Plant Essential Oils Research Articles

Nanoparticle-Enriched Edible Coatings with Plant Extracts and Essential Oils for Extending Postharvest Quality of Fruits and Vegetables

Fruits and vegetables are affected by postharvest diseases and physiological processes such as transpiration and respiration after harvest, leading to significant quality losses during transportation and storage. To control postharvest diseases and extend shelf life, synthetic fungicides are commonly used. However, the extensive use of these chemicals raises concerns about potential health risks, environmental impact, and the development of fungicide-resistant pathogens. Therefore, alternative approaches, such as edible coatings with plant extracts, essential oils and nanoparticles loaded with plant extracts are explored to address these challenges while maintaining quality and safety of fresh fruits and vegetables. Nanoparticles loaded with essential oils or plant extracts are synthesized using ionic gelation method, spontaneous emulsification, phase inversion temperature, emulsion inversion point, and solvent displacement methods etc. Nanoparticle enriched edible coating delivers plant compound gradually over time. This controlled release provides a consistent and long-lasting effect, effectively inhibiting microbial growth, slowing nutrient degradation, and reducing oxidative stress on the produce. The nanoscale size of these particles increases their surface area, enhancing their adhesion to the surface of fruits or vegetables. This results in a more efficient barrier against moisture loss and gas exchange, further preserving the quality and extending the shelf life of the produce. The synergistic effects of the nano-reinforced matrices show promising results in reducing post-harvest losses while maintaining food safety standards. This innovative approach holds immense potential for revolutionizing the postharvest management of fruits and vegetables by offering a safer, more sustainable alternative to synthetic fungicides. Future research should focus on optimizing the formulation and scalability of nanoparticle-enriched edible coatings, evaluating their efficacy across diverse produce types, and assessing their long-term safety and environmental impact. This review examines the current developments in edible coating technology, focusing on various plant extracts, essential oils, and nanoparticles loaded with plant extracts enriched edible coating for extending shelf life and preserving the quality of fruits and vegetables.

Exploring the Effects of Ionic Liquid on the Toughness of Palm Leaf Manuscripts.

Palm leaf manuscripts, crafted from specially treated palm leaves, are invaluable historical documents. However, they degrade and tend to become brittle over time. To date, plant essential oils and glycerin are the used materials to improve the flexibility of palm leaf manuscripts, but the effective duration of these materials is short due to their volatility. This work introduces ionic liquids, a nonvolatile and stable material, to achieve durable toughening of the palm leaf manuscripts. We select 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIm][BF4]), one of the most used ionic liquids, as the subject of research. We find that [BMIm][BF4] does not alter the palm leaf manuscripts' appearance and significantly improves their tensile strength and fracture toughness by 39.9 and 101.0%, respectively, while reducing the bending modulus by 25.7% and increasing the bending fracture deflection by 2.6 times. Notably, [BMIm][BF4]'s toughening effect for palm leaf manuscripts is sustainable for over 2 months, outperforming traditional methods that last only about 1 week. Even under harsh conditions, such as low humidity, high temperatures, alkalinity, and UV exposure, [BMIm][BF4] still maintains its effectiveness. Through the analysis of its composition, structure, and theoretical simulation, we reveal that [BMIm][BF4] penetrates the manuscripts, filling the pores between the inner structure of them and adsorbing strongly with cellulose. This enhances load transfer and reduces the stress concentration, resulting in increased toughness. This research provides innovative materials for palm leaf manuscript conservation and deepens our understanding of their mechanical properties.

Antibiotic Resistance of Staphylococcus aureus Strains—Searching for New Antimicrobial Agents—Review

Inappropriate and excessive use of antibiotics is responsible for the rapid development of antimicrobial resistance, which is associated with increased patient morbidity and mortality. There is an urgent need to explore new antibiotics or alternative antimicrobial agents. S. aureus a commensal microorganism but is also responsible for numerous infections. In addition to innate resistance to β-lactam antibiotics, S. aureus strains resistant to methicillin (MRSA) often show resistance to other classes of antibiotics (multidrug resistance). The advancement of phage therapy against MRSA infections offers a promising alternative in the context of increasing antibiotic resistance. Therapeutic phages are easier to obtain and cheaper to produce than antibiotics. However, there is still a lack of standards to ensure the safe use of phages, including purification, dosage, means of administration, and the quantity of phages used. Some bacteria have developed defense mechanisms against phages. The use of phage cocktails or the combination of antibiotics and phages is preferred. For personalized therapy, it is essential to set up large collections to enable phage selection. In the future, the fight against MRSA strains using phages should be based on a multidisciplinary approach, including molecular biology and medicine. Other therapies in the fight against MRSA strains include the use of endolysin antimicrobial peptides (including defensins and cathelicidins). Researchers’ activities also focus on the potential use of plant extracts, honey, propolis, alkaloids, and essential oils. To date, no vaccine has been approved against S. aureus strains.

