Effect Of Essential Oil Research Articles

Chemical composition and repellent effects of powders and essential oils from Juniperus oxycedrus, Juniperus phoenicea, and Juniperus thurifera against Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae)

The present study evaluated the chemical composition and the potential repellent effect of powders and essential oils (EOs) from Juniperus oxycedrus, Juniperus phoenicea, and Juniperus thurifera against T. castaneum adults. The EOs were extracted by the hydrodistillation method, and their chemical composition was analyzed using gas chromatography-mass spectrometry (GC-MS) analysis. The repellent effect of powders and EOs was assessed using the area preference method. GC-MS revealed that the major components of the studied EOs were α-pinene (28.27%) and cubenol (10.75%) for J. phoenicea, β-Eudesmol (23.74%), hedycaryol (12.54%), and olopanone (10.04%) for J. oxycedrus, and oplopanone (26.84%) and α-Santanol acetate (17.28%) for J. thurifera. The powders of three Juniperus species had a repellent effect (class IV) against T. castaneum adults. Among the powders tested, J. phoenicea had the highest average repellency rate of 75.40%, followed by J. oxycedrus with 62.30%, and J. thurifera had the lowest average repellency rate of 60.30%. Moreover, J. phoenicea EO had the highest average repellency rate of 72.50%, followed by J. oxycedrus with 67.40%, while J. thurifera had the lowest average repellency rate of 61.80%.The potential of Juniperus species can be used as biopesticides to control T. castaneum infestations as an alternative to synthetic pesticides.

First Report on Salvia Sahendica Boiss & Buhs roots biocomponents characterization by GC-MS and HPLC and Antibacterial Potency

Treatment of bacterial infections with antibiotic resistance is complicated. For this reason, new therapeutic methods are needed to control bacterial infections. Therefore, it is necessary to discover new antibiotics from medicinal plants that can destroy drug-resistant bacteria. Essential oils (EO) of some medicinal plants have antimicrobial effects and can be used as antimicrobial agents in the treatment of infections and food industries. The aim of this study was to determine the EO composition and antimicrobial effects of EO and polyphenols profile of Salvia Sahendica roots for the first time. Chemical compounds and antibacterial activity of EOs against Staphylococcus aureus and Bacillus cereus as gram-positive and Escherichia coli and Pseudomonas aeruginosa as gram- negative bacteria were evaluated using microtiter broth dilution method. Studied organs of S. sahendica showed significant diversity in terms of type and percentage of essential oil and polyphenol compounds. Overall, 44, 46, 42, and 45 compounds were identified in the essential oil of leaves, flowers, stems, and roots of this plant, which constituted 99.6, 99.3, 98.2, and 99.4% of total oil composition, respectively. The current study collectively demonstrated inhibitory effects ranged from strong (S. aureus) to low inhibition (P. aeruginosa). According to the HPLC result, the amounts of coumaric acid, chlorogenic acid, and gallic acid compounds in the root are higher than in other plant parts, which indicate that the root can be a suitable source for the production of these valuable polyphenol compounds. Due to the results, it is possible to hope for the application of EO from S. sahendica as natural antibacterial in the pharmaceutical and food industries.

