Limonin Enhances the Antifungal Activity of Eugenol Nanoemulsion against Penicillium Italicum In Vitro and In Vivo Tests

Nobiletin enhances the antifungal activity of eugenol nanoemulsion against Penicillium italicum in both in vitro and in vivo settings

The study prepared and used eugenol nanoemulsion loaded with nobiletin as fungistat to study its antifungal activity and potential mechanism of Penicillium italicum (P. italicum). The results showed that the minimum inhibitory concentration (MIC) of eugenol nanoemulsion loaded with nobiletin (EGN) was lower than that of pure eugenol nanoemulsion (EG), which were 160 μg/mL and 320 μg/mL, respectively. At the same time, the mycelial growth inhibition rate of EGN nanoemulsion (54.68 %) was also higher than that of EG nanoemulsion (9.92 %). This indicates that EGN nanoemulsion is more effective than EG nanoemulsion. Compared with EG nanoemulsion, the treatment of EGN nanoemulsion caused more serious damage to the cell structure of P. italicum. At the same time, in vitro inoculation experiments found that EGN nanoemulsion has better control and delay the growth and reproduction of P. italicum in citrus fruits. And the results reflected that EGN nanoemulsion may be considered as potential resouces of natural antiseptic to inhibit blue mold disease of citrus fruits, because it has good antifungal activity.

Eugenol and Aloe vera blended natural wax-based coating for preserving postharvest quality of Kaji lemon (Citrus jambhiri)

Edible coatings on fruits and vegetables preserve postharvest quality by reducing water loss and lowering respiration, and metabolic activities. The primary objectives of this study were to develop composite coating formulations using natural waxes (carnauba and shellac wax), eugenol nanoemulsion, and Aloe vera gel, and assess the potential impacts of the coating formulations on the postharvest quality and shelf-life of the Kaji lemon. The results show that eugenol nanoemulsion and Aloe vera gel enhanced the physico-chemical, antimicrobial and antioxidant properties of the developed coating. Notably, the fruits coated with optimized nanocomposite of wax with eugenol and aloe vera gel inclusion (SW + CW/EuNE-20/AVG-2) showed the lowest weight loss (16.56%), while the coatings of wax with only aloe vera gel (SW + CW/AVG-2) exhibited the highest firmness (48 N), in contrast to the control fruit, which had 27.33% weight loss and 9.6 N firmness after 28 days of storage, respectively.

Validating the protective role of orange and tangerine peel extracts foramending food safety against microorganisms' contamination using molecular docking

Latest studies indicated that agro-food wastes are considered renewable sources of bioactive compounds. This investigation aimed to utilize natural extracts of citrus peels as antimicrobial and anti-aflatoxigenic agents for food safety. The bioactivity of two citrus peels was assessed by total phenolic, flavonoids, and antioxidant activity. Nanoemulsions were manufactured using high-speed homogenization. The mean particle size of the nanoemulsions ranged from 29.41 to 66.41 nm with a polydispersity index of 0.11-0.16. The zeta potential values ranged from -14.27 to -26.74 mV, indicating stability between 81.44% and 99.26%. The orange peel extract showed the highest contents of total phenolic and flavonoids compared to the other extracts and nanoemulsions (39.54 mg GAE/g and 79.54 mg CE/100 g, respectively), which agreed with its potential antioxidant activity performed by DPPH free radical-scavenging and ABTS assays. Chlorogenic, caffeic, ferulic, and catechin were the dominant phenolic acids in the extracts and nanoemulsions, while quercitrin, rutin, and hesperidin were the most abundant flavonoids. Limonene was the major volatile component in both oils; however, it was reduced dramatically from 92.52% to 76.62% in orange peel oil and from 91.79 to 79.12% in tangerine peel oil. Consistent with the differences in phenolics, flavonoids, and volatiles between orange and tangerine peel extracts, the antibacterial properties of orange extracts had more potential than tangerine ones. Gram-positive bacteria were more affected by all the examined extracts than Gram-negative ones. The antifungal activity of orange extract and nanoemulsion on seven fungal strains from Aspergillus spp had more potential than tangerine extracts. Additionally, using a simulated media, the orange peel extract and its nanoemulsion had a more anti-aflatoxigenic influence. Molecular docking confirmed the high inhibitory action of flavonoids, especially hesperidin, on the polyketide synthase (-9.3 kcal/mol) and cytochrome P450 monooxygenase (-10.1 kcal/mol) key enzymes of the aflatoxin biosynthetic mechanism.

Comparative physiological and transcriptome analysis provide insights into the inhibitory effect of osthole on Penicillium choerospondiatis

Blue mold induced by Penicillium choerospondiatis is a primary cause of growth and postharvest losses in the fruit of Phyllanthus emblica. There is an urgent need to explore novel and safe fungicides to control this disease. Here, we demonstrated osthole, a natural coumarin compound isolated from Cnidium monnieri, exhibited a strong inhibitory effect on mycelia growth, conidial germination rate and germ tube length of P. choerospondiatis, and effectively suppressed the blue mold development in postharvest fruit of P. emblica. The median effective concentration of osthole was 9.86 mg/L. Osthole treatment resulted in cellular structural disruption, reactive oxygen species (ROS) accumulation, and induced autophagic vacuoles containing cytoplasmic components in fungal cells. Transcriptome analysis revealed that osthole treatment led to the differentially expressed genes mainly enriched in the cell wall synthesis, TCA cycle, glycolysis/ gluconeogenesis, oxidative phosphorylation. Moreover, osthole treatment led to increase genes expression involved in peroxisome, autophagy and endocytosis. Particularly, the autophagy pathway related genes (PcATG1, PcATG3, PcATG15, PcATG27, PcYPT7 and PcSEC18) were prominently up-regulated by osthole. Summarily, these results revealed the potential antifungal mechanism of osthole against P. choerospondiatis. Osthole has potentials to develop as a natural antifungal agent for controlling blue mold disease in postharvest fruits.

Preparation and Characterization of Eugenol Incorporated Pullulan-Gelatin Based Edible Film of Pickering Emulsion and Its Application in Chilled Beef Preservation

The purpose of this study was to develop a composite film composed of eugenol Pickering emulsion and pullulan-gelatin, and to evaluate its preservation effect on chilled beef. The prepared composite film was comprehensively evaluated in terms of the stability of emulsion, the physical properties of the film, and an analysis of freshness preservation for chilled beef. The emulsion size (296.0 ± 10.2 nm), polydispersity index (0.457 ± 0.039), and potential (20.1 ± 0.9 mV) proved the success of emulsion. At the same time, the films displayed good mechanical and barrier properties. The index of beef preservation also indicated that eugenol was a better active ingredient than clove essence oil, which led to the rise of potential of hydrogen, chroma and water content, and effectively inhibited microbial propagation, protein degradation and lipid oxidation. These results suggest that the prepared composites can be used as promising materials for chilled beef preservation.

Environmental sustainable: Biogenic copper oxide nanoparticles as nano-pesticides for investigating bioactivities against phytopathogens

Endocrine-disrupting chemicals (EDCs) are of interest in human physiopathology and have been extensively studied for their effects on the endocrine system. Research also focuses on the environmental impact of EDCs, including pesticides and engineered nanoparticles, and their toxicity to organisms. Green nanofabrication has surfaced as an environmentally conscious and sustainable approach to manufacture antimicrobial agents that can effectively manage phytopathogens. In this study, we examined the current understanding of the pathogenic activities of Azadirachta indica aqueous formulated green synthesized copper oxide nanoparticles (CuONPs) against phytopathogens. The CuONPs were analyzed and studied using a range of analytical and microscopic techniques, such as UV-visible spectrophotometer, Transmission electron microscope (TEM), Scanning electron microscope (SEM), X-ray diffraction (XRD) and Fourier transformed infrared spectroscopy (FTIR). The XRD spectral results revealed that the particles had a high crystal size, with an average size ranging from 40 to 100 nm. TEM and SEM images were utilized to verify the size and shape of the CuONPs, revealing that they varied between 20 and 80 nm. The existence of potential functional molecules involved in the reduction of the nanoparticles was confirmed by FTIR spectra and UV analysis. Biogenically synthesized CuONPs revealed significantly enhanced antimicrobial activities at 100 mg/L concentration in vitro by the biological method. The synthesized CuONPs at 500 μg/ml had a strong antioxidant activity which was examined through the free radicle scavenging method. Overall results of the green synthesized CuONPs have demonstrated significant synergetic effects in biological activities which can play a crucial impact in plant pathology against numerous phytopathogens.

Removal of Erythrosine B dye from wastewater by Penicillium italicum: experimental, DFT, and molecular docking studies

The study involved the adsorption of Erythrosine B onto the dead, dry, and unmodified Penicillium italicum cells and the analytical, visual, theoretical assessment of the adsorbent-adsorbate interactions. It also included desorption studies and reiterative usability of the adsorbent. The fungus was a local isolate and it was identified by partial proteomic experiment in a MALDI-TOFF mass spectrometer. Chemical features of the adsorbent surface were analysed by FT-IR and EDX. Surface topology was visualized by SEM. Isotherm parameters of the adsorption were determined by using three most frequently used models. Erythrosine B appeared to form a monolayer onto the biosorbent and some of the dye molecules could have also penetrated into the adsorbent particles. Kinetic results suggested a spontaneous and exothermic reaction taken place between the dye molecules and the biomaterial. Theoretical approach involved the determination of some of the quantum parameters as well as the toxic or drug potentials of the some of the components of the biomaterial.

Polymethoxylated flavonoids (PMFs)-loaded citral nanoemulsion controls green mold in citrus by damaging the cell membrane of Penicillium digitatum

Citrus is susceptible to Penicillium digitatum (P. digitatum) infection in post-harvest storage, resulting in enormous economic losses. This study aimed to investigate the antifungal activity and potential mechanism of the combination of Polymethoxylated flavones (PMFs) and citral (two natural antifungal components derived from citrus) against P. digitatum in vitro and citrus fruit. The results show that PMFs can enhance the antifungal activity of citral nanoemulsion, and PMFs-loaded citral nanoemulsion (PCT) has significant antifungal activity in a concentration-dependent manner. PCT can evidently inhibit spore germination and mycelial growth in vitro, and effectively control the growth of green mold on postharvest citrus fruit. Furthermore, PCT treatment resulted in the alteration of mycelia morphology, accumulation of reactive oxygen species, and membrane lipid peroxidation. These changes can disrupt the normal structure and function of the cell membrane, as evidenced by the reduction of total lipid and ergosterol content in the mycelia and the stronger red fluorescence of the cells emitted after PI staining. Based on the above results, we infer that PCT has a strong inhibitory effect on P. digitatum, and its potential mechanism is related to the destruction of the cell membrane. Therefore, PCT can be considered as a botanical fungicide for citrus preservation.

Antifungal Activity of Polymethoxylated Flavonoids (PMFs)-Loaded Citral Nanoemulsion against Penicillium italicum by Causing Cell Membrane Damage

A major citrus postharvest pathogen, Penicillium italicum (P. italicum), causes substantial economic losses in citrus. In this study, a citral nanoemulsion containing polymethoxylated flavonoids (PMFs), the antimicrobial compounds from citrus, was prepared. The antifungal activity and potential antifungal mechanisms of the nanoemulsion against P. italicum were evaluated. The results showed that the growth of P. italicum was effectively inhibited by the nanoemulsion, with a minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of 62.5 and 250 mg L−1, respectively. The nanoemulsion significantly inhibited spore germination and mycelial growth, and it altered the morphology of P. italicum. In addition, the permeability of the cell membrane increased with increasing nanoemulsion concentrations, as evidenced by a rapid rise in extracellular electric conductivity and stronger red fluorescence from mycelia (propidium iodide staining). Compared with the control, the nanoemulsion treatment induced a decrease in total lipid and ergosterol contents in P. italicum cells by 64.61% and 60.58%, respectively, demonstrating that membrane integrity had been disrupted. The results indicated that the PMFs-loaded nanoemulsion exerted antifungal activity against P. italicum by disrupting cell membrane integrity and permeability; such a nanoemulsion may be used as a potential fungicide substitute for preservation in citrus fruits.