Chemical composition and insecticidal activity of Mentha rotundifolia and Chrysanthemum coronarium essential oils against the tomato leaf miner, Tuta absoluta

Tuta absoluta is one of the most destructive pests of tomatoes. Chemical insecticides used to control this leafminer harm all organisms, increasing the risk to public health and the environment. Developing natural alternatives, such as bioinsecticides formulated from essential plant oils, is a key strategy to address this problem. These volatile compounds, derived from the secondary metabolic pathways of plants, exhibit targeted activity against specific pest species. Their use is consistent with an environmentally responsible framework that reduces adverse impacts on ecosystems, protects non-target organisms, safeguards human health, and enhances the efficacy of integrated crop management systems. This study aims to determine the chemical composition of the essential oils (EOs) of from round leaf mint (Mentha rotundifolia) and crown chrysanthemum (Chrysanthemum coronarium) and to evaluate their toxicity to T. absoluta larvae in-vitro. The chemical composition of EOs obtained by steam distillation from the leaves of the plants was analyzed by gas chromatography coupled with mass spectrometry (GC-MS). Indeed, 77 volatile compounds representing 98.19% of the total oil of M. rotundifolia, including cyclobutane acetonitrile, 1-methyl-2-(1-methyl ethenyl)-, terpinene-4-ol, p-menthane, germacrene D, caryophyllene and myrcene, were the main compounds. However, farnesene, myrcene, eugenol, germacrene D, phytol, and pinene were significant components among 69 compounds representing 95.39% of the total oil of C. coronarium. Results showed that the EOs were toxic to the different larval stages. According to the Finney method, concentrations 2.88 and 1.07% are the LC50 of M. rotundifolia and C. coronarium oils, which induce 50% mortality of T. absoluta within 7 days of exposure. Statistical analysis of in-vitro tests showed that both EOs had a similar level of insecticidal efficacy by contact. The overall results showed that the oils used have been shown to have an important insecticidal effect and can be used as a source of biological and natural treatment against tomato leafminer (TLM).

A cinnamon and clove essential oil mix microencapsulated with hydroxypropyl-β-cyclodextrin: Study on physicochemical, antibacterial, and low salt pickles preservation properties.

In order to overcome the technical challenges of poor stability and weak antibacterial effects of individual essential oil in food preservation applications, the present study aimed to encapsulate cinnamon and clove essential oil compound by using spray-drying technique. The combination of cinnamon and clove essential oils was determined to have good synergistic bacteriostatic effects by the checkerboard dilution method, and the best bacteriostatic effect could be obtained when the volume ratio was 7:3 for compounding. Microcapsules were prepared using hydroxypropyl-β-cyclodextrin (HPCD) as wall material and compound essential oil as core material, the optimal conditions for the microcapsule preparation process through a one-way test were: homogenizing speed of 8000r/min, wall material addition of 2%, HPCD to EO ratio of 1:3, EO to T-80 ratio of 1.5:1, and homogenizing time of 8min. The physicochemical properties of the prepared compound essential oil microcapsules (EOM) were characterized, and the results showed that the EOM was successfully encapsulated in HPCD with good physicochemical properties, and the encapsulation rate of the prepared microcapsules was measured to be 65.82±4.00%. The thermal stability of the encapsulated EOM was improved, and volatilization of the essential oils was effectively inhibited. In addition, the EOM showed antibacterial activity against the five types of bacteria tested, and the number of surviving bacteria decreased by about 17-18% after 72h. The preservation experiment of low salt pickles showed that the EOM was more effective in maintaining the quality and prolonging the shelf life of the pickles compared with commercial sodium benzoate, which also demonstrated the potential application of EOM in preserving low-salt pickles. This study provides a feasible and new technical strategy for more effective application of plant essential oils in food preservation.