Essential oils application as Bacillus cereus antispore agent in food hygiene

Adherence of Bacillus cereus spores to dairy industry equipment is a serious problem, causing food spoilage and, occasionally, outbreaks of foodborne diseases. Antimicrobial essential oils (EOs) have been proposed as an alternative to synthetic disinfectants due to their environmentally friendly properties. The aim of this study was to assess the effect of Cymbopogon winterianus and Juniperus phoenicea EOs on planktonic and adherent B. cereus spores to stainless steel surfaces. Eleven strains of B. cereus were used in this study. The chemical composition of the C. winterianus and J. phoenicea oils was analyzed by gas chromatography (GC)/mass spectrometry (MS). Ninety components were identified for C. winterianus, being geranial (37 %), neral (29 %), beta-myrcene (16 %) and geraniol (4 %) the most abundant constituents. Twelve components were identified for J. phoenicea, being alpha-pinene (65 %) the most abundant constituent. The results of the minimal inhibitory concentration and minimal bactericidal concentration revealed that C. winterianus was the most effective EO (p < 0.05) against all eleven strains. In addition, there was a large log10 reduction (from 4.93 to 2.42; p < 0.05) between spores in planktonic form versus spores adhered to stainless steel surface. C. winterianus can be used for effective detachment of B. cereus spores capable to adhere and form biofilms on stainless steel surfaces, being a valid alternative for the development of natural disinfectant that may reduce negative effects of synthetic chemical disinfectants.

Essential oils from Cuminum cyminum and Laurus nobilis and their principal constituents: evaluation of antifungal and antimycotoxigenic potential in Aspergillus species.

The antifungal and antimycotoxigenic activities of the essential oils (EO) from Cuminum cyminum and Laurus nobilis, and their respective principal compounds, cuminaldehyde and 1,8-cineole, were evaluated against fungi of the genus Aspergillus: A.carbonarius, A.niger, A.ochraceus and A.westerdijkiae. The antifungal activity was determined by the contact method and the mycelial growth of the fungi was evaluated. Scanning Electron Microscopic (SEM) images were obtained to suggest modes of action of the compounds analyzed. The antimycotoxigenic activity was determined by HPLC. A.carbonarius was completely inhibited by cumin EO (500 µL L-1), by laurel EO and by cuminaldehyde (5000 µL L-1). The cumin EO (500 µL L-1) completely inhibited the growth of A.niger. All the samples inhibited the mycelial growth of A.ochraceus, especially cumin EO and cuminaldehyde (250 µL L-1). A.westerdijkiae was completely inhibited by cumin EO and cuminaldehyde (1000 µL L-1), by laurel EO and 1,8-cineole (10000 µL L-1). A decrease in the production of ochratoxin A (OTA) was observed post-treatment, except in A. ochraceus, only inhibited by laurel EO. SEM images showed morphological changes in fungal structures and spore inhibition post-treatment. The results confirmed the antifungal and antimycotoxigenic effect of EO and their principal constituents on fungi evaluated.

Comparative Biochemical and Pharmacodynamic Analyses of Asarum heterotropoides Fr. Schmidt var. Mandshuricum (Maxim) Kitag and Asarum sieboldii Miq var. Seoulense Nakai Roots

Background:Asarum heterotropoides and Asarum sieboldii are commonly used in traditional Chinese medicine. However, little is known about how they differ in terms of essential oil (EO) and ethanol extract (EE) content and composition. Moreover, the effect of various geographical locations on the essential oil (EO), ethanol extract (EE), and asarinin content of different Asarum samples remains unknown. We tested four root-drying methods, i.e., soil removal and shade drying (P1), water washing and shade drying (P2), and water washing and drying at 30 °C (P3) and 40 °C (P4). We used LC-MS and GC-MS to investigate these differences. We also investigated the pharmacodynamic effects of EO and EE. Results: Overall, the EO, EE and asarinin contents of the analysed samples were 19.21–51.53 μL.g−1, 20.00–45.00 μL.g−1, and 1.268–2.591 mg.g−1, respectively. P1 treatment yielded the lowest volatile oil content compared to the other three treatments. GC-MS analysis revealed 78 EO components. Among the six major EO components, eucarvone, 3,5-dimethoxytoluene, and methyl eugenol were higher in A. heterotropoides than in A. sieboldii. However, the latter had a higher myristicin content. LC-MS analysis identified 888 EE components in roots and leaves of A. heterotropoides and A. sieboldii; 317 differentially accumulated metabolites were identified. EO and EE showed a dose-dependent reduction in the degree of swelling and an increase in the inhibition rate of drug concentration on acetic acid writhing in mice. Asarum EO proved to be more effective than EE in the pharmacodynamic study. Conclusions: We conclude that Asarum species show inter- and intra-specific differences in EO and EE content and composition, which may influence the pharmacodynamics of Asarum root extracts.

