Essential oils: their antibacterial properties and potential applications in foods--a review

Advanced analytical techniques for authenticity identification and quality evaluation in Essential oils: A review

Essential oils (EO), secondary metabolites of plants are fragrant oily liquids with antibacterial, antiviral, anti-inflammatory, anti-allergic, and antioxidant effects. They are widely applied in food, medicine, cosmetics, and other fields. However, the quality of EOs remain uncertain owing to their high volatility and susceptibility to oxidation, influenced by factors such as the harvesting season, extraction, and separation techniques. Additionally, the huge economic value of EOs has led to a market marked by widespread and varied adulteration, making the assessment of their quality challenging. Therefore, developing simple, quick, and effective identification techniques for EOs is essential. This review comprehensively summarizes the techniques for assessing EO quality and identifying adulteration. It covers sensory evaluation, physical and chemical property evaluation, and chemical composition analysis, which are widely used and of great significance for the quality evaluation and adulteration detection of EOs.

Optimization of organogels prepared with turpentine oil and wax mixtures via response surface methodology and determination of vaporization kinetic parameters

BACKGROUND

The main aim of the study is to investigate the thermal, textural and vaporization behaviors of turpentine oil (representing essential oils) organogels prepared with wax mixtures (beeswax, BW; shellac wax, SHW) instead of a single wax. The second aim was to determine the optimum level of wax addition to minimize vaporization of volatiles using response surface methodology.

RESULTS

Both weighing and thermogravimetric analyses showed that when the total wax concentration increased, the vaporization was decelerated. The variation of the hardness and melting point values depended on both wax types and amounts in the mixtures. Additionally, the kinetics of the vaporization of the volatile compounds at 37 °C were evaluated, and both first- and second-order reaction kinetic models fitted well for the vaporization with R2 values of 0.96-0.99. The organogelation increased the thermal stability and limited the release of volatiles. The multiple response optimization results showed that the melting point, the reaction rate constant and the weight loss of the organogels produced with 24.43% BW and 17.68% SHW were 44.40 °C, 4.00 × 10-3 day-1 and 30.02%, respectively.

CONCLUSION

As a result, essential oil organogels produced with a wax mixture instead of a single wax can provide controlled release of volatiles as well as tailored texture and melting range. © 2024 Society of Chemical Industry.

Microencapsulation of multi-component traditional Chinese herbs extracts and its application to traditional Chinese medicines loaded textiles

Extracts of traditional Chinese herbs (TCH) contain a variety of anti-allergic, anti-inflammatory and other bioactive factors. However, the defect of easy degradation or loss of active ingredients limits its application in traditional Chinese medicines (TCM) loaded textiles. In this work, TCH extracts containing different active ingredients were innovatively proposed as the core material of microcapsules. The feasibility of microencapsulation of multi-component TCH extracts in the essential oil state was initially demonstrated. Polyacrylate was also used as a binder to load the microcapsules onto the fabric to improve the durability and wash resistance of the treated fabric. Modeling the oil release of microcapsules for controlled release under different conditions may provide new possible uses for the materials. Results show that the constructed microcapsule has a smooth surface without depression and can be continuously released for over 30 days. The release behavior of microcapsules follows different release mechanisms and can be modulated by temperature and water molecules. The incorporation of microcapsules and polyacrylate does not significantly change the fabric's air permeability, water vapor transmission and hydrophilicity. The washing durability and friction properties of the microcapsule-based fabric are greatly improved, and it can withstand 30 washing tests and 200 friction tests. Moreover, the results of methyl thiazolyl tetrazolium (MTT) release assay using human dermal papilla cells (HDP) as an in vitro template confirm that the microcapsule has no toxic effects on human cells. Therefore, the successful microencapsulation of multi-component TCH extracts indicates their potential application in the field of TCM-loaded textiles.

Food safety control in poultry industry: prevalence and antimicrobial susceptibility of Escherichia coli isolated from raw chicken and the potential use of Origanum essential oils as alternative to antibiotics

1. The extensive use of antimicrobials in poultry production may contribute to the emergence of resistant bacteria. This study was conducted to determine the prevalence and resistance of different E. coli strains isolated from raw chicken meat and to investigate the possibility to use Lebanese native oregano essential oils as alternatives.2. In total, 250 chickens from Lebanese markets were examined for the presence of E. coli. Isolates were then screened for susceptibility using 19 antibiotics and two essential oils extracted from oregano plants.3. Of the 250 chickens tested, 80% were contaminated with E. coli. Main resistance was seen against amoxycillin, ampicillin, penicillin, tetracycline, tylosin, streptomycin and erythromycin. The highest rate of sensitivity was found in 86.1% of strains to Amoxycillin/Clavulanic acid, 80.09% to Tilmicosin. Both essential oils from Origanum syriacum (98%) and O. ehrenbergii (97.3%) showed promising potential in inhibiting the growth of the tested bacteria. Oil from O. syriacum exhibited superior efficacy against 200 E. coli strains, inhibiting 46.1% at 200 mg/l and all at 400 mg/l, while O. ehrenbergii oil showed slightly lower inhibition, affecting 41.6% at 200 mg/l and all at 400 mg/l.

Chemical composition, cytotoxicity, antimicrobial, antibiofilm, and anti-quorum sensing potential of Mentha Piperita essential oil against the oral pathogen Streptococcus mutans

Dental caries is a highly prevalent oral disease affecting billions of individuals globally. The disease occurs chemically as a result of breakdown of the tooth surface attributed to metabolic activity in colonizing biofilm. Biofilms, composed of exopolysaccharides and proteins, protect bacteria like Streptococcus mutans, which is notable for its role in tooth decay due to its acid-producing abilities. While various antimicrobial agents may prevent biofilm formation, these drugs often produce side effects including enamel erosion and taste disturbances. This study aimed to examine utilization of the Mentha piperita essential oil as a potential antibiofilm activity agent against S. mutans. M. piperita oil significantly (1) reduced bacterial biofilm, (2) exhibited a synergistic effect when combined with chlorhexidine, and (3) did not induce cell toxicity. Chemical analysis identified the essential oil with 99.99% certainty, revealing menthol and menthone as the primary components, constituting approximately 42% and 26%, respectively. Further, M. piperita oil eradicated preformed biofilms and inhibited biofilm formation at sub-inhibitory concentrations. M. piperita oil also interfered with bacterial quorum sensing communication and did not produce any apparent cell toxicity in immortalized human keratinocytes (HaCaT). M. piperita represented an alternative substance for combating S. mutans and biofilm formation and a potential combination option with chlorhexidine to minimize side effects. An in-situ performance assessment requires further studies.

Unveiling the mechanism of essential oil action against skin pathogens: from ancient wisdom to modern science

Essential oils are among the most well-known phyto-compounds, and since ancient times, they have been utilized in medicine. Over 100 essential oils have been identified and utilized as therapies for various skin infections and related ailments. While numerous commercial medicines are available in different dosage forms to treat skin diseases, the persisting issues include their side effects, toxicity, and low efficacy. As a result, researchers are seeking novel classes of compounds as substitutes for synthetic drugs, aiming for minimal side effects, no toxicity, and high efficacy. Essential oils have shown promising antimicrobial activity against skin-associated pathogens. This review presents essential knowledge and scientific information regarding essential oil's antimicrobial capabilities against microorganisms that cause skin infections. Essential oils mechanisms against different pathogens have also been explored. Many essential oils exhibit promising activity against various microbes, which has been qualitatively assessed using the agar disc diffusion experiment, followed by determining the minimum inhibitory concentration for quantitative evaluation. It has been observed that Staphylococcus aureus and Candida albicans have been extensively researched in the context of skin-related infections and their antimicrobial activity, including established modes of action. In contrast, other skin pathogens such as Staphylococcus epidermidis, Streptococcus pyogens, Propionibacterium acnes, and Malassezia furfur have received less attention or neglected. This review report provides an updated understanding of the mechanisms of action of various essential oils with antimicrobial properties. This review explores the anti-infectious activity and mode of action of essential against distinct skin pathogens. Such knowledge can be valuable in treating skin infections and related ailments.

Effect of active composite coating based on nanochitosan-whey protein isolate on the microbial safety of chilled rainbow trout fillets packed with oxygen absorber

This study aimed to assess the effect of coating based on nanochitosan-whey protein isolate (NCH-WPI) containing summer savory essential oil (SEO) combined with oxygen absorber (OA) packaging on Pseudomonas aeruginosa, Listeria monocytogenes, and Escherichia coli O157H7, inoculated to rainbow trout fillets stored under refrigeration. Except control and OA groups, L. monocytogenes decreased (0.49-1.82 log CFU/g) in all treatment groups until the eighth day, and then increased (0.39-0.68 log CFU/g). This indicates that the treatments were ineffective to inhibit the proliferation of this bacterium. Considering the forced aerobic nature of inoculated P. aeruginosa, the counts of these bacteria become undetectable in groups packed with OA after the fourth day of storage, while the other groups showed an increase (0.99-2.23 log CFU/g) in this bacteria population during entire storage period. This growth rate was slower in the NCH-WPI + 1%SEO and NCH-WPI + 2%SEO groups. Regarding the inoculated E. coli, its count was decreased (1.48-2.41 log CFU/g) during storage, and this reduction (2.24-2.41 log CFU/g) was the highest in NCH-WPI + 1%SEO + OA and NCH-WPI + 2%SEO + OA groups. In conclusion, NCH-WPI treatments delayed the growth of all pathogenic bacteria, but the ternary treatment (NCH-WPI + SEO + OA) was the most effective treatment in this regard.

