Recent updates on the chemistry, bioactivities, mode of action, and industrial applications of plant essential oils

Antibacterial effect of protease-responsive cationic eugenol liposomes modified by gamma-polyglutamic acid against Staphylococcus aureus

Eugenol, as a natural antibacterial agent, has been widely studied for its inhibitory effect on the common food-borne pathogen Staphylococcus aureus (S. aureus). However, the widespread application of eugenol is still limited by its instability and volatility. Herein, γ-polyglutamic acid coated eugenol cationic liposomes (pGA-ECLPs) were successfully constructed by self-assembly with an average particle size of 170.7 nm and an encapsulation efficiency of 36.2%. The formation of pGA shell significantly improved the stability of liposomes, and the encapsulation efficiency of eugenol only decreased by 20.7% after 30 days of storage at 4 °C. On the other hand, the pGA layer can be hydrolyzed by S. aureus, achieving effective control of release through response to bacterial stimuli. The application experiments further confirmed that pGA-ECLPs effectively prolonged the antibacterial effect of eugenol in fresh chicken without causing obvious sensory effects on the food. The above results of this study provide an important reference for extending the action time of natural antibacterial substances and developing new stimuli-responsive antibacterial systems.

Optimization of Enzyme-Assisted Extraction of Rosemary Essential Oil Using Response Surface Methodology and Its Antioxidant Activity by Activating Nrf2 Signaling Pathway

Rosemary essential oil (REO) is widely recognized as a food flavoring and traditional herb and possesses potential antioxidant activity. However, its low yield rate and unclarified antioxidant mechanism warrant further investigation. In this study, an enzyme pretreatment-assisted extraction method with Box-Behnken design (BBD) and response surface methodology (RSM) models was employed to optimize the main factors of REO, and its antioxidant molecular mechanism under oxidative stress was elucidated in hydrogen peroxide-induced human lung carcinoma (A549) cells. The optimized yield (4.10%) of REO was recorded with the following optimum conditions: enzyme amount 1.60%, enzyme digestion pH 5.0, enzyme digestion temperature 46.50 °C, and enzyme digestion time 1.7 h. Meanwhile, 1.8-cineole (53.48%) and β-pinene (20.23%) exhibited radical scavenging activity higher than that of BHA and BHT. At the cellular level, REO (12.5-50 µg/mL) increased the levels of cell viability, CAT, SOD, and GSH significantly while reducing the contents of ROS, MDA, and GSSG, when compared to H2O2 exposure. Mechanically, REO relieved oxidative stress via activating the Nrf2 signaling pathway and enhancing the protein expression of Nrf2, NQO-1, and HO-1, which was further verified by molecular docking between the main component 1.8-cineole and the Kelch domain of KEAP1. Therefore, REO could be considered as a potent natural antioxidant with a potential strategy in the food and pharmaceutical industries.

GC-MS analysis, phytochemical composition of Hertia cheirifolia L. essential oil with pharmacological assessments: antioxidant, antibacterial, and antifungal activities