Toxicity of Essential Oil from Artemisia herba-alba (Asso.) against Two Insect Pests of Stored Products

This study aimed to examine the insecticide properties of Artemisia herba-alba essential oil (EO) against two main insect pests of stored products Tribolium castaneum and Sitophilus zeamais. The toxicity of EO was tested using contact and fumigant bioassays. Repellent activity was also studied using the preference zone method on filter paper. Using GC/MS analysis, the major compounds were, respectively, camphor (23.61%), α-thujone (13.67%), chrysanthenone (11.21%), 1,8-cineole (10%) and β-thujone (7.65%). In both insects, the toxicity tests applied showed a significant increase in the percentage of mortality according to the doses tested (p ≤ 0.05). Moreover, the probit analysis exposed lower values of doses and lethal concentrations (LD50, LD90, LC50, and LC90), which justified the toxic effect of EO on the two insects. In addition, EO caused a significant repulsion after 1 h and 2 h of exposure. The results obtained suggest that A. herba-alba EO can be an excellent alternative to chemical insecticides in the conservation of stored products.

Chemical composition and antimicrobial activity of Plinia rivularis essential oil against multidrug-resistant bacteria

IntroductionThe increasingly common occurrences of multidrug-resistant bacteria represent a global health threat and the discovery of new alternative remedies is necessary. The use of essential oils (EOs) in the treatment of many pathogenic bacteria is promising and several examples have already been highlighted regarding their inhibitory action. Among the botanical families, Myrtaceae stands out for presenting important species that supply bioactive products. MethodsIn this work we investigate the chemical composition of Plinia rivularis (Myrtaceae) leaf EO and its antibacterial activity against resistant and non-resistant bacteria. The EO was obtained by two methods, hydrodistillation and steam distillation. Gas chromatography-flame ionization detector (GC-FID), gas chromatograph-mass spectrometry (GC-MS), nuclear magnetic resonance spectroscopy (NMR) and Fourier transform infrared spectroscopy (FTIR) were the techniques used in the EO chemical characterization. ResultsThe EOs were obtained with yields of 0.37 and 0.16% by hydrodistillation and steam distillation methods, respectively. The analyzes revealed the EOs chemical profile showing the compounds 2H-benzocyclohepten-2-one,3,4,4a,5,6,7,8,9-octahydro-4a-methyl (synonym: 4a-methyl-3,4,4a,5,6,7,8,9-octahydro-2H-benzo[7]annulen-2-one), rosifoliol, β-eudesmol and the diterpene kaurene as main constituents. Through preparative thin-layer chromatography (PTLC), it was possible to obtain the diterpene kaurene with a content of 91%, which was also characterized by NMR. The minimum inhibitory concentrations of EO against bacteria ranged from 0.56 to 2.25 mg.ml−1 and 2.25–36 mg.ml−1 for sensitive and resistant bacteria, respectively. Also, EO showed synergistic activity with amikacin and cefotaxime against carbapenem-resistant Pseudomonas aeruginosa (KPC). ConclusionsThis is the first report on the chemical composition of P. rivularis EO. Comparison of extraction methods showed variation in yields and small changes in component content. The EO demonstrated activity against resistant and non-resistant bacteria. In addition, the synergistic effect of EO against resistant bacteria may be explored in future studies.

The Role of Essential Oils on Sleep Quality and Other Sleep-related Issues: Evidence from Clinical Trials.

