The progress of essential oils as potential therapeutic agents: a review

Biosynthesis of 2-phenylethanol from styrene using engineered Escherichia coli whole cells

2-Phenylethanol, an aromatic alcohol with a rose scent, is widely used in the cosmetics, food, and pharmaceutical industries. We designed an efficient multi-enzyme cascade pathway for production of 2-phenylethanol from styrene as the substrate. Initially, 2-phenylethanol was produced by overexpression of styrene monooxygenase A (styA), styrene monooxygenase B (styB), styrene oxide isomerase (SOI), alcohol dehydrogenase (yahK), and glucose dehydrogenase (gdh) in Escherichia coli to give 6.28 mM 2-phenylethanol. Subsequently, plasmids with different copy numbers were employed to balance the expression of pathway enzymes to produce 10.28 mM 2-phenylethanol, resulting in a 63.7 % increase in the final yield. Furthermore, the pH and temperature of the whole-cell conversion reaction were optimized, the optimum pH and temperature are 7.5 and 35℃, respectively. Finally, whole-cell conversion experiment was conducted, and the production of 2-phenylethanol reached 48.17 mM within 10 h. This study provides a theoretical and practical foundation for production of 2-phenylethanol.

Comparison of Major Compounds in Essential Oils Steam Distilled from Fresh Plant Material of South African Hop Varieties

Apart from the importance of bittering acids in the brewing sector, hops also produce terpene-rich essential oils, recognised for their therapeutic benefits. Agri-processing practices of this crop in South Africa produce tonnes of discarded (waste) plant material that could still contain sufficient bioactive compounds to justify upcycling. This research aimed to determine the chemical composition of steam distilled essential oils from fresh hop plant material destined for disposal. Essential oils from eight hop varieties unique to South Africa were produced on industrial scale using steam distillation. Chemical profiling was performed using GC-FID and MS. A total of 208 compounds were identified and oil consisted largely of terpenes (89.04 ± 1.89%) as well as aliphatic esters and -ketones (6.1 ± 1.15%). Myrcene (27.8-48.15%) was the most abundant monoterpene and α-humulene (19.52-24.98%), β-caryophyllene (8.47-13.73%) and β-farnesene (2.08-7.57%) constituted the majority of the sesquiterpenes fraction. Experimental variety XJA2/436 had the highest myrcene fraction (48.15%) and its chemical composition was markedly different from the other varieties. The major compounds in African Queen hop oil were methyl (4Z) decanoate (0.74%), 2-tridecanone (0.77%) and β-farnesene (7.57%). Southern Dawn hop oil contained the highest fractions of 2-undecanone (1.21%) and α-humulene (24.89%) and Southern Passion hop oil contained the highest β-caryophyllene fraction (13.73%). These findings established that fresh hop vegetative biomass shows promise to be transformed into a valuable resource.

Release Profile and Antibacterial Activity of Thymus sibthorpii Essential Oil-Incorporated, Optimally Stabilized Type I Collagen Hydrogels

Antimicrobial resistance is one of the drastically increasing major global health threats due to the misuse and overuse of antibiotics as traditional antimicrobial agents, which render urgent the need for alternative and safer antimicrobial agents, such as essential oils (EOs). Although the strong antimicrobial activity of various EOs has already been studied and revealed, their characteristic high sensitivity and volatility drives the need towards a more efficient drug administration method via a biomaterial system. Herein, the potential of Thymus sibthorpii EO incorporated in functionalized antibacterial collagen hydrogels was investigated. At first, the optimally stabilized type I collagen hydrogels via six different multi-arm poly (ethylene glycol) succinimidyl glutarate (starPEG) crosslinkers were determined by assessing the free amine content and the resistance to enzymatic degradation. Subsequently, 0.5, 1, and 2% v/v of EO were incorporated into optimized collagen hydrogels, and the release profile, as well as release kinetics, were studied. Finally, biomaterial cytocompatibility tests were performed. Thymus sibthorpii EO was released from the hydrogel matrix via Fickian diffusion and showed sustained release and 0.5% v/v EO-loaded hydrogels showed adequate antibacterial activity against Staphylococcus aureus and did not show any statistically significant difference compared to penicillin (p < 0.05). Moreover, none of the fabricated composite antibacterial scaffolds displayed any cytotoxicity on NIH-3T3 fibroblasts. In conclusion, this work presents an innovative antibacterial biomaterial system for tissue engineering applications, which could serve as a promising alternative to antibiotics, contributing to coping with the issue of antimicrobial resistance.

Evaluation of Cinnamon Essential Oil and Its Emulsion on Biofilm-Associated Components of Acinetobacter baumannii Clinical Strains

BACKGROUND/OBJECTIVES

Acinetobacter baumannii, one of the most dangerous pathogens, is able to form biofilm structures and aggravate its treatment. For that reason, new antibiofilm agents are in need, and new sources of antibiofilm compounds are being sought from plants and their products. Cinnamon essential oil is associated with a wide spectrum of biological activities, but with a further improvement of its physicochemical properties it could provide even better bioavailability. The aim of this work was the evaluation of the antibiofilm properties of cinnamon essential oil and its emulsion.

METHODS

In order to evaluate the antibiofilm activity, crystal violet assay was performed to determine biofilm biomass. The main components of the biofilm matrix were measured as well as the motile capacity of the tested strains. Gene expression was monitored with RT-qPCR, while treated biofilms were observed with Raman spectroscopy.

RESULTS

A particularly strong potential against pre-formed biofilm with a decreased biomass of up to 66% was found. The effect was monitored not only with regard to the whole biofilm biomass, but also on the individual components of the biofilm matrix such as exopolysaccharides, proteins, and eDNA molecules. Protein share drops in treated biofilms demonstrated the most consistency among strains and rose to 75%. The changes in strain motility and gene expressions were investigated after the treatments were carried out. Raman spectroscopy revealed the influence of the studied compounds on chemical bond types and the components present in the biofilm matrix of the tested strains.

CONCLUSIONS

The results obtained from this research are promising regarding cinnamon essential oil and its emulsion as potential antibiofilm agents, so further investigation of their activity is encouraged for their potential use in biomedical applications.

Current Progress and Emerging Role of Essential Oils in Drug Delivery Therapeutics

The utilization of novel drug delivery systems loaded with essential oils has gained significant attention as a promising approach for biomedical applications in recent years. Plants possess essential oils that exhibit various medicinal properties, i.e., anti-oxidant, anti-microbial, anti- inflammatory, anti-cancer, immunomodulatory, etc., due to the presence of various phytoconstituents, including terpenes, phenols, aldehydes, ketones, alcohols, and esters. An understanding of conventional and advanced extraction techniques of essential oils (EOs) from several plant sources is further required before considering or loading EOs into drug delivery systems. Therefore, this article summarizes the various extraction techniques of EOs and their existing limitations. The in-built biological applications of EOs are of prerequisite importance for treating several diseases. Thus, the mechanisms of action of EOs for anti-inflammatory, anti-oxidant, anti-bacterial activities, etc., have been further explored in this article. The encapsulation of essential oils in micro or nanometric systems is an intriguing technique to render adequate stability to the thermosensitive compounds and shield them against environmental factors that might cause chemical degradation. Thus, the article further summarizes the advanced drug delivery approaches loaded with EOs and current challenges in the future outlook of EOs for biomedical applications.