Elucidating the Phytochemical Landscape of Leaves, Stems, and Tubers of Codonopsis convolvulacea through Integrated Metabolomics

Codonopsis convolvulacea is a highly valued Chinese medicinal plant containing diverse bioactive compounds. While roots/tubers have been the main medicinal parts used in practice, leaves and stems may also harbor valuable phytochemicals. However, research comparing volatiles across tissues is lacking. This study performed metabolomic profiling of leaves, stems, and tubers of C. convolvulacea to elucidate tissue-specific accumulation patterns of volatile metabolites. Ultra-high performance liquid chromatography-tandem mass spectrometry identified 302 compounds, belonging to 14 classes. Multivariate analysis clearly differentiated the metabolic profiles of the three tissues. Numerous differentially accumulated metabolites (DAMs) were detected, especially terpenoids and esters. The leaves contained more terpenoids, ester, and alcohol. The stems accumulated higher levels of terpenoids, heterocyclics, and alkaloids with pharmaceutical potential. The tubers were enriched with carbohydrates like sugars and starch, befitting their storage role, but still retained reasonable amounts of valuable volatiles. The characterization of tissue-specific metabolic signatures provides a foundation for the selective utilization of C. convolvulacea parts. Key metabolites identified include niacinamide, p-cymene, tridecanal, benzeneacetic acid, benzene, and carveol. Leaves, stems, and tubers could be targeted for antioxidants, drug development, and tonics/nutraceuticals, respectively. The metabolomic insights can also guide breeding strategies to enhance the bioactive compound content in specific tissues. This study demonstrates the value of tissue-specific metabolite profiling for informing the phytochemical exploitation and genetic improvement of medicinal plants.

Prophylactic efficacy of baicalin and carvacrol against Salmonella Typhimurium biofilm on food and food contact surfaces

This study examines the antimicrobial and antibiofilm effectiveness of baicalin and carvacrol against Salmonella enterica ser. Typhimurium on food contact surfaces and chicken meat. The minimum inhibitory concentrations (MIC) for baicalin and carvacrol were found to be 100 μg/mL and 200 μg/mL, respectively, which aligns with findings from previous studies. The compounds exhibited a concentration-dependent decrease in microbial populations and biofilm formation. When used together, they displayed a remarkable synergistic effect, greatly augmenting their antibacterial activity. The assessment of food quality demonstrated that these treatments have no negative impact on the sensory characteristics of chicken meat. The impact of the structure on biofilms was observed through the use of Field Emission Scanning Electron Microscopy (FE-SEM) and Confocal Laser Scanning Microscopy (CLSM), revealing disrupted biofilm architectures and decreased cell viability. Crucially, RT-PCR analysis revealed a marked downregulation of quorum sensing (luxS), virulence (hilA), and stress response (rpoS) genes, highlighting the multifaceted antimicrobial mechanism of action. This gene-specific suppression suggests a targeted disruption of bacterial communication and virulence pathways, offering insight into the comprehensive antibiofilm strategy. This provides further insight into the molecular mechanisms that contribute to their antibiofilm effects.

Flow cytometry: Unravelling the real antimicrobial and antibiofilm efficacy of natural bioactive compounds

Flow cytometry (FCM) provides unique information on bacterial viability and physiology, allowing a real-time early warning antimicrobial and antibiofilm monitoring system for preventing the spread risk of foodborne disease. The present work used a combined culture-based and FCM approach to assess the in vitro efficacy of essential oils (EOs) from condiment plants commonly used in Mediterranean Europe (i.e., thyme EO, oregano EO, basil EO, and lemon EO) against planktonic and sessile cells of food-pathogenic Listeria monocytogenes 56 LY, and contaminant and alterative species Escherichia coli ATCC 25922 and Pseudomonas fluorescens ATCC 13525. Evaluation of the bacterial response to the increasing concentrations of natural compounds posed FCM as a crucial technique for the quantification of the live/dead, and viable but non-culturable (VBNC) cells when antimicrobial agents exert no real bactericidal action. Furthermore, the FCM results displayed higher numbers of viable bacteria expressed as Active Fluorescent Units (AFUs) with a greater level of repeatability compared with outcomes of the plate-count method. Overall, accurate counting of viable microbial cells is a critically important parameter in food microbiology, and flow cytometry provides an innovative approach with high-throughput potential for applications in the food industry as "flow microbiology".

Lavandula angustifolia Essential Oil Inhibits the Ability of Fusobacterium nucleatum to Produce Volatile Sulfide Compounds, a Key Components in Oral Malodor

Oral malodor still constitutes a major challenge worldwide. A strong effort is invested in eliminating volatile sulfur compound-producing oral bacteria through organic natural products such as essential oils. Fusobacterium nucleatum is a known volatile sulfur compound-producing bacteria that inspires oral malodor. The aim of the present study was to test the effect of lavender essential oil on the bacterium's ability to produce volatile sulfide compounds, the principal components of oral malodor. Lavender (Lavandula angustifolia) essential oil was extracted by hydrodistillation and analyzed using GC-MS. The minimal inhibitory concentration (MIC) of lavender essential oil on Fusobacterium nucleatum was determined in a previous trial. Fusobacterium nucleatum was incubated anaerobically in the presence of sub-MIC, MIC, and above MIC concentrations of lavender essential oil, as well as saline and chlorhexidine as negative and positive controls, respectively. Following incubation, volatile sulfur compound levels were measured using GC (Oralchroma), and bacterial cell membrane damage was studied using fluorescence microscopy. Chemical analysis of lavender essential oil yielded five main components, with camphor being the most abundant, accounting for nearly one-third of the total lavender essential oil volume. The MIC (4 µL/mL) of lavender essential oil reduced volatile sulfur compound secretion at a statistically significant level compared to the control (saline). Furthermore, the level of volatile sulfur compound production attributed to 1 MIC of lavender essential oil was in the range of the positive control chlorhexidine with no significant difference. When examining bacterial membrane damage, 2 MIC of lavender essential oil (i.e., 8 µL/mL) demonstrated the same, showing antibacterial membrane damage values comparative to chlorhexidine. Since lavender essential oil was found to be highly effective in hindering volatile sulfur compound production by Fusobacterium nucleatum through the induction of bacterial cell membrane damage, the results suggest that lavender essential oil may be a suitable alternative to conventional chemical-based anti-malodor agents.

Effect of thyme, ginger, and their nano-particles on growth performance, carcass characteristics, meat quality and intestinal bacteriology of broiler chickens

This study was conducted to evaluate the effects of thyme, ginger, and their nano-particles, as alternatives to antibiotic growth promotors (AGP), on productive performance, carcass traits, meat quality and gut health of broiler chickens. A total of 270 one-day-old broiler chicks were randomly distributed into 6 groups, each consisting of 3 replicates (n = 15 chicks/replicate). The birds in group 1 were fed the control diet which contained neither antibiotic growth promotors nor phytogenic feed additives (PFA). Birds in group 2 were fed diets containing 0.05% of AGP (Bacitracin methylene disalicylate). Chicks in group 3 and 4 were fed diets supplemented with 1.0% of thyme and ginger, respectively, whereas birds in group 5 and 6 were offered diets including 0.10% of nano-thyme and nano-ginger, respectively. The experiment lasted for 35 days. It was found that thyme and ginger with their nano-products, like the antibiotic, improved the body weight, weight gain and feed conversion rate of birds. The effect of ginger and nano-ginger on body weight and weight gain was greater than other treatments. During the overall feeding period, the feed cost of production was the highest in antibiotic group, but was the lowest in ginger and nano-ginger treatments. There was no effect of dietary treatments on carcass yield or organs weight except bursa of Fabricius and abdominal fat. Thyme, ginger and their nano-composites increased the weight of bursa and reduced the abdominal fat amount. The phytogenic additives and their nano-particles improved the colour, water holding capacity, and flavor of meat. Moreover, these additives reduced the total intestinal bacterial count as well as the total aerobic mesophilic count of meat. The effect of PFA and their nano-particles on the bacterial count was similar to that of antibiotic. In conclusion, thyme and ginger with their nano- particles can be considered as promising agents in feeding of broilers to improve the growth performance, gut health and meat quality. Moreover, these additives can be used as alternatives to AGP to overcome its health hazards and the high cost. The nanotechnology of herbal plants enables them to be added in smaller amounts in poultry diets with producing the same effect of raw ingredients, and this could be due to the higher bioavailability.