Essential oils (EOs) are a volatile mixture of bioactive compounds extracted from aromatic plants. The composition of EOs varies, which majorly depends on the extraction methods and plant parts. Aromatherapy using EOs has been reported for its several beneficial effects in humans. Aromatherapy is considered a complementary and/ or adjuvant therapeutic approach for treating several illnesses, especially to improve mental health and well-being. The incidence of sleep disorders, specifically insomnia, is nowadays increased, possibly due to urbanization and lifestyle. The studies showed that EOs-based treatments using lavender EO, bergamot EO, cinnamon EO, and rosemary EO (alone or in combinations) could improve sleep quality, duration, and deprivation in healthy subjects and patients, those who suffer from sleep-related issues. The current manuscript details the outcomes of EO-based treatments on the sleep quality of humans and the possible mechanisms associated with the health-promoting properties of EOs. Also, the toxicity and adverse effects of EOs have been discussed. The study indicated that EOs are potent adjuvant therapeutic candidates to manage mood-associated complications in humans. Moreover, the aromatherapeutic field requires detailed studies on toxicity and dose determination, which could provide safe and effective therapeutic results.

Algerian Artemisia herba-alba (Asso): Extract and Essential Oils Investigation

Background/Objective: Numerous studies have demonstrated the ethno-and pharmacological properties of various Artemisia species. However, this plant genus which grows abundantly and wildly in the ‘Tébessa’ Algerian region has not been investigated. This study focuses on the phytochemical characterization, biological activities evaluation with the antibacterial fraction identification of the aerial part aqueous extract (AE) and essential oil (EO) from Algerian Artemisia herba alba ( Aha) growing wild in the ‘Tebessa' region. Methods: Polyphenols, flavonoids, and condensed tannins were analyzed by spectrophotometer and the antimicrobial activity was determined by the gel diffusion followed by micro-dilution methods. The antioxidant effect was assayed using 2,2-diphenyl-1-picrilhidrazil (DPPH), total antioxidant capacity (TAC), and ferric reducing power (FRAP) tests. The cytotoxic and anti-leishmaniasis activities were experienced on Raw 264.7 cell line and on L. infantum and L. major promastigotes respectively. Thin-layer chromatography (TLC)/autobiography and gas chromatography-mass spectrometry (GC-MS) techniques were used to isolate and identify the antibacterial compounds. EO profile was determined by GC-MS analysis. Results: The extracts (AE and EO) demonstrated antioxidant activity, with the AE exhibiting the most pronounced levels. Both extracts showed antimicrobial activity against all the strains tested however; the EO effect was more effective, especially against the E. feacalis strain with a minimum inhibitory concentration (MIC) value of 0.0625 mg/mL. The antibacterial fraction exerted by AE towards E. feacalis was identified. AE and EO extracts showed antileishmanial activity and no toxic effect however, volatile extract was the most effective. EO profile revealed 19 identified compounds, led by camphor (51.14%), followed by 1,8 Cineole (19.30%), camphene (6.90%) and chrysanthenone (5.68%). Conclusion: As a result, the both extracts promise a high potential applications in agri-food, pharmaceutical, cosmetic sectors. This study aligns with Sustainable Development Goals (SDGs) 3, 12, and 15, emphasizing potential health benefits, the responsible use of natural resources, and biodiversity conservation.

HS-GC-IMS Analysis of Volatile Organic Compounds in Six Spicy Spices and Their Effects on Ulcerative Colitis.

