Efficiency Of Essential Oils Research Articles

Research Progress in Essential Oil Nanodelivery Systems

Essential Oil (EO) is widely usedin medicine because of its antioxidant, antiinflammatory, antibacterial, antimicrobial, and antiviral properties. However, the hydrophobicity, volatility, instability, and potential toxicity of EO make it difficult to achieve efficient delivery in vivo, which limits its application. In recent years, nano drug delivery systems have been gradually applied to encapsulate EO to improve their physical and chemical properties. In order to further improve the delivery efficiency of EOs, this review summarized the commonly used nano delivery systems for EOs, analyzed their preparation principles, and listed the factors affecting the delivery efficiency of essential oils. Moreover, the challenges faced by the EO delivery system are sorted out, and the corresponding solutions are proposed, with the hope of indicating the development direction for expanding the application of the nano drug delivery system in EO.

The efficiency of Thymus vulgaris, Lavandula angustifolia, and Cupressus sempervirens essential oils in suppression of Hymenoscyphus fraxineus on Fraxinus angustifolia seedlings

AbstractDue to intense ash dieback, this research tested the bioactivity of Thymus vulgaris, Lavandula angustifolia, and Cupressus sempervirens essential oils (EO) against Hymenoscyphus fraxineus. In vitro testing showed that EOs had a pronounced fungitoxic effect on H. fraxineus. The most effective EO was extracted from T. vulgaris, while EOs obtained from L. angustifolia and C. sempervirens were less effective and showed the same effect. At a concentration of 1%, all tested EOs inhibited mycelial growth, while 0.01% and 0.1% concentrations of EO extracted from T. vulgaris also inhibited the growth of H. fraxineus. The in planta test of EO extracted from T. vulgaris conducted on three‐year‐old Fraxinus angustifolia seedlings showed a reduction in the size of necrotic lesions and a better crown condition compared to untreated seedlings. This research demonstrates, for the first time, the efficiency of EOs in suppressing ash dieback making a path for the development of new biological protection measures against H. fraxineus.

Eco-friendly management of the citrus nematode Tylenchulus semipenetrans using some aromatic and medicinal plants

Tylenchulus semipenetrans is among the most damaging obligate plant parasitic nematodes (PPNs) in citrus. The use of chemical nematicides has successfully been used to lower the population of T. semipenetrans, but the repetitive use of these compounds can be environmentally harmful requiring the implementation of ecological strategies. The present study aimed at assessing the biological control potential of Essential Oils (EOs) of seven aromatic and medicinal plants (AMP), Rosmarinus officinalis, Thymus vulgaris, Laurus nobilis, Verbena officinalis, Foeniculum vulgare, Moringa oleifera, and Chamaemelum nobile against the citrus nematode T. semipenetrans in terms of juvenile J2 mortality and eggs hatch inhibition. Obtained results showed that all EOs exhibited high toxicity against T. semipenetrans. Indeed, the juvenile J2 mortality (ranging between 4% and 23% after 24 h of incubation), and eggs hatch inhibition (varying between 0% and 69% after 48 h of incubation) increased with increasing EOs concentration and incubation period reaching 100% of mortality after 96 h and complete eggs hatch after 144 h of incubation at EOs concentration of 20 μl/ml. In addition, the efficiency of EOs varied significantly between the seven AMP species. Indeed, R. officinalis and T. vulgaris were highly active on T. semipenetrans inducing 100% of J2 mortality recorded after 72 h of incubation at 15 µl/ml, and complete eggs hatch inhibition regardless of the EOs concentration and incubation period. As a result of this study, EOs of the AMP studied, particularly R. officinalis and T. vulgaris, could be used as healthy nematicidal products that are highly effective against T. semipenetrans.