Preserving plum perfection: Buckwheat starch edible coating with xanthan gum and lemongrass essential oil

The research focused on the fabrication of composite coatings using buckwheat starch (BS) and xanthan gum (XG) with incorporation of lemongrass (Cymbopogon citratus) essential oil (LEO) with varying concentration (0.75 %, 1.0 % and 1.25 % (w/v). BS was extracted from buckwheat groats (Fagopyrum esculentum) and its physico-chemical characteristics were determined. BS showed spherical and polygonal morphology and its XRD pattern was similar to starch extracted from other cereal sources. The amount of reducing sugar, starch and amylose content in extracted BS were 0.99 ± 0.33 %, 86.32 ± 0.22 % and 21.02 ± 1.89 % respectively, which indicates that BS is a suitable base material for the formation of edible coatings. XG was mixed with BS in different ratios (1:1, 2:1, 3:1 and 4:1) to optimize the best ratio of combination for composite coatings. The coating with a ratio of 2:1 was very smooth and was chosen for incorporation of LEO and the coatings physical, functional, mechanical, thermal and micro-structural characteristics were examined. The coating S5 with 1.25 % (w/v) concentration of LEO showed the best results with least moisture content (MC), minimum water vapor permeability (WVP) and maximum contact angle value. Moreover, the S5 formulation had the highest antioxidant (73.3 %) ability and maximum antimicrobial efficiency with inhibition zones of 22.09 ± 0.06 mm and 28.65 ± 0.14 mm against S. aureus and E. coli respectively. The coatings were then coated on plum fruit, and various parameters like weight loss, pH, shrinkage and TSS were calculated every 4th day during the 20 days of refrigeration period. The coated plums' ripening pace was delayed by the S5 formulation which improved moisture retention, maintained the plums' TSS value and overall pH. Therefore, composite coatings made up of BS, XG and 1.25 % (w/v) can be used as a cost-effective bio-active coating material for plum preservation under refrigeration conditions.

Antiviral Activity of Natural Compounds for Food Safety

Gastroenteritis and hepatitis are the most common illnesses resulting from the consumption of food contaminated with human enteric viruses. Several natural compounds have demonstrated antiviral activity against human enteric viruses, such as human norovirus and hepatitis A virus, while little information is available for hepatitis E virus. Many in-vitro studies have evaluated the efficacy of different natural compounds against human enteric viruses or their surrogates. However, only few studies have investigated their antiviral activity in food applications. Among them, green tea extract, grape seed extract and carrageenans have been extensively investigated as antiviral natural compounds to improve food safety. Indeed, these extracts have been studied as sanitizers on food-contact surfaces, in produce washing solutions, as active fractions in antiviral food-packaging materials, and in edible coatings. The most innovative applications of these antiviral natural extracts include the development of coatings to extend the shelf life of berries or their combination with established food technologies for improved processes. This review summarizes existing knowledge in the underexplored field of natural compounds for enhancing the safety of viral-contaminated foods and underscores the research needs to be covered in the near future.

Antimicrobial activity of chitosan- edible films containing a combination of carvacrol and rosemary nano-emulsion against Salmonella enterica serovar Typhimurium and Listeria monocytogenes for ground meat

This research aimed to assess the potential of active food packaging as an innovative approach to enhance the quality of fresh food products. Specifically, our focus was on developing chitosan edible films combined with rosemary nanoemulsion (Ch-RNE) and carvacrol nano-emulsion (Ch-CNE) as effective antibacterial food packaging solutions. The efficacy of these films against artificially inoculated L. monocytogenes (NCTC 13372\ ATCC® 7644) as a Gram-positive bacterium, and S. enterica serovar Typhimurium (ATCC 14028) as a Gram-negative bacterium, in ground meat was investigated. The size of the prepared nano-emulsions was characterized using zeta sizer, FTIR and HRTEM. The MIC of both nano-emulsions against both pathogens was found to be 0.78 % and 1.56 %. Filmogenic mixtures were casted using these concentrations, which were then dried and evaluated for their physical and mechanical properties.

Use of nanotechnology-based nanomaterial as a substitute for antibiotics in monogastric animals

Nanotechnology has emerged as a promising solution for tackling antibiotic resistance in monogastric animals, providing innovative methods to enhance animal health and well-being. This review explores the novel use of nanotechnology-based nanomaterials as substitutes for antibiotics in monogastric animals. With growing global concerns about antibiotic resistance and the need for sustainable practices in animal husbandry, nanotechnology offers a compelling avenue to address these challenges. The objectives of this review are to find out the potential of nanomaterials in improving animal health while reducing reliance on conventional antibiotics. We examine various forms of nanomaterials and their roles in promoting gut health and also emphasize fresh perspectives brought by integrating nanotechnology into animal healthcare. Additionally, we delve into the mechanisms underlying the antibacterial properties of nanomaterials and their effectiveness in combating microbial resistance. By shedding light on the transformative role of nanotechnology in animal production systems. This review contributes to our understanding of how nanotechnology can provide safer and more sustainable alternatives to antibiotics.

Peppermint essential oil enhances the vase life of Dendrobium orchids

To extend the vase life of cut flowers, there is now a trend of using plant essential oils in place of synthetic chemicals, as they are fully biodegradable, more eco-friendly, and safer. The objective of this study was to examine the possible application and postharvest quality effects of three plant essential oils namely, ginger (Zingiber officinale Roscoe), peppermint (Mentha piperita L.), and citronella (Cymbopogon nardus Rendle), as natural vase solution for cut Dendrobium flowers. Peppermint essential oil showed promise as a holding solution for extending the vase life of Dendrobium orchids. To confirm vase life extension, emulsions containing peppermint essential oil at concentrations of 50 and 100 μg mL-1 combined with 4 % glucose to formulate holding solutions applied to Dendrobium orchids. Vase life, some biochemical changes, electrolyte leakage, total microbial count in the holding solution, and physical condition via scanning electron microscopy (SEM) were evaluated over a period of 25 days. The three major compounds in peppermint essential oil were identified as menthol (33.24 %), 1-menthone (18.91 %) and menthofuran (14.85 %). The essential oil was applied in emulsion form as a holding solution. Treatment with 4 % glucose and either 50 or 100 μg mL-1 peppermint essential oil prolonged the vase life of Dendrobium orchids to up to 28 days. Scanning electron microscopy on Day 7 showed that the xylem vessels of treated orchids remained clear, suggesting reduced microbial plugging at the stalk end. Similarly, on Day 20, a reduced microbial cell count was observed for treated orchids (<1 log CFU mL-1) in comparison with controls (7.20 ± 0.04 log CFU mL-1). Finally, the essential oil improved flower quality by helping preserve petal membrane stability and petal anthocyanin content. Our results suggest the application of peppermint essential oil as a novel alternative to chemicals used in holding solutions for extending the vase life of Dendrobium orchids.

In vitro and in vivo antibacterial activity of selected essential oil components against Pectobacterium carotovorum subsp. carotovorum and Pectobacterium atrosepticum causing bacterial soft rot of potato tubers

Pectinolytic bacteria cause bacterial soft rot of potato tubers. The most significant losses occur during storage. The efficacy of essential oil (EO) components carvacrol, cinnamaldehyde, d-carvone, l-menthone, R-(+)-limonene and thymol was tested against Pectobacterium carotovorum subsp. carotovorum (Pcc) and Pectobacterium atrosepticum (Pa). Disc diffusion, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) tests were performed in vitro, as well as potato disc and whole tuber maceration tests in vivo. Under in vitro conditions, cinnamaldehyde was the most effective against both bacteria (MIC 0.5 μL/mL, MBC 1.5 μL/mL). Both bacteria were found to be more susceptible to d-carvone (MIC 1.5-2.5 μL/mL, MBC 2.5 μL/mL) and thymol (MIC 2.5-5 μL/mL, MBC 3-5 μL/mL). R-(+)-limonene was the least effective. Results from the potato tuber disc maceration test confirmed a significant antibacterial effect of cinnamaldehyde at a concentration of 1.5 μL/mL. No rotted area was observed on potato tuber discs after treatment with l-menthone at concentrations of 2.5 μL/mL and 10 μL/mL against Pcc. A more pronounced effect was obtained when carvacrol was used at concentrations of 5 μL/mL against Pcc and 10 μL/mL against Pa. Disease severity tests on potato tubers after soaking for 20 min at MIC concentration of the EO components followed by 7 days of incubation at room temperature and 15 °C confirmed the antibacterial activity of cinnamaldehyde (0.5 μl/ml), l-menthone (2.5 μl/ml) and carvacrol (5-10 μl/ml). Cinnamaldehyde, l-menthone, and carvacrol may be recommended for further testing to treat stored potato tubers.

Synergistic Bactericidal Effects of Quaternary Ammonium Compounds with Essential Oil Constituents

Antimicrobial tolerance is a significant concern in the food industry, as it poses risks to food safety and public health. To overcome this challenge, synergistic combinations of antimicrobials have emerged as a potential solution. In this study, the combinations of two essential oil constituents (EOCs), namely carvacrol (CAR) and eugenol (EUG), with the quaternary ammonium compounds (QACs) benzalkonium chloride (BAC) and didecyldimethylammonium chloride (DDAC) were evaluated for their antimicrobial effects against Escherichia coli and Bacillus cereus, two common foodborne bacteria. The checkerboard assay was employed to determine the fractional inhibitory concentration index (FICI) and the fractional bactericidal concentration index (FBCI), indicating the presence of bactericidal, but not bacteriostatic, synergy in all QAC-EOC combinations. Bactericidal synergism was clearly supported by Bliss independence analysis. The bactericidal activity of the promising synergistic combinations was further validated by time-kill curves, achieving a >4-log10 reduction of initial bacterial load, which is significant compared to typical industry standards. The combinations containing DDAC showed the highest efficiency, resulting in the eradication of bacterial population in less than 2-4 h. These findings emphasize the importance of considering both bacteriostatic and bactericidal effects when evaluating antimicrobial combinations and the potential of EOC-QAC combinations for sanitization and disinfection in the food industry.