Therapeutic applications of eucalyptus essential oils

Eucalyptus essential oils (EEOs) have gained significant attention recently anticipated to their broad range of prospective benefits in various biological applications. They have been proven to have strong antibacterial properties against a variety of bacteria, fungi, and viruses. This makes them valuable in combating infections and supporting overall hygiene. The active compounds present in these oils can help alleviate inflammation, making them valuable in addressing inflammatory conditions such as arthritis, respiratory ailments, and skin disorders. Respiratory health benefits are another prominent aspect of EEOs. Inhalation of these oils can help promote clear airways, relieve congestion, and ease symptoms of respiratory conditions like coughs, colds, and sinusitis. They are often utilized in inhalation therapies and chest rubs. They can be used topically or in massage oils to alleviate muscle and joint pain. Furthermore, these oils have shown potential in supporting wound healing. Their antimicrobial activity helps prevent infection, while their anti-inflammatory and analgesic properties contribute to reducing inflammation and pain associated with wounds. In aromatherapy, EEOs are renowned for their invigorating and uplifting qualities, promoting mental clarity, relaxation, and stress relief. Overall, EEOs hold great promise in biological applications, offering a natural and versatile approach to promote health and well-being. Continued research and exploration of their therapeutic potential will further unveil their benefits and broaden their applications in various fields.

Carvacrol Essential Oil as a Neuroprotective Agent: A Review of the Study Designs and Recent Advances

Neurodegenerative diseases were mostly perceived as diseases of ageing populations, but now-a-days, these diseases pose a threat to populations of all age groups despite significant improvements in quality of life. Almost all essential oils (EOs) have been reported to have some neuroprotective abilities and have been used as supplements for good mental health over the centuries. This review highlights the therapeutic potential of one such monoterpene phenolic EO, carvacrol (CV), that has the potential to be used as a main therapeutic intervention for neurodegenerative disorders. Three libraries, Google Scholar, PubMed, and ScienceDirect, were explored for research studies related to the neuroprotective roles of CV. All the research articles from these libraries were sorted out, with the first article tracing back to 2009, and the latest article was published in 2024. The positive effects of CV in the treatment of Alzheimer's and Parkinson's Diseases, multiple sclerosis, ischemia, and behavioural disorders have been supported with evidence. This review not only focused on study designs and the pharmacological pathways taken by CV for neuroprotection but also focused on demographics, illustrating the trend of CV research studies in certain countries and the preferences for the use of in vitro or in vivo models in studies. Our review provides useful evidence about the neuroprotective potential of CV; however, a lack of studies was observed regarding CV encapsulation in proper dosage forms, in particular nanoparticles, which could be further explored for CV delivery to the central nervous system.

The Effects of a Blend of Essential Oils in the Milk of Suckling Calves on Performance, Immune and Antioxidant Systems, and Intestinal Microbiota

The objective of the present study was to determine whether the addition of a blend based on the essential oils of cinnamon, oregano, and eucalyptus to the liquid diets of calves would stimulate the immune system combined with anti-inflammatory action, minimize oxidative responses, and alter the intestinal microbiota, consequently enhancing animal growth. Twenty-four male Holstein calves (approximately five days old) were suckled for 60 days, underwent a weaning process, and were followed up until day 75 of the experiment. The calves were divided into control (n = 12) and phytobiotic (n = 12) groups, receiving commercial milk replacer and pelleted concentrate ad libitum. For the phytobiotic group, we added the blend to the liquid diet twice daily at 5 mL/feeding in the first 15 days and 10 mL/feeding until day 60. We detected no differences in weight gain, but animals in the phytobiotic group tended to consume less feed. Calves treated with phytobiotics showed better conversion and feed efficiency than the animals in the control group. Lower leukocyte and lymphocyte counts were observed, as was a higher cholesterol concentration. Immunoglobulin A, ceruloplasmin, and transferrin also differed between groups, with higher IgA and lower levels of acute-phase proteins (ceruloplasmin and transferrin) in calves that consumed the phytobiotic. Higher glutathione S-transferase activity was found in the serum of calves in the treatment group. The intestinal microbiota did not differ between the groups; however, the genera Acinetobacter, Pseudomonas, and Psychrobacter were the most abundant regardless of treatment. We concluded that the blend of oils based on cinnamon, oregano, and eucalyptus improved the calves' immune and antioxidant systems, improving feed efficiency without affecting the intestinal microbiota.

Eugenia Pohliana Leaves Essential Oil Inhibits Fungal Virulence and Restores Antibiotic Efficacy in Multidrug-Resistant Bacterial Strains

This study aims to investigate the essential oil from leaves of Eugenia pohliana (EOEP) in regard to its chemical composition, antimicrobial and drug-enhancing activity, as well as the reduction of fungal virulence capacity. Chemical characterization using GC-MS showed as major components the sesquiterpenes δ-cadinene, Epi-α-Muurolol, and bicyclogermacrene. The results of antibacterial tests indicated that Staphylococcus aureus was more sensitive to EOEP, that also enhanced the efficacy of gentamicin, erythromycin, and norfloxacin. EOEP exhibited antifungal properties against Candida albicans, in addition to potentiating the effectiveness of fluconazole against Candida tropicalis. It showed anti-virulence effects in all fungal strains. These findings underscore E. pohliana as a potential candidate for the prospection of novel therapeutic agents to treat infectious diseases caused by resistant microbes.

Enhancing bioactivity of Callistemon citrinus (Curtis) essential oil through novel nanoemulsion formulation

The main focus of this study was to create a stable and efficient nanoemulsion (NE) using Callistemon citrinus essential oil (EO). Various factors affecting the NE's stability were optimized including oil %, Tween 80%, time of sonication, and its accelerated stability was examined. The research also considered the antibacterial, antifungal, and larvicidal effects of the optimized NE (B10). The optimum NE stood out for its stability, featuring a particle size of 33.15 ± 0.32 nm. Analysis via IR spectroscopy confirmed successful EO encapsulation in B10. The formulation remained stable for six months, with B10 showing significantly higher antibacterial and antifungal potency compared to the pure oil. When samples were subjected to tests against Fusarium oxysporum, B10 exhibited a MIC value of 62.5 mg/mL, whereas the pure oil showed a MIC value of 250 mg/mL. This indicates that the B10 formulation was 50 times more effective than the EO. In terms of antibacterial activity against Escherichia coli, the MIC value was 0.256 mg/mL for B10 and 4 mg/mL for the EO. Also, pure oil and B10 displayed larvicidal effects against Chilo suppressalis (Walker) larvae, with B10 eliminating 95.2% of larvae in 48 h. Overall, stable and optimum C. citrinus NE with its strong antimicrobial qualities, shows promise as an effective fungicide and insecticide.

Special Issue "Advances in the Physiology of Primary and Secondary Plant Metabolism Under Abiotic and Biotic Stress"

One of the most relevant areas of biology is the study of plant adaptation processes to the action of various stress factors of abiotic and biotic nature, which is reflected in the works of molecular biologists, geneticists, microbiologists, plant physiologists, and biochemists, as well as biotechnologists [...].

Beyond aromatherapy: can essential oil loaded nanocarriers revolutionize cancer treatment?

Cancer, a complex global health burden, necessitates the development of innovative therapeutic strategies. While chemotherapy remains the primary treatment approach, its severe side effects and chemoresistance drive the search for novel alternatives. Essential oils (EOs), consisting of diverse bioactive phytochemicals, offer promise as anticancer agents. However, their limitations, such as instability, limited bioavailability, and non-specific targeting, hinder their therapeutic potential. These challenges were circumvented by utilizing nanoparticles and nanosystems as efficient delivery platforms for EOs. This review highlights the accumulating evidence based on loading EOs into several nanocarriers, including polymeric nanoparticles, nanoemulsions, nanofibers, lipid-based nanocapsules and nanostructures, niosomes, and liposomes, as effective anticancer regimens. It covers extraction and chemical composition of EOs, their mechanisms of action, and targeting strategies to various tumors. Additionally, it delves into the diverse landscape of nanocarriers, including their advantages and considerations for cancer targeting and EO encapsulation. The effectiveness of EO-loaded nanocarriers in cancer targeting and treatment is examined, highlighting enhanced cellular uptake, controlled drug release, and improved therapeutic efficacy. Finally, the review addresses existing challenges and future perspectives, emphasizing the potential for clinical translation and personalized medicine approaches.