Essential oil‐based active polymer‐based packaging system: A review of its effect on the antimicrobial, antioxidant, and sensory properties of beef and chicken meat

Meat is characterized by high perishability and a short shelf-life under improper storage. The evolution of food packaging in response to the growing need for clean-label technology has resulted in a sustainable, effective, safe, and natural method of prolonging the shelf-life of food using eco-friendly technologies. Active packaging presents a peculiar approach to preserving and packaging foods such as fresh and processed meat. They are composed of films and/or coatings obtained from natural sources of polysaccharides, lipids, and proteins that are edible, biodegradable, and can act as carriers of active ingredients from natural sources. Essential oils (EOs) are plant-extracted volatile aromatic compounds that have been the center of attention several types of research owing to their potential in food as natural additives and active ingredients with antimicrobial and antioxidant properties. Their utilization into biodegradable components for instance edible films to develop an active packaging system with enhanced functionalities and usefulness to the packaging and food industry is described. This review provides critical insights into the inclusion of EOs into bio-based materials with an emphasis on muscle food applications. Encapsulation was also emphasized as a key factor in optimizing the usage, stability, and efficiency of EOs in active packaging. The shelf-life of food is prolonged by the packaging system through preventing the actions of external aggressors such as oxygen and moisture, delaying the proliferation of spoilage and pathogenic microorganisms, slowing oxidative processes, and extending the duration that products are organoleptically acceptable. While cost and commercialization are the main concern for food industry professionals, consumers' main concerns are safety and awareness. In a nutshell, EO-based active packaging holds a lot of potential for shelf-life extension of meat and quality preservation. Novelty impact statement EO-based active packaging system has the potential to offer clean-label technology to consumers while alleviating food wastage and utilization of plastics by extending the shelf-life of food through eco-friendly processes. Encapsulation can improve the stability and effectiveness of EOs as antioxidants and antimicrobial agents, as well as address the challenges that have limited their application in the food system.

Inhibition of Fungal Strains Isolated from Cereal Grains via Vapor Phase of Essential Oils.

Fungal contamination in stored food grains is a global concern and affects food economics and human and animal health. It is clear that there is a need to develop new technologies with improved performances that are also eco-friendly in nature. Due to the bioactivity of essential oils (EOs) in the vapor phase, their low toxicity for humans, and their biodegradability and antifungal properties, EOs could be a suitable solution. In this study, we explored the potential of thyme, oregano, lemongrass, clove, and cajeput EOs in the vapor phase. For 17 days, inhibitory activity was assessed against five strains of postharvest pathogens—Aspergillus spp., Fusarium s. l. spp., and Penicillium ochrochloron—isolated from cereal grains. A modified disc volatilization method was used, which is more effective in comparison to traditional screening methods. Three concentrations were tested (250, 125, and 62.5 μL/L). The two highest concentrations resulted in complete inhibition of fungal growth; however, even 62.5 μL/L showed a significant antifungal effect. The efficiency of EOs followed this order: thyme > oregano > lemongrass > clove > cajeput. From our findings, it appears that the use of EOs vapors is a better option not only for laboratory experiments, but for subsequent practice.

Effect of imidazolium ionic liquids as microwave absorption media for the intensification of microwave-assisted extraction of Citrus sinensis peel essential oils

Ionic liquid-based microwave-assisted extraction (MAE-IL) has been applied for the separation of essential oils (EOs) from Citrus sinensis var. Valencia peels. Two imidazolium ionic liquids, 1-ethyl-3-methyl imidazolium acetate ([C2mim]OAc) and 1-butyl-3-methyl imidazolium chloride ([C4mim]Cl), were investigated for extraction efficiency, thermal behavior of the process, and chemical composition of the EOs obtained. During extractions, two different concentrations of ionic liquids (ILs) were studied (5% or 10 %), and the proposed MAE-IL was evaluated in comparison with usual microwave-assisted extraction (MAE) using water as solvent. Results indicated that both concentrations of ILs influenced EO extraction, thermal behavior, and chemical composition. However, [C2mim]OAc was more efficient, increasing extraction velocity by 10 times, enhancing extraction efficiency of EOs (39 %), and increasing the presence of oxyterpene compounds in the EOs. However, the great ability of ILs to interact with microwaves had an impact on the thermal history of the sample, reaching almost 110 °C, promoting the presence of compounds related to thermal effect.

Oregano essential oil vapour prevents Plasmopara viticola infection in grapevine (Vitis Vinifera) and primes plant immunity mechanisms.

