Potential fungicidal and antiaflatoxigenic effects of cinnamon essential oils on Aspergillus flavus inhabiting the stored wheat grains.

Wheat is one of the essential crops for the human and animal nutrition, however, contamination with aflatoxigenic fungi, due to the improper storage conditions and high humidity, was the main global threats. So, preventing the growth of aflatoxigenic fungi in stored wheat grains, by using different essential oils was the main objective of this work. Aspergillus flavus EFBL-MU12 PP087400, EFBL-MU23 PP087401 and EFBL-MU36 PP087403 isolates were the most potent aflatoxins producers inhabiting wheat grains. The effect of storage conditions of wheat grains "humidity, temperature, incubation period, and pH" on growth of A. flavus, was assessed by the response surface methodology using Plackett-Burman design and FCCD. The highest yield of aflatoxins EFBL-MU12 B1 and B2 by A. flavus grown on wheat grains were 145.3 and 7.6 µg/kg, respectively, at incubation temperature 35°C, 16% moisture contents, initial pH 5.0, and incubated for 14 days. The tested oils had a powerful antifungal activity for the growth and aflatoxins production by A. flavus in a concentration-dependent manner. Among these oils, cinnamon oil had the highest fungicidal activity for A. flavus at 0.125%, with about 85-90 % reduction to the aflatoxins B1 and B2, conidial pigmentation and chitin contents on wheat grains. From the SEM analysis, cinnamon oils had the most deleterious effect on A. flavus with morphological aberrations to the conidial heads, vegetative mycelia, alteration in conidiophores identity, hyphae shrank, and winding. To emphasize the effect of the essential oils on the aflatoxins producing potency of A. flavus, the molecular expression of the aflatoxins biosynthetic genes was estimated by RT-qPCR. The molecular expression of nor-1, afLR, pKsA and afLJ genes was suppressed by 94-96%, due to cinnamon oil at 0.062% compared to the control. Conclusively, from the results, cinnamon oils followed by the peppermint oils displayed the most fungicidal activity for the growth and aflatoxins production by A. flavus grown on wheat grains.

Antifungal mechanisms of binary combinations of volatile organic compounds produced by lactic acid bacteria strains against Aspergillusflavus.

Aspergillus flavus（A. flavus）, a common humic fungus known for its ability to infect agricultural products, served as the subject of investigation in this study. The primary objective was to assess the antifungal efficacy and underlying mechanisms of binary combinations of five volatile organic compounds (VOCs) produced by lactic acid bacteria, specifically in their inhibition of A. flavus. This assessment was conducted through a comprehensive analysis, involving biochemical characterization and transcriptomic scrutiny. The results showed that VOCs induce notable morphological abnormalities in A. flavus conidia and hyphae. Furthermore, they disrupt the integrity of the fungal cell membrane and cell wall, resulting in the leakage of intracellular contents and an increase in extracellular electrical conductivity. In terms of cellular components, VOC exposure led to an elevation in malondialdehyde content while concurrently inhibiting the levels of total lipids, ergosterol, soluble proteins, and reducing sugars. Additionally, the impact of VOCs on A. flavus energy metabolism was evident, with significant inhibition observed in the activities of key enzymes, such as Na+/K+-ATPase, malate dehydrogenase, succinate dehydrogenase, and chitinase. And they were able to inhibit aflatoxin B1 synthesis. The transcriptomic analysis offered further insights, highlighting that differentially expressed genes (DEGs) were predominantly associated with membrane functionality and enriched in pathways about carbohydrate and amino acid metabolism. Notably, DEGs linked to cellular components and energy-related mechanisms exhibited down-regulation, thereby corroborating the findings from the biochemical analyses. In summary, these results elucidate the principal antifungal mechanisms of VOCs, which encompass the disruption of cell membrane integrity and interference with carbohydrate and amino acid metabolism in A. flavus.

Synthesis, Characterization, and Antifungal Activity of Benzimidazole-Grafted Chitosan against Aspergillus flavus.