Эффективное использование отходов сельскохозяйственного производства для выращивания органической продукции в районах с неблагоприятными агроклиматическими и почвенными условиями

The article presents the results of research on the development of a technological method for the safe cultivation of essential oil plants Hyssop officinalis (Hyssopus officinalis L.), Moldovan Snakehead (Dracocephalum moldavica) and Elsholtzia patrinii using the protective and stimulating complex "ZSK-5" as an organomineral fertilizer, a preparation based on humic, fulvic- and amino acids, oligosaccharides, peptides in combination with macro and microelements and as soil improvers and substrate in soil-free cultivation, sugar production waste and humified cereal stalks - waste from cereal production, the chemical composition of which is rich in a high content of organic components (cellulose, starch, lipids, protein). The influence of the studied objects on the morphophysiological parameters and productivity of essential oil plants grown by hydroponic and traditional soil methods has been studied. It has been established that the developed technological method involves the use of beet production waste in the proportion of 50 g per 1 kg of soil (for the climate chamber) and coconut fiber for hydroponics, together with humified cereal stalks and the protective-stimulating complex ZSK-5 in concentration No. 2 (1:100), in the form of pre-sowing soaking of seeds. and spraying of vegetative plants, without the use of chemical fertilizers, contributed to obtaining a higher yield relative to control samples (with the use of fertilizers). This gives reason to recommend this technique in organic farming to confirm its effectiveness in large-scale organic production. Keywords: ZSK-5, HYSSOP OFFICINALIS, ELSGOLZIA PATREN, MOLDOVAN SNAKEHEAD, SUGAR PRODUCTION WASTE, HUMIFIED CEREAL STALKS, ORGANIC FARMING, PROTECTIVE AND STIMULATING COMPLEX

Исследование технологического приёма выращивания эфиромасличных растений гидропонным и почвенным способом с использованием соломы гречихи и физиологически активных веществ органического происхождения

The article presents the results of research on the development of a technological method for the safe cultivation of the essential oil plant hyssop officinalis L. using the protective-stimulating complex "ZSK-5" as an organomineral fertilizer - a preparation based on humic, fulvic and amino acids, oligosaccharides, peptides in combination with macro and microelements and as a soil improver. and the substrate in groundless cultivation, buckwheat straw - waste from buckwheat production, the chemical composition of which is rich in a high content of organic components (cellulose, starch, lipids, protein). The influence of the studied objects on the morphophysiological parameters and productivity of medicinal hyssop grown by hydroponic and traditional soil methods has been studied. It was found that the developed technological method in the form of using buckwheat production waste in the proportion of 1 g per 1 kg of soil (for the climate chamber)/peat substrate for hydroponics, together with ZSK-5 in concentration No. 3, in the form of pre-sowing soaking of seeds and spraying of vegetative plants, without the use of chemical fertilizers, contributed to obtaining a higher yield, regarding control samples (using fertilizers). This gives reason to recommend this technique in organic farming to confirm its effectiveness in large-scale organic production. Keywords: ZSK-5, MEDICINAL HYSSOP, BUCKWHEAT STRAW, PLANT GROWTH AND DEVELOPMENT REGULATORS, ORGANIC FARMING, HYDROPONIC CULTIVATION, ORGANO-MINERAL COMPLEX

Determination of essential oil components of Achillea millefolium

Medicinal plants used in traditional medicine are being investigated and employed more and more in the food, pharmaceutical, and nutraceutical industries these days. Achillea sp. which is in the Asteraceae family is one of the most widely used medicinal and aromatic plants for the treatment of various diseases. Both traditional medicine and modern medicine make extensive use of yarrow (Achillea millefolium L.). The objective of this study was to ascertain the essential oil content and essential oil constituents of Achillea millefolium species, which are found in Ulus Mountain in the Sındırgı district of Balıkesir province. The components of the essential oil were examined using a GC-MS device after the hydrodistillation process as used to obtain it. The analysis revealed a significant concentration of the carvacrol component (10.16 %) in the essential oil of the Achillea millefolium plants. A total of 95 components were identified in A. millefolium essential oil which accounted for 89.95 %. Carvacrol (10.16 %), γ-Muurolene (9.58 %), Grandisol (5.28 %), Artemisia ketone (3.70 %) were found as major constituents of A. millefolium essential oil.