The reduction of synthetic fungicides in agriculture is necessary to guarantee a sustainable production that protects the environment and consumers’ health. Downy mildew caused by the oomycete Plasmopara viticola is the major pathogen in viticulture worldwide and responsible for up to 60% of pesticide treatments. Alternatives to reduce fungicides are thus utterly needed to ensure sustainable vineyard-ecosystems, consumer health and public acceptance. Essential oils (EOs) are amongst the most promising natural plant protection alternatives and have shown their antibacterial, antiviral and antifungal properties on several agricultural crops. However, the efficiency of EOs highly depends on timing, application method and the molecular interactions between the host, the pathogen and EO. Despite proven EO efficiency, the underlying processes are still not understood and remain a black box. The objectives of the present study were: a) to evaluate whether a continuous fumigation of a particular EO can control downy mildew in order to circumvent the drawbacks of direct application, b) to decipher molecular mechanisms that could be triggered in the host and the pathogen by EO application and c) to try to differentiate whether essential oils directly repress the oomycete or act as plant resistance primers. To achieve this a custom-made climatic chamber was constructed that enabled a continuous fumigation of potted vines with different EOs during long-term experiments. The grapevine (Vitis vinifera) cv Chasselas was chosen in reason of its high susceptibility to Plasmopara viticola. Grapevine cuttings were infected with P. viticola and subsequently exposed to continuous fumigation of different EOs at different concentrations, during 2 application time spans (24 hours and 10 days). Experiments were stopped when infection symptoms were clearly observed on the leaves of the control plants. Plant physiology (photosynthesis and growth rate parameters) were recorded and leaves were sampled at different time points for subsequent RNA extraction and transcriptomics analysis. Strikingly, the Oregano vulgare EO vapour treatment during 24h post-infection proved to be sufficient to reduce downy mildew development by 95%. Total RNA was extracted from leaves of 24h and 10d treatments and used for whole transcriptome shotgun sequencing (RNA-seq). Sequenced reads were then mapped onto the V. vinifera and P. viticola genomes. Less than 1% of reads could be mapped onto the P. viticola genome from treated samples, whereas up to 30% reads from the controls mapped onto the P. viticola genome, thereby confirming the visual observation of P. viticola absence in the treated plants. On average, 80% of reads could be mapped onto the V. vinifera genome for differential expression analysis, which yielded 4800 modulated genes. Transcriptomic data clearly showed that the treatment triggered the plant’s innate immune system with genes involved in salicylic, jasmonic acid and ethylene synthesis and signaling, activating Pathogenesis-Related-proteins as well as phytoalexin synthesis. These results elucidate EO-host-pathogen interactions for the first time and indicate that the antifungal efficiency of EO is mainly due to the triggering of resistance pathways inside the host plants. This is of major importance for the production and research on biopesticides, plant stimulation products and for resistance-breeding strategies.

Antibacterial activity of essential oils against Stenotrophomonas maltophilia and the effect of citral on cell membrane

Stenotrophomonas maltophilia has both the pathogenic potential and the ability to cause food spoilage, and is characterized by multi-resistance to many antibiotics. Essential oils (EOs) have been reported as good antimicrobial agents. In this study, seven EOs were selected to evaluate the antibacterial effect against foodborne spoilage S. maltophilia 4–1 by disk diffusion method, broth dilution method, and fumigation treatment. The chemical compositions of EOs were analyzed via gas chromatography–mass spectrometry injecting with both gas and liquid, hoping to reveal the relationship between active compounds and antibacterial activity. The results indicated that litsea cubeba oil (LCO) exhibited a strong inhibitory effect with minimum bactericidal concentration (MBC) value of 0.125% (v/v), and only LCO showed bacteriostatic effect in fumigation treatment within the tested range. Its key active component, citral, was responsible for the antibacterial property by causing damage and rupture of cell membrane determined using fluorescent dyes and field emission scanning electron microscope. The minimum inhibitory concentration and MBC of citral against S. maltophilia 4–1 was determined to be 0.25% (v/v) and 0.5% (v/v), respectively. This study reveals the high efficiency of EOs to inhibit bacteria in terms of key active component, and provides an alternative to reduce the resistant bacteria.

Biochemical and Pharmacological Applications of Essential Oils in Human Health Especially in Cancer Prevention.