Aspergillus flavus contamination in agriculture and food industries poses threats to human health, leading to a requirement of a safe and effective method to control fungal contamination. Chitosan-based nitrogen-containing derivatives have attracted much attention due to their safety and enhanced antimicrobial applications. Herein, a new benzimidazole-grafted chitosan (BAC) was synthesized by linking the chitosan (CS) with a simple benzimidazole compound, 2-benzimidazolepropionic acid (BA). The characterization of BAC was confirmed by Fourier transform infrared (FTIR) spectroscopy and nuclear magnetic resonance spectroscopy (1H and 13C NMR). Then, the efficiency of BAC against A. flavus ACCC 32656 was investigated in terms of spore germination, mycelial growth, and aflatoxin production. BAC showed a much better antifungal effect than CS and BA. The minimum inhibitory concentration (MIC) value was 1.25 mg/mL for BAC, while the highest solubility of CS (16.0 mg/mL) or BA (4.0 mg/mL) could not completely inhibit the growth of A. flavus. Furthermore, results showed that BAC inhibited spore germination and elongation by affecting ergosterol biosynthesis and the cell membrane integrity, leading to the permeabilization of the plasma membrane and leakage of intracellular content. The production of aflatoxin was also inhibited when treated with BAC. These findings indicate that benzimidazole-derived natural CS has the potential to be used as an ideal antifungal agent for food preservation.

Nitric oxide-mediated regulation of Aspergillus flavus asexual development by targeting TCA cycle and mitochondrial function.

Nitric oxide (NO) is a signaling molecule with diverse roles in various organisms. However, its role in the opportunistic pathogen Aspergillus flavus remains unclear. This study investigates the potential of NO, mediated by metabolites from A. oryzae (AO), as an antifungal strategy against A. flavus. We demonstrated that AO metabolites effectively suppressed A. flavus asexual development, a critical stage in its lifecycle. Transcriptomic analysis revealed that AO metabolites induced NO synthesis genes, leading to increased intracellular NO levels. Reducing intracellular NO content rescued A. flavus spores from germination inhibition caused by AO metabolites. Furthermore, exogenous NO treatment and dysfunction of flavohemoglobin Fhb1, a key NO detoxification enzyme, significantly impaired A. flavus asexual development. RNA-sequencing and metabolomic analyses revealed significant metabolic disruptions within tricarboxylic acid (TCA) cycle upon AO treatment. NO treatment significantly reduced mitochondrial membrane potential (Δψm) and ATP generation. Additionally, aberrant metabolic flux within the TCA cycle was observed upon NO treatment. Further analysis revealed that NO induced S-nitrosylation of five key TCA cycle enzymes. Genetic analysis demonstrated that the S-nitrosylated Aconitase Acon and one subunit of succinate dehydrogenase Sdh2 played crucial roles in A. flavus development by regulating ATP production. This study highlights the potential of NO as a novel antifungal strategy to control A. flavus by compromising its mitochondrial function and energy metabolism.

Production of kojic acid by Aspergillus flavus OL314748 using box-Behnken statistical design and its antibacterial and anticancer applications using molecular docking technique.

Kojic acid is a wonderful fungal secondary metabolite that has several applications in the food, medical, and agriculture sectors. Many human diseases become resistant to normal antibiotics and normal treatments. We need to search for alternative treatment sources and understand their mode of action. Aspergillus flavus ASU45 (OL314748) was isolated from the caraway rhizosphere as a non-aflatoxin producer and identified genetically using 18S rRNA gene sequencing. After applying the Box-Behnken statistical design to maximize KA production, the production raised from 39.96 to 81.59 g/l utilizing (g/l) glucose 150, yeast extract 5, KH2PO4 1, MgSO4.7H2O 2, and medium pH 3 with a coefficient (R2) of 98.45%. Extracted KA was characterized using FTIR, XRD, and a scanning electron microscope. Crystalized KA was an effective antibacterial agent against six human pathogenic bacteria (Bacillus cereus, Staphylococcus aureus, Escherichia coli, Klebsiella pneumonia, Serratia marcescens, and Serratia plymuthica). KA achieves high inhibition activity against Bacillus cereus, K. pneumonia, and S. plymuthica at 100 µg/ml concentration by 2.75, 2.85, and 2.85 compared with chloramphenicol which gives inhibition zones 1, 1.1, and 1.6, respectively. Crystalized KA had anticancer activity versus three types of cancer cell lines (Mcf-7, HepG2, and Huh7) and demonstrated high cytotoxic capabilities on HepG-2 cells that propose strong antitumor potent of KA versus hepatocellular carcinoma. The antibacterial and anticancer modes of action were illustrated using the molecular docking technique. Crystalized kojic acid from a biological source represented a promising microbial metabolite that could be utilized as an alternative antibacterial and anticancer agent effectively.

Purification of andibenin and a chromanone analogue from rhizospheric Aspergillus flavus and soil-borne Penicillium notatum exhibiting cytotoxic and antibacterial properties.

The discovery of bioactive compounds from fungal natural sources holds immense potential for the development of novel therapeutics. The present study investigates the extracts of soil-borne Penicillium notatum and rhizosphere-inhabiting Aspergillus flavus for their antibacterial, antifungal, and cytotoxic potential. Additionally, two compounds were purified using chromatographic and spectroscopic techniques. The results demonstrated that the ethyl acetate fraction of A. flavus exhibited prominent cytotoxic activity against Artemia salina, whereas the ethyl acetate fraction of P. notatum displayed promising antibacterial potential. At dose concentrations of 10, 100, and 1000 µg mL-1, the ethyl acetate fraction of A. flavus showed mortality percentages of 7.6%, 66.4%, and 90%, respectively. The ethyl acetate fraction of P. notatum extract exhibited significant antibacterial activity, forming inhibition zones measuring 41, 38, 34, 34, and 30 mm against B. subtilis, S. flexneri, E. coli, K. pneumoniae, and S. aureus, respectively, at 1000 µg mL-1. At this concentration, inhibition zones of 28, 27, and 15 mm were recorded for P. vulgaris, S. typhi, and X. oryzae. Using bioassay-guided approach, one compound each was purified from the fungal extracts. The initial purification involved mass spectroscopic analysis, followed by structural elucidation using 500 MHz nuclear magnetic resonance (NMR) spectroscopy. Compound 1, derived from A. flavus, was identified as ethyl 2-hydroxy-5,6-dimethyl-4-oxocyclohex-2-ene-1-carboxylate, with a mass of 212, whereas compound 2, isolated from P. notatum, was identified as 3-amino-2-(cyclopenta-2,4-dien-1-ylamino)-8-methoxy-4H-chromen-4-one, with an exact mass of 270. Based on bioassay results, compound 1 was subjected to brine shrimp lethality assay and compound 2 was tested for its antibacterial potential. Compound 1 exhibited 30% lethality against brine shrimp larvae at a concentration of 100 µg mL-1, whereas at 1000 µg mL-1 the mortality increased to 70%. Compound 2 displayed notable antibacterial potential, forming inhibition zones of 30, 24, 19, and 12 mm against S. aureus, E. coli, B. subtilis, and S. flexneri, respectively. In comparison, the standard antibiotic tetracycline produced inhibition zones of 18, 18, 15, and 10 mm against the respective bacterial strains at the same concentration.

Nanofabrication of citronellal with chitosan biopolymer to boost its efficacy against aflatoxin B1 and Aspergillus flavus mediated biodeterioration of active ingredient of Piper longum.