Essential oils from Colombian Croton spp. exhibit antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA) and ampicillin- and streptomycin-resistant Escherichia coli

Bacterial resistance, a global public health concern prioritized by the World Health Organization, is particularly alarming in Staphylococcus aureus and Escherichia coli. Urgently addressing this, the search for new antibiotics has turned to plant essential oils. Our study focused essential oils derived from Colombian plants Croton killipianus, Croton smithianus, Croton leptostachyus, Croton hondensis, and Croton gossypiifolius. We performed antimicrobial susceptibility tests targeting Staphylococcus aureus, methicillin-resistant Staphylococus aureus, sensitive Escherichia coli, and ampicillin- and streptomycin-resistant Escherichia coli. Simultaneosly, citotoxic assays and chemical analysis were carried out. The essential oil derived from C. hondensis demonstrated superior inhibitory efficacy, effectively targeting methicillin-resistant S. aureus, susceptible S. aureus, and both sensitive and ampicillin- and streptomycin-resistant strains of E. coli. Furthermore, it exhibited notable potential for protective activity in Chinese hamster ovary cells. C. killipianus manifested inhibitory effects against MRSA and susceptible S. aureus, whereas C. smithianus specifically affected susceptible strains of S. aureus. Chemical analysis of the essential oils revealed rich content in phenolic compounds, flavonoids, tannins, and steroids. Gas-coupled mass spectrometry identified key compounds like γ-muurolene, α-humulene, (E)-caryophyllene, α-copaene, curcumene, and (E)-nerolidol. These findings underscore C. hondensis, C. killipianus, and C. smithianus as potential natural sources for antibacterial agent development.

Enhanced antimicrobial and biofilm disruption efficacy of the encapsulated Thymus pallidus and Lavandula stoechas essential oils and their mixture: A synergistic approach.

The antimicrobial and antibiofilm properties of plant essential oils (EOs) have aroused significant interest for their potential as effective alternatives or supplements in combating microbial infections and biofilm-associated challenges. For these applications, EOs must be encapsulated to overcome some key technical limitations, including high volatility, poor stability, and low solubility. This study aimed to develop microencapsulated EOs derived from two valuable Moroccan medicinal plants, Lavandula stoechas L. and Thymus pallidus Batt., both individually and in combination, using the spray drying method. The antimicrobial and antibiofilm effects of these encapsulated EOs were evaluated against various pathogenic microorganisms using microdilution and crystal violet assays. Key physico-chemical characteristics of the EO microcapsules, including optimal particle size, favorable zeta potential, low water content, and high encapsulation yield and efficiency were observed, indicating strong stability and effective encapsulation. The major chemical compounds identified in the studied EOs were thymol (26.72 %), γ-terpinene (23.26 %), and p-cymene (19.07 %) in T. pallidus EO; and camphor (47.67 %), fenchone (20.78 %), and 1.8-cineole (12.17 %) in L. stoechas EO. The results from antimicrobial assays demonstrated that the encapsulated T. pallidus EO exhibited stronger inhibitory and microbicidal effects against all tested strains, with MIC and MMC values ranging from 0.312 mg/mL to 2.50 mg/mL. The encapsulated EOs combination demonstrated interesting antimicrobial effect, with varying type of interactions depending on the target microorganisms. Additionally, the antibiofilm activity of the microencapsulated EOs combination, evaluated against Staphylococcus aureus, Klebsiella pneumoniae and Bacillus subtilis, showed significant biofilm inhibition with percentages reaching up to 92.68 % at MIC concentration and BIC50 ranging from 0.05 ± 0.00 mg/mL to 0.17 ± 0.01 mg/mL. The eradication of preformed biofilms was also measured, showing a notable effect with eradication rates exceeding 78 % at concentrations of 4MIC, and BEC50 values ranging from 0.16 ± 0.02 mg/mL to 1.30 ± 0.37 mg/mL. Overall, these finding indicate that the encapsulated EO combination derived from these two Moroccan medicinal plants presents a promising formulation capable of overcoming the limitations associated with free EOs and contributing to the fight against antimicrobial resistance and biofilm-related challenges.

Trans-2-hexenal reduces postharvest mango stem-end rot by oxidative damage to Neofusicoccum parvum cell membranes.

Neofusicoccum parvum is one of the most hazardous pathogens causing mango fruit decay. The present study utilized trans-2-hexenal (TH), a typical antifungal component of plant essential oils (EOs), to control N. parvum both in vivo and in vitro, and attempted to explore the mechanisms involved. The findings showed that at concentrations greater than 0.4 µL/mL, TH exhibited exceptional antifungal activity against N. parvum in vitro. TH application led to the disruption of the structural integrity of both cell walls and cell membranes, with a particular impact on the latter, as evidenced by the dramatically increased propidium iodide level, as well as reduced total lipids and ergosterol content. Further DCFH-DA staining experiments showed that TH induced mycelial reactive oxygen species (ROS) accumulation, which exacerbated cell membrane lipid peroxidation. For easier application of TH, we fabricated aerogel-loaded TH (ALTH) materials, which demonstrated excellent antifungal activity in vitro. Infestation studies on fruits demonstrated that ALTH mitigated mango stem-end rot in a dose-dependent fashion, with a concentration of 40 µL/L showing efficacy comparable to the conventional fungicide prochloraz, while maintaining fruit quality. In light of these results, TH works by inducing ROS buildup and oxidative damage to the cell membrane of N. parvum, and is a particularly promising preservative for preventing postharvest infections in mangoes.

Constructing High-Yielding Serratia marcescens for (-)-α-Bisabolol Production Based on the Exogenous Haloarchaeal MVA Pathway and Endogenous Molecular Chaperones.

(-)-α-Bisabolol exhibits analgesic, anti-inflammatory, and skin-soothing properties and is widely applied in the cosmetic and pharmaceutical industries. The use of plant essential oil distillation or chemical synthesis to produce (-)-α-bisabolol is both inefficient and unsustainable. Currently, the microbial production of (-)-α-bisabolol mainly relies on Escherichia coli and Saccharomyces cerevisiae as chassis strains; however, high concentrations of (-)-α-bisabolol have certain toxicity to the strain. This study uses synthetic biology and metabolic engineering strategies to redesign a solvent-tolerant Serratia marcescens for the efficient production of (-)-α-bisabolol. By introducing the Haloarchaea-type mevalonate (MVA) pathway and the (-)-α-bisabolol biosynthesis pathway, we successfully constructed a strain capable of producing (-)-α-bisabolol. The coexpression of the chaperone protein DnaK/J significantly enhanced the soluble expression of the (-)-α-bisabolol synthase, resulting in a 10% increase in (-)-α-bisabolol titer. Furthermore, knockout of the PhoA gene, which reduced the formation of the byproduct farnesol (FOH), further increased the (-)-α-bisabolol titer to 3.21 g/L. In a 5 L bioreactor, S. marcescens achieved a final (-)-α-bisabolol titer of 30.2 g/L, representing the highest titer reported to date. This research provides guidance for the production of (-)-α-bisabolol in nonmodel microorganisms without the requirement for induction.

Natural terpenes II. Concentration-dependent profile of effects on dynamic organization of biological and model membranes.

Monoterpenes (MTs), the major constituents of plant essential oils, cover a broad spectrum of biological activities through their interaction with biomembranes. MTs are highly hydrophobic substances with a net electrical dipole, but are not clearly amphipathic. As a result, they aggregate at increasing concentrations in aqueous media, and in membrane environments their behavior changes from dynamics modulators to disruptors. In the present work we have tried to find the boundaries between these conditions. Using spin-label electron paramagnetic resonance (EPR) spectroscopy, we studied the effect of a wide range of concentrations of camphor, cineole, thymol, menthol and geraniol on the dynamics of phospholipid model membranes, with or without cholesterol, organized in different initial lyotropic phases, as well as on synaptosomal membranes from bovine brain cortex. EPR spectra of two fatty acid spin probes incorporated into the membranes (5-SASL and 12-SASL) provided information on molecular order and mobility at different bilayer depths. Qualitative changes in the spectra indicated transitions between monomeric and aggregated MTs, as well as membranes with different degrees of order and disrupted membranes. Analyzed in conjunction with the kinetics of [3H]flunitrazepam membrane binding, either non-specifically to the membrane or specifically to the GABAA receptor, the present results allowed us to define 200μM as the concentration limit to safely evaluate MT effects in non-disrupted biological and model membranes. These findings may be helpful in the interpretation and design of pharmacological assays and provide concentration references that allow correlating a variety of biophysical and pharmacological data in the literature.

Physiological and transcriptomic analysis reveal the regulation of adventitious root formation in Cinnamomum parthenoxylon cuttings

Cinnamomum parthenoxylon is a significant essential oil plant in southern China, however, the challenge of rooting cuttings poses a hindrance to its development and widespread cultivation. Adventitious root (AR) formation is a vital mechanism for plants to acclimate to environmental changes, yet the precise regulatory mechanisms governing this process remain largely unknown. This study investigated the morphological, physiological, and transcriptomic alterations during AR formation in C. parthenoxylon. Our findings revealed that the AR in C. parthenoxylon originated from callus tissue. Nutrients, enzymes, and plant hormones exerted crucial functions in cutting propagation, with some gradually shifting roles in the rooting process until the pivotal stage of root primordium initiation. Analysis of differentially expressed genes (DEGs) highlighted the significance of auxin, ethylene, and plant wound signaling pathways in regulating AR. Furthermore, 14 hub genes were identified through protein-protein interaction (PPI) networks, shedding light on key molecular players. Understanding the dynamics involved in AR formation enhances our comprehension of the regulatory mechanisms, offering insights for optimizing cutting treatment methods.

Performance of Biodegradable Active Packaging in the Preservation of Fresh-Cut Fruits: A Systematic Review.

Fresh-cutting fruits is a common practice in markets and households, but their short shelf life is a challenge. Active packaging is a prominent strategy for extending food shelf life. A systematic review was conducted following the PRISMA guidelines to explore the performance and materials used in biodegradable active packaging for fresh-cut fruits. Sixteen studies were included from a search performed in July 2024 on Scopus and Web of Science databases. Only research articles in English on biodegradable active films tested on cut fruits were selected. Polysaccharides were the most employed polymer in film matrices (87.5%). Antioxidant and anti-browning activities were the active film properties that were most developed (62.5%), while plant extracts and essential oils were the most employed active agents (56.3%), and fresh-cut apples were the most commonly tested fruit (56.3%). Appropriate antioxidant, antibacterial, and barrier properties for fresh-cut fruit packaging were determined. Furthermore, there is a wide range of experimental designs to evaluate shelf-life improvements. In each case, shelf life was successfully extended. The findings show that different storage conditions, fruits, and material configurations can lead to different shelf-life extension performances. Thus, biodegradable active packaging for fresh-cut fruits has a strong potential for growth in innovative, sustainable, and functional ways.

Is Linalyl Anthranilate Indeed Found In Plant Samples? GC-MS Misidentifications in the Scientific Literature.

Linalyl anthranilate (LNA) has been identified in a number of plant extracts and essential oils by various authors using gas chromatography-mass spectrometry (GC-MS). However, the reported retention behavior of LNA in these studies is inconsistent with the retention data provided in the NIST database. Therefore, the objective of this study was to determine whether the reports of LNA were the result of misidentifications in GC-MS analyses or if the linear NIST retention index was inaccurate. To accomplish this, linalyl anthranilate was synthesized in a two-step procedure, and the resulting product was authenticated using nuclear magnetic resonance (NMR) and GC-MS analyses. This is a new synthetic route to linalyl anthranilate. Subsequently, retention indices for linalyl anthranilate were determined on three commonly used GC phases: polydimethylsiloxane, 5% diphenyl-95% polydimethylsiloxane, and polyethylene glycol. The study confirmed the accuracy of the NIST retention data, establishing the linear retention index data for LNA on a semi-nonpolar GC column as 2051. However, LNA reported in the literature by various authors exhibited a retention index in the elution window of approximately 1000-1400, strongly suggesting that these reports were the result of GC-MS misidentifications. A review of all reported occurrences of LNA in natural samples found no credible evidence of its presence. In many cases, it appears to be a misidentification of linalyl acetate caused by the occurrence of an erroneous spectrum in the older versions of the NIST mass spectra database.

Study of Essential Oil Plants of Azerbaijan and the Importance of Their Extracts

There are many valuable essential oil plants growing in Azerbaijan that can be used in all areas of the national economy. Growing conditions contribute to the accumulation of a large amount of essential oils in plants. Effective use of essential oil plants increases the production of feed, medicines, food products, leather, dyeing, etc., and ensures the development of industrial areas. Most essential oil plants are medicinal plants and are widely used in phytotherapy. The author suggests using various methods to obtain essential oil. Some methods of extracting oils from plants are considered, and their effectiveness is assessed.

Pharmacokinetics of Geraniol and Its Metabolites in Mice After Oral Administration.

Geraniol is an acyclic monoterpene alcohol that is extracted from the essential oils of aromatic plants. Geraniol has several biological activities such as anti-cancer, anti-inflammatory, antioxidant, and neuroprotective effects. However, the pharmacokinetics of geraniol and its metabolites after oral administration remain unknown in mice. To investigate the pharmacokinetics, the blood concentrations were measured in C57BL/6J mice by LC-MS/MS after oral administration of geraniol at a dose of 200 mg/kg. The C max for blood levels of geraniol was only 0.05 ± 0.01 μg/mL at 1 h after administration. In contrast, geranic acid, one of the geraniol metabolites, rapidly reached a peak level that was markedly higher than that of geraniol. Furthermore, the glucuronide conjugate of geraniol was detected at a higher level than geraniol. These results indicate that geraniol is rapidly converted to geranic acid or glucuronide conjugate after oral administration. Moreover, geraniol was detected in the liver and the brain, whereas 8-hydroxygeraniol was not detected in any tissues. In contrast, geranic acid was detected in several tissues in the order of kidney > liver = lung > brain. Therefore, the metabolites of geraniol are present in the blood and tissues of mice treated with geraniol, and various pharmacological effects of geraniol may be caused by its metabolites.

In vitro Antifungal Effects of Various Essential Oils against Aspergillus Crown Rot of Peanut

Synthetic fungicides that combat plant pathogenic fungi can enhance crop yields, ensuring stable crop production and market quality. However, the increase in the use of fungicides may cause to development of fungicide-resistant pathogen strains and the accumulation of fungicide residues in the food chain above safe limits. This situation underscores the need for improved fungal disease management through alternatives to synthetic fungicides. These alternatives include plant-derived compounds such as essential oils and extracts. Essential oils are known to be potent antifungal compounds against both human and plant pathogens. Aspergillus niger is a toxin-producing fungal disease agent that causes Aspergillus crown rot in peanuts. In this study, the antifungal activities of nine different essential oils from Foeniculum vulgare, Lippia citriodora, Origanum majorana, Origanum minutiflorum, Origanum onites, Origanum syriacum, Origanum vulgare, Salvia aramiensis and Thymus syriacus plants were evaluated against A. niger under in vitro conditions by using disc diffusion test. Among the nine essential oils tested, the highest antifungal activities were displayed by O. vulgare essential oil (with an inhibition zone diameter of 49.33 mm) which was followed by T. syriacus, O. onites, O. syriacum and O. minutiflorum essential oils (48.67, 47.00, 46.33 and 43.33 mm, respectively). The essential oils of F. vulgare, L. citriodora, and O. majorana showed relatively lower antifungal effects. The essential oil of S. aramiensis did not show antifungal effect against pathogen. The results indicated that plant essential oils could be valuable in promoting research aimed at developing new antifungal agent(s) for fungal disease management. However, further studies are needed to optimize the in vivo application conditions of essential oils against A. niger.

Evaluation of the antibacterial activity of some plant essential oils against Ralstonia solanacearum and the molecular diagnosis of the bacterium

Background Evaluation of the antibacterial activity of some essential oils for controlling potato bacterial wilt. Objective In vitro and planta trials, five essential oils, lemongrass, eucalyptus, thyme, ginger, and peppermint, were evaluated for their aptitude to impede the progress of Ralstonia solanacearum. Materials and methods Five essential oils were assessed for their activity to inhibit R. solanacearum growth using the disc diffusion method. Certain volumes of each tested plant essential oil were added on filter paper discs using tetrazolium chloride agar medium, which contained the tested bacterium to obtain the proposed concentrations used to evaluate the most efficient oil for controlling potato bacterial wilt. Serological and molecular identification was also conducted. Results and conclusion R. solanacearum was characterized using cultural characteristics on the selective medium South Africa, “which is the most effective in suppressing the growth of contaminating microorganisms, and the highest recovery rate of the tested bacterium,” immunofluorescence antibody staining tomato bioassay test and molecular identification via real-time PCR (Taq-man) assay. In-vitro studies showed that all tested plant essential oils (lemongrass, eucalyptus, thyme, ginger, and peppermint) significantly reduced R. solanacearum progress. Eucalyptus (Eucalyptus globulus) and peppermint (Mentha piperita) essential oils were the most efficient in suppressing R. solanacearum growth, where it showed the highest mean inhibition zone, followed by thyme oil (Thymus vulgaris), lemongrass oil (Comybogen citratus), and ginger oil (Zingiber officinale), respectively. Phenotypic variances in bacterial cell construction have been noticed via a transmission electron microscope. Eucalyptus oil led to cell wall lysis, cell laceration, bubble-like structures, and degraded cellular components in bacterial cells.