Essential oils (EOs) are aromatic, volatile and concentrated hydrophobic liquids extracted from plant material. EOs are also called as ethereal oils, volatile oils or aetherolea. EOs also play a crucial role in plant defence and signalling processes. They are mostly used in perfumes, cosmetics, soaps and other products for flavouring food, drinks, adding scents to incense and household cleaning products. EOs have a long medicinal history. Reported research literature and online contents related to the use of EOs for their biochemical pharmacological applications in cancer prevention therapy were reviewed. The most relevant and updated citations were included in this review. This review elaborates the various types of EOs, their biochemical characteristics, and pharmacology. Medicinal benefits of essential oil products range from various skin treatments to different types of therapies for cancer and are dependent entirely on historical backgrounds of use of EOs for these properties. EOs have antimicrobial, anticancer, antioxidant, antiparasitical, insecticidal, anti-inflammatory, viricidal, fungicidal, wound healing, antihypertensive, analgesic properties and other medicinal properties. The efficiency of EOs in medical treatments and treatment of cancers are these days a subject of interest in most countries. This review elaborated the potentials of EOs in regulating cancer cell growth and have explored the probable EOs that can be used in drug development.

Chemical composition and antimicrobial activities of essential oils of Ruta graveolens plants treated with salicylic acid under drought stress conditions

This study aims to investigate the effect of foliar application of 0.0 and 1.5 mM salicylic acid (SA) under normal [100% field capacity (FC)] and reduced irrigation (75 and 50% FC) on the yield, chemical composition and antimicrobial activities of essential oils (EOs) obtained from leaves and flowers of Ruta graveolens L. in field condition. The highest yields of EOs (0.366 and 0.215% v/w for leaves and flowers, respectively) were obtained from plants grown in 50% FC treated with 1.5 mM SA. Similarly, EOs from the flowers of plants maintained under the same conditions provided the highest percentage of long chain methyl ketones (94.2%). Moreover, the percentage of 2-undecanone and 2-nonanone, the two major components of the EOs, varied between 52.52-58.10% and 18.00–25.14% for leaves as well as 70.22–84.57% and 3.00–7.44% for flowers, respectively according to the treatment. On the other hand, the obtained EOs exhibited significant antimicrobial activities with minimum inhibitory concentrations (MIC) of 3.5–7.94 μg/ml for the tested bacterial strains; Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli and Klebsiella pneumonia, and 1.14–2.5 μg/ml for the tested Candida species. Interestingly, a direct correlation between the percentage of long chain methyl ketones and the antimicrobial efficiency of EOs was observed. Furthermore, the most potent EO exerted concentration-dependent antimicrobial effects against all the bacterial and fungal strains in the killing kinetics studies. It also showed considerable morphological alterations on Candida albicans, including cell surface abnormalities, deformation, disruption, and prevented the germ tube production using scanning electron microscopy and germ tube test.

Algerian Mentha pulegium L. leaves essential oil: Chemical composition, antimicrobial, insecticidal and antioxidant activities

Essential oils are responsible for wide bioactivities, the reason why, this search is focused on the study of the chemical composition and the antimicrobial, insecticidal and antioxidant activities of Algerian Mentha pulegium L. leaves essential oil (EO). EO is obtained by steam distillation with a yield of 1.45±0.01% and analyzed by gas chromatography coupled to mass spectrometry (GC/MS) where 39 compounds were identified. The analysis has revealed that EO contains pulegone (70.66%) and neo-menthol (11.21%), were the major compounds. Antimicrobial study showed good activity tested against 11 bacteria (3g+ and 8g-) and 2 yeasts, also showed good inhibitory (MIC) and bactericidal (MBC) properties.Insecticide assessment was carried out against food pest Sitophilus granarius (L.). Three toxicity tests of EO were performed using three different methods: contact, inhalation and ingestion. Also, assessment of the toxicity of M. pulegium EO was carried out using leaves at different status (fresh, dried and semi-dried) ground and non ground. Inhalation and ingestion methods were implemented on wheat seeds that showed high efficiency (100% mortality), and a lethal dose of (LD50=9.11±2.53μl/ml) was obtained using the contact method. Leaves in various statuses didn’t show any efficiency except crushed ones. To compare the efficiency of EO, was assessed the toxicity test of chemical pesticide (malathion) against food pest S. grananarius which showed an average efficiency.The Antioxidant activity was defined using the scavenging test of free radicals (DPPH), while BHT and ascorbic acid were used as positive controls. The results of IC50=69.60±1.72μg/ml, showed a very good radical scavenging ability.As a result Algerian M. pulegium EO can be used in food and pharmaceutical industries.