, p < 0.005); apoptosis (16.6%); ROS production; and overexpression of biomarkers related to inflammation (63.15% cytokines and 66.67% chemokines), oxidative stress, and signaling proteins when compared to untreated cells. ZnO was effective in counteracting the effect of LPS, and 73.68% cytokines and 91.67% of chemokines were recovered. FRSM was better at restoring normal protein expression for 78.94% of cytokines, 91.67% of chemokines, and 61.11% of signaling molecules. FRSM was able to mitigate negative effects of LPS and might be an alternative to ZnO in pig diets.

Arabic Gum Could Alleviate the Aflatoxin B1-provoked Hepatic Injury in Rat: The Involvement of Oxidative Stress, Inflammatory, and Apoptotic Pathways

Aflatoxin B₁ (AF) is an unavoidable environmental pollutant that contaminates food, feed, and grains, which seriously threatens human and animal health. Arabic gum (AG) has recently evoked much attention owing to its promising therapeutic potential. Thus, the current study was conducted to look into the possible mechanisms beyond the ameliorative activity of AG against AF-inflicted hepatic injury. Male Wistar rats were assigned into four groups: Control, AG (7.5 g/kg b.w/day, orally), AF (200 µg/kg b.w), and AG plus AF group. AF induced marked liver damage expounded by considerable changes in biochemical profile and histological architecture. The oxidative stress stimulated by AF boosted the production of plasma malondialdehyde (MDA) level along with decreases in the total antioxidant capacity (TAC) level and glutathione peroxidase (GPx) activity. Additionally, AF exposure was associated with down-regulation of the nuclear factor erythroid2–related factor2 (Nrf2) and superoxide dismutase1 (SOD1) protein expression in liver tissue. Apoptotic cascade has also been evoked following AF-exposure, as depicted in overexpression of cytochrome c (Cyto c), cleaved Caspase3 (Cl. Casp3), along with enhanced up-regulation of inflammatory mediators such as tumor necrosis factor-α (TNF-α), interleukin (IL)-6, inducible nitric oxide synthase (iNOS), and nuclear factor kappa-B transcription factor/p65 (NF-κB/p65) mRNA expression levels. Interestingly, the antioxidant and anti-inflammatory contents of AG may reverse the induced oxidative damage, inflammation, and apoptosis in AF-exposed animals.

SeMet attenuates AFB1-induced intestinal injury in rabbits by activating the Nrf2 pathway

The aim of this study was to investigate the role of selenomethionine (SeMet) in alleviating AFB1 induced intestinal injury by inhibiting intestinal oxidative stress. Forty 35-day-old rabbits were divided randomly into 4 groups (control group, AFB1 group, 0.2 mg/kg Se + AFB1 group, 0.4 mg/kg Se + AFB1 group). From the first day of the experiment, the two treatment groups were fed 0.2 mg/kg SeMet or 0.4 mg/kg SeMet daily for 21 days. On the 17th day, all rabbits in the model group and the two treatment groups were given intragastric AFB1 daily for 5 days. The ADG, ADFI and FCR of the rabbits were examined. Rabbit jejunum tissue was collected for hematoxylin- eosin staining (HE), PCNA detection, immunofluorescence and WB. Intestinal tissue IL-1β, IL-6 and TNF-α were examined by enzyme-linked immunosorbent assay (ELISA). The results showed that the production performance was decreased, the levels of ROS and MDA were increased in intestinal tissues, the activity of antioxidant enzymes was decreased and the expression levels of Nrf2 and HO-1 were decreased in AFB1-exposed rabbits. In addition, AFB1 induces an inflammatory response in the jejunum and promotes the expression of TNF-α, IL-6 and IL-1β. SeMet pretreatment significantly improved the performance of the rabbits, alleviated intestinal oxidative stress and the inflammatory response. Therefore, we confirmed that SeMet protects against AFB1 induced oxidative damage and improves productivity in rabbits by activating the Nrf2/HO-1 signaling pathway.

Does Bentonite Cause Cytotoxic and Whole-Transcriptomic Adverse Effects in Enterocytes When Used to Reduce Aflatoxin B1 Exposure?

Aflatoxin B1 (AFB1) is a major food safety concern, threatening the health of humans and animals. Bentonite (BEN) is an aluminosilicate clay used as a feed additive to reduce AFB1 presence in contaminated feedstuff. So far, few studies have characterized BEN toxicity and efficacy in vitro. In this study, cytotoxicity (WST-1 test), the effects on cell permeability (trans-epithelial electrical resistance and lucifer yellow dye incorporation), and transcriptional changes (RNA-seq) caused by BEN, AFB1 and their combination (AFB1 + BEN) were investigated in Caco-2 cells. Up to 0.1 mg/mL, BEN did not affect cell viability and permeability, but it reduced AFB1 cytotoxicity; however, at higher concentrations, BEN was cytotoxic. As to RNA-seq, 0.1 mg/mL BEN did not show effects on cell transcriptome, confirming that the interaction between BEN and AFB1 occurs in the medium. Data from AFB1 and AFB1 + BEN suggested AFB1 provoked most of the transcriptional changes, whereas BEN was preventive. The most interesting AFB1-targeted pathways for which BEN was effective were cell integrity, xenobiotic metabolism and transporters, basal metabolism, inflammation and immune response, p53 biological network, apoptosis and carcinogenesis. To our knowledge, this is the first study assessing the in vitro toxicity and whole-transcriptomic effects of BEN, alone or in the presence of AFB1.