Impacts of thyme and/or garlic oils on growth, immunity, antioxidant and net farm income in Damascus goats

This study aimed to evaluate the impact of thyme and/or garlic oil administration on growth performance, immunity, antioxidant, biochemical parameters, and net farm income of Damascus goats. Forty weaned Damascus goats were allocated into four groups. The first group was the control without oral administration, while the 2nd (Th), 3rd (Gr), and 4th (ThGr) groups were orally administrated by (2 ml/goat/day) of thyme oil, garlic oil and their mixture (1:1), respectively during the whole experiment period. The final body weight of goats orally administered oil mixture was the heaviest group, it was 10, 4.5 and 3.5% than the control, Th. and Gr. groups, respectively with better feed conversion ratio and high net farm income. Goats of ThGr. group revealed the best immunity, antioxidant and general health condition than the control group with 50% reduction of MDA. Liver (AST, 33% and ALT, 38%) and kidney (creatinine, 88%) functions improved by oils mixtures orally administration compared with the control group. LDL, triglyceride and cholesterol were reduced by 47, 33 and 21% compared with the control group, respectively. Thus, mixture oil administration (thyme and garlic at the ratio of 1:1, 2 ml/goat/day) improved growth (10%), antioxidant status (MDA 50%), liver (AST, 33% and ALT, 38%), kidney function (creatinine, 88%), the FCR (17.4%) and net farm income (21%), of Damascus goats.

Impact of Abiotic and Biotic Environmental Conditions on the Development and Infectivity of Entomopathogenic Nematodes in Agricultural Soils

Many organisms, including beneficial entomopathogenic nematodes (EPNs), are commonly found in the soil environment. EPNs are used as biopesticides for pest control. They have many positive characteristics and are able to survive at sites of application for a long time, producing new generations of individuals. The occurrence of populations depends on many environmental parameters, such as temperature, moisture, soil texture, and pH. Extreme temperatures result in a decrease in the survival rate and infectivity of EPNs. Both high humidity and acidic soil pH reduce populations and disrupt the biological activity of EPNs. Nematodes are also exposed to anthropogenic agents, such as heavy metals, oil, gasoline, and even essential oils. These limit their ability to move in the soil, thereby reducing their chances of successfully finding a host. Commonly used fertilizers and chemical pesticides are also a challenge. They reduce the pathogenicity of EPNs and negatively affect their reproduction, which reduces the population size. Biotic factors also influence nematode biology. Fungi and competition limit the reproduction and survival of EPNs in the soil. Host availability enables survival and affects infectivity. Knowledge of the influence of environmental factors on the biology of EPNs will allow more effective use of the insecticidal capacity of these organisms.

A Novel Bis-Trifluoromethylated Compound Demonstrates High Efficacy as a Nematicide Against Root-Knot Nematodes on Pistachio, Supported by Docking Studies

Three novel trifluoromethylated compounds were designed and synthesized by reacting trifluoroacetimidoyl chloride derivatives with acetamidine hydrochloride or thiourea in the presence of potassium carbonate or sodium hydrogen carbonate as a base. In vitro and in vivo assays demonstrated the efficacy of the tested compounds in controlling root-knot nematode disease on pistachio rootstocks caused by Meloidogyne incognita. Bis-trifluoromethylated derivatives, namely N,N''-thiocarbonylbis(N'-(3,4-dimethylphenyl)-2,2,2-trifluoroacetimidamide) (compound A1), showed high efficacy as novel and promising nematicides, achieving up to 78.28% control at a concentration of 0.042 mg/liter. This effect is attributed to four methyl and two trifluoromethyl groups. In the pre-inoculation application of compound A1, all three concentrations (0.033, 0.037, and 0.042 mg/liter, and Velum) exhibited a higher level of control, with 83.79, 87.46, and 80.73% control, respectively. In the microplot trials, compound A1 effectively reduced population levels of M. incognita and enhanced plant growth at a concentration of 0.037 mg/liter. This suggests that compound A1 has the potential to inhibit hedgehog protein and could be utilized to prevent the progression of root-knot disease. Furthermore, the molecular docking results revealed that compounds A1 and A3 interact with specific amino acid residues (Gln60, Asp530, Glu70, Arg520, and Thr510) located in the active site of hedgehog protein. Based on the experimental findings of this study, compound A1 shows promise as a lead compound for future investigations.

In vitro effects of phytogenic feed additive on Piscirickettsia salmonis growth and biofilm formation

Piscirickettsiosis is the main cause of mortality in salmonids of commercial importance in Chile, which is caused by Piscirickettsia salmonis, a Gram-negative, γ-proteobacteria that can produce biofilm as one of its virulence factors. The Chilean salmon industry uses large amounts of antibiotics to control piscirickettsiosis outbreaks, which has raised concern about its environmental impact and the potential to induce antibiotic resistance. Thus, the use of phytogenic feed additives (PFA) with antibacterial activity emerges as an interesting alternative to antimicrobials. Our study describes the antimicrobial action of an Andrographis paniculate-extracted PFA on P. salmonis planktonic growth and biofilm formation. We observed complete inhibition of planktonic and biofilm growth with 500 and 400 μg/mL of PFA for P. salmonis LF-89 and EM-90-like strains, respectively. Furthermore, 500 μg/mL of PFA was bactericidal for both evaluated bacterial strains. Sub-inhibitory doses of PFA increase the transcript levels of stress (groEL), biofilm (pslD), and efflux pump (acrB) genes for both P. salmonis strains in planktonic and sessile conditions. In conclusion, our results demonstrate the antibacterial effect of PFA against P. salmonis in vitro, highlighting the potential of PFA as an alternative to control Piscirickettsiosis.

Mechanisms of polyphenols on quality control of aquatic products in storage: A review

Aquatic products are easily spoiled during storage due to oxidation, endogenous enzymes, and bacteria. At the same time, compared with synthetic antioxidants, based on the antibacterial and antioxidant mechanism of biological agents, the development of natural, nontoxic, low-temperature, better-effect green biological preservatives is more acceptable to consumers. The type and molecular structure of polyphenols affect their antioxidant and antibacterial effectiveness. This review will describe how they achieve their antioxidant and antibacterial effects. And the recent literature on the mechanism and application of polyphenols in the preservation of aquatic products was updated and summarized. The conclusion is that in aquatic products, polyphenols alleviate lipid oxidation, protein degradation and inhibit the growth and reproduction of microorganisms, so as to achieve the effect of storage quality control. And put forward suggestions on the application of the research results in aquatic products. We hope to provide theoretical support for better exploration of the application of polyphenols and aquatic product storage.

Remarkable enhancement of cinnamaldehyde antimicrobial activity encapsulated in capped mesoporous nanoparticles: A new "nanokiller" approach in the era of antimicrobial resistance

Combating antimicrobial resistance is one of the biggest health challenges because of the ineffectiveness of standard biocide treatments. This challenge could be approached using natural products, which have demonstrated powerful therapeutics against multidrug-resistant microbes. In the present work, a nanodevice consisting of mesoporous silica nanoparticles loaded with an essential oil component (cinnamaldehyde) and functionalized with the polypeptide ε-poly-l-lysine is developed and used as an antimicrobial agent. In the presence of the corresponding stimuli (i.e., exogenous proteolytic enzymes from bacteria or fungi), the polypeptide is hydrolyzed, and the cinnamaldehyde delivery is enhanced. The nanodevice's release mechanism and efficacy are evaluated in vitro against the pathogenic microorganisms Escherichia coli, Staphylococcus aureus, and Candida albicans. The results demonstrate that the new device increases the delivery of the cinnamaldehyde via a biocontrolled uncapping mechanism triggered by proteolytic enzymes. Moreover, the nanodevice notably improves the antimicrobial efficacy of cinnamaldehyde when compared to the free compound, ca. 52-fold for E. coli, ca. 60-fold for S. aureus, and ca. 7-fold for C. albicans. The enhancement of the antimicrobial activity of the essential oil component is attributed to the decrease of its volatility due to its encapsulation in the porous silica matrix and the increase of its local concentration when released due to the presence of microorganisms.

Synergistic rosemary extract with TBHQ and citric acid improves oxidative stability and shelf life of peanut

Lipid oxidation often accompanies the processing and storage of peanuts, which causes a serious waste of peanut resources. To solve the problem of being prone to oxidation in peanut processing, a ternary complex antioxidant based on rosemary extract (RE) was constructed to investigate its effect on the oxidative and thermal stability of peanuts, and the inhibition of peanut oxidation by compound antioxidants was revealed by dynamic Arrhenius formula and complexation theory. The results showed that there was a synergistic effect between RE and Tert-butyl hydroquinone (TBHQ), and the antioxidant effects of RE and TBHQ were 4.86 and 1.45 times higher when used in combination than when used alone, respectively. In addition, RE-TBHQ-CA (citric acid) effectively inhibited primary and secondary oxidation of peanuts with a shelf life 8.7 times longer than that of control peanuts. This study provides a novel antioxidant compounding idea, which has a positive effect on improving the quality of peanut and other nut products, prolonging the shelf life and reducing the waste of resources. PRACTICAL APPLICATION: Compounding a complex antioxidant that permits its use in peanuts. It was found that rosemary and TBHQ might have synergistic antioxidant effects. Meanwhile, this combination of RE-TBHQ-CA effectively inhibited the oxidation of peanut oils and prolonged the shelf life of peanuts. RE-TBHQ-CA is a highly efficient complex antioxidant that can reduce the amounts of antioxidants added while maintaining high antioxidant efficiency, which may be useful for the future preservation and storage of nut products as it positively affects the quality and shelf life of the product.