Integrated supercritical fluid extraction of essential oils

Supercritical fluid extraction (SFE) stands out as an incredibly efficient, environmentally conscious, and fast method for obtaining essential oils (EOs) from plants. These EOs are abundant in aromatic compounds that play a crucial role in various industries such as food, fragrances, cosmetics, perfumery, pharmaceuticals, and healthcare. While there is a wealth of existing literature on using supercritical fluids for extracting plant essential oils, there's still much to explore in terms of combining different techniques to enhance the SFE process. This comprehensive review presents a sophisticated framework that merges SFE with EO extraction methods. This inclusive categorization encompasses a range of methods, including the integration of pressurized liquid processes, ultrasound assistance, steam distillation integration, microfluidic techniques, enzyme integration, adsorbent facilitation, supercritical antisolvent treatments, molecular distillation, microwave assistance, milling process and mechanical pressing integration. Throughout this in-depth exploration, we not only elucidate these combined techniques but also engage in a thoughtful discussion about the challenges they entail and the array of opportunities they offer within the realm of SFE for EOs. By dissecting these complexities, our objective is to tackle the current challenges associated with enhancing SFE for commercial purposes. This endeavor will not only streamline the production of premium-grade essential oils with improved safety measures but also pave the way for novel applications in various fields.

Ibuprofen as an adjuvant to conventional antimicrobials and essential oil compounds against skin pathogens

AIMS

Antimicrobial resistance continues to be a growing concern, resulting in increased use of drug combinations. Antibiotic adjuvants are an emerging strategy that may potentiate an antibiotics efficacy. Ibuprofen's polypharmacological properties have been investigated for their antimicrobial and host-modulating potential. This study aimed to investigate the potential of a novel multidrug combination involving ibuprofen, essential oil compounds (EOCs), and conventional antimicrobials against skin pathogens.

METHODS AND RESULTS

The minimum inhibitory concentrations of ibuprofen, conventional antimicrobials, and EOCs were determined and then combined and tested against 14 (reference and clinical) skin pathogens. The cytotoxicity was analysed using the MTT assay, whilst the anti-inflammatory effects were evaluated using lipopolysaccharide activated RAW264.7 murine macrophages. Four pairwise (Ibuprofen and antibiotic) (ΣFIC 0.33-0.50) and three triple (Ibuprofen and antibiotic with EOC) (ΣFIC 0.44-0.47) synergistic antimicrobial interactions were identified. These combinations demonstrated cell viability of 77.59%-100%. No combination significantly reduced nitric oxide production.

CONCLUSION

The results from this study provide insight into the potential of a multidrug combination involving ibuprofen with conventional antimicrobials and EOCs against common skin pathogens.

Understanding emulsifier influence on complex coacervation: Essential oils encapsulation perspective

The objective of this research was to explore the viability of pea protein as a substitute for gelatin in the complex coacervation process, with a specific focus on understanding the impact of incorporating an emulsifier into this process. The study involved the preparation of samples with varying polymer mixing ratios (1:1, 1:2, and 2:1) and emulsifier content. As core substances, black pepper and juniper essential oils were utilized, dissolved beforehand in grape seed oil or soybean oil, to minimize the loss of volatile compounds. In total, 24 distinct samples were created, subjected to freeze-drying to produce powder, and then assessed for their physicochemical properties. Results revealed the significant impact of emulsifier addition on microcapsule parameters. Powders lacking emulsifiers exhibited higher water solubility (57.10%-81.41%) compared to those with emulsifiers (24.64%-40.13%). Moreover, the emulsifier significantly decreased thermal stability (e.g., without emulsifier, Ton = 137.21°C; with emulsifier, Ton = 41.55°C) and adversely impacted encapsulation efficiency (highest efficiency achieved: 67%; with emulsifier: 21%).

Microencapsulation to Harness the Antimicrobial Potential of Essential Oils and Their Applicability in Dairy Products: A Comprehensive Review of the Literature

This literature review explores cutting-edge microencapsulation techniques designed to enhance the antimicrobial efficacy of essential oils in dairy products. As consumer demand for natural preservatives rises, understanding the latest advancements in microencapsulation becomes crucial for improving the shelf life and safety of these products. The bibliometric analysis utilized in this review highlighted a large number of documents published on this topic in relation to the following keywords: essential oils, AND antimicrobials, AND dairy products, OR microencapsulation. The documents published in the last 11 years, between 2013 and 2023, showed a diversity of authors and countries researching this topic and the keywords commonly used. However, in the literature consulted, no study was identified that was based on bibliometric analysis and that critically evaluated the microencapsulation of essential oils and their antimicrobial potential in dairy products. This review synthesizes findings from diverse studies, shedding light on the various encapsulation methods employed and their impact on preserving the quality of dairy goods. Additionally, it discusses the potential applications and challenges associated with implementation in the dairy industry. This comprehensive analysis aims to provide valuable insights for researchers, food scientists, and industry professionals seeking to optimize the use of essential oils with antimicrobial properties in dairy formulations.

Coatings Based on Essential Oils for Combating Antibiotic Resistance

In the current era of widespread antimicrobial resistance, the utilization of essential oils (EOs) derived from plants has emerged as a promising alternative in combating pathogens that have developed resistance to antibiotics. This review explores the therapeutic potential of essential oils as valuable tools in restoring the efficacy of antibiotics, highlighting their unique ability to affect bacteria in multiple ways and target various cellular systems. Despite the challenge of elucidating their precise mode of action, EOs have shown remarkable results in rigorous testing against a diverse range of bacteria. This review explores the multifaceted role of EOs in combating bacterial microorganisms, emphasizing their extraction methods, mechanisms of action, and comparative efficacy against synthetic antibiotics. Key findings underscore the unique strategies EOs deploy to counter bacteria, highlighting significant differences from conventional antibiotics. The review extends to advanced coating solutions for medical devices, exploring the integration of EO formulations into these coatings. Challenges in developing effective EO coatings are addressed, along with various innovative approaches for their implementation. An evaluation of these EO coatings reveals their potential as formidable alternatives to traditional antibacterial agents in medical device applications. This renaissance in exploring natural remedies emphasizes the need to combine traditional wisdom with modern scientific advancements to address the urgent need for effective antimicrobial solutions in the post-antibiotic era.

Essential oil components interacting with insect odorant-binding proteins: a molecular modelling approach

Essential oils (EOs) are natural products currently used to control arthropods, and their interaction with insect odorant-binding proteins (OBPs) is fundamental for the discovery of new repellents. This in silico study aimed to predict the potential of EO components to interact with odorant proteins. A total of 684 EO components from PubChem were docked against 23 odorant binding proteins from Protein Data Bank using AutoDock Vina. The ligands and proteins were optimized using Gaussian 09 and Sybyl-X 2.0, respectively. The nature of the protein-ligand interactions was characterized using LigandScout 4.0, and visualization of the binding mode in selected complexes was carried out by Pymol. Additionally, complexes with the best binding energy in molecular docking were subjected to 500 ns molecular dynamics simulations using Gromacs. The best binding affinity values were obtained for the 1DQE-ferutidine (-11 kcal/mol) and 2WCH-kaurene (-11.2 kcal/mol) complexes. Both are natural ligands that dock onto those proteins at the same binding site as DEET, a well-known insect repellent. This study identifies kaurene and ferutidine as possible candidates for natural insect repellents, offering a potential alternative to synthetic chemicals like DEET.

Enhancing the nitric oxide inhibitory activity using a combination of plant essential oils and mixture design approach

The synergistic effects of essential oils (EOs) from three aromatic plant species, Foeniculum vulgare subsp. piperitum (C.Presl) Bég. (FV), Origanum heracleoticum L. (OH) and Lavandula austroapennina N.G.Passal., Tundis & Upson. (LA), were evaluated for their inhibitory properties on nitric oxide production in RAW 264.7 macrophages stimulated with lipopolysaccharide (LPS). We utilized a Design of Experiments (DoE) methodology to optimize a formulation by combining three Essential Oils (EOs), while simultaneously taking into account two response variables, maximization of NO inhibition with minimum cytotoxicity. The optimal blend of components was predicted, and the statistical outcome's efficacy was experimentally verified. The combination corresponding to 87.7 % FV, 12.3 % LA and 0.0 % OH showed high inhibitory effect (76.3 %) with negligible cytotoxicity (4.5 %). This research provides new information on the interactions among fennel, oregano and lavender essential oils and shows how they can synergistically inhibit in vitro LPS-induced NO production.