The study reports the efficacy of nanofabricated citronellal inside the chitosan biopolymer (NeCn) against Aspergillus flavus growth, aflatoxin B1 (AFB1) production, and active ingredient biodeterioration (Piperine) in Piper longum L. The prepared NeCn was characterized by Scanning Electron Microscopy (SEM), Dynamic Light Scattering (DLS), and Fourier Transform Infrared Spectroscopy (FTIR). The results revealed that the NeCn exhibited distantly improved antifungal (1.25 µL/mL) and AFB1 inhibition (1.0 µL/mL) compared to free Cn. The perturbances in membrane function, mitochondrial membrane potential, antioxidant defense system, and regulatory genes (Ver-1 and Nor-1) of AFB1 biosynthesis were reported as probable modes of action of NeCn. The NeCn (1.25 µL/mL) effectively protects the P. longum from A. flavus (78.8%), AFB1 contamination (100%), and deterioration of Piperine (62.39%), thus demonstrating its potential as a promising novel antifungal agent for food preservation.

Exploring the Diverse Biological Properties of Cannabidiol: A Focus on Plant Growth Stimulation.

The aim of the current study was to compare some biological activities of edible oils enriched with 10 % of cannabidiol (CBD samples) from the Slovak market. In addition, hemp, coconut, argan, and pumpkin pure oils were also examined. The study evaluated the fatty acids content, as well as antibacterial, antifungal, antioxidant, cytotoxic, and phytotoxic activities. The CBD samples presented antimicrobial activity against the tested bacterial strains at higher concentrations (10000 and 5000 mg/L) and antifungal activity against Alternaria alternata, Penicillium italicum and Aspergillus flavus. DPPH⋅ and FRAP assays showed greater activity in CBD-supplemented samples compared to pure oils and vitamin E. In cell lines (IPEC-J2 and Caco-2), a reduced cell proliferation and viability were observed after 24 hours of incubation with CBD samples. The oils showed pro-germinative effects. The tested activities were linked to the presence of CBD in the oils.

Pharmacokinetics of isavuconazole at different target sites in healthy volunteers after single and multiple intravenous infusions.

BACKGROUND: Invasive aspergillosis is a severe fungal infection that affects multiple organ systems including the CNS and the lungs. Isavuconazole, a novel triazole antifungal agent, has demonstrated promising activity against Aspergillus spp. However, data on the penetration of isavuconazole into the CNS and ELF and intracellular accumulation remain limited. MATERIALS AND METHODS: We conducted a prospective single-centre pharmacokinetic (PK) study in 12 healthy volunteers. Subjects received seven doses of 200 mg isavuconazole to achieve an assumed steady-state. After the first and final infusion, plasma sampling was conducted over 8 and 12 h, respectively. All subjects underwent one lumbar puncture and bronchoalveolar lavage, at either 2, 6 or 12 h post-infusion of the final dose. PBMCs were collected in six subjects from blood to determine intracellular isavuconazole concentrations at 6, 8 or 12 h. The AUC/MIC was calculated for an MIC value of 1 mg/L, which marks the EUCAST susceptibility breakpoint for Aspergillus fumigatus and Aspergillus flavus. RESULTS: C max and AUC0-24h of isavuconazole in plasma under assumed steady-state conditions were 6.57 ±â€Š1.68 mg/L (mean ±â€ŠSD) and 106 ±â€Š32.1 h·mg/L, respectively. The average concentrations measured in CSF, ELF and in PBMCs were 0.07 ±â€Š0.03, 0.94 ±â€Š0.46 and 27.1 ±â€Š17.8 mg/L, respectively. The AUC/MIC in plasma, CSF, ELF and in PBMCs under steady-state conditions were 106 ±â€Š32.1, 1.68 ±â€Š0.72, 22.6 ±â€Š11.0 and 650 ±â€Š426 mg·h/L, respectively. CONCLUSION: Isavuconazole demonstrated moderate penetration into ELF, low penetrability into CSF and high accumulation in PBMCs. Current dosing regimens resulted in sufficient plasma exposure in all subjects to treat isolates with MICs ≤ 1 mg/L.

Characterization of tea (Camellia sinensis L.) flower extract and insights into its antifungal susceptibilities of Aspergillus flavus.