Chemical composition and antioxidant and antibacterial properties of the essential oils extracted from Citrus sinensis peels by hydrodistillation and microwave methods

The present study is devoted to evaluate in vitro the chemical composition and the antioxidant and antibacterial properties of essential oils (Eo) extracted by hydrodistillation (HD) and microwave (MW) from the plant peels of Citrus sinensis. The extraction provided yields of 0.26% and 0.02%, respectively. The essential oils were analyzed by GC-MS whose major component is limonene that has a remarkable percentage (78.192% and 58.6%, respectively) for the essential oil extracted by HD and MW. The results of the antioxidant potential were noticeable in each of the essential oils with a higher priority to that extracted by hydrodistillation. The evaluation of the antioxidant power by the free radical scavenging method (DPPH) showed that the essential oils studied have good antioxidant activity, especially for the oil extracted by HD having presented an IC50 of (13.07 ± 0.169) mg/ml, while BHT and ascorbic acid showed very potent and effective anti-free radical activity with IC50 of the order of (19.54 ± 0.32) µg/ml and (1.17 ± 0.05) µg/ml respectively. According to the β-carotene/linoleic acid test, the oxidation of β-carotene was effectively inhibited by the two essential oils of Citrus sinensis peels with a percentage of inhibition of (56.46 ± 0.76) % and (31.39 ± 1.49) % respectively for HD and MW. Eo extracted by HD is more active than ascorbic acid (15.43%). In the antibacterial test, the activity was evaluated by the disc-diffusion method, the two types of sweet orange essential oils inhibited the growth of five bacterial strains out of six: The best activity was obtained against E. coli, Listeria monocytogenes, and Agrobacterium with a diameter of the zone of inhibition between 70 and 84 mm, with the exception of the strain of Bacillus subtilis, there is no zone of inhibition has been observed.

Eradication of multiple-species biofilms from food industrial and domestic surfaces using essential oils

Microbial biofilm formation represents a serious problem for both food industry and households. Natural biofilms are formed mostly by multiple species, and show resistance against most of the usual sanitizers. In this study, the effects of cinnamon (Cinnamomum zeylanicum), marjoram (Origanum majorana) and thyme (Thymus vulgaris) essential oils (EOs) and their main components (cinnamaldehyde, terpinene-4-ol, and thymol) were investigated on four-species biofilms of Escherichia coli, Listeria monocytogenes, Pseudomonas putida and Staphylococcus aureus. Minimum bactericide concentration (MBC) and killing time were determined by means of the microdilution method. MBC of the investigated EOs and components was between 0.5 mg/mL (cinnamaldehyde) to 25 mg/mL (terpinene-4-ol). Killing times for the four-species suspension were 5 or 10 min, time spans usable in the food industry. For eradication of the mixed-population biofilm from stainless steel (SS), polypropylene (PP), tile and wood surfaces, EO- or EO component-based disinfectant solutions were developed, and their effects were compared to a peracetic acid-based industrial sanitizer (HC-DPE). Total eradication of biofilms (99.9%) was achieved, with solutions containing cinnamon and thyme EO and EO components, from SS and PP, but not from tile or wood surfaces. Apparently, cinnamon EO, terpinene-4-ol and thymol have better disinfectant activity than HC-DPE.

Pectin/sodium alginate-based active film integrated with microcrystalline cellulose and geraniol for food packaging applications

Biopolymer-based packaging films were prepared from pectin (PEC) and sodium alginate (SA), with the incorporation of 10 % MCC and different concentrations of geraniol (GER at 2.5, 5.0, 7.5, and 10.0 %). Rheological properties suggested that film-forming solutions and film-forming emulsions exhibited a shear-thinning or pseudo-plastic non-Newtonian behaviour. The dried films were crosslinked with 2.0 % CaCl2. The addition of MCC into PEC/SA film enhanced the TS but reduced it with the impregnation of GER without influencing the EAB and toughness of the film. The water solubility of the films significantly reduced with the rise in the GER levels but enhanced the water vapor and oxygen barrier attributes. TGA demonstrated that incorporating MCC reduced the film's thermal degradation (44.92 % to 28.81 %), but GER had an insignificant influence on the thermal stability. FTIR spectra revealed that hydrogen bond formation was positively linked with the GER addition in the film formulation. X-ray diffractograms showed that prepared films were predominantly amorphous. Antimicrobial studies showed a complete reduction of Escherichia coli and Bacillus cereus in 24 h. Overall, the composite film displayed excellent physical and active properties and PEC/SA/MCC/5.0 %GER/CaCl2 film was considered the best formulation for food packaging applications.

Chitosan nanoemulsion incorporated with Carum carvi essential oil as ecofriendly alternative for mitigation of aflatoxin B1 contamination in stored herbal raw materials

The present investigation entails the first report on entrapment of Carum carvi essential oil (CCEO) into chitosan polymer matrix for protection of stored herbal raw materials against fungal inhabitation and aflatoxin B1 (AFB1) production. Physico-chemical characterization of nanoencapsulated CCEO was performed through Fourier transform infrared spectroscopy, dynamic light scattering, X-ray diffractometry, and scanning electron microscopy. The nanoencapsulated CCEO displayed improved antifungal and AFB1 suppressing potentiality along with controlled delivery over unencapsulated CCEO. The encapsulated CCEO nanoemulsion obstructed the ergosterol production and escalated the efflux of cellular ions, thereby suggesting plasma membrane as prime target of antifungal action in Aspergillus flavus cells. The impairment in methyglyoxal production and modeling based carvone interaction with Afl-R protein validated the antiaflatoxigenic mechanism of action. In addition, CCEO displayed augmentation in antioxidant potentiality after encapsulation into chitosan nanomatrix. Moreover, the in-situ study demonstrated the effective protection of Withania somnifera root samples (model herbal raw material) against fungal infestation and AFB1 contamination along with prevention of lipid peroxidation. The acceptable organoleptic qualities of W. somnifera root samples and favorable safety profile in mice (animal model) strengthen the application of nanoencapsulated CCEO emulsion as nano-fungitoxicant for preservation of herbal raw materials against fungi and AFB1 mediated biodeterioration.

Therapeutic Potential of Essential Oils Against Ulcerative Colitis: A Review

Ulcerative colitis (UC) is a chronic non-sp ecific inflammatory disease of the colorectal mucosa. Researchers have associated UC onset with familial genetics, lifestyle behavior, inflammatory immune factors, intestinal microbiota, and the integrity of the intestinal mucosal barrier. The primary therapeutic interventions for UC consist of pharmacological management to control inflammation and promote mucosal healing and surgical interventions. The available drugs effectively control and decelerate the progression of UC in most patients; nonetheless, their long-term administration can exert adverse effects and influence the therapeutic effect. Plant essential oils (EOs) refer to a group of hydrophobic aromatic volatile substances. EOs have garnered considerable attention in both domestic and international research because of their anti-inflammatory, antibacterial, and antioxidant properties. They include peppermint, peppercorns, rosemary, and lavender, among others. Researchers have investigated the role of EOs in medicine and have elucidated their potential to mitigate the detrimental effects of UC through their anti-inflammatory, antioxidant, antidepressant, and anti-insomnia properties as well as their ability to regulate the intestinal flora. Furthermore, EOs exert minimal toxic adverse effects, further enhancing their appeal for therapeutic applications. However, these speculations are based on theoretical experiments, thereby warranting more clinical studies to confirm their effectiveness and safety. In this article, we aim to provide an overview of the advancements in utilizing natural medicine EOs for UC prevention and treatment. We will explore the potential pathogenesis of UC and examine the role of EOs therapy in basic research, quality stability, and management specification of inadequate EOs for UC treatment. We intend to offer novel insights into the use of EOs in UC prevention and management.

Determination of antimicrobial and modulatory activity of bacterial resistance by nettle (Cnidoscolus urens) extracts in multiresistant bacteria isolated from bovine mastitis

The present study aimed to evaluate the antimicrobial and modulating activity of the ethanol extract obtained from the leaves, stems, and roots of Cnidoscolus urens in multiresistant bacteria. The Minimum Inhibitory Concentration (MIC) values obtained for the extracts of leaves, stems, and roots were greater than 1024 µg/mL for all isolates. In the antimicrobial resistance modulation test, the extract of the leaves of C. urens showed a better modulating effect than that of the stems and roots for gentamicin, highlighting the reduction of MIC for Escherichia coli, Lactococcus garvieae and Staphylococcus sciuri. For erythromycin, a reduction of MIC was observed in L. garvieae, Staphylococcus aureus, Staphylococcus epidermidis, and Streptococcus agalactiae. The extract from the leaves of C. urens has an important modulating effect on resistance in multiresistant bacteria, especially with gentamicin and erythromycin.