Perceived Barriers to Administration of Aromatherapy in Nurses Caring for Pediatric Patients With Postoperative Nausea and Vomiting: An Evidence-based Practice Project

INTRODUCTION

Postoperative nausea and vomiting (PONV) is prevalent among surgical patients, causing hospitalizations, extended stays, and patient dissatisfaction. Children are twice as likely to experience PONV than adult patients. Complementary therapy holds promise for PONV treatment but meets clinical use barriers. We explored perioperative nurses' perceived barriers to the use of complementary aromatherapy.

METHOD

Presurvey and postsurveys assessed nurses' (n = 27) knowledge and barriers to aromatherapy use before and after an educational in-service.

RESULTS

Primary PONV treatment involved antiemetics. Barriers to aromatherapy included product availability, caregiver refusal, and patient-specific factors. Post-in-service, the nurses felt more familiar with aromatherapy and inclined to use it.

DISCUSSION

Increased education and guidelines on aromatherapy promote its incorporation into clinical practice. Institutional policies addressing the selection, administration, documentation, and monitoring of aromatherapy should be established to ensure the consistency and standardization of its use.

The use of essential oils in atopic dermatitis: a review

Atopic dermatitis (AD) has become a common childhood disease that affects a large number of children worldwide and has become a chronic skin disease that causes huge economical and psychological damage to the whole family. Despite the use of steroids, immunosuppressants, and various topical preparation, the prognosis is still poor. Hence, this review aimed to explore the potential of using essential oils (EO) as an active ingredient in managing AD. The review was completed by using Pubmed, Scopus, and Medline to search for relevant articles that study the pathophysiology of AD, the properties of EO, the use of EO in managing AD, and the suitable advanced formulation to incorporate EO. From the review conducted, it was concluded that EO have huge potential in managing AD and can be used as complimentary therapeutic agents in AD treatment. Scientists and industries should venture into commercializing more topical products with EO to help manage AD more effectively.

Carvacrol and Thymol Content Affects the Antioxidant and Antibacterial Activity of Origanum compactum and Thymus zygis Essential Oils

Essential oils are of great interest due to their potent pharmaceutical and biological activities. In this study, essential oils extracted from Origanum compactum and Thymus zygis originating from the Middle Atlas of Morocco were investigated. Their chemical compositions were analyzed using gas chromatography and mass spectrometry, while the assessment of the trapping power of the radical (DPPH: 1,1-diphenyl-2-picrylhydrazyl) and the reducing antioxidant potential of ferric ions (FRAP: Ferric Reducing Antioxidant Power) were performed in order to evaluate the antioxidant activity. Their antibacterial potency was tested against six bacterial strains through the disk diffusion method. The chromatography analyses of the extracted essential oils highlighted the presence of two main components, namely carvacrol at 75.70% in O. compactum and thymol at 40.67% in T. zygis. The antioxidant activity tests showed that both essential oils demonstrated a significant antioxidant activity comparable to the positive control (e.g., ascorbic acid). The antibacterial activity results showed a strong antimicrobial effect for both essential oils, compared to synthetic antibiotics. This study affirms the presence of bioactive components with interesting antioxidant and antibacterial activities in the essential oils extracted from Origanum compactum and Thymus zygis, which could find several applications in the food and pharmaceutical industries through the substitution of synthetic antioxidants and antibiotics.

Long-Term Stability of Lavandula x intermedia Essential Oil Nanoemulsions: Can the Addition of the Ripening Inhibitor Impact the Biocidal Activity of the Nanoformulations?

In this work, Lavandula x intermedia essential oil (LEO) was encapsulated in lipid-based nanoemulsions (NanoLEO) using the solvent-displacement technique. In order to preserve the colloidal stability of the formulation, LEO was appropriately doped with the incorporation of different levels of a water-insoluble oil used as a ripening inhibitor. All the nanoemulsion samples were evaluated in terms of the impact of the water-insoluble oil on the nanoemulsion formation, physical-chemical properties, and antibacterial effectiveness against E. coli (Gram-negative) and B. cereus (Gram-positive). The presence of the inert oil added benefits to the formulations in terms of appearance, colloidal stability, and loss of volatile components. However, the antimicrobial activity of the nanoemulsions dramatically decreased with the ripening inhibitor addition, probably because it hampered the internalization of the antimicrobial components of LEO within the bacterial cell membranes, thus nullifying the delivery ability of the nanoemulsion formulation. On the contrary, the undoped NanoLEO formulation showed unaltered antibacterial activity in both E. coli and B. cereus up to 40 weeks from the preparation.

Molecular genetic divergence analysis amongst high curcumin lines of Golden Crop (Curcuma longa L.) using SSR marker and use in trait-specific breeding

Curcuma longa L., is recognized worldwide as a medicinally and economically important plant species due to its curcumin content which is an industrially important compound. In this study, a total of 329 accessions were collected from four states of India and planted in the experimental farm of CSIR-NEIST, Jorhat, India, in augmented design. Among these, 152 high curcumin (> 1.50%) accessions were screened for molecular divergence study using 39 SSR primers. The primers showed the most efficient outcome with 2-8 allele/ loci and a total 163 number of alleles with 100% polymorphism. Cluster analysis revealed the construction of three clusters, out of which one cluster was geographically dependent, and germplasm was particularly from Assam state. Jaccard's pairwise coefficient showed maximum genetic dissimilarity of (0.75) between accession RRLJCL 3 and RRLJCL 126, indicating high variation as it was from two different states viz Arunachal Pradesh and Nagaland respectively and minimum genetic dissimilarity of (0.09) between RRLJCL 58 and RRLJCL 59 indicating significantly less variation as the two accessions were from same state, i.e., Arunachal Pradesh. Analysis of Molecular Variance (AMOVA) revealed high molecular variation within the population (87%) and significantly less variation among the population (13%). Additionally, Neighbour Joining dendrogram, Principal Component Analysis (PCA), and bar plot structure revealed similar clustering of germplasm. This diversity assessment will help in selecting the trait-specific genotypes, crop improvement program, conservation of gene pool, marker-assisted breeding, and quantitative trait loci identification. Moreover, to the best of our knowledge, it is the first molecular diversity report among 152 high curcumin lines of C. longa from North East India using 39 SSR primers.

Assessment of the in Vitro Antimelanoma Potential of Lippia microphylla Cham (Verbenaceae) Essential Oil

Essential oils stand out among natural products for their complex composition, frequently described in the literature with a range of biological effects. This study evaluated the cytotoxic activity against several human cancer cell lines of essential oils extracted from the leaves of Lippia microphylla (EO-LM) Cham. (Verbenaceae). The melanoma cell line SK-MEL-28 was the most sensitive to the EO-LM, presenting an IC50 of 33.38±1.16 μg/mL. Afterward, the effects of EO-LM on the cell cycle, induction of apoptosis, and production of reactive oxygen species (ROS) were evaluated. We stated a significant increase in the sub-G1 population, indicating apoptosis, later confirmed by an increase of SK-MEL-28 cells labeled with Annexin V-FITC and by the formation of apoptotic bodies and membrane blebs, observed by confocal microscopy. Additionally, EO-LM reduced the production of ROS, indicating antioxidant activity. Therefore, EO-LM exhibits anti-melanoma activity in vitro, suggesting its potential as an anticancer agent.