The volatile organic compounds of six spices, including black pepper, dried ginger, cinnamon, fennel, clove, and zanthoxylum, were analyzed by gas chromatography-ion mobility spectrometry (HS-GC-IMS) combined with principal component analysis (PCA) and Euclidean distance. In further analyses, the effects of volatile oils in six spices on ulcerative colitis were assayed in a zebrafish model induced by 3-nitrobenzenesulfonic acid. A total of 120 kinds of volatile organic compounds were detected and 80 among them were identified, which included 10 common components and 3 to 24 characteristic components belonging to different spices. The major VOCs in six spices were estimated to be terpenes with the contents of 45.02%, 56.87%, 36.68%, 58.19%, 68.68%, and 30.62%, respectively. Meanwhile, the volatile components of fennel, dried ginger, black pepper, and cinnamon are quite similar, but differ from clove and zanthoxylum. The volatile oils in six spices presented efficient activity to improve ulcerative colitis which can decrease the number of neutrophils, restore the structure of intestinal epithelial and the morphology of the epithelial cells. Our study achieved rapid analysis of the volatile organic compounds and flavors in six spices and further revealed the potential health benefits of their volatile oils on ulcerative colitis, especially for clove and zanthoxylum. This study is expected to provide certain data support for the quality evaluation and the potential use in functional foods of six spices.

Contact Toxicity and Repellent Effects of Essential Oils from Toddalia asiatica Against Two Stored-Product Insects.

Insect infestations continually endanger stored goods, underscoring the significance of discovering eco-friendly insecticides for pest management. Essential oils (EOs) from different parts of Toddalia asiatica (leaf, fruit and branch) were extracted by hydrodistillation and analyzed by GC-MS. Carvene, p-cymene and muurolene are the principal compounds of T. asiatica leaf (TAL), T. asiatica fruit (TAF) and T. asiatica branch (TAB) EO respectively. Our work aimed to assess the contact toxicity and repellent effects of EOs on two storage pests, Tribolium castaneum and Lasioderma serricorne. All tested EOs exhibited obvious contact toxicity, especially, TAL EO against T. castaneum (33.48 μg/adult) and TAF EO against L. serricorne (16.42 μg/adult). Repellency tests revealed that TAL and TAF EOs, at a concentration of 78.63 nL/cm2, achieved nearing 100 % efficiency against T. castaneum. These results suggest that EOs of T. asiatica could be used as effective botanical insecticides for managing stored-product insects.

Composition, Bioactivities, Microbiome, Safety Concerns, and Impact of Essential Oils on the Health Status of Domestic Animals

Essential oils (EOs) are highly concentrated and volatile blends of nonpolar substances that are derived from aromatic plant components and comprise terpenes, terpenoids, and phenylpropanoids, exhibiting diverse biological and pharmacological properties. The burgeoning pet industry is interested in EOs as a potential solution for common health issues in domestic animals, particularly in addressing antimicrobial resistance. The present literature review summarizes the composition, properties, benefits, safety considerations, and effects of EOs on domestic animals. The applications of EOs range from antimicrobial effects to antioxidant, anti-inflammatory, and anticancer activities, etc. The chemical constituents of EOs, exemplified by eucalyptus EO and rosemary EO, highlight their distinct aromatic profiles and potential benefits. Nevertheless, understanding the chemical makeup of EOs is fundamental to assessing their potential impacts on biological systems. The gut microbiota plays a crucial role in regulating various metabolic processes in the host, including energy homeostasis, glucose metabolism, and lipid metabolism. Safety considerations, including potential toxicity risk awareness, are essential when incorporating EOs into animal care routines. The feed additives incorporating EOs have shown promise in influencing gut microbiota balance, reducing inflammation, and acting as antioxidants. However, considering the potential risks associated with high doses or multiple administrations, cautious application is paramount. Preliminary studies suggest low toxicity levels, but further research is required to evaluate the safety of EOs. Though studies have reported the beneficial effects of EOs on pets and animals, further research is needed to validate the findings in real-world conditions. The paper also discussed the regulatory considerations and future perspectives on applying EOs in veterinary medicine.

