The Potential of Plant-Based Bioactive Compounds on Inhibition of Aflatoxin B1 Biosynthesis and Down-regulation of aflR, aflM and aflP Genes

Phytochemical analysis and biological activities of the aerial parts of Odontites vulgaris Moench

In this work, the first specific phytochemical analysis on Odontites vulgaris Moench collected in Central Italy was performed. The aerial parts ethanolic extract was studied and eight compounds were identified: pheophytin a (1), aucubin (2), catalpol (3), shanzhiside methyl ester (4), melampyroside (5), 8-epi-loganin (6), caryoptoside (7) and quinic acid (8). To the best of our knowledge, in this study, compounds (7-8) resulted to be isolated from the genus for the first time. The chemophenetic markers of the family and order were evidenced and several important ecological conclusions could be drawn. The ethanolic extract was also tested for several biological activities showing high effects in the antioxidant, cytoprotective and aflatoxin B1 production inhibitory assays. A brief explanation on these activities under the phytochemical standpoint was also included.

Effects of Tripleurospermum caucasicum, Salvia rosmarinus and Tanacetum fruticulosum essential oils on aflatoxin B1 production and aflR gene expression in Aspergillus flavus

Aflatoxin B1 (AFB1) is one of the most hazardous mycotoxins for humans and livestock that mainly produced by members of the genus Aspergillus in a variety of food commodities. In this study, the effect of S. rosmarinus, T. fruticulosum, and T. caucasicum essential oils (EOs) was studied on fungal growth, AFB1 production and aflR gene expression in toxigenic A. flavus IPI 247. The AFB1 producer A. flavus strain was cultured in YES medium in presence of various two-fold concentrations of the plant EOs (62.5-500 μg/mL) for 4 days at 28 °C. EO composition of plants was analyzed by Gas Chromatography/Mass Spectrometry (GC/MS). The amount of fungal growth, ergosterol content of fungal mycelia and AFB1 content of EO-treated and non-treated controls were measured. The expression of aflR gene was evaluated using Real-time PCR in the fungus exposed to minimum inhibitory concentration (MIC50) of EOs. The main constituents of the oils analyzed by GC/MS analysis were elemicin (33.80 %) and 2,3-dihydro farnesol (33.19 %) in T. caucasicum, 1,8-cineole (17.87 %), trans-caryophyllene (11.14 %), α and ẞ-pinene (10.92 and 8.83 %) in S. rosmarinus, and camphor (17.65 %), bornyl acetate (15.08 %), borneol (12.48 %) and camphene (11.72 %) in T. fruticulosum. The results showed that plant EOs at the concentration of 500 μg/mL suppressed significantly the fungal growth by 35.24-71.70 %, while mycelial ergosterol content and AFB1 production were inhibited meaningfully by 36.20-65.51 % and 20.61-89.16 %. T. caucasicum was the most effective plant, while T. fruticulosum showed the lowest effectiveness on fungal growth and AFB1 production. The expression of aflR in T. caucasicum and S. rosmarinus -treated fungus was significantly down-regulated by 2.85 and 2.12 folds, respectively, while it did not change in T. fruticulosum-treated A. flavus compared to non-treated controls. Our findings on the inhibitory activity of T. caucasicum and S. rosmarinus EOs toward A. flavus growth and AFB1 production could promise these plants as good candidates to control fungal contamination of agricultural crops and food commodities and subsequent contamination by AFB1. Down-regulation of aflR as the key regulatory gene in AF biosynthesis pathway warrants the use of these plants in AF control programs. Further studies to evaluate the inhibitory activity of studied plants EOs in food model systems are recommended.

Promising role of Lawsonia inermis L. leaves extract and its nano-formulation as double treatment against aflatoxin toxicity in ulcerated-rats: Application in milk beverage

Aflatoxins are an unavoidable contaminant of foods. The current work aimed to study the ameliorating effect of Lawsonia inermis L. extract and its nano-formulation versus aflatoxin ingestion in ulcerative rats. Lawsonia inermis L. bioactivity was evaluated by both antioxidant & antimicrobial assays. The nanoparticles characterization measurements were evaluated. Different parameters in the fortified milk beverage were assessed. Seventy two Sprague-Dawley male rats were randomized into 12 groups (6 rats/group) where peptic ulcer was induced with a single aspirin dose (500 mg/kg BW) orally. The nutritional and biochemical parameters were evaluated. The results showed that antioxidant activity and total phenolic content increased with increasing nano-formulation ratio. A remarkable improvements in all the treated groups, either for ulcer alone or for aflatoxin exposed ulcerative groups in normal and nano-formulation. Conclusively, Lawsonia inermis L. & its nano-formulation could act as dual therapy for ulcer treatment and the hazardous effects of aflatoxin exposure.

