Synergistic Impact of Bioactive Byproduct Extract Leads to Anti-Fusarium and Anti-Mycotoxin Secretion

Hesperidin Alleviates Hepatic Injury Caused by Deoxynivalenol Exposure through Activation of mTOR and AKT/GSK3β/TFEB Pathways

Deoxynivalenol (DON) is a common agricultural mycotoxin that is chemically stable and not easily removed from cereal foods. When organisms consume food made from contaminated crops, it can be hazardous to their health. Numerous studies in recent years have found that hesperidin (HDN) has hepatoprotective effects on a wide range of toxins. However, few scholars have explored the potential of HDN in attenuating DON-induced liver injury. In this study, we established a low-dose DON exposure model and intervened with three doses of HDN, acting on male C57 BL/6 mice and AML12 cells, which served as in vivo and in vitro models, respectively, to investigate the protective mechanism of HDN against DON exposure-induced liver injury. The results suggested that DON disrupted hepatic autophagic fluxes, thereby impairing liver structure and function, and HDN significantly attenuated these changes. Further studies revealed that HDN alleviated DON-induced excessive autophagy through the mTOR pathway and DON-induced lysosomal dysfunction through the AKT/GSK3β/TFEB pathway. Overall, our study suggested that HDN could ameliorate DON-induced autophagy flux disorders via the mTOR pathway and the AKT/GSK3β/TFEB pathway, thereby reducing liver injury.

Low-dose deoxynivalenol exposure inhibits hepatic mitophagy and hesperidin reverses this phenomenon by activating SIRT1

Deoxynivalenol (DON) is by far the most common mycotoxin contaminating cereal foods and feeds. Furthermore, cleaning up DON from contaminated cereal items is challenging. Low-dose DON consumption poses a danger to humans and agricultural animals. The benefits of hesperidin (HDN) include liver protection, anti-oxidative stress, nontoxicity, and a broad range of sources. The study used immunoblotting, immunofluorescence, and transmission electron microscopy to identify factors associated with mitophagy in vitro and in vivo. We demonstrated that low-dose DON exposure inhibited mitophagy in the liver tissue of mice. SIRT1 was a crucial regulator of mitophagy. Moreover, DON stimulated the dephosphorylation of SIRT1 and the acetylation-regulated FOXO3 protein, which resulted in the transcriptional inhibition of FOXO3-driven BNIP3 and compromised the stability of the PINK1 protein mediated by BNIP3. Moreover, HDN's effect was comparable to that of a SIRT1 agonist, which led to a significant decrease in the level of mitophagy inhibition caused by low-dose DON exposure. When combined, these findings suggested that HDN might be a useful treatment approach for liver damage brought on by low-dose DON exposure. Above all, this research will offer fresh perspectives on a viable approach that will encourage further research into risk reduction initiatives for low-dose DON exposure.

Plant extracts as biocontrol agents against Aspergillus carbonarius growth and ochratoxin A production in grapes

Aspergillus carbonarius (Bainier) Thom. is an important pathogen and ochratoxin A (OTA) producer in grapes that can be controlled by adopting sustainable approaches. Here we evaluate the application of natural plant extracts as an alternative to synthetic fungicides to reduce OTA contamination and to prevent infection of grapes by two isolates of A. carbonarius. In a preliminary screening, natural extracts of chestnut flower, cistus, eucalyptus, fennel, and orange peel were evaluated for their antifungal and anti-mycotoxigenic efficiency in a grape-based medium at concentrations of 10 and 20 mg/mL. Cistus and orange peel extracts demonstrated the best antifungal activity at both concentrations. Although the eucalyptus extract demonstrated no significant effect on Aspergillus vegetative growth, it significantly reduced OTA by up to 85.75 % at 10 mg/mL compared to the control. Chestnut flower, cistus, eucalyptus, and orange peel extracts were then tested at the lowest concentration (10 mg/mL) for their antifungal activity in artificially inoculated grape berries. The cistus and orange peel extracts demonstrated the greatest antifungal activity and significantly reduced mold symptoms in grapes. Moreover, all tested natural extracts were able to reduce OTA content in grape berries (17.7 ± 8.3 % - 82.3 ± 3.85 % inhibition), although not always significantly. Eucalyptus extract was particularly efficient, inhibiting OTA production by both strains of A. carbonarius by up to >80 % with no effects on fungal growth. The use of natural eucalyptus extract represents a feasible strategy to reduce OTA formation without disrupting fungal growth, apparently maintaining the natural microbial balance, while cistus and orange peel extracts appear promising as inhibitors of A. carbonarius mycelial growth. Our findings suggest that plant extracts may be useful sources of bioactive chemicals for preventing A. carbonarius contamination and OTA production. Nonetheless, it will be necessary to evaluate their effect on the organoleptic properties of the grapes.