Phytochemical Characterization and Biological Activities of Essential Oil from Satureja montana L., a Medicinal Plant Grown under the Influence of Fertilization and Planting Dates

The rising demand for safe plant compounds and herbal products that contribute positively to human health is in line with current market trends. Plants belonging to the Satureja genus, particularly the aromatic medicinal S. montana L. from the Lamiaceae family, are well suited to these trends as they serve as pharmaceutical raw materials. This research aimed to assess the influence of sowing date and fertilization doses, as well as their interaction, on the fresh weight, essential oil content, and composition of S. montana. Experimental cultivation involved varying nitrogen and phosphorus levels. The second cut had the highest fresh weight and oil production compared to the first cut. The highest total plant biomass was achieved with autumn sowing and fertilization at 55 kg N/ha and 37 kg P/ha, whereas Spring sowing exhibited higher essential oil production, with the maximum oil % with 74 kg P/ha and oil yield after applying 55 kg N/ha and 74 kg P/ha. The GC-MS analysis revealed that carvacrol was the predominant compound, with it being recommended to grow S. montana in Spring at doses of 55 kg N/ha and 74 kg P/ha for the superior oil yield. Additionally, S. montana essential oil demonstrated notable biological and antimicrobial activity, positioning it as a potential alternative to chemical food preservatives.

Efficacy of Essential Oil Vapours in Reducing Postharvest Rots and Effect on the Fruit Mycobiome of Nectarines

Nectarines can be affected by many diseases, resulting in significant production losses. Natural products, such as essential oils (EOs), are promising alternatives to pesticides to control storage rots. This work aimed to test the efficacy of biofumigation with EOs in the control of nectarine postharvest diseases while also evaluating the effect on the quality parameters (firmness, total soluble solids, and titratable acidity) and on the fruit fungal microbiome. Basil, fennel, lemon, oregano, and thyme EOs were first tested in vitro at 0.1, 0.5, and 1.0% concentrations to evaluate their inhibition activity against Monilinia fructicola. Subsequently, an in vivo screening trial was performed by treating nectarines inoculated with M. fructicola, with the five EOs at 2.0% concentration by biofumigation, performed using slow-release diffusers placed inside the storage cabinets. Fennel, lemon, and basil EOs were the most effective after storage and were selected to be tested in efficacy trials using naturally infected nectarines. After 28 days of storage, all treatments showed a significant rot reduction compared to the untreated control. Additionally, no evident phytotoxic effects were observed on the treated fruits. EO vapors did not affect the overall quality of the fruits but showed a positive effect in reducing firmness loss. Metabarcoding analysis showed a significant impact of tissue, treatment, and sampling time on the fruit microbiome composition. Treatments were able to reduce the abundance of Monilinia spp., but basil EO favored a significant increase in Penicillium spp. Moreover, the abundance of other fungal genera was found to be modified.

Phytochemical investigation of the n-hexane-extracted oil from four umbelliferous vegetables using GC/MS analysis in the context of antibacterial activity

Umbelliferous (Apiaceae) vegetables are widely consumed worldwide for their nutritive and health benefits. The main goal of the current study is to explore the compositional heterogeneity in four dried umbelliferous vegetables viz, celery, coriander, dill, and parsley targeting their volatile profile using gas chromatography-mass spectrometry (GC-MS). A total of 133 volatile metabolites were detected belonging to 12 classes. Aromatic hydrocarbons were detected as the major components of the analyzed vegetables accounting ca. 64.0, 62.4, 59.5, and 47.8% in parsley, dill, celery, and coriander, respectively. Aliphatic hydrocarbons were detected at ca. 6.39, 8.21, 6.16, and 6.79% in parsley, dill, celery, and coriander, respectively. Polyunsaturated fatty acids (PUFA) of various health benefits were detected in parsley and represented by roughanic acid and α-linolenic acid at 4.99 and 0.47%, respectively. Myristicin and frambinone were detected only in parsley at 0.45 and 0.56%. Investigation of antibacterial activity of umbelliferous vegetables n-hexane extract revealed a moderate antibacterial activity against Gram-positive and Gram-negative bacteria with higher activity for celery and dill against Staphylococcus aureus with inhibition zone 20.3 mm compared to 24.3 mm of the standard antibacterial drug.

Nanoemulsions and nanocapsules loaded with Melaleuca alternifolia essential oil for sepsis treatment

Sepsis represents a complex clinical syndrome that results from a harmful host response to infection. The infections most associated with sepsis are pneumonia, intra-abdominal infection, and urinary tract infection. Tea tree oil (TTO) has shown high antibacterial activity; however, it exhibits low aqueous solubility and high volatility, which have motivated its nanoencapsulation. In this study, the performance of nanoemulsions (NE) and nanocapsules (NC) loaded with TTO was compared. These systems were prepared by spontaneous emulsification and nanoprecipitation methods, respectively. Poly-ε-caprolactone or Eudragit® RS100 were tested as polymers for NCs whereas Tween® 80 or Pluronic® F68 as surfactants in NE preparation. Pluronic® F68 and Eudragit® RS100 resulted in more homogeneous and stable nanoparticles. In accelerated stability studies at 4 and 25 °C, both colloidal suspensions (NC and NE) were kinetically stable. NCs showed to be more stable to photodegradation and less cytotoxic than NEs. After sepsis induction by the cecal ligation and puncture (CLP) model, both NE and NC reduced neutrophil infiltration into peritoneal lavage (PL) and kidneys. Moreover, the systems increased group thiols in the kidney and lung tissue and reduced bacterial growth in PL. Taken together, both systems showed to be effective against injury induced by sepsis; however, NCs should be prioritized due to advantages in terms of cytotoxicity and physicochemical stability.

Inhibitory Effects of Endemic Thyme's Thymol-Carvacrol Chemotype Essential Oil on Aspergillus Species with Free Radical Scavenging Properties

There is a burgeoning focus on utilizing the antifungal and antioxidant properties of essential oils derived from various plants as a modern and natural approach to combat the growth of fungi that contaminate food. In this study, we used essential oils extracted from Thymus daenensis Celak. subsp. daenensis to address three mycotoxin-producing species of Aspergillus, specifically A. flavus, A. parasiticus, and A. niger, all of which are recognized contaminants of food and agricultural products. Concurrently, the antioxidant properties of the essential oils were evaluated, revealing their noteworthy role in the antifungal activity. Essential oils were derived from T. daenensis subsp. daenensis was observed to have a significant inhibitory effect on all three species of Aspergillus, as evidenced by the minimum inhibitory concentration (MIC) ranging from 575 to 707 ppm and the half-maximal inhibitory concentration (IC50) ranging from 237 to 280 ppm. These results confirm the strong antifungal activity of the essential oils. Furthermore, the essential oil exhibited free radical scavenging activity, resulting in an EC50 value of 37.1 μg/ml. In summary, T. daenensis subsp. daenensis essential oil demonstrated a competitive advantage over other similar plants and synthetic antibiotics. This indicates the promising potential of this essential oil as a natural antifungal agent to control Aspergillus growth and mycotoxin contamination. It offers an alternative or complementary approach to conventional antifungal agents and could be a valuable addition to the arsenal of natural remedies to address fungal contamination in food and agricultural products.

Antioxidant and antimicrobial activities of tarragon and Zataria multiflora Boiss essential oils and their applications as active agents to improve the shelf life of freshly cut potato strips

This study investigated the possibility of using active coatings based on Zedo gum containing essential oils of Zataria multiflora Boiss (ZE) and tarragon (TE) to increase the shelf life and maintain the quality of freshly cut potato strips. The chemical compositions of ZE and TE were initially identified, and their antioxidant and antimicrobial activities were investigated. ZE consisted mainly of carvacrol (26.26%), p-cymene (21.50%), thymol (18.05%), and linalool (11.31%), and those of TE comprised p-allylanisole (81.92%), β-Ocimene E (8.06%), and β-Ocimene Z (5.35%). Afterwards, a Zedo gum active coating (1% v/w) containing 1% (v/v) essential oil was prepared, and the produced coating solutions were used to soak the potato strips for 5 min. The coated potatoes were kept fresh in a refrigerator for 9 days, and their quality characteristics were examined every 3 days. The results show that the weight loss, browning index, total microbial count, and mold and yeast counts in the strips increased during 9 days of cold storage, and hardness decreased (p < .05). However, the coatings of strips, especially those containing essential oils, reduced the intensity of changes in moisture, color, and hardness, increased microbial stability, and maintained the sensory acceptance of strips compared with the uncoated sample (control). Finally, this study demonstrated that the quality and shelf life of fresh potato strips can be improved by using active coatings based on Zedo gum containing ZE and TE (especially ZE).

Potentiation of the Antimicrobial Effect of Oxytetracycline Combined with Cinnamon, Clove, Oregano, and Red Thyme Essential Oils against MDR Salmonella enterica Strains

Tetracyclines have a high resistance percentage in Salmonella spp. of both human and animal origin. Essential oils, such as cinnamon (Cinnamomum zeylanicum), clove (Eugenia caryophyllata), oregano (Origanum vulgare), and red thyme (Thymus zygis), have shown bactericidal activity against this bacterium. However, in many cases, the minimum inhibitory concentration (MIC) exceeds the cytotoxicity limits. The objective of this study was to assess the in vitro efficacy of combining oxytetracycline with essential these oils against field multidrug-resistant (MDR) Salmonella enterica strains. The MIC of each product was determined using the broth microdilution method. The interaction was evaluated using the checkerboard method, by means of the fractional inhibitory concentration index (FICindex) determination. The results showed a positive interaction (synergy and additivity) between oxytetracycline and the four oils tested, resulting in a reduction in both products' MICs by 2 to 4 times their initial value, in the case of oils, and by 2 to 1024 times in the case of the antibiotic. The combination of oxytetracycline and cinnamon achieved the best results (FICindex 0.5), with a decrease in the antibiotic effective concentration to below the sensitivity threshold (MIC of the combined oxytetracycline 0.5 µg/mL). There was no antagonistic effect in any case, although differences in response were observed depending on the bacterial strain. The results of this study suggest that combining oxytetracycline with cinnamon oil could be an effective alternative for controlling tetracycline-resistant strains of Salmonella. However, its individual use should be further evaluated through in vitro susceptibility tests.