BACKGROUND: Tea (Camellia sinensis L.) flowers will compete with tea leaves in nutrition and are abandoned as an undesirable by-product. In this study, the biological efficacy of tea flowers was investigated. Further exploration of its antifungal activity was explained. METHODS: Tea flowers harvested from China were characterized in term of component, antioxidant ability, tyrosinase inhibition, and antifungal ability. Chemical compounds of tea flowers were analyzed by LC-MS. Disinfectant compounds were identified in tea flowers, and 2-ketobutyric acid exhibited antifungal activity against Aspergillus flavusCCTCC AF 2023038. The antifungal mechanism of 2-ketobutyric acid was further investigated by RNA-seq. RESULTS: Water-soluble tea flower extracts (TFEs) exhibited free radical scavenging activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2, 2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)(ABTS) as well as a high ferric-reducing ability. However, no inhibition of tyrosinase activity was observed. In the antifungal test, 6.4 mg/mL TFE reached 71.5% antifungal rate and the electrical conductivity of the culture broth increased with increasing concentration of TFE, implying that it damaged the fungal cell membrane by the TFE. Several disinfectants were identified in TFE by LC-MS, and 2-ketobutyric acid was also confirmed to be capable of fungal inhibition. Propidium iodide (PI) staining indicated that 2-ketobutyric acid caused damage to the cell membrane. RNA-seq analysis revealed that 3,808 differentially expressed genes (DEGs) were found in A. flavus CCTCC AF 2023038 treated by 2-ketobutyric acid, and more than 1,000 DEGs involved in the integral and intrinsic component of membrane were affected. Moreover, 2-ketobutyric acid downregulated aflatoxin biosynthesis genes and decreased the aflatoxin production. CONCLUSIONS: Overall, TFE exhibited excellent antioxidant ability and fungal inhibition against A. flavus CCTCC AF 2023038 due to its abundant disinfectant compounds. As a recognized food additive, 2-ketobutyric acid is safe to use in the food industry and can be utilized as the basis for the research and development of strong fungicides.

Aneuploidy Formation in the Filamentous Fungus Aspergillus flavus in Response to Azole Stress.

Aspergillus flavus is a mycotoxigenic fungus that contaminates many important agricultural crops with aflatoxin B1, the most toxic and carcinogenic natural compound. This fungus is also the second leading cause of human invasive aspergillosis, after Aspergillus fumigatus, a disease that is particularly prevalent in immunocompromised individuals. Azole drugs are considered the most effective compounds in controlling Aspergillus infections both in clinical and agricultural settings. Emergence of azole resistance in Aspergillus spp. is typically associated with point mutations in cyp51 orthologs that encode lanosterol 14α-demethylase, a component of the ergosterol biosynthesis pathway that is also the target of azoles. We hypothesized that alternative molecular mechanisms are also responsible for acquisition of azole resistance in filamentous fungi. We found that an aflatoxin-producing A. flavus strain adapted to voriconazole exposure at levels above the MIC through whole or segmental aneuploidy of specific chromosomes. We confirm a complete duplication of chromosome 8 in two sequentially isolated clones and a segmental duplication of chromosome 3 in another clone, emphasizing the potential diversity of aneuploidy-mediated resistance mechanisms. The plasticity of aneuploidy-mediated resistance was evidenced by the ability of voriconazole-resistant clones to revert to their original level of azole susceptibility following repeated transfers on drug-free media. This study provides new insights into mechanisms of azole resistance in a filamentous fungus. IMPORTANCE Fungal pathogens cause human disease and threaten global food security by contaminating crops with toxins (mycotoxins). Aspergillus flavus is an opportunistic mycotoxigenic fungus that causes invasive and noninvasive aspergillosis, diseases with high rates of mortality in immunocompromised individuals. Additionally, this fungus contaminates most major crops with the notorious carcinogen, aflatoxin. Voriconazole is the drug of choice to treat infections caused by Aspergillus spp. Although azole resistance mechanisms have been well characterized in clinical isolates of Aspergillus fumigatus, the molecular basis of azole resistance in A. flavus remains unclear. Whole-genome sequencing of eight voriconazole-resistant isolates revealed that, among other factors, A. flavus adapts to high concentrations of voriconazole by duplication of specific chromosomes (i.e., aneuploidy). Our discovery of aneuploidy-mediated resistance in a filamentous fungus represents a paradigm shift, as this type of resistance was previously thought to occur only in yeasts. This observation provides the first experimental evidence of aneuploidy-mediated azole resistance in the filamentous fungus A. flavus.