In-Vitro and In-Silico Investigation for the Spent-Coffee Bioactive Phenolics as a Promising Aflatoxins Production Inhibitor

Aflatoxin, is a naturally occurring polyketide generated by Aspergillus flavus via biosynthetic pathways, including polyketide synthase (PKS) and non-ribosomal enzymes. The in vitro analysis supported by molecular dynamics (MD) techniques was used to examine the antifungal and anti-aflatoxigenic activity of spent coffee grounds (SCGs) methanol extract. The High-Performance Liquid Chromatography results revealed the presence of 15 phenolic acids and five flavonoids. (R)-(+)-Rosmarinic acid (176.43 ± 2.41 µg/g) was the predominant of the detected acids, followed by gallic acid (34.83 ± 1.05 µg/g). At the same time, apigenin-7-glucoside is the dominant flavonoid in the SCGs extract by 1717.05 ± 5.76 µg/g, and naringin (97.27 ± 1.97 µg/g) comes next. The antifungal and anti-aflatoxigenic activity of the SCGs extracts was 380 µL/mL and 460 µL/mL, respectively. The SGGs’ effect of inhibiting five Aspergillus strains’ growth on the agar media ranged between 12.81 ± 1.71 to 15.64 ± 1.08 mm by two diffusion assays. Molecular docking results confirmed the inhibitory action of different phenolics and flavonoids on the PKS and NPS key enzymes of the aflatoxin biosynthetic mechanism. The SCGs extract components with the highest free binding energy, naringin (−9.1 kcal/mL) and apigenin 7-glucoside (−9.1 kcal/mol), were subjected to an MD simulation study. The computational results infer the stabilizing effects on the enzymes upon ligand binding led to the impairment in its functionality. The current study represents a novel attempt to assess the anti aflatoxins mechanism of phenolics and flavonoids targeting PKS and NPS via computational approaches compared to in-vitro assays.

Plant-Pathogenic Fusarium Species

Fusarium species are ubiquitous fungi, both saprotrophic and pathogenic to plants, animals and humans. They are also potent mycotoxin producers which makes them one of the most devastating plant pathogens. Mycotoxin biosynthesis and regulation has recently become one of the mainstream research topics, since knowledge concerning individual metabolic pathways became available and modern 'omics' techniques allowed us to expand this even further. Independently, high-throughput sequencing methodology helped researchers gain insight into the complex phylogenetic relationships among closely related genotypes comprising Fusarium populations, species and species complexes. Molecular tools have so far been very powerful in species identification and phylogeny, as the great diversity of the Fusarium genus has forced scientists to continuously revise previously described taxons.

Outstanding Approach to Enhance the Safety of Ready-to-Eat Rice and Extend the Refrigerated Preservation

Rice is a broad-spectrum meal consumed annually in large amounts. Ready-to-eat rice is a member of dishes with a high risk of contamination. The present study aimed to increase the safety and shelflife of ready-to-eat rice during temporary storage. To prepare a mixture for extraction, three spices were chosen ginger: thyme:coriander (1:2:1). Two types of extract were prepared, aromatic and water extracts. The bioactive aromatic extract was preserved by encapsulation using chitosan nanoparticle preparation, while water extracts were prepared by warm diffusion. The aromatic extract possessed volatiles with antimicrobial features, including α-pinene, cymene, camphor, 1, 8 cineol, and limonene. The results expressed the extracts' better antifungal and antibacterial effect, with a distinguishing aromatic one. Water extract was recorded as being rich in phenolic and flavonoids, like Salysilic, p-hydroxybenzoic acid, ferulic, Luteolin 7 glucoside, and quercitin. These molecules play functionality for microbial inhibition in the simulated media. Ready-to-eat rice shelflife was extended by applying the aromatic extract of the encapsulated mixture at the late stage of cooking and before packaging. It can preserve the samples for up to five days at room temperature and up to eight days of refrigerator storage (8 °C). However, water extract had lower activity as antibacterial and antifungal than the aromatic one. Again, water extract activity reduces fungal citrinin secretion by low efficiency more than the aromatic extract. These results recommended the addition of aromatic extract to the ready-to-eat rice meals as a final additive just before packaging.