Pitaya Juice Consumption Protects against Oxidative Damage Induced by Aflatoxin B1

Mycotoxins are toxic fungal metabolites and are responsible for contaminating several foods. The intake of foods contaminated by these substances is related to hepatotoxicity and carcinogenic effects, possibly due to increasing oxidative stress. The current study evaluated Pitaya fruit juice's antioxidant effects on oxidative damage aflatoxin B1 (AFB1)-induced. Rats received 1.5 mL of Pitaya juice via gavage (for 30 days), and on the 31st day, they received AFB1 (250 µg/kg, via gavage). Forty-eight hours after the AFB1 dose, rats were euthanized for dosages of alanine transaminase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP); dosage of oxidative markers (thiobarbituric acid reactive species (TBARS), reactive species (RS)) and antioxidant defenses (catalase (CAT), superoxide dismutase (SOD), Glutathione S-transferase (GST) activities and Glutathione (GSH)) levels in the liver; and detection of Heat shock protein 70 (Hsp-70) and nuclear factor- erythroid 2-related factor 2 (Nrf2) immunocontent in the liver. Our results indicated that the Pitaya juice reduced ALP activity. Further, rats exposed to AFB1 experienced liver damage due to the increase in TBARS, RS, and Hsp-70 and the reduction in CAT, GSH, and Nrf2. Pitaya juice could, however, protect against these damages. Finally, these results indicated that pre-treatment with Pitaya juice was effective against the oxidative damage induced. However, other aspects may be elucidated in the future to discover more targets of its action against mycotoxicosis.

Advanced mycotoxin control and decontamination techniques in view of an increased aflatoxin risk in Europe due to climate change

Aflatoxins are toxic secondary metabolites produced by Aspergillus spp. found in staple food and feed commodities worldwide. Aflatoxins are carcinogenic, teratogenic, and mutagenic, and pose a serious threat to the health of both humans and animals. The global economy and trade are significantly affected as well. Various models and datasets related to aflatoxins in maize have been developed and used but have not yet been linked. The prevention of crop loss due to aflatoxin contamination is complex and challenging. Hence, the set-up of advanced decontamination is crucial to cope with the challenge of climate change, growing population, unstable political scenarios, and food security problems also in European countries. After harvest, decontamination methods can be applied during transport, storage, or processing, but their application for aflatoxin reduction is still limited. Therefore, this review aims to investigate the effects of environmental factors on aflatoxin production because of climate change and to critically discuss the present-day and novel decontamination techniques to unravel gaps and limitations to propose them as a tool to tackle an increased aflatoxin risk in Europe.

Antifungal activity of potential probiotic Limosilactobacillus fermentum strains and their role against toxigenic aflatoxin-producing aspergilli

Two major aflatoxin-producing strains are Aspergillus flavus and Aspergillus niger. Probiotic bacteria have been identified as a potential means to fight aspergilli and reduce the availability of aflatoxin (AFs) as well as other food contaminants. In this study, the potential of ABRIIFBI-6 and ABRIIFBI-7 strains to inhibit the growth of aspergilli was investigated. Both strains survived in the simulated gastrointestinal conditions and inhibited the growth of Aspergillus significantly. Auto-aggregation ranged from 67.4 ± 1.9 for ABRIIFBI-6 to 75.8 ± 2.3% for ABRIIFBI-7, and hydrophobicity ranged from 57.3 ± 1.6 to 61.2 ± 1.4% for ABRIIFBI-6 and ranged from 51.2 ± 1.4 to 55.4 ± 1.8% for ABRIIFBI-7. The ranges of coaggregation with Staphylococcus aureus were 51.3 ± 1.7 and 52.4 ± 1.8% for ABRIIFBI-6 and ABRIIFBI-7, respectively, while coaggregation with Bacillus cereus was 57.9 ± 2.1 and 49.3 ± 1.9% for ABRIIFBI-6 and ABRIIFBI-7, respectively. Both strains indicated remarkable sensitivity to clinical antibiotics. According to the analysis of the identified potential probiotics, the findings of this study could significantly contribute to the understanding of the probiotic potential of LAB in dairy products in order to access their probiotic characterization for use as biocontrol of aflatoxin-producing species.