Eco-Friendly Sanitization of Indoor Environments: Effectiveness of Thyme Essential Oil in Controlling Bioaerosol Levels and Disinfecting Surfaces

Bioaerosols and pathogens in indoor workplaces and residential environments are the primary culprits of several infections. Techniques for sanitizing air and surfaces typically involve the use of UV rays or chemical sanitizers, which may release chemical residues harmful to human health. Essential oils, natural substances derived from plants, which exhibit broad antimicrobial properties, could be a viable alternative for air and surface sanitation. The objective of this study has been to investigate the efficacy of thyme essential oil (TEO) in environmental sanitation processes. In Vitro assays through agar well diffusion, disk volatilization and tube dilution methods revealed significant antimicrobial activity of TEO 100% against foodborne and environmental isolates, with both bacteriostatic/fungistatic and bactericidal/fungicidal effects. Therefore, aqueous solutions of TEO 2.5% and 5% were formulated for air sanitation through nebulization and surface disinfection via direct contact. Bioaerosol samples and surface swabs were analyzed before and after sanitation, demonstrating the efficacy of aqueous solutions of TEO in reducing mesophilic and psychrophilic bacteria and environmental fungi levels in both air and on surfaces. The obtained results prove the antimicrobial potential of aqueous solutions of TEO in improving indoor air quality and surface cleanliness, suggesting thyme essential oil as an effective and safe natural sanitizer with minimal environmental impact compared to dangerous chemical disinfectants.

Promising Antileishmanial Activity of Micromeria nervosa Essential Oil: In Vitro and In Silico Studies

The present study aimed to evaluate the leishmanicidal potential of the essential oil (EO) of Micromeria (M.) nervosa and to investigate its molecular mechanism of action by qPCR. Furthermore, in silicointeraction study of the major M. nervosa EO compounds with the enzyme cytochrome P450 sterol 14α-demethylase (CYP51) was also performed. M. nervosa EO was analyzed by gas chromatography-mass spectrometry (GC-MS). Results showed that α-pinene (26.44%), t-cadinol (26.27%), caryophyllene Oxide (7.73 ± 1.04%), and α-Cadinene (3.79 ± 0.12%) are the major compounds of M. nervosa EO. However, limited antioxidant activity was observed, as this EO was ineffective in neutralizing DPPH free radicals and in inhibiting β-carotene bleaching. Interestingly, it displayed effective leishmanicidal potential against promastigote (IC50 of 6.79 and 5.25 μg/mL) and amastigote (IC50 of 8.04 and 7.32 μg/mL) forms of leishmania (L.) infantum and L. major, respectively. Molecular mechanism investigation showed that M. nervosa EO displayed potent inhibition on the thiol regulatory pathway. Furthermore, a docking study of the main components of the EO with cytochrome P450 sterol 14α-demethylase (CYP51) enzyme revealed that t-cadinol exhibited the best binding energy values (-7.5 kcal/mol), followed by α-cadinene (-7.3 kcal/mol) and caryophyllene oxide (-7 kcal/mol). These values were notably higher than that of the conventional drug fluconazole showing weaker binding energy (-6.9 kcal/mol). These results suggest that M. nervosa EO could serve as a potent and promising candidate for the development of alternative antileishmanial agent in the treatment of leishmaniasis.

Trans-Cinnamaldehyde Primes More Robust Channel Catfish Immune Responses to Edwardsiella ictaluri Infection

Infection with Edwardsiella ictaluri, a causative agent of enteric septicemia of catfish, threatens profitable catfish production through inventory losses. We previously demonstrated that trans-cinnamaldehyde (TC) enhances the survival of catfish following E. ictaluri infection. The present study was conducted to investigate catfish immune responses to TC feeding and E. ictaluri infection. The expression of 13 proinflammatory, innate, and adaptive immune-related genes was evaluated over time in two sets of experiments using real-time polymerase chain reaction (PCR). In the first experiment, catfish were fed a basal diet with or without TC supplementation, while in the second they were fed a TC-supplemented or normal diet followed by infection with E. ictaluri. The catfish group infected with E. ictaluri and fed a TC-diet showed significant changes in the expression of innate and adaptive immune-related genes compared to control group. At 21 and 28 days post-infection, recovered fish showed significant increases in the expression of IgM in the anterior kidney and spleen. These results suggest that the supplemental dietary intake of TC can improve the immune status of catfish via engaging innate and adaptive immune responses and the production of memory cells in immunocompetent tissues. Together, this study provides an important foundation for the potential application of TC as an antimicrobial alternative in aquaculture.

Role of mitochondrial farnesyltransferase gene in the prevention of the food spoilage fungi Aspergillus flavus by the antimicrobial natural preservative perillaldehyde

Aspergillus flavus, one of the most widely distributed and abundant genus of Aspergillus worldwide, poses an evident threat as a source of food contamination in grains and cereals. Perillaldehyde (PAE), a volatile essential oil extracted from the stem and leaves of Perilla frutescens L., exhibits potent antifungal activity. In our study, we investigated the role of Cox10, a key enzyme in the heme A synthesis pathway crucial for maintaining mitochondrial function. We found that cox10 is a sensitive gene of A. flavus in response to PAE by gene expression assay and GFP fluorescent localization tagging, and then we found that the deletion of this gene affects the growth and development of A. flavus, but the drug resistance is elevated. Through transcriptome sequencing and its experimental validation, the molecular mechanisms of stress triggered by the deletion of cox10 were further clarified, such as the decrease in intracellular drug content due to the increase in the expression of drug efflux proteins, and the increase in the thickness of cell wall due to the increase in the content of cell wall chitin. Clearly, cox10 plays a critical role in regulating various cellular processes of A. flavus, including growth, reproduction, development, as well as pathogenicity and drug resistance. These significant findings establish a solid theoretical foundation for the development of environmentally friendly, safe, and effective antifungal agents to combat A. flavus contamination.

The Zanthoxylum armatum fruit's oil exterminates Candida cells by inhibiting ergosterol biosynthesis without generating reactive oxygen species

Candida spp. is a significant cause of topical and fungal infections in humans. In addition to Candida albicans, many non-albicans species such as C. krusei, C. glabrata, C. parapsilosis, C. tropicalis, C. guilliermondii cause severe infections. The main antifungal agents belong to three different classes, including azoles, polyenes, and echinocandins. However, resistance to all three categories of drugs has been reported. Therefore, there is an urgent need to search for other alternatives with antifungal activity. Many herbal extracts and compounds from natural sources show excellent antifungal activity. In this study, we used an oil extract from the fruits of Zanthoxylum armatum, which showed significant antifungal activity against various Candida spp. by two different methods-minimum inhibitory concentration (MIC) and agar diffusion. In addition, we attempted to explore the possible mechanism of action in C. albicans. It was found that the antifungal activity of Z. armatum oil is fungicidal and involves a decrease in the level of ergosterol in the cell membrane. The decrease in ergosterol level resulted in increased passive diffusion of a fluorescent molecule, rhodamine6G, across the plasma membrane, indicating increased membrane fluidity. The oil-treated cells showed decreased germ tube formation, an important indicator of C. albicans' virulence. The fungal cells also exhibited decreased attachment to the buccal epithelium, the first step toward invasion, biofilm formation, and damage to oral epithelial cells. Interestingly, unlike most antifungal agents, in which the generation of reactive oxygen species is responsible for killing, no significant effect was observed in the present study.

The antimicrobial property of JY-1, a complex mixture of Traditional Chinese Medicine, is linked to it abilities to suppress biofilm formation and disrupt membrane permeability

The substantial increase of infections, caused by novel, sudden, and drug-resistant pathogens, poses a significant threat to human health. While numerous studies have demonstrated the antibacterial and antiviral effects of Traditional Chinese Medicine, the potential of a complex mixture of traditional Chinese Medicine with a broad-spectrum antimicrobial property remains underexplored. This study aimed to develop a complex mixture of Traditional Chinese Medicine (TCM), JY-1, and investigate its antimicrobial properties, along with its potential mechanism of action against pathogenic microorganisms. Antimicrobial activity was assessed using a zone of inhibition assay and the drop plate method. Hyphal induction of Candida albicans was conducted using RPMI1640 medium containing 10% FBS, followed by microscopic visualization. Quantitative real-time PCR (RT-qPCR) was employed to quantify the transcript levels of hyphal-specific genes such as HWP1 and ALS3. The impact of JY-1 on biofilm formation was evaluated using both the XTT reduction assay and scanning electron microscopy (SEM). Furthermore, the cell membrane integrity was assessed by protein and nucleic acid leakage assays. Our results clearly showed that JY-1 significantly inhibits the vegetative growth of Candida spp. and Cryptococcus spp. In addition, this complex mixture is effectively against a wide range of pathogenic bacteria, including Staphylococcus aureus, Vancomycin-resistant enterococci, Escherichia coli, Klebsiella pneumoniae and Enterobacter cloacae. More interestingly, JY-1 plays a direct anti-viral role against the mammalian viral pathogen vesicular stomatitis virus (VSV). Further mechanistic studies indicate that JY-1 acts to reduce the expression of hyphal specific genes HWP1 and ALS3, resulting in the suppression of the hyphal formation of C. albicans. The antimicrobial property of JY-1 could be attributed to its ability to reduce biofilm formation and disrupt the cell membrane permeability, a process resulting in microbial cell death and the release of cellular contents. Taken together, our work identified a potent broad-spectrum antimicrobial agent, a complex mixture of TCM which might be developed as a potential antimicrobial drug.