The genus Hertia, which belongs to the Asteraceae family, is a flowering genus with 12 species found in Africa, North and South. Among the species present in Algeria, Hertia cheirifolia L. is distributed in the eastern regions of Algeria. The aim of this study is to evaluate its phytochemical composition with following pharmacological assessments: the antioxidant, antibacterial, and antifungal activities of Hertia cheirifolia L. essential oil (EO). GC-MS analysis was used to analyze the chemical constituents of H. cheirifolia essential oil. The antioxidant capacity was assessed using DPPH, FRAP, and H2O2 tests. The EO was also tested for its ability to inhibit six strains of microorganisms, including two Gram (+) and four Gram (-) strains. The antifungal activity was tested by analyzing the effect of the EO on the mycelial growth of Fusarium oxysporum f.sp. lycopersici (FOL) fungi. Results showed that primary volatile components were α-pinene (32.59%), 2-(1-cyclopent-1-enyl-1-methylethyl) cyclopentanone (14.62%), (-)-germacrene D (11.37%), and bakkenolide A (9.57%). H. cheirifolia EO showed inhibitory effects against DPPH, H2O2, and FRAP (IC50 = 0.34 ± 0.1, 0.053 ± 0.1, and 0.047 ± 0.01 mg mL-1, respectively). The EO also exhibited moderate antibacterial effects against Staphylococcus aureus ATCC 25923 (S. aureus), Streptococcus pneumoniae ATCC 49619 (S. pneumoniae), and Enterobacter aerogenes ATCC 13048 (E. aerogenes), as well as significant antioxidant potential and varied antifungal activity based on dosage and fungal strain. To our knowledge, no previous research has examined the antifungal capacity of H. cheirifolia oil and oil-mycelial development of the FOL relationship. To fully explore the benefits of H. cheirifolia EO, more in vivo research is necessary, along with more testing on other bacterial and fungal strains.

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.

Gelatin/dextran active films incorporated with cinnamaldehyde and α-tocopherol for scallop (Patinopecten yessoensis) adductor muscle preservation

Scallops are rich in eicosapentaenoic acid (EPA) and docosahexaenoic acid but perishable due to their microbial growth and lipid oxidation. In this study, gelatin/dextran films containing cinnamaldehyde and α-tocopherol (0% + 0%, 0.3% + 0.3%, 0.6% + 0.6%, 0.9% + 0.9%, and 1.2% + 1.2%, w/w) as active fillers were developed by solution casting method, and their preservation effects on scallop adductor muscle refrigerated at 4°C for 0, 3, 6, 9, and 12 days were evaluated. Inclusion of the two active fillers did not influence the thermal stability of the films but created heterogenous and discontinuous film microstructure and increased the film hydrophobicity. Increase in the concentrations of active fillers lowered the mechanical properties and water vapor permeability of the films but increased their crystallinity, thickness, water contact angle, opacity, antibacterial property, and antioxidant property. The longest release times for both cinnamaldehyde and α-tocopherol were found in 95% (v/v) ethanol solution. The gelatin/dextran films containing 1.2% (w/w) of active fillers (Gelatin [Ge]/Dextran [Dx]/1.2 film) improved the chemical stability of refrigerated scallop adductor muscle. The total viable count (TVC) of the unpackaged scallop adductor muscle exceeded the recommended limit of 7 lg CFU/g on day 6 (7.07 ± 0.50 lg CFU/g), whereas the TVC of the Ge/Dx/1.2 film-packaged scallop adductor muscle was still below the limit on day 9 (5.60 ± 0.50 lg CFU/g). Thus, the Ge/Dx/1.2 film can extend the shelf life of refrigerated scallop adductor muscle by at least 3 days. Overall, the developed gelatin/dextran active packaging films are promising for the preservation of aquatic food products.

Combining the Pharmaceutical and Toxicological Properties of Selected Essential Oils with their Chemical Components by GC-MS Analysis

In the current investigation, a comprehensive analysis was carried out on essential oils (EOs) extracted from six aromatic plant species, namely Rosmarinus officinalis, Pelargonium graveolens, Thymus vulgaris, Origanum vulgare, Laurus nobilis, and Aloysia citrodora. An exploration was conducted into the chemical composition using Gas Chromatography-Mass Spectrometry (GC/MS), antioxidant properties assessed through DPPH, ABTS, CUPRAC, FRAP, MCA, and PBD assays, ecotoxicological impacts evaluated via allelopathy and the Daphnia magna heartbeat test, as well as bio-pharmacological effects including anticancer activity and gene expression analysis. Results revealed strong antioxidant activity in all essential oils, with T. vulgaris EO (2748.00 mg TE/g) and O. vulgare EO (2609.29 mg TE/g) leading in CUPRAC assay. R. officinalis EO showed the highest α-amylase inhibition at 1.58 mmol ACAE/g, while O. vulgare EO excelled in α-glucosidase inhibition at 1.57 mmol ACAE/g. Additionally, cytotoxic effects were evaluated on human colorectal cancer (HCT116) cells. A. citrodora, O. vulgare, and R. officinalis EOs were found the most potent anticancer, as also witnessed by their higher modulatory effects on the gene expression of BAX and Bcl-2. Collectively, the present data highlight the importance to implement the knowledge and to valorize the supply chain of aromatic plants.