Antibacterial, Antifungal, Antiviral, and Antiparasitic Activities of Peganum harmala and Its Ingredients: A Review

Infectious diseases have always been the number one enemy threatening health and well-being. With increasing numbers of infectious diseases, growing resistance of pathogens, and declining roles of antibiotics in the treatment of infectious diseases, it is becoming increasingly difficult to treat new infectious diseases, and there is an urgent need to develop new antibiotics to change the situation. Natural products tend to exhibit many special biological properties. The genus Peganum (Zygophyllaceae) has been used, for a long time, to treat cough, asthma, lumbago, hypertension, diabetes, and Alzheimer’s disease. Over the past two decades, a growing number of studies have shown that components from Peganum harmala Linn and its derivatives can inhibit a variety of microorganisms by inducing the accumulation of ROS in microorganisms, damaging cell membranes, thickening cell walls, disturbing cytoplasm, and interfering with DNA synthesis. In this paper, we provide a review on the antibacterial, antifungal, antiviral, and antiparasitic activities of P. harmala, with a view to contribute to research on utilizing P. harmala for medicinal applicaitons and to provide a reference in the field of antimicrobial and a basis for the development of natural antimicrobial agents for the treatment of infectious diseases.

Inhibition of Aspergillus Parasiticus Growth and Aflatoxins Production by Natural Essential Oils and Phenolic Acids

Aflatoxins represent a significant risk to food safety, and strategies are being implemented to reduce their entry into the food chain. The aim of this study was to evaluate the in vitro effect of four essential oils (EOs) (lavandins Grosso and Abrial, Origanum virens, and Rosmarinus officinalis) and four natural phenolic acids (PAs) (caffeic, chlorogenic, ferulic, and p-coumaric) on the growth and aflatoxins (B1, B2, G1, and G2) production by Aspergillus parasiticus. Minimal inhibitory concentration (MIC) and minimal fungicide concentration (MFC) were determined by the broth macrodilution method. Additionally, the mycelia weight was determined at concentration levels lower than MIC. The antiaflatoxigenic activity was evaluated in the two concentrations of the EOs right before MIC and at concentrations below the MIC value for the PAs. To this end, in-house validated methodology based on high-performance liquid chromatography with post-column photochemical derivatization and fluorescence detection (HPLC-PHRED-FLD) was used. EOs of O. virens and lavandins (Grosso and Abrial) completely inhibited mold growth. In addition, a significant reduction in mycelial mass (p < 0.05) was observed for all EOs and PAs at different concentrations. In all cases except for lavandin Abrial, EO concentrations just before the MIC value strongly reduced (p < 0.05) aflatoxins synthesis. Aflatoxins production was completely inhibited by all PAs at a concentration of 20 mM; although at low concentrations, mycotoxin production was stimulated in some cases. The present study provides a scientific basis for further study of the inhibiting mechanisms.

Apigeninidin-rich Sorghum bicolor (L. Moench) extracts suppress A549 cells proliferation and ameliorate toxicity of aflatoxin B1-mediated liver and kidney derangement in rats

Sorghum bicolor plant has a high abundance of 3-deoxyanthocyanins, flavonoids and other polyphenol compounds that have been shown to offer numerous health benefits. Epidemiological studies have linked increased intake of S. bicolor to reduced risk of certain cancer types, including lung adenocarcinoma. S. bicolor extracts have shown beneficial effects in managing hepatorenal injuries. This study investigated the cytotoxic potential of three apigeninidin-rich extracts of S. bicolor (SBE-05, SBE-06 and SBE-07) against selected cancer cell lines and their ameliorative effect on aflatoxin B₁ (AFB₁)-mediated hepatorenal derangements in rats. We observed that, among the three potent extracts, SBE-06 more potently and selectively suppressed the growth of lung adenocarcinoma cell line (A549) (IC₅₀ = 6.5 μg/mL). SBE-06 suppressed the expression of STAT3 but increased the expression of caspase 3. In addition, SBE-05, SBE-06 and SBE-07 inhibited oxidative and nitrosative stress, inflammation, and apoptosis and preserved the histoarchitectural networks of the liver and kidney of rats treated with AFB₁. These in vitro and in vivo studies indicate the potential of these cheap and readily accessible extracts for cancer therapy and as chemo-preventive agents in preventing aflatoxin-related health issues.