Chemical Composition and Biocontrol Activity of Different Essential Oils against Soil-Borne Fungal Pathogens

In this study, the efficacy of the essential oil of Mentha longifolia, Achillea arabica and Artemisia absinthium plants were evaluated against important soil-borne fungal pathogens as Verticillium dahliae, Rhizoctonia solani, and Fusarium oxysporum. Essential oils were obtained from plants by hydrodistillation method and the chemical components of essential oils were determined by analyzing by gas chromatography-mass spectrometry. The main components found as piperitone oxide (13.61%), piperitenone oxide (15.55%), pulegone (12.47%), 1-menthone (5.75%), and camphor (5.75%) in M. longifolia, á-selinene 13.38%, camphor 13.34%, L-4-terpineneol 8.40%, (-)-á-Elemene 7.01%, 1,8-cineole 4.71%, and (-)-spathulenol 3.84% in A. arabica, and á-thujone (34.64%), 1,8-cineole (19.54%), pulegone (7.86%), camphene (5.31%), sabinene (4.86%), and germacrene-d (3.67%) in A. absinthium. The antifungal activities of the oils were investigated 0.05, 0.1, 0.25, 0.5, 1.00, and 2.00 μl/ml concentrations with the contact effect method. M. longifolia oil (1.00 and 2.00 μl/ml) has displayed remarkable antifungal effect and provided 100% inhibition on mycelial growth of V. dahliae, R. solani and F. oxysporum. The results obtained from this study may contribute to the development of new alternative and safe methods against soil-borne fungal pathogens.

Evaluation of dietary lignin on broiler performance, nutrient digestibility, cholesterol and triglycerides concentrations, gut morphometry, and lipid oxidation

Two trials were performed in order to evaluate the effects of dietary Kraft lignin inclusion on broiler performance, ileal nutrient digestibility, blood lipid profile, intestinal morphometry, and lipid oxidation of meat. Trial 1 was conducted in order to evaluate performance and ileal digestibility for the period of 1 to 21 d of age, randomly distributing 490 day-old broiler chicks across 5 dietary treatments with 14 replicates containing 7 birds each in metabolic cages, while trial 2 was executed in order to evaluate performance, blood parameters, intestinal morphometry, carcass yield and abdominal fat, and lipid oxidation for the period of 1 to 42 d of age, randomly distributing 900 day-old broiler chicks across 5 dietary treatments with 15 replicates of 12 birds each in floor pens, being each bird in trial 2 challenged with coccidiosis vaccine at 10 d of age. The treatments used in both trials were: positive control (PC): basal diet + antimicrobial; negative control (NC): Basal diet; NC1: NC + 1% lignin; NC2: NC + 2% lignin; NC3: NC + 3% lignin. For trial 1, it was observed that birds fed diets containing 1% lignin had a significant positive effect for BW, feed intake (FI), average daily weight gain (BWG) and feed conversion rate (FCR), similar to the PC, but also showing better EE, CP and AAs ileal digestibility percentages when compared to other treatments. For trial 2, it was observed that during the period of 21 to 35 d, the inclusion of lignin in the diet provided better results in animal performance, similar to the PC group, but at 42 d, animals fed with dietary lignin showed results lower than animals fed the PC diet (P < 0.05). Animals fed with increasing lignin concentrations showed decreasing levels of HDL (P < 0.05). As of intestinal morphometry, animals fed with 1% and 3% lignin showed longer intestinal length (P < 0.05). At 14 d of age, it was observed that animals fed with lignin showed oxidation levels similar to the control treatments. The inclusion of up to 1% lignin in the diet provides beneficial effects on productive performance and nutrient digestibility, while the inclusion of 2% lignin provided lower cholesterol levels, lower villus/crypt ratio, and better internal organ development, therefore, it can be considered an alternative to performance-enhancing antimicrobials in broiler chicken diets.

Synergistic interactions of essential oil components with antibiotics against multidrug-resistant Corynebacterium striatum

AIM

In this study, it was aimed to examine the antibacterial activity of the essential oil components (EOCs), carvacrol (CAR), cinnamaldehyde (CIN), thymol (TH), alpha pinene (α-PN), eucalyptol (EU), limonene (LIM), and the antibiotics, linezolid (LZD), vancomycin (VAN), gentamicin (GEN), ciprofloxacin (CIP), clindamycin (CLN), and penicillin (PEN) against 50 multidrug resistant Corynebacterium striatum strains, and the synergistic interactions of CAR and CIN with the antibiotics against 10 randomly selected Coryne. striatum strains to explore synergistic interactions to determine if their combined use could enhance antibiotic activity and potentially reduce resistance.

METHODS AND RESULTS

The activity of the EOCs and the antibiotics against Coryne. striatum strains isolated from clinical specimens, was examined by broth microdilution method. The synergistic interactions of the EOCs with the antibiotics against 10 randomly selected Coryne. striatum strains were determined by checkerboard method. EOCs, CIN, and CAR and antibiotics, LZD, VAN, GEN, CIP, and CLN were detected to have antibacterial activity against Coryne. striatum strains alone and either synergistic interactions were observed in combinations of the antibiotics with EOCs.

CONCLUSIONS

All Coryne. striatum strains were determined to be susceptible to VAN and LZD and resistant to GEN, PEN, CIP, and CLN. Synergistic interactions were observed in all combinations of antibiotics tested with CAR and CIN.

Antioxidant and antimicrobial effect of sodium alginate nanoemulsion coating enriched with oregano essential oil (Origanum vulgare L.) and Trachyspermum ammi oil (Carum cupticum) on food pathogenic bacteria

Today, microbial contamination in food is one of the major problems of the food industry and public health in general around the world. Foodborne illnesses, such as diarrheal diseases, kill many people around the world each year. The general objective of this study was to evaluate the antioxidant and antibacterial activity of sodium alginate nanoemulsion coating incorporated with oregano essential oil (Origanum vulgare L.) and Trachyspermum ammi oil (Carum cupticum) on Escherichia coli, and Listeria monocytogenes. To achieve this study, fresh chicken meat was used for this experiment. Listeria monocytogenes ATCC 19111 and Escherichia coli ATCC 35218 were obtained from the American Type Culture Collection (Manassas, VA, USA). After the preparation of the essential oil, the chemical composition of this essential oil was determined by using (GC-MS). The physicochemical properties of the nanoemulsion essential oil prepared were characterized and their antimicrobial activity was evaluated. The results showed that the GC-MS analysis of the volatile constituents of the Origanum vulgare essential oil compounds allowed the identification of 19 compounds representing 93.72% of the total oil. The major components detected in Origanum vulgare essential oil were pulegone (49.25%), eucalyptol (18.23%), and menthone (12.37%). About the Carum cupticum essential oil, 21 compounds representing 98.5% of the total oil were identified. The major components detected in Origanum vulgare essential oil were thymol (23.3%), p-cymene (17.5%), and γ-terpinene (16.8%). The best z-average (d.nm) is 483.4 nm (Carum cupticum essential oil + nano) followed by 470.1 nm (nanochitosan). The results of the antimicrobial test showed that the different preparations have a good inhibitory activity for the in vitro growth of Escherichia coli and Listeria monocytogenes. According to the MIC and MBC results of this study, the nanoemulsion also presented a good bacteriostatic activity against the two pathogenic bacteria tested in this study.

Efficacy and Synergistic Potential of Cinnamon (Cinnamomum zeylanicum) and Clove (Syzygium aromaticum L. Merr. & Perry) Essential Oils to Control Food-Borne Pathogens in Fresh-Cut Fruits

The presence of microbial pathogens in ready-to-eat produce represents a serious health problem. The antibacterial activity of cinnamon (Cinnamomum zeylanicum) and clove (Syzygium aromaticum L. Merr. & Perry) essential oils (EOs) was determined toward food-borne pathogens by agar disk diffusion and minimum inhibitory concentration (MIC) assays. The growth kinetics of all strains, both in a buffer suspension assay and "on food" in artificially contaminated samples, were also investigated. The two EOs demonstrated a good antibacterial effect both alone and in combination (EO/EO). The use of EO/EO led to a synergistic antibacterial effect, also confirmed by the growth kinetics studies, where the EOs were active after 10 h of incubation (p < 0.0001) at significantly lower concentrations than those when alone. In the "on food" studies performed on artificially contaminated fruit samples stored at 4 °C for 8 days, the greatest killing activity was observed at the end of the trial (8 days) with a reduction of up to 7 log CFU/g compared to the control. These results confirm the good antibacterial activity of the EOs, which were more effective when used in combination. Data from the "on food" studies suggest cinnamon and clove essential oils, traditionally used in the food industry, as a possible natural alternative to chemical additives.