Preservation of Mimosa tenuiflora Antiaflatoxigenic Activity Using Microencapsulation by Spray-Drying.

Mimosa tenuiflora aqueous extract (MAE) is rich in phenolic compounds. Among them, condensed tannins have been demonstrated to exhibit a strong antioxidant and antiaflatoxin B1 activities in Aspergillus flavus. Since antioxidant capacity can change with time due to environmental interactions, this study aimed to evaluate the ability of encapsulation by spray-drying of Mimosa tenuiflora aqueous extract to preserve their biological activities through storage. A dry formulation may also facilitate transportation and uses. For that, three different wall materials were used and compared for their efficiency. Total phenolic content, antioxidant activity, antifungal and antiaflatoxin activities were measured after the production of the microparticles and after one year of storage at room temperature. These results confirmed that encapsulation by spray-drying using polysaccharide wall materials is able to preserve antiaflatoxin activity of Mimosa tenuiflora extract better than freezing.

Study on inhibitory activity and mechanism of chitosan oligosaccharides on Aspergillus Flavus and Aspergillus Fumigatus.

Chitosan oligosaccharides (COS) are a derivative of low molecular weight chitosan and are potent natural antimicrobial agents. The antimicrobial activity of COS against Aspergillus flavus and Aspergillus fumigatus was evaluated by minimum inhibitory concentration (MIC) and inhibition of mycelial growth. The MICs of COS against these two fungi were 31.2 and 15.6 mg/mL, respectively. COS treatment rendered fungal mycelia wrinkled and deformed with a fractured appearance. COS also increased cellular permeability leading to a significant leakage of cellular components indicating membrane damage. This compound also dose-dependently reduced chitin production and enhanced chitinase activity while enhancing the accumulation of reactive oxygen species (ROS). These characteristics suggested that COS has inhibitory effects against food spoilage fungi and acts on the cell wall and membrane and alters cellular metabolism. COS shows promise for food industry applications since it is non-toxic to higher organisms.

In vivo synergism of free miltefosine or in alginate-based nanocarrier combined with voriconazole on aspergillosis.

Aim: To evaluate the activity of miltefosine (MFS), in its free form or loaded-alginate nanoparticles (MFS-AN), alone or combined with voriconazole (VRC) on Aspergillus fumigatus and Aspergillus flavus. Materials & methods: A broth microdilution assay was used for the susceptibility testing of Aspergillus isolates, and the antifungal efficacy was assessed using the aspergillosis model in Galleria mellonella larvae. Results: The in vitro synergistic effect of MFS with VRC was observed only against A. fumigatus, whereas both combined therapies (MFS + VRC and MFS-AN + VRC) showed synergism in reducing the larval mortality rate and fungal burden in the larvae infected by A. fumigatus and A. flavus. Conclusions: MFS and MFS-AN combined with VRC may be an important strategy for improving antifungal therapy against aspergillosis.

EGCG Alleviates Oxidative Stress and Inhibits Aflatoxin B1 Biosynthesis via MAPK Signaling Pathway.

Aflatoxin biosynthesis has established a connection with oxidative stress, suggesting a prevention strategy for aflatoxin contamination via reactive oxygen species (ROS) removal. Epigallocatechin gallate (EGCG) is one of the most active and the richest molecules in green tea with well-known antioxidant effects. Here, we found EGCG could inhibit aflatoxin B1 (AFB1) biosynthesis without affecting mycelial growth in Aspergillus flavus, and the arrest occurred before the synthesis of toxin intermediate metabolites. Further RNA-seq analysis indicated that multiple genes involved in AFB1 biosynthesis were down-regulated. In addition, EGCG exposure facilitated the significantly decreased expression of AtfA which is a bZIP (basic leucine zipper) transcription factor mediating oxidative stress. Notably, KEGG (Kyoto Encyclopedia of Genes and Genomes) analysis indicated that the MAPK signaling pathway target transcription factor was down-regulated by 1 mg/mL EGCG. Further Western blot analysis showed 1 mg/mL EGCG could decrease the levels of phosphorylated SakA in both the cytoplasm and nucleus. Taken together, these data evidently supported that EGCG inhibited AFB1 biosynthesis and alleviated oxidative stress via MAPK signaling pathway. Finally, we evaluated AFB1 contamination in soy sauce fermentation and found that EGCG could completely control AFB1 contamination at 8 mg/mL. Conclusively, our results supported the potential use of EGCG as a natural agent to prevent AFB1 contamination in fermentation industry.

Formulation, optimization, and nephrotoxicity evaluation of an antifungal in situ nasal gel loaded with voriconazole‒clove oil transferosomal nanoparticles.

Fungal infections of the paranasal cavity are among the most widely spread illnesses nowadays. The aim of the current study was to estimate the effectiveness of an in situ gel loaded with voriconazole‒clove oil nano-transferosomes (VRC-CO-NT) in enhancing the activity of voriconazole against Aspergillus flavus, which causes rhinosinusitis. The nephrotoxic side effects of voriconazole may be reduced through the incorporation of the clove oil, which has antioxidant activity that protects tissue. The Box‒Behnken design was applied to formulate the VRC-CO-NT. The particle size, entrapment efficiency, antifungal inhibition zone, and serum creatinine concentration were considered dependent variables, and the soybean lecithin, VRC, and CO concentrations were considered independent ones. The final optimized formulation was loaded into a deacetylated gellan gum base and evaluated for its gelation, rheological properties, drug release profile, permeation capabilities, and in vivo nephrotoxicity. The optimum formulation was determined to be composed of 50 mg/mL lecithin, 18 mg/mL VRC, and 75 mg/mL CO, with a minimum particle size of 102.96 nm, an entrapment efficiency of 71.70%, an inhibition zone of 21.76 mm, and a serum creatinine level of 0.119 mmol/L. The optimized loaded in situ gel released 82.5% VRC after 12 hours and resulted in a 5.4-fold increase in drug permeation. The in vivo results obtained using rabbits resulted in a nonsignificant differentiation among the renal function parameters compared with the negative control group. In conclusion, nasal in situ gel loaded with VRC-CO-NT is considered an efficient novel carrier with enhanced antifungal properties with no signs of nephrotoxicity.

Effect of the essential oils of Satureja montana L., Myristica fragrans H. and Cymbopogon flexuosus S. on mycotoxin-producing Aspergillus flavus and Aspergillus ochraceus antifungal properties of essential oils.

Essential oils can be a useful alternative to the use of synthetic fungicides because they have biological potential and are relatively safe for food and agricultural products. The objectives of the present study were to evaluate the antifungal and antimycotoxigenic activities of the essential oils from Satureja montana L., Myristica fragrans H. and Cymbopogon flexuosus S. against Aspergillus flavus and Aspergillus ochraceus, as well as their effects on ergosterol synthesis and membrane morphology. The antifungal potential was evaluated by mycelial growth analysis and scanning electron microscopy. Fungicidal effects against A. flavus, with MFC of 0.98, 15.62 and 0.98 µL/mL, respectively, were observed for the essential oils from S. montana, M. fragrans and C. flexuosus. Aspergillus ochraceus did not grow in the presence of concentrations of 3.91, 15.62 and 0.98 µL/mL of the essential oils from S. montana, M. fragrans and C. flexuosus, respectively. The essential oils significantly inhibited the production of ochratoxin A by the fungus A. ochraceus. The essential oils also inhibited the production of aflatoxin B1 and aflatoxin B2. The biosynthesis of ergosterol was inhibited by the applied treatments. Biological activity in the fungal cell membrane was observed in the presence of essential oils, given that deleterious effects on the morphologies of the fungi were detected. The essential oils under study are promising as food preservatives because they significantly inhibit toxigenic fungi that contaminate food. In addition, the essential oils hindered the biosynthesis of mycotoxins.