Effects of Ethanol Extracts of Origanum vulgare and Thymus vulgaris on the Mycotoxin Concentrations and the Hygienic Quality of Maize (Zea mays L.) Silage

The aim of this study was to assess the usefulness of oregano (Origanum vulgare L.) and thyme (Thymus vulgaris L.) extracts to decrease mycotoxin contents and improve the hygienic quality of maize (Zea mays L.) silage. Under laboratory conditions, maize silage samples were fermented with oregano (OE), thyme (TE), oregano and thyme mixture (MIX), and two commercial inoculants. After 90 days of fermentation, silos were opened and silage samples were taken for evaluation of mycotoxin concentrations and for hygienic quality analysis: assessment of fermentation parameters, the content of biogenic amines, and microbiological status. It was determined that the mycotoxin concentrations decreased differentially: ochratoxin A concentration was below the detection limit after treatment with the TE and MIX extracts, the lowest zearalenone and deoxynivalenol concentrations were achieved with the OE extract treatment, T-2 toxin concentration was significantly lower after treatment with the TE extract, and HT-2 toxin concentration was lower after treatment with the MIX extract. The lowest content of biogenic amines in maize silage was established with the MIX extract. Concerning the silage hygienic quality, the best results of fermentation parameters and microbiological status were also achieved with the MIX extract. The present study indicated that oregano and thyme herbal plant extracts can be used to decrease mycotoxin concentrations and improve the hygienic quality of maize silage.

Spent Coffee Grounds Valorization as Bioactive Phenolic Source Acquired Antifungal, Anti-Mycotoxigenic, and Anti-Cytotoxic Activities

Spent coffee grounds (SCGs), which constitute 75% of original coffee beans, represent an integral part of sustainability. Contamination by toxigenic fungi and their mycotoxins is a hazard that threatens food production. This investigation aimed to examine SCGs extract as antimycotic and anti-ochratoxigenic material. The SCGs were extracted in an eco-friendly way using isopropanol. Bioactive molecules of the extract were determined using the UPLC apparatus. The cytotoxicity on liver cancer cells (Hep-G2) showed moderate activity with selectivity compared with human healthy oral epithelial (OEC) cell lines but still lower than the positive control (Cisplatin). The antibacterial properties were examined against pathogenic strains, and the antifungal was examined against toxigenic fungi using two diffusion assays. Extract potency was investigated by two simulated models, a liquid medium and a food model. The results of the extract showed 15 phenolic acids and 8 flavonoids. Rosmarinic and syringic acids were the most abundant phenolic acids, while apigenin-7-glucoside, naringin, epicatechin, and catechin were the predominant flavonoids in the SCGs extract. The results reflected the degradation efficiency of the extract against the growth of Aspergillus strains. The SCGs recorded detoxification in liquid media for aflatoxins (AFs) and ochratoxin A (OCA). The incubation time of the extract within dough spiked with OCA was affected up to 2 h, where cooking was not affected. Therefore, SCGs in food products could be applied to reduce the mycotoxin contamination of raw materials to the acceptable regulated limits.

Integrated Mycotoxin Management System in the Feed Supply Chain: Innovative Approaches

Exposure to mycotoxins is a worldwide concern as their occurrence is unavoidable and varies among geographical regions. Mycotoxins can affect the performance and quality of livestock production and act as carriers putting human health at risk. Feed can be contaminated by various fungal species, and mycotoxins co-occurrence, and modified and emerging mycotoxins are at the centre of modern mycotoxin research. Preventing mould and mycotoxin contamination is almost impossible; it is necessary for producers to implement a comprehensive mycotoxin management program to moderate these risks along the animal feed supply chain in an HACCP perspective. The objective of this paper is to suggest an innovative integrated system for handling mycotoxins in the feed chain, with an emphasis on novel strategies for mycotoxin control. Specific and selected technologies, such as nanotechnologies, and management protocols are reported as promising and sustainable options for implementing mycotoxins control, prevention, and management. Further research should be concentrated on methods to determine multi-contaminated samples, and emerging and modified mycotoxins.