Enhancing the Functional Properties of Tea Tree Oil: In Vitro Antimicrobial Activity and Microencapsulation Strategy

In the context of addressing antimicrobial drug resistance in periocular infections, Tea Tree Oil (TTO) has emerged as a promising therapeutic option. This study aimed to assess the efficacy of TTO against bacterial strains isolated from ocular infections, with a particular focus on its ability to inhibit biofilm formation. Additionally, we designed and analyzed microcapsules containing TTO to overcome certain unfavorable physicochemical properties and enhance its inherent biological attributes. The quality of TTO was confirmed through rigorous analysis using GC-MS and UV-Vis techniques. Our agar diffusion assay demonstrated the effectiveness of Tea Tree Oil (TTO) against ocular bacterial strains, including Corynebacterium spp., coagulase-negative Staphylococcus spp., and Staphylococcus aureus, as well as a reference strain of Staphylococcus aureus (ATCC 25923). Notably, the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) for all tested microorganisms were found to be 0.2% and 0.4%, respectively, with the exception of Corynebacterium spp., which exhibited resistance to TTO. Furthermore, TTO exhibited a substantial reduction in biofilm biomass, ranging from 30% to 70%, as determined by the MTT method. Through the spray-drying technique, we successfully prepared two TTO-containing formulations with high encapsulation yields (80-85%), microencapsulation efficiency (90-95%), and embedding rates (approximately 40%). These formulations yielded microcapsules with diameters of 6-12 μm, as determined by laser scattering particle size distribution analysis, and exhibited regular, spherical morphologies under scanning electron microscopy. Importantly, UV-Vis analysis post-encapsulation confirmed the presence of TTO within the capsules, with preserved antioxidant and antimicrobial activities. In summary, our findings underscore the substantial therapeutic potential of TTO and its microcapsules for treating ocular infections.

Nanoemulsion of Lavandula angustifolia Essential Oil/Gold Nanoparticles: Antibacterial Effect against Multidrug-Resistant Wound-Causing Bacteria

Hospitalized patients are severely impacted by delayed wound healing. Recently, there has been a growing focus on enhancing wound healing using suitable dressings. Lavandula angustifolia essential oil (LEO) showed potential antibacterial, anti-inflammatory, and wound healing properties. However, the prepared gold nanoparticles possessed multifunctional properties. Consequently, the present investigation aimed to synthesize a novel nanosystem consisting of nano-Lavandula angustifolia essential oil and gold nanoparticles prepared through ultrasonic nanoemulsifying techniques in order to promote wound healing and combat bacterial infection. LEO showed potent antibacterial activity against Klebsiella pneumoniae, MRSA and Staphylococcus aureus with minimum inhibitory concentration (MIC) values of 32, 16 and 16 µg/mL, respectively, while exhibiting low activity against Proteus mirabilis. Interestingly, the newly formulated nano-gold/nano-Lavandula angustifolia penetrated the preformed P. mirabilis biofilm with a full eradication of the microbial cells, with MIC and MBEC (minimal biofilm eradication concentration) values reaching 8 and 16 µg/mL, respectively. The cytotoxic effect of the novel nanoformula was also assessed against WI-38 fibroblasts vero (normal) cells (IC50 = 0.089 mg/mL) while nano-gold and nano-Lavandula angustifolia showed higher results (IC50 = 0.529, and 0.209 mg/mL, respectively). Nano-gold/nano-Lavandula angustifolia formula possessed a powerful wound healing efficacy with a 96.78% wound closure. These findings revealed that nano-gold/nano-Lavandula angustifolia nanoemulsion can inhibit bacterial growth and accelerate the wound healing rate.

Effects of Rosmarinus officinalis L. (Laminaceae) essential oil on adult and larvae of Drosophila melanogaster

Rosmarinus officinalis (Lamiaceae family), also known as "alecrim," is a perennial herb, typical of the Mediterranean region and widely distributed in Brazilian territory. Despite having demonstrated several properties of human interest, insecticide/larvicidal effect of essential oil from R. officinalis on insects remains unclear. In this study, we tested the effects of R. officinalis essential oil on biomarkers of oxidative damage in Drosophila melanogaster. Exposure to R. officinalis essential oil increased adult mortality and decreased geotaxis behavior in adult fruit flies. In addition, essential oil increased of larval mortality and impaired the developmental success in D. melanogaster. R. officinalis essential oil showed a significant repellent effect, with duration time of about 6 h. To understand the mechanism underlying the toxicity of essential oil both pro-oxidant effects and biomarkers of oxidative damage were evaluated in exposed flies. Exposure to essential oil caused a significant redox imbalance with impairment of both enzymatic and non-enzymatic antioxidant system and increased the lipid peroxidation levels. These results suggest that R. officinalis essential oil can be used as a bioinsecticide and/or larvicide as well as an alternative insect repellent.

Bacterial diseases in marine fish species: current trends and future prospects in disease management

The fisheries sub-sector of aquaculture-i.e., the pisciculture industry, contributes significantly to a country's economy, employing a sizable proportion of the population. It also makes important contributions to household food security because the current demand for animal protein cannot be fulfilled by harvesting wild fish from riverines, lakes, dams, and oceans. For good pond management techniques and sustaining fish health, the fisherfolk, and the industry require well-established regulatory structures, efficient disease management strategies, and other extended services. In rearing marine fish, infections resulting from disease outbreaks are a weighty concern because they can cause considerable economic loss due to morbidity and mortality. Consequently, to find effective solutions for the prevention and control of the major diseases limiting fish production in aquaculture, multidisciplinary studies on the traits of potential fish pathogens, the biology of the fish as hosts, and an adequate understanding of the global environmental factors are fundamental. This review highlights the various bacterial diseases and their causative pathogens prevalent in the pisciculture industry and the current solutions while emphasising marine fish species. Given that preexisting methods are known to have several disadvantages, other sustainable alternatives like antimicrobial peptides, synthetic peptides, probiotics, and medicinal treatments have emerged to be an enormous potential solution to these challenges.

Chemical Composition, In Vitro Antitumor Effect, and Toxicity in Zebrafish of the Essential Oil from Conyza bonariensis (L.) Cronquist (Asteraceae)

The essential oil from Conyza bonariensis (Asteraceae) aerial parts (CBEO) was extracted by hydrodistillation in a Clevenger-type apparatus and was characterized by gas chromatography-mass spectrometry. The antitumor potential was evaluated against human tumor cell lines (melanoma, cervical, colorectal, and leukemias), as well as non-tumor keratinocyte lines using the MTT assay. The effect of CBEO on the production of Reactive Oxygen Species (ROS) was evaluated by DCFH-DA assay, and a protection assay using the antioxidant N-acetyl-L-cysteine (NAC) was also performed. Moreover, the CBEO toxicity in the zebrafish model was assessed. The majority of the CBEO compound was (Z)-2-lachnophyllum ester (57.24%). The CBEO exhibited selectivity towards SK-MEL-28 melanoma cells (half maximal inhibitory concentration, IC50 = 18.65 ± 1.16 µg/mL), and induced a significant increase in ROS production. In addition, the CBEO's cytotoxicity against SK-MEL-28 cells was reduced after pretreatment with NAC. Furthermore, after 96 h of exposure, 1.5 µg/mL CBEO induced death of all zebrafish embryos. Non-lethal effects were observed after exposure to 0.50-1.25 µg/mL CBEO. Additionally, significant alterations in the activity of enzymes associated with oxidative stress in zebrafish larvae were observed. These results provide evidence that CBEO has a significant in vitro antimelanoma effect by increasing ROS production and moderate embryotoxicity in zebrafish.

Myrcene: A Natural Compound Showing Anticancer Activity in HeLa Cells

γ-terpinene, α-terpinene, p-cymene, and myrcene are monoterpenes found in many essential oils extracted from a variety of plants and spices. Myrcene also occurs naturally in plants such as hops, cannabis, lemongrass, and verbena and is used as a flavoring agent in food and beverage manufacturing. In this research, the biological efficacy of γ-terpinene, α-terpinene, p-cymene, and myrcene was studied in human cell lines (HeLa, SH-SY5Y, and HDFa). Cytotoxicity, cell proliferation, cell migration, and morphology assays were performed to obtain detailed information on the anticancer properties. Our results show that myrcene has potential biological activity, especially in HeLa cells. In this cell line, it leads to an arrest of proliferation, a decrease in motility and morphological changes with loss of sphericity and thickness, and DNA damage. In addition, the interaction of γ-terpinene, α-terpinene, p-terpinene, and myrcene with calf thymus DNA (ct-DNA) was studied by UV-visible spectrophotometry. DNA binding experiments show that only myrcene can interact with DNA with an apparent dissociation constant (Kd) of 29 × 10-6 M.