Aspergillus flavus Infections in Children With Leukemia Despite Liposomal Amphotericin-B Prophylaxis.

Liposomal amphotericin-B (L-AmB) prophylaxis is used in children with leukemia when azoles are contraindicated, but its effect is debated. We reviewed cases of invasive aspergillosis despite L-AmB 2.5 mg/kg twice weekly in children with high-risk leukemia during 2012-2019. Ten (16%) of 62 children had proven or probable aspergillosis. Thus, L-AmB prophylaxis offered insufficient protection for Aspergillus, in particular for Aspergillus flavus.

Mimosa tenuiflora Aqueous Extract: Role of Condensed Tannins in Anti-Aflatoxin B1 Activity in Aspergillus flavus.

Aflatoxin B1 (AFB1) is a potent carcinogenic mycotoxin that contaminates numerous crops pre- and post-harvest. To protect foods and feeds from such toxins without resorting to pesticides, the use of plant extracts has been increasingly studied. The most interesting candidate plants are those with strong antioxidative activity because oxidation reactions may interfere with AFB1 production. The present study investigates how an aqueous extract of Mimosa tenuiflora bark affects both the growth of Aspergillus flavus and AFB1 production. The results reveal a dose-dependent inhibition of toxin synthesis with no impact on fungal growth. AFB1 inhibition is related to a down-modulation of the cluster genes of the biosynthetic pathway and especially to the two internal regulators aflR and aflS. Its strong anti-oxidative activity also allows the aqueous extract to modulate the expression of genes involved in fungal oxidative-stress response, such as msnA, mtfA, atfA, or sod1. Finally, a bio-guided fractionation of the aqueous extract demonstrates that condensed tannins play a major role in the anti-aflatoxin activity of Mimosa tenuiflora bark.

Inhibition of Aspergillus flavus growth and aflatoxins production on peanuts over α-Fe2O3 nanorods under sunlight irradiation.

Peanut is an important resource of edible oil and digestible protein in daily life, which is rich in the nutriments and antioxidants such as vitamins, minerals and polyphenols. However, peanut is susceptible to the contamination of Aspergillus flavus (A. flavus), which can produce highly carcinogenic toxins that brings serious threats to human health and food safety. Exploring green and effective methods to control A. flavus is meaningful. Herein, a green and economical way to control A. flavus on peanuts was demonstrated. It was found that the growth of A. flavus hyphae and germination of its spores could be inhibited in the presence of α-Fe2O3 nanorods under sunlight irradiation according to the agar diffusion method, flat colony counting method and fluorescence-based live/dead test. The diameter of inhibition zone was 22.3 ± 0.2 mm and the inhibition rate of spores germination was about 60 ± 5%, when the concentration of α-Fe2O3 was 10 mg/mL for 7 h sunlight irradiation. Most important, α-Fe2O3 showed the photocatalytic inhibition of A. flavus on peanuts under sunlight irradiation with the inhibition rate of about 90 ± 5%, and the production of aflatoxin B1 and aflatoxin B2 were reduced by 90 ± 2% and 70 ± 3%, respectively. By comparing the fat contents, protein contents, acid value, peroxide value and antioxidative compositions of peanuts, it was found that there was no obvious effect on the quality of peanuts after inhibition treatment. The findings provide a green, safe and economical strategy to control A. flavus on peanuts, which may be as a promising way to be used in food and agro-food preservation.