Curcumin activates the Nrf2 Pathway to alleviate AFB1-induced immunosuppression in the spleen of ducklings

Ducklings is one of the most susceptible poultry to Aflatoxin B1 (AFB1) which widely existed in duckling products will also in turn affect human health. Curcumin (CUR) has significant effects on immune regulation and anti-oxidation. But whether CUR alleviates toxic effects on duckling spleen induced by AFB1 remains largely unknown. In this study we treated duckings with AFB1 and CUR for 21 days before harvesting serum and spleen tissue for analyses. The results showed that AFB1 damaged the spleen tissue of ducklings by activating the NF-κB signaling pathway. And the addition of CUR not only promoted the growth of ducklings, but also enhanced the immune function of the spleen and reduced the damage of AFB1 to the spleen tissue. At the same time, CUR activated the Nrf2 signaling pathway, upregulated the expression of related antioxidant enzymes, inhibited the NF-kB signaling pathway, and ultimately reducing the inflammation of the duckling spleen induced by AFB1. It has been suggested from these results that Nrf2 pathway might be a potential therapeutic target for CUR to treat AFB1-induced immunosuppression in ducklings.

Bioaccessibility Study of Aflatoxin B1 and Ochratoxin A in Bread Enriched with Fermented Milk Whey and/or Pumpkin

The presence of mycotoxins in cereals and cereal products remains a significant issue. The use of natural ingredients such as pumpkin and whey, which contain bioactive compounds, could be a strategy to reduce the use of conventional chemical preservatives. The aim of the present work was to study the bioaccessibility of aflatoxin B₁ (AFB1) and ochratoxin (OTA) in bread, as well as to evaluate the effect of milk whey (with and without lactic acid bacteria fermentation) and pumpkin on reducing mycotoxins bioaccessibility. Different bread typologies were prepared and subjected to an in vitro digestion model. Gastric and intestinal extracts were analyzed by HPLC-MS/qTOF and mycotoxins bioaccessibility was calculated. All the tested ingredients but one significantly reduced mycotoxin intestinal bioaccessibility. Pumpkin powder demonstrated to be the most effective ingredient showing significant reductions of AFB1 and OTA bioaccessibility up to 74% and 34%, respectively. Whey, fermented whey, and the combination of pumpkin-fermented whey showed intestinal bioaccessibility reductions between 57-68% for AFB1, and between 11-20% for OTA. These results pointed to pumpkin and milk whey as potential bioactive ingredients that may have promising applications in the bakery industry.

Aflatoxin B1 alters meat quality associated with oxidative stress, inflammation, and gut-microbiota in sheep

Aflatoxin B1 (AFB1) is an unavoidable contaminant in animal feed and agricultural products. AFB1 has been found to impair the liver and kidney function of sheep. However, few data are available, which explain the toxic damage of AFB1 exposure on meat quality. In the study, male Dorper RAMS sheep (6-month-old) were orally administrated with AFB1 at the dose of 1 mg/kg body weight once. The body temperature, serum biochemistry, meat quality-related parameters, oxidation indicators in meat and serum, the mRNA expression of pro-inflammatory cytokines and anti-inflammatory, and microbiota composition of feces were measured 24 h after AFB1 exposure. The results showed that the body temperature was slightly increased, the mental state of mutton sheep was suppressed, and biochemical indicators were significantly changed after AFB1 exposure. AFB1 impaired mutton quality reflected by the structure of muscle fibers was changed, and increased muscle drip loss and lightness (L*), and decreased muscle redness (a*). Moreover, we found that AFB1 caused changes in the oxidative stress indicators T-SOD, T-AOC, MDA, GSH level, and GSH/GSSG ratio, and inflammation damage of mutton reflected by increasing pro-inflammatory TNF-α and reducing anti-inflammatory IL-10 mRNA levels, disrupts the secretion of inflammatory factors, and changed the composition of gut microbiota reflected by significantly increased Firmicutes/Bacteroidetes ratio and decreased the abundances of Butyrivibrio, which are related to the quality of the mutton. In summary, gut microbiota participates in AFB1 to damage mutton quality, which may be co-mediated by oxidative stress, inflammation, and gut microbiota.

Discovering the Protective Effects of Resveratrol on Aflatoxin B1-Induced Toxicity: A Whole Transcriptomic Study in a Bovine Hepatocyte Cell Line

Aflatoxin B1 (AFB1) is a natural feed and food contaminant classified as a group I carcinogen for humans. In the dairy industry, AFB1 and its derivative, AFM1, are of concern for the related economic losses and their possible presence in milk and dairy food products. Among its toxic effects, AFB1 can cause oxidative stress. Thus, dietary supplementation with natural antioxidants has been considered among the strategies to mitigate AFB1 presence and its toxicity. Here, the protective role of resveratrol (R) has been investigated in a foetal bovine hepatocyte cell line (BFH12) exposed to AFB1, by measuring cytotoxicity, transcriptional changes (RNA sequencing), and targeted post-transcriptional modifications (lipid peroxidation, NQO1 and CYP3A enzymatic activity). Resveratrol reversed the AFB1-dependent cytotoxicity. As for gene expression, when administered alone, R induced neglectable changes in BFH12 cells. Conversely, when comparing AFB1-exposed cells with those co-incubated with R+AFB1, greater transcriptional variations were observed (i.e., 840 DEGs). Functional analyses revealed that several significant genes were involved in lipid biosynthesis, response to external stimulus, drug metabolism, and inflammatory response. As for NQO1 and CYP3A activities and lipid peroxidation, R significantly reverted variations induced by AFB1, mostly corroborating and/or completing transcriptional data. Outcomes of the present study provide new knowledge about key molecular mechanisms involved in R antioxidant-mediated protection against AFB1 toxicity.