Antioxidant and antimicrobial effects of essential oils from two salvia species with in vitro and in silico analysis targeting 1AJ6 and 1R4U proteins

The Middle Atlas is a Moroccan territory that serves as an abode to plants with incredible biodiversity, of which aromatic and medicinal plants that have been of folkloric use are a significant component. However, their effective utilization in modern medicine requires the characterization of their phytochemicals to facilitate their entry into drug discovery pipelines. Hence, this study aimed to characterize and investigate the antioxidant activity and antimicrobial effects of the essential oils (EOs) of Salvia lavandulifolia subsp. mesatlantica and Salvia officinalis L. by use of in vitro and in silico assays. Ten phytochemicals were identified in the EOs of S. lavandulifolia, while twenty phytochemicals were identified in S. officinalis. Camphor was the most abundant compound in both species, comprising 26.70% and 39.24% of the EOs of S. lavandulifolia and S. officinalis, respectively. The EOs of both plants exhibited significant DPPH free radical scavenging activity, with S. lavandulifolia and S. officinalis showing estimated scavenging rates of 92.97% and 75.20%, respectively. In terms of Ferric Reducing Antioxidant Power (FRAP), S. officinalis demonstrated a higher value (72.08%) compared to that of S. lavandulifolia (64.61%). Evaluation of the antimicrobial effects of the EOs of S. officinalis and S. lavandulifolia against microorganisms revealed bactericidal activities against Proteus mirabilis and Bacillus subtilis at low concentrations. It showed bactericidal activities against Staphylococcus aureus and Candida albicans at a relatively higher concentration. Molecular docking of antioxidant and antimicrobial proteins offers significant insights into ligand-protein interactions, facilitating the development of innovative therapeutics from the current study. Ultimately, this study identified the phytochemical composition of S. lavandulifolia and S. officinalis and highlighted their potential for therapeutic discovery.

Composition and Anti-Helicobacter pylori Properties of Essential Oils Obtained from Selected Mentha Cultivars

Helicobacter pylori infections are highly common amongst the global population. Such infections have been shown to be the cause of gastric ulcers and stomach carcinoma and, unfortunately, most cases are asymptomatic. Standard treatment requires antibiotics such as metronidazole or azithromycin to which many strains are now resistant. Mentha species have been used as a natural treatment for gastrointestinal diseases throughout history and essential oils (EOs) derived from these plants show promising results as potential antimicrobial agents. In this study, EOs obtained from the leaves and flowers of five cultivars of Mentha × piperita and M. spicata were examined by GC-MS. The investigated mints are representatives of four chemotypes: the menthol chemotype (M. × piperita 'Multimentha' and M. × piperita 'Swiss'), the piperitenone oxide chemotype (M. × piperita 'Almira'), the linalool chemotype (M. × piperita 'Granada'), and the carvone chemotype (M. spicata 'Moroccan'). The chemical composition of EOs from mint flowers and leaves was comparable with the exception of the Swiss cultivar. Menthol was the most abundant component in the leaves while menthone was highest in flowers. The H. pylori ATCC 43504 reference strain and 10 other H. pylori clinical strains were examined for their sensitivity to the EOs in addition to their major monoterpenoid components (menthol, menthone, carvone, dihydrocarvone, linalool, 1,8-cineole, and limonene). All tested mint EOs showed inhibitory activity against both the reference H. pylori ATCC 43504 strain (MIC 15.6-31.3 mg/L) and clinical H. pylori strains (MIC50/90 31.3-250 mg/L/62.5-500 mg/L). Among the reference monoterpenes, menthol (MIC50/90 7.8/31.3 mg/L) and carvone (MIC50/90 31.3/62.5 mg/L) had the highest anti-H. pylori activity, which also correlated with a higher activity of EOs containing these compounds (M. × piperita 'Swiss' and M. spicata 'Moroccan'). A synergistic and additive interaction between the most active EOs/compounds and antibiotics possibly points to a new plant-based anti-H. pylori treatment.

Enhancing Wound Healing: A Novel Topical Emulsion Combining CW49 Peptide and Lavender Essential Oil for Accelerated Regeneration and Antibacterial Protection

Wound healing is a complex process involving blood cells, extracellular matrix, and parenchymal cells. Research on biomimetics in amphibian skin has identified the CW49 peptide from Odorrana grahami, which has been demonstrated to promote wound regeneration. Additionally, lavender essential oil exhibits anti-inflammatory and antibacterial activities. Given these considerations, we propose an innovative emulsion that combines the CW49 peptide with lavender oil. This novel formulation could serve as a potent topical treatment, potentially fostering the regeneration of damaged tissues and providing robust antibacterial protection for skin wounds. This study investigates the physicochemical properties, biocompatibility, and in vitro regenerative capacity of the active components and the emulsion. The results show that the emulsion possesses appropriate rheological characteristics for topical application. Both the CW49 peptide and lavender oil exhibit high viability in human keratinocytes, indicating their biocompatibility. The emulsion induces hemolysis and platelet aggregation, an expected behavior for such topical treatments. Furthermore, the lavender-oil emulsion demonstrates antibacterial activity against both Gram-positive and Gram-negative bacterial strains. Finally, the regenerative potential of the emulsion and its active components is confirmed in a 2D wound model using human keratinocytes. In conclusion, the formulated emulsion, which combines the CW49 peptide and lavender oil, shows great promise as a topical treatment for wound healing. Further research is needed to validate these findings in more advanced in vitro models and in vivo settings, potentially leading to improved wound-care management and novel therapeutic options for patients with skin injuries.

Chemical Composition, Antioxidant, and Antimicrobial Activities of the Leaf and Fruit Essential Oils of the West African Plum, Vitex doniana

Vitex doniana (West African plum or black plum) is a plant with varying phytoconstituents and biological activities across different countries. In this study, essential oils extracted from the leaves and fruits of Vitex doniana cultivated in Ghana were investigated for their antimicrobial and antioxidant activities. The antioxidant actions of the essential oils were determined using hydrogen peroxide (H2O2), phosphomolybdenum, thiobarbituric acid reactive substances (TBARS), and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assays. For both essential oils, the total antioxidant capacities ranged from 44 to 68 µg/g AAE, the IC50 values for H2O2 scavenging activity were between 87 and 242 µg/mL, whereas that for DPPH assay were between 322 and 599 µg/mL. The IC50 for the TBARS assay for both essential oils also ranged from 247 to 414 µg/mL. The antimicrobial activities of the essential oils were investigated using the broth dilution assay. The minimum inhibition concentration for the essential oils ranged from 12.5 to 50 mg/mL. Biofilm inhibitory activity was also evaluated for both essential oils, and the fruit essential oil showed a half-maximal inhibition of biofilm formation (BIC50) at 44.40 ± 0.6 mg/mL, whereas the BIC50 value of the leaf essential oil was 109.1 ± 0.9 mg/mL. The fruit essential oil was superior to the leaf essential oil in inhibiting the secretion of pyoverdine. Molecular docking analyses suggested that methyl cinnamate, ethyl cinnamate, p-menth-4-en-3-one, trans-α-ionone, benzyl benzoate, isobutyl cinnamate, and folic acid likely interacted with LasR and algC proteins, and hence, contributed to the inhibition of biofilm formation and pyoverdine secretion. Essential oils from Vitex doniana could, therefore, be exploited as a natural source of radical scavenging and antimicrobial agents and could be useful in the pharmaceutical, food, and cosmetic industries.

Essential oil and nanocarrier-based formulations approaches for vaginal candidiasis

An exclusive site for local drug delivery is the vagina, especially for vaginal infections. The fungus Candida albicans causes vaginal infection known as vulvovaginal candidiasis, a highly prevalent and recurrent gynaecological disease among women. Vaginal candidiasis affects over 75% of women at a certain point in their life and has a recurrence rate of 40-50%. Medicinal plants provide some very effective phytoconstituents which when delivered as nanosystems have enhanced therapeutic action and efficacy by alteration in their characteristics. Antifungal drugs are used to treat these conditions, alternative medicine is required for prophylaxis and improved prognosis. The current review focuses on the research carried out on various nanocarrier-based approaches and essential oil-based formulations for vaginal candidiasis.

Separation and Qualitative Study of Mentha asiatica Boriss. Essential Oil Components by prep-GC, GC-QTOF-MS, NMR and Prediction of Bioactive Compounds

In order to understand the material basis of wild Mentha asiatica Boris. in Xinjiang, the chemical constituents of essential oil extracted from aerial parts of this plant were studied. A total 52 components were detected and 45 compounds were identified. First of all, the essential oil was separated by silica gel column chromatography, and divided into several parts according to the results of thin layer chromatography. Eight fractions were obtained, and then each fragment was preliminarily screened for antibacterial activity. It was found that all eight fragments had certain antibacterial activity in different level. Then the fractions were subjected to preparative gas chromatography (prep-GC) for further isolation. Ten compounds were identified by ¹³ C-NMR, ¹ H-NMR and gas chromatography-quadrupole time of flight-Mass spectrometry (GC-QTOF-MS). They are sabinene, limonene and β-caryophyllene, (1R*,3S*,5R*)-sabinyl acetate, piperitone oxide, rotundifolone, thymol, piperitone, 4-hydroxypiperiditone, cedrol. After screened by bioautography, 4-hydroxypiperone and thymol were showed best antibacterial activity. The inhibitory effects of the two isolated compounds on Candida albicans and their related mechanisms were studied. The results showed that, 4-hydroxypiperone and thymol significantly reduced ergosterol content on the surface of Candida albicans cell membrane in a dose-dependent manner. This work has accumulated experience for the development and utilization of Xinjiang characteristic medicinal plant resources and new drug research and development, and provided scientific basis and support for the later research and development of Mentha asiatica Boris.

Antifungal activity and mechanism of action of natural product derivates as potential environmental disinfectants

There have been a considerable number of antifungal studies that evaluated natural products (NPs), such as medicinal plants and their secondary metabolites, (phenolic compounds, alkaloids), essential oils, and propolis extracts. These studies have investigated natural antifungal substances for use as food preservatives, medicinal agents, or in agriculture as green pesticides because they represent an option of safe, low-impact, and environmentally friendly antifungal compounds; however, few have studied these NPs as an alternative to disinfection/sanitation for indoor air or environmental surfaces. This review summarizes recent studies on NPs as potential fungal disinfectants in different environments and provides information on the mechanisms of inactivation of these products by fungi. The explored mechanisms show that these NPs can interfere with ATP synthesis and Ca++ and K+ ion flow, mainly damaging the cell membrane and cell wall of fungi, respectively. Another mechanism is the reactive oxygen species effect that damages mitochondria and membranes. Inhibition of the overexpression of the efflux pump is another mechanism that involves damage to fungal proteins. Many NPs appear to have potential as indoor environmental disinfectants.

ONE-SENTENCE SUMMARY

This review shows the latest advances in natural antifungals applied to different indoor environments. Fungi have generated increased tolerance to the mechanisms of traditional antifungals, so this review also explores the various mechanisms of action of various natural products to facilitate the implementation of technology.

Chemical Composition, Antimicrobial and Antioxidant Bioautography Activity of Essential Oil from Leaves of Amazon Plant Clinopodium brownei (Sw.)

The Amazonian region of Ecuador has an extremely rich vegetal biodiversity, and its inhabitants have proven to have a millennial ancestral knowledge of the therapeutic and medicinal use of these resources. This work aimed to evaluate the chemical composition and biological activity of the essential oil obtained from the medicinal plant Clinopodium brownei (Sw.) Kuntze, which is widely spread in tropical and subtropical America. This species is traditionally used for treating respiratory and digestive diseases and is also known for its analgesic properties. Most of the molecules detected on a non-polar column were ethyl cinnamate 21.4%, pulegone 20.76%, methyl cinnamate 16.68%, caryophyllene 8.17%, β-selinene 7.92% and menthone 7.51%, while those detected on a polar column were: pulegone 29.90%, ethyl cinnamate 18.75%, methyl cinnamate 13.82%, caryophyllene 10.0% and menthone 8.04%. The antioxidant activity by the assays, DPPH (2.2-diphenyl-1-picrylhydrazyl) and ABTS (2.2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid)), shows the following values of 50% inhibition of oxidation, IC50 DPPH 1.77 mg/mL, IC50 ABTS 0.06 mg/mL, which, compared to the essential oil of Thymus vulgaris (natural positive control), turn out to be less active. Bioautography indicates that the molecules responsible for the antioxidant activity are derived from cinnamic acid: ethyl cinnamate and methyl cinnamate, and caryophyllene. The antimicrobial activity on the nine microorganisms evaluated shows bacterial growth inhibitory concentrations ranging from 13.6 mg/mL for Staphylococcus epidermidis ATCC 14990 to 3.1 mg/mL for Candida albicans ATCC 10231; the results are lower than those of the positive control. Bioautography assigns antimicrobial activity to caryophyllene. The results indicate a very interesting activity of the essential oil and several of its molecules, validating the traditional use and the importance of this medicinal plant from Ecuador.

Antimicrobial potential of Indian Cinnamomum species

Cinnamomum is the largest genus of Lauraceae family and has been used as spices, food, and food additives by the people. Total 15 Cinnamomum species are distributed in different parts of Indian sub-continent. Different parts (leaves, stem bark, stem wood, roots, flowers, and fruits) of these species were shade-dried and used for the determination of essential oils. A total of 19 essential oils were identified and quantified from the different parts of (leaf, stem bark, stem wood, root, flower, and fruit) of 15 Cinnamomum species. The stem bark of C. altissimum was rich in the presence of essential oils (52.2 %) whereas minimum levels of essential oils were recorded in roots (17.9 %). The γ-terpinene (11.1 %) was reported as the major component essential oil in C. subavenium flowers. Methanol extract of C. camphora stem wood showed stronger lowest minimum inhibitory concentration against S. aureus (25 ± 0.01 μg/ml), H. pylori (29 ± 0.05 μg/ml), B. subtilis (31 ± 0.03 μg/ml), E. faecalis (33 ± 0.01 μg/ml), C. albicans (38 ± 0.03 μg/ml) when compared to amoxycillin (S. aureus 56 ± 0.05 μg/ml; B. subtilis 27 ± 0.04 μg/ml, E. faecalis 22 ± 0.01 μg/ml), streptomycin (H. pylori 38 ± 0.02 μg/ml) and fluconazole (C. albicans 56 ± 0.01 μg/ml). Methanolic extract of C. camphora stem wood demonstrated maximum antimicrobial activity against S. aureus, H. pylori, B. subtilis, E. faecalis and C. albicans. The essential oil of C. altissimum stem bark displayed significant lowest MIC against S. aureus (21 ± 0.03 μg/ml), E. coli (22 ± 0.03 μg/ml), E. cloacae (37 ± 0.06 μg/ml), L. monocytogenes (47 ± 0.08 μg/ml), and P. chrysogenum (101 ± 0.07 μg/ml) when compared to amoxycillin (E. coli 18 ± 0.01 μg/ml, E. cloacae 21 ± 0.05 μg/ml, L. monocytogenes 31 ± 0.03 μg/ml), and fluconazole (P. chrysogenum 101 ± 0.07 μg/ml). The essential oil of C. altissimum stem bark displayed maximum antimicrobial activity against S. aureus, E. coli, E. cloacae, L. monocytogenes, and P. chrysogenum. Cinnamomum essential oils may be used as an alternative source of antibacterial and antifungal compounds in the treatment of various types of infections.