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

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

Evaluation of the efficacy of cinnamon oil on Aspergillus flavus and Fusarium proliferatum growth and mycotoxin production on paddy and polished rice: Towards a mitigation strategy

In the present investigation, the effect of cinnamon oil (CO) (10, 30, 50 and 70 %) on the growth rate (mm/day) and aflatoxin B1 (AFB1) and fumonisin B1 (FB1) production of Aspergillus flavus (AF01) and Fusarium proliferatum (FP01) isolates, respectively was determined at optimum water activities (0.95 and 0.99 aw) and temperatures (25, 30 and 35 °C) on paddy and polished rice grains. The results showed that the growth rate, AFB1 and FB1 production of all the fungal isolates decreased with an increase in CO concentrations on both matrices. AF01 and FP01 failed to grow under all conditions on paddy at 50 % of CO concentration whereas both fungi were completely inhibited (No Growth-NG) at 70 % of CO on polished rice. Regarding mycotoxin production, 30 % of CO concentrations could inhibit AFB1 and FB1 production in both matrices (No Detection-ND). In this study, the production of mycotoxins was significantly influenced by cinnamon oil compared to the growth of both fungi. These results indicated the promising potential of CO in improving the quality of rice preservation in post-harvest; however, further investigations should be evaluated on the effects on the qualitative characteristics of grains. Especially, the prospective application of CO in rice storage in industry scales to mitigate mycotoxin contamination need also to be further researched. Moreover, collaboration between researchers, agricultural experts, and food industry should be set up to achieve effective and sustainable strategies for preserving rice.

Analysis of Primary and Secondary Metabolites, Physical Properties, Antioxidant and Antidiabetic Activities, and Chemical Composition of Rosmarinus officinalis Essential Oils under Differential Water Stress Conditions

This study investigated the effects of varying water stress levels on Rosmarinus officinalis essential oils (EO). Three samples (S1, S2, and S3) were cultivated under different stress levels (40, 60, and 80%). Increased water stress led to changes in primary and secondary metabolites, EO contents, and physical properties. Antioxidant activity varied, with S2 exhibiting the highest IC50 value. In terms of antidiabetic activity, S2 showed robust α-amylase inhibition, while S3 displayed a commendable influence. For α-galactosidase inhibition, S3 had a moderate effect, and S2 stood out with increased efficacy. Gas chromatography-mass spectrometry analysis revealed stress-induced changes in major compounds. The study enhances the understanding of plant responses to water stress, with potential applications in antioxidant therapy and diabetes management. The findings emphasize the importance of sustainable water management for optimizing the EO quality in its various uses.

Physicochemical comparison of chitin characteristics in three major stored-product beetle pests: Implications for biofumigant toxicity

The present study investigates the chitin properties of stored-product insect pests and their association with the fumigant toxicity of garlic essential oil. Chitin isolates of Callosobruchus maculatus, Sitophilus oryzae, and Tribolium castaneum adults were characterized using FT-IR, XRD, EA, SEM-EDS, and NMR techniques. Fumigant toxicity assay was performed under airtight condition in glass vial. The S. oryzae contains highest chitin content (19 %), followed by T. castaneum (10 %) and C. maculatus (8 %). The degree of crystallinity was lower in C. maculatus (67.13 %) than in S. oryzae (77.05 %) and T. castaneum (76.56 %). Morