Allergenic components, biocides, and analysis techniques of some essential oils used in food products

Enhancing Therapeutic Efficacy of Cinnamon Essential Oil by Nanoemulsification for Intravaginal Treatment of Candida Vaginitis

Background

Due to its prevalence, recurrence, and the emergence of drug-resistance, Candida vaginitis significantly impacts the well-being of women. Although cinnamon essential oil (CEO) possesses antifungal activity, its hydrophobic properties limit its clinical application.

Purpose

To overcome this challenge, a nanoemulsification technology was employed to prepare cinnamon essential oil-nanoemulsion (CEO@NE), and its therapeutic efficacy and action mechanism for Candida vaginitis was investigated in vivo and in vitro.

Materials and Methods

CEO@NE, composed of 4% CEO, 78% distilled water, and 18% Tween 80, was prepared by ultrasonic nanoemulsification. The physical properties, anti-Candida activity, cytotoxicity, immunomodulatory potential and storage stability of CEO@NE were explored. Subsequently, the effect of intravaginal CEO@NE treatment on Candida vaginitis was investigated in mice. To comprehend the possible mechanism of CEO@NE, an analysis was conducted to ascertain the production of intracellular reactive oxygen species (ROS) in C. albicans.

Results

CEO@NE, with the droplet size less than 100 nm and robust storage stability for up to 8 weeks, exhibited comparable anti-Candida activity with CEO. CEO@NE at the concentration lower than 400 μg/mL had no cytotoxic and immunomodulatory effects on murine splenocytes. Intravaginal treatment of CEO@NE (400 μg/mL, 20 μL/day/mouse for 5 consecutive days) curbed Candida colonization, ameliorated histopathological changes, and suppressed inflammatory cytokine production in mice intravaginally challenged with C. albicans. Notably, this treatment preserved the density of vaginal lactic acid bacteria (LAB) crucial for vaginal health. Co-culturing C. albicans with CEO@NE revealed concentration-dependent augmentation of intracellular ROS generation and ensuing cell death. In addition, co-culturing LPS-stimulated murine splenocytes with CEO@NE yielded a decrease in the generation of cytokines.

Conclusion

This discovery provides insight into the conceivable antifungal and anti-inflammatory mechanisms of CEO@NE to tackle Candida vaginitis. CEO@NE offers a promising avenue to address the limitations of current treatments, providing novel strategy for treating Candida vaginitis.

Egyptian mandarin peel oil's anti-scabies potential via downregulation-of-inflammatory/immune-cross-talk: GC-MS and PPI network studies

The current study investigated the scabicidal potential of Egyptian mandarin peel oil (Citrus reticulata Blanco, F. Rutaceae) against sarcoptic mange-in-rabbits. Analysis of the oil's GC-MS identified a total of 20 compounds, accounting for 98.91% of all compounds found. Mandarin peel oil topical application improved all signs of infection, causing a scabicidal effect three days later, whereas in vitro application caused complete mite mortality one day later. In comparison to ivermectin, histopathological analysis showed that the epidermis' inflammatory-infiltration/hyperkeratosis-had disappeared. In addition to TIMP-1, the results of the mRNA gene expression analysis showed upregulation of I-CAM-1-and-KGF and downregulation of ILs-1, 6, 10, VEGF, MMP-9, and MCP-1. The scabies network was constructed and subjected to a comprehensive bioinformatic evaluation. TNF-, IL-1B, and IL-6, the top three hub protein-coding genes, have been identified as key therapeutic targets for scabies. From molecular docking data, compounds 15 and 16 acquired sufficient affinity towards the three screened proteins, particularly both possessing higher affinity towards the IL-6 receptor. Interestingly, it achieved a higher binding energy score than the ligand of the docked protein rather than displaying proper binding interactions like those of the ligand. Meanwhile, geraniol (15) showed the highest affinity towards the GST protein, suggesting its contribution to the acaricidal effect of the extract. The subsequent, MD simulations revealed that geraniol can achieve stable binding inside the binding site of both GST and IL-6. Our findings collectively revealed the scabicidal ability of mandarin peel extract for the first time, paving the way for an efficient, economical, and environmentally friendly herbal alternative for treating rabbits with Sarcoptes mange.

Chemical Variability of the Essential Oils from Two Portuguese Apiaceae: Coriandrum sativum L. and Foeniculum vulgare Mill

Coriandrum sativum L. and Foeniculum vulgare Mill. are two aromatic and medicinal Apiaceae species commonly grown in Portugal, whose essential oils (EOs) are used in the food, pharmaceutical, and cosmetics industries. The present study evaluated EOs isolated from the fruits and vegetative aerial parts (VAPs) of 11 samples of Coriandrum sativum L. and from the fruits of 19 samples of Foeniculum vulgare Mill. The plant material was grown in experimental fields, after collection from several regions of mainland Portugal. The EOs were isolated by hydrodistillation and analyzed by gas chromatography and gas chromatography-mass spectrometry. The coriander EOs analysis evidenced two main clusters, with the first containing the fruits' EOs dominated by linalool (60-73%), γ-terpinene, and α-pinene and the second with the VAPs' EOs, which showed 2-trans-decenal (37-63%) and n-decanal (13-30%) as the main compounds. The fennel EOs analysis revealed two well correlated clusters, the first dominated by estragole (34-76%) and fenchone (16-30%) and the other dominated by trans-anethole (37-56%) and fenchone (14-34%). The present data suggest coriander EOs' chemical descriptors as linalool for the fruits' EOs and 2-trans-decenal with n-decanal for the VAPs' EOs. For the fennel fruit EOs, the putative descriptors were trans-anethole and estragole, with variable fenchone content. The gathered data reinforce the relevance of clarifying variability of these species' EOs, particularly when considering aromatic and medicinal plants with such a wide range of applications.

Food matrix design can influence the antimicrobial activity in the food systems: A narrative review

Antimicrobial agents are safe preservatives having the ability to protect foods from microbial spoilage and extend their shelf life. Many factors, including antimicrobials' chemical features, storage environments, delivery methods, and diffusion in foods, can affect their antimicrobial activities. The physical-chemical characteristics of the food itself play an important role in determining the efficacy of antimicrobial agents in foods; however the mechanisms behind it have not been fully explored. This review provides new insights and comprehensive knowledge regarding the impacts of the food matrix, including the food components and food (micro)structures, on the activities of antimicrobial agents. Studies of the last 10 years regarding the influences of the food structure on the effects of antimicrobial agents against the microorganisms' growth were summarized. The mechanisms underpinning the loss of the antimicrobial agents' activity in foods are proposed. Finally, some strategies/technologies to improve the protection of antimicrobial agents in specific food categories are discussed.

Bio-fabrication of zinc oxide nanoparticles from Picea smithiana and their potential antimicrobial activities against Xanthomonas campestris pv. Vesicatoria and Ralstonia solanacearum causing bacterial leaf spot and bacterial wilt in tomato

Due to an inevitable disadvantage of chemical or physical synthesis routes, biosynthesis approach to nanoparticles, especially metallic oxide is attractive nowadays. Metallic oxides nanoparticles present a new approach to the control of plant pathogens. ZnO nanoparticles (ZNPs) have very important role in phytopathology. In current study, biosynthesized ZNPs were tested against two devastating bacterial pathogens including Xanthomonas campestris pv. vesicatoria and Ralstonia solanacearum causing bacterial leaf spot and bacterial wilt in tomato. ZNPs were produced using a new extract from the plant Picea smithiana using an environmentally friendly, cost-effective and simple procedure. Zinc acetate was added to P. smithiana extract, stirred and heated to 200 °C. The white precipitation at the bottom were clear indication of synthesis of nanoparticles, which were further dried by subjecting them at 450 °C. X-ray diffraction pattern determined that the ZNPs had a crystallite size of about 26 nm, Fourier transform infrared spectroscopy indicated a peak between 450 and 550 cm^-1 and the particle size estimated by dynamic light scattering was about 25 nm on average. Scanning electron microscopic analysis indicated that the particles were hexagonal in shape 31 nm in diameter. Antibacterial tests showed ZNPs synthesized by P. smithiana resulted in clear inhibition zones of 20.1 ± 1.5 and 18.9 ± 1.5 mm and 44.74 and 45.63% reduction in disease severity and 78.40 and 80.91% reduction in disease incidence in X. compestris pv. vesicatoria and R. solanacearum respectively at concentration of 100 µg/ml. Our findings reveal that the concentration of ZNPs was important for their efficient antibacterial activity. Overall, the biosynthesized ZNPs have been found to have effective antimicrobial activities against bacterial wilt and bacterial leaf spot in tomato.

Savory, Oregano and Thyme Essential Oil Mixture (HerbELICO®) Counteracts Helicobacter pylori

Fifty percent of the world's population is infected with Helicobacter pylori, which can trigger many gastrointestinal disorders. H. pylori eradication therapy consists of two to three antimicrobial medicinal products, but they exhibit limited efficacy and may cause adverse side effects. Alternative therapies are urgent. It was assumed that an essential oil mixture, obtained from species from genera Satureja L., Origanum L. and Thymus L. and called the HerbELICO^® essential oil mixture, could be useful in H. pylori infection treatment. HerbELICO^® was analyzed by GC-MS and assessed in vitro against twenty H. pylori clinical strains isolated from patients of different geographical origins and with different antimicrobial medicinal products resistance profiles, and for its ability to penetrate the artificial mucin barrier. A customer case study included 15 users of HerbELICO^®liquid/HerbELICO^®solid dietary supplements (capsulated HerbELICO^® mixture in liquid/solid form). Carvacrol and thymol were the most dominant compounds (47.44% and 11.62%, respectively), together with p-cymene (13.35%) and γ-terpinene (18.20%). The minimum concentration required to inhibit in vitro H. pylori growth by HerbELICO^® was 4-5% (v/v); 10 min exposure to HerbELICO^® was enough to kill off the examined H. pylori strains, while HerbELICO^® was able to penetrate through mucin. A high eradication rate (up to 90%) and acceptance by consumers was observed.

Behavioral avoidance and biological safety of vetiver oil and its constituents against Aedes aegypti (L.), Aedes albopictus (Skuse) and Culex quinquefasciatus Say

Numerous plant-based repellents are widely used for personal protection against host-seeking mosquitoes. Vitiveria zizanioides (L.) Nash essential oil and its constituents have demonstrated various mosquito repellent activities. In this study, three chemical actions of vetiver oil and five constituents (terpinen-4-ol, α-terpineol, valencene, vetiverol and vetivone) were characterized against Aedes aegypti, Aedes albopictus and Culex quinquefasciatus by using the high-throughput screening assay system (HITSS). Significant contact escape responses in Ae. aegypti and Ae. albopictus to all test compounds at concentrations between 2.5 and 5% were observed. Spatial repellency responses were also observed in some tested mosquito populations depending upon concentrations. The most significant toxic response on mosquitoes was found at the highest concentration, except for vetivone which had no toxic effect on Ae. aegypti and Ae. albopictus. Results on phototoxic and genotoxic hazard revealed that vetiver oil and their constituents showed no phototoxic potential or any significant genotoxic response. In conclusion, vetiver oil and two constituents, valencene and vetiverol, are potentials as active ingredients for mosquito repellency and present no toxicity.

Essential Oil-Based Bioherbicides: Human Health Risks Analysis

In recent years, the development of new bio-based products for biocontrol has been gaining importance as it contributes to reducing the use of synthetic herbicides in agriculture. Conventional herbicides (i.e., the ones with synthetic molecules) can lead to adverse effects such as human diseases (cancers, neurodegenerative diseases, reproductive perturbations, etc.) but also to disturbing the environment because of their drift in the air, transport throughout aquatic systems and persistence across different environments. The use of natural molecules seems to be a very good alternative for maintaining productive agriculture but without the negative side effects of synthetic herbicides. In this context, essential oils and their components are increasingly studied in order to produce several categories of biopesticides thanks to their well-known biocidal activities. However, these molecules can also be potentially hazardous to humans and the environment. This article reviews the state of the literature and regulations with regard to the potential risks related to the use of essential oils as bioherbicides in agricultural and horticultural applications.