In-vitro assessment of α-amylase, photoprotective, antimicrobial activities, and chemical composition of Asphodelus microcarpus (Liliaceae) Essential Oils from Constantine (Eastern Algeria)

&lt;p&gt;This study examines the antidiabetic, photoprotective, and antibacterial properties of Asphodelus microcarpus (Liliaceae) essential oil (EO) collected from Constantine, Eastern Algeria. The EO was obtained by hydro-distillation and the composition was determined by Gas chromatography (GC) and gas chromatography-mass spectrometry (GC/MS). Fifty-one (51) compounds were identified in the EO; the major components are α-phellandrene (15.18%), α-pinene (14.27%), Sabinene (13.81%), β-Ocimene (Z) (12.69%), and δ-3- carène (9.20%). Based on the findings of the biological assays, the EO appeared to have dose-dependent anti-diabetic activity in the α-amylase test, with an IC50 value of 412.73±5.83µg/ml. Additionally, according to the Recommendation of the European Commission (2006), this oil displayed significant activity with a sun protection factor (SPF) of 31.89±0.10. Furthermore, the EO was tested for its antibacterial activity against five bacteria strains, and its antifungal activity against Aspergillus niger using the agar-well diffusion method. The studied EO showed only marginal activity against the tested microorganisms and was inactive against Pseudomonas aeruginosa. However, A.microcarpus EO showed notable antifungal activity against Aspergillus niger with a minimum concentration of 25µg/mL. It is important to note that this is the first report on the α-amylase and SPF effects of Asphodelus microcarpus EO.&lt;/p&gt;

Companion basil plants prime the tomato wound response through volatile signaling in a mixed planting system

Key messageVolatile compounds released from basil prime the tomato wound response by promoting jasmonic acid, mitogen-activated protein kinase, and reactive oxygen species signaling.Within mixed planting systems, companion plants can promote growth or enhance stress responses in target plants. However, the mechanisms underlying these effects remain poorly understood. To gain insight into the molecular nature of the effects of companion plants, we investigated the effects of basil plants (Ocimum basilicum var. minimum) on the wound response in tomato plants (Solanum lycopersicum cv. ‘Micro-Tom’) within a mixed planting system under environmentally controlled chamber. The results showed that the expression of Pin2, which specifically responds to mechanical wounding, was induced more rapidly and more strongly in the leaves of tomato plants cultivated with companion basil plants. This wound response priming effect was replicated through the exposure of tomato plants to an essential oil (EO) prepared from basil leaves. Tomato leaves pre-exposed to basil EO showed enhanced expression of genes related to jasmonic acid, mitogen-activated protein kinase (MAPK), and reactive oxygen species (ROS) signaling after wounding stress. Basil EO also enhanced ROS accumulation in wounded tomato leaves. The wound response priming effect of basil EO was confirmed in wounded Arabidopsis plants. Loss-of-function analysis of target genes revealed that MAPK genes play pivotal roles in controlling the observed priming effects. Spodoptera litura larvae-fed tomato leaves pre-exposed to basil EO showed reduced growth compared with larvae-fed control leaves. Thus, mixed planting with basil may enhance defense priming in both tomato and Arabidopsis plants through the activation of volatile signaling.

The Influence of Physical Fields (Magnetic and Electric) and LASER Exposure on the Composition and Bioactivity of Cinnamon Bark, Patchouli, and Geranium Essential Oils.

In recent years, essential oils (EOs) have received increased attention from the research community, and the EOs of cinnamon, patchouli, and geranium have become highly recognized for their antibacterial, antifungal, antiviral, and antioxidant effects. Due to these properties, they have become valuable and promising candidates for addressing the worldwide threat of antimicrobial resistance and other diseases. Simultaneously, studies have revealed promising new results regarding the effects of physical fields (magnetic and electric) and LASER (MEL) exposure on seed germination, plant growth, biomass accumulation, and the yield and composition of EOs. In this frame, the present study aims to investigate the influence of MEL treatments on cinnamon, patchouli, and geranium EOs, by specifically examining their composition, antimicrobial properties, and antioxidant activities. Results showed that the magnetic influence has improved the potency of patchouli EO against L. monocytogenes, S. enteritidis, and P. aeruginosa, while the antimicrobial activity of cinnamon EO against L. monocytogenes was enhanced by the electric and laser treatments. All exposures have increased the antifungal effect of geranium EO against C. albicans. The antioxidant activity was not modified by any of the treatments. These findings could potentially pave the way for a deeper understanding of the efficiency, the mechanisms of action, and the utilization of EOs, offering new insights for further exploration and application.