Limonin ameliorates acute pancreatitis by suppressing JAK2/STAT3 signaling pathway

Acute pancreatitis (AP) is one of the most common acute abdomen of digestive system and has the characteristics of dangerous condition and rapid development. Limonin has been confirmed to hold anti-inflammatory and antioxidant effects in various diseases. However, its potential beneficial effect on AP and the concrete mechanisms have never been revealed. Here, two mouse models were used to investigate the protective effects of limonin on AP, the caerulein-induced mild acute pancreatitis (MAP) model and L-arginine-induced severe AP (SAP) model. Firstly, it was found that limonin administration attenuated lipase and serum amylase levels and ameliorated the histopathological manifestations of pancreatic tissue in a dose-dependent manner. Additionally, the amelioration of AP by limonin was associated with reduced levels of inflammation initiators (IL-6, IL-1β, CCL2, and TNF-α). Mechanistically, we found that limonin suppressed the Janus Activating Kinase 2 (JAK2)/Signal Transducer and Activator of Transcription 3 (STAT3) signaling pathway, as evident by the decreased levels of JAK2 and p-STAT3. And activation of JAK2 using JAK2 activator rescued the protective effects of limonin on AP. Thus, our results demonstrate that limonin can ameliorate AP in two mice models via suppressing JAK2/STAT3 signaling pathway.

Nanoencapsulation-Based Edible Coating of Essential Oils as a Novel Green Strategy Against Fungal Spoilage, Mycotoxin Contamination, and Quality Deterioration of Stored Fruits: An Overview

Currently, applications of essential oils for protection of postharvest fruits against fungal infestation and mycotoxin contamination are of immense interest and research hot spot in view of their natural origin and possibly being an alternative to hazardous synthetic preservatives. However, the practical applications of essential oils in broad-scale industrial sectors have some limitations due to their volatility, less solubility, hydrophobic nature, and easy oxidation in environmental conditions. Implementation of nanotechnology for efficient incorporation of essential oils into polymeric matrices is an emerging and novel strategy to extend its applicability by controlled release and to overcome its major limitations. Moreover, different nano-engineered structures (nanoemulsion, suspension, colloidal dispersion, and nanoparticles) developed by applying a variety of nanoencapsulation processes improved essential oil efficacy along with targeted delivery, maintaining the characteristics of food ingredients. Nanoemulsion-based edible coating of essential oils in fruits poses an innovative green alternative against fungal infestation and mycotoxin contamination. Encapsulation-based coating of essential oils also improves antifungal, antimycotoxigenic, and antioxidant properties, a prerequisite for long-term enhancement of fruit shelf life. Furthermore, emulsion-based coating of essential oil is also efficient in the protection of physicochemical characteristics, viz., firmness, titrable acidity, pH, weight loss, respiration rate, and total phenolic contents, along with maintenance of organoleptic attributes and nutritional qualities of stored fruits. Based on this scenario, the present article deals with the advancement in nanoencapsulation-based edible coating of essential oil with efficient utilization as a novel safe green preservative and develops a green insight into sustainable protection of fruits against fungal- and mycotoxin-mediated quality deterioration.

Preparation of Antarctic Krill Oil Emulsion and Its Stability under Catalase Treatment

Making Antarctic krill oil into emulsion is a good way to utilize Antarctic krill, but proliferation of microorganisms cannot be ignored. H₂O₂ is widely used in the sterilization of liquid food since its decomposition products are environmentally friendly, although residual H₂O₂ should be removed for food safety. Adding catalase (CAT) is an effective means to do this. However, the enzyme activity center of CAT is the iron porphyrin group, which has the risk of accelerating lipid oxidation in the oil emulsion. Therefore, we hypothesized that CAT might not be suitable for the removal of H₂O₂ in Antarctic krill oil emulsion. In this paper, Antarctic krill oil emulsion was prepared, and then the effect of CAT on the emulsion was studied through visual observation, microscopic morphology observation, turbidity and stability, particle size, and ζ-potential; finally, the mechanism of CAT destroying the emulsion was explored from the perspective of lipid oxidation. The results showed that a stable Antarctic krill emulsion was prepared using Tween-80 as the emulsifier, with the oil concentration of 1% (v/v) and the ratio of surfactant to oil phase of 1:5 (v/v). The emulsion treated with CAT had undergone demulsification, stratification, and coagulation after 2 days of incubation, while the emulsion treated with superoxide dismutase (SOD) and bovine serum albumin (BSA) changed little. In addition, the thiobarbituric acid reactive substances (TBARS) value and the content of hydroxyl radicals in the CAT group increased significantly. The preliminary research results indicated that the effect of CAT on the emulsion related to the lipid oxidation caused by the iron porphyrin group at the center of the enzyme activity. All these results indicated that CAT was not suitable for the removal of residual H₂O₂ in Antarctic krill oil emulsion. Moreover, it is helpful to avoid the contact of Antarctic krill oil emulsion and CAT during the processing of the krill.