Essential Oils Composition and Biological Activity of Chamaecyparis obtusa, Chrysopogon nigritanus and Lavandula coronopifolia Grown Wild in Sudan

Generally, there are scant data about the constituents and eventually the biological activity of essential oils (EOs) from aromatic plants that grow naturally in Sudan. The present study aimed to determine the chemical composition, and antioxidant and enzyme inhibitory activities of EO extracted from the fruit of Chamaecyparis obtusa (Siebold and Zucc.) Endl. (family Cupressaceae), root of Chrysopogon nigritanus (Benth.) Veldkampis (family Poaceae) and aerial part of Lavandula coronopifolia Poir (family Lamiaceae). The fruit of C. obtusa contained only monoterpenes, mainly hydrogenated ones, with α-pinene (69.07%) as the major component. Oxygenated sesquiterpenes comprised the highest content of the C. nigritanus root EO with cedr-8-en-15-ol (28.69%) as the major constituent while aerial parts of L. coronopifolia contained both monoterpenes and sesquiterpenes and the oxygenated monoterpene lavandulol (26.56%) as dominant compounds. The EO of the root of C. nigritanus significantly displayed (p < 0.05) the highest anti-DPPH radical, Fe³⁺- and Cu²⁺-reducing and metal-chelating activities, while that of C. obtusa fruit significantly exerted (p < 0.05) the best anti-ABTS radical and total antioxidant activity. The two EOs significantly exhibited (p < 0.05) the highest anti-acetylcholinesterase and -butyrylcholinesterase activities, respectively, while EO of L. coronopifolia was the only oil to show a considerable inhibitory effect against the tyrosinase and α-glucosidase enzymes. In conclusion, EOs from these three plants could be natural agents with promising functional properties for food, cosmetics, and pharmaceutical applications.

Plant Essential Oils as Healthy Functional Ingredients of Nutraceuticals and Diet Supplements: A Review

Essential oils (EOs) are mixtures of volatile molecules endowed with health-promoting biological activities that go beyond their role as aromas and natural preservatives and can be exploited to develop functional foods and diet supplements. Their composition is briefly addressed along with regulatory aspects. The potential health benefit of human diet supplementation with EOs is outlined through a review of the recent literature on available clinical trials and preclinical research concerning EOs activity towards: (1) irritable bowel syndrome; (2) inflammatory bowel disease; (3) regulation of microbiota; (4) gastroprotection; (5) hepatoprotection; (6) protection of the urinary tract and diuresis; (7) management of metabolic disorders including hyperglycemia and hyperlipidemia; (8) anti-inflammatory and pain control; (9) immunomodulation and protection from influenza; and (10) neuroprotection and modulation of mood and cognitive performance. The emerging potential in such activities of selected EOs is given focus, particularly green and black cumin, bergamot, orange, myrtle, peppermint, sage, eucalyptus, lavender, thyme, lemon balm, ginger, and garlic.

Antibacterial Effect of 16 Essential Oils and Modulation of mex Efflux Pumps Gene Expression on Multidrug-Resistant Pseudomonas aeruginosa Clinical Isolates: Is Cinnamon a Good Fighter?

The purpose of the study was to describe the antimicrobial activity of 16 common essential oils (EOs) on multidrug-resistant (MDR) Pseudomonas aeruginosa clinical isolates, including the determination of the effects on mex efflux pumps gene expression. Seventy-two clinical isolates of P. aeruginosa collected between 2020-2022 were screened for susceptibility to EOs using Kirby-Bauer disk diffusion to identify potential candidates for future alternative therapies. The minimal inhibitory concentration (MIC) was further determined for the EO that proved antibacterial activity following the disk diffusion screening. Positive and negative controls were also used for method validation. Since cinnamon EO exhibited the best antimicrobial activity, it was further used to evaluate its influence on mex A, B, C, E, and X efflux pumps gene expression using real-time RT-PCR. Cinnamon EO inhibited all P. aeruginosa strains, followed by thyme EO (37.5%, n = 27) and lavender EO (12.5%, n = 9). The other EOs were less efficient. The MIC detection showed that cinnamon at a concentration of 0.05% v/v inhibited all MDR P. aeruginosa isolates. Thyme, turmeric, peppermint, basil, clove, and lavender EOs presented various results, most of them having activity at concentrations higher than 12.5% v/v. By studying the activity of cinnamon EO on mex efflux pumps, it was found that mexA and mexB (66.5%) were generally under-expressed. The remarkable results produced using the very low concentrations of cinnamon EO, with 100% antimicrobial activity against multi-, extended-, and pan- drug-resistant (MDR, XDR, PDR) P. aeruginosa clinical isolates, completed with the severe alteration of the RNA messaging system, supports its potential to be used as adjuvant treatment, with impact on therapeutic results.

Biotechnological Applications of Nanoencapsulated Essential Oils: A Review

Essential oils (EOs) are complex mixtures of volatile and semi-volatile organic compounds that originate from different plant tissues, including flowers, buds, leaves and bark. According to their chemical composition, EOs have a characteristic aroma and present a wide spectrum of applications, namely in the food, agricultural, environmental, cosmetic and pharmaceutical sectors. These applications are mainly due to their biological properties. However, EOs are unstable and easily degradable if not protected from external factors such as oxidation, heat and light. Therefore, there is growing interest in the encapsulation of EOs, since polymeric nanocarriers serve as a barrier between the oil and the environment. In this context, nanoencapsulation seems to be an interesting approach as it not only prevents the exposure and degradation of EOs and their bioactive constituents by creating a physical barrier, but it also facilitates their controlled release, thus resulting in greater bioavailability and efficiency. In this review, we focused on selecting recent articles whose objective concerned the nanoencapsulation of essential oils from different plant species and highlighted their chemical constituents and their potential biotechnological applications. We also present the fundamentals of the most commonly used encapsulation methods, and the biopolymer carriers that are suitable for encapsulating EOs.

Chemical Composition and Biological Activity of Tanacetum balsamita Essential Oils Obtained from Different Plant Organs

The aim of this study is to evaluate the chemical composition of Tanacetum balsamita L. essential oils (EOs) obtained from different plant organs, flowers (FEO), leaves (LEO), and stems (SEO), as well as to assess their biological properties. The results obtained by using GC and GC/MS analysis indicate that this plant belongs to the carvone chemotype. Moreover, we examined the oil's antimicrobial and antitumor potential. Antimicrobial effects were determined using minimum inhibitory concentrations assay and the vapor phase method. Obtained results indicate better antimicrobial activity of investigated EO samples compared to the commercially available antibiotics. On the treatment with FEO, Y. enterocolitica and H. influenzae showed high sensitivity, while treatment with LEO and SEO showed the highest effects against S. aureus. The vapor phase method, as an in situ antibacterial analysis, was performed using LEO. Obtained results showed that this EO has significant activity toward S. pneumoniae in the apple and carrot models, L. monocytogenes in the pear model, and Y. enterocolitica in the white radish model. The potential antitumor mechanisms of FEO, LEO, and SEO were determined by the means of cell viability, redox potential, and migratory capacity in the MDA-MB-231 and MDA-MB-468 cell lines. The results show that these EOs exert antiviability potential in a time- and dose-dependent manner. Moreover, treatments with these EOs decreased the levels of superoxide anion radical and increased the levels of nitric oxide in both tested cell lines. The results regarding total and reduced glutathione revealed, overall, an increase in the levels of total glutathione and a decrease in the levels of reduced glutathione, indicating strong antioxidative potential in tested cancer cells in response to the prooxidative effects of the tested EOs. The tested EOs also exerted a drop in migratory capacity, which indicates that they can be potentially used as chemotherapeutic agents.