Effects of Essential Oils on Biological Characteristics and Potential Molecular Targets in Spodoptera frugiperda.

Spodoptera frugiperda control methods have proved to be inefficient, which justifies the search for new control measures. In this search for botanical insecticides for controlling S. frugiperda, the following were evaluated: (i) the toxicity of essential oils (EOs) from Cinnamodendron dinisii, Eugenia uniflora, and Melaleuca armillaris; (ii) the effect of EOs on life table parameters against S. frugiperda; (iii) the chemical characterization of EOs; and (iv) the in silico interaction of the chemical constituents present in the three EOs with the molecular targets of S. frugiperda. The EO from E. uniflora had the lowest LD50 (1.19 µg of EO/caterpillar). The major compounds bicyclogermacrene (18.64%) in C. dinisii and terpinolene (57.75%) in M. armillaris are highly predicted to interact with the octopamine receptor (OctpR). The compound 1,8-cineole (21.81%) in M. armillaris interacts mainly with a tolerant methoprene receptor (MET) and curzerene (41.22%) in E. uniflora, which acts on the OctpR receptor. Minor compounds, such as nerolidol in C. dinisii and β-elemene in E. uniflora, are highly ranked for multiple targets: AChE, MET, OctpR, and 5-HT1. It was concluded that the EO from E. uniflora negatively affects several biological parameters of S. frugiperda development and is promising as an active ingredient in formulations for controlling this insect pest.

Essential oils ameliorate the intestinal damages induced by nonylphenol exposure by modulating tryptophan metabolism and activating aryl hydrocarbon receptor via gut microbiota regulation

Nonylphenol (NP) is a ubiquitous endocrine disruptor that persists in the environment and can significantly contribute to serious health hazards, particularly intestinal barrier injury. Plant essential oils (EOs) have recently gained widespread interest due to their potential for improving intestinal health. However, the precise mechanism and protective effects of EOs ameliorating the intestinal damages induced by NP exposure remain unclear. To clarify the potential mechanism and protective impact of EOs against intestinal injury induced by NP, a total of 144 one-day-old male ducks were randomly allocated to four groups: CON (basal diet), EO (basal diet + 200 mg/kg EOs), NP (basal diet + 40 mg/kg NP), and NPEO (basal diet + 200 mg/kg EOs + 40 mg/kg NP). The data revealed that NP exposure significantly damaged intestinal barrier, as evidenced by a reduction in the levels of tight junction gene expression and an increase in intestinal permeability. Additionally, it disturbed gut microbiota, as well as interfered with tryptophan (Trp) metabolism. The NP-induced disorder of Trp metabolism restrained the activation of aryl hydrocarbon receptor (AhR) and resulted in decreased the expression levels of CYP1A1, IL-22, and STAT3 genes, which were alleviated after treatment with EOs. Taken together, NP exposure resulted in impairment of the intestinal barrier function, disruption of gut microbiota, and disturbances in Trp metabolism. Dietary EOs supplementation alleviated the intestinal barrier injury induced by NP through the Trp/AhR/IL-22 signaling pathway.

In Vitro Evaluation of Synergistic Essential Oils Combination for Enhanced Antifungal Activity against Candida spp.

In recent years, a significant number of infections have been attributed to non-albicidal Candida species (NAC), mainly due to the increasing resistance of NAC to antifungal agents. As only a few antifungal agents are available (azoles, echinocandins, polyenes, allylamines and nucleoside analogues), it is very important to look for possible alternatives to inhibit resistant fungi. One possibility could be essential oils (EOs), which have been shown to have significant antifungal and antibacterial activity. Therefore, in this study, the efficacy of 12 EOs and their combinations was evaluated against four yeasts of the genus Candida (C. albicas, C. glabrata, C. tropicalis and C. parapsilosis). GC-MS and GC-MS FID techniques were used for the chemical analysis of all EOs. VITEK-2XL was used to determine the antifungal susceptibility of the tested Candida spp. strains. The agar disc diffusion method was used for primary screening of the efficacy of the tested EOs. The broth dilution method was used to determine the minimum inhibitory concentrations (MICs) of the most potent EOs. After MIC cultivation, the minimum fungicidal concentration (MFC) was determined on Petri dishes (60 mm). The synergistic effect of combined EOs was evaluated using the checkerboard method and expressed as a fractional inhibitory concentration index (FICI). The results showed that ginger > ho-sho > absinth > dill > fennel > star anise > and cardamom were the most effective EOs. For all Candida species tested, the synergy was mainly observed in these combinations: ginger/fennel for C. albicans FICI 0.25 and C. glabrata, C. tropicalis and C. parapsilosis FICI 0.5 and absinth/fennel for C. albicans FICI 0.3125, C. tropicalis FICI 0.3125 and C. parapsilosis FICI 0.375. Our results suggest that the resistance of fungal pathogens to available antifungals could be reduced by combining appropriate EOs.

Evaluation of natural compounds against Listeria innocua: Translating in vitro success to processed meat models

Ensuring food safety is a significant challenge in the processed meat industry. Listeria monocytogenes represents a persistent threat due to its ability to grow in adverse conditions. Nowadays, there's a growing interest in natural preservatives to inhibit its proliferation in foods. Accordingly, the aim of the present study was to preliminarily evaluate the in vitro inhibitory activity of various natural antimicrobial agents against Listeria innocua, used as a surrogate for L. monocytogenes. Thyme essential oil (EO) emerged as the most effective candidate for further in vivo testing in pork minced meat with 40% fat and no additional fat, deliberately contaminated with L. innocua. The samples were stored for 20 days under two different temperature conditions, mimicking common procedures used to produce salami with short ripening periods and high fat content, such as the Italian Ciauscolo PGI salami, either through spontaneous fermentation or with the use of starter cultures. In vivo, the inhibitory effect of thyme EO was minimal or absent, regardless of fat content. Statistically significant decreases in L. innocua counts (<2%) were sporadic and observed solely in samples stored under temperature conditions mimicking the typical procedure for spontaneously fermented salami production. However, this effect was not sustained until the end of the experiment. While thyme EO demonstrated potential as an antilisterial agent in vitro, our findings highlight the complex interaction between antimicrobial agents and food matrices, revealing challenges in practical applications. This underscores the importance of further investigation elucidating the effectiveness of antimicrobial agents in real food systems.

Insecticidal activity of Baccharis essential oils against Duponchelia fovealis, toxicity to strawberry leaves, and in vitro biocompatibility with entomopathogenic fungi

ABSTRACT Duponchelia fovealis is responsible for great losses in the strawberry production, and entomopathogenic fungi (EPF) are an alternative to control this larva. They can be used in combination with other natural compounds with insecticidal activity, such as plant extracts or essential oils (EOs). Thus, our objectives are to evaluate the effects of Baccharis dracunculifolia and Baccharis uncinella EOs on strawberry leaves and third instar larvae of D. fovealis, and to evaluate their in vitro compatibility with strains of Beauveria bassiana and Cordyceps javanica. EOs were not phytotoxic to strawberry leaves at 2% v/v. Larval mortality ranged between 48% and 83% at 1% and 2%, and B. dracunculifolia EO at 2% presented the higher mortality. EO of B. uncinella (BU) at 1% was compatible with two strains of B. bassiana and C. javanica. Therefore, the combined use of BU EO with EPF may be an alternative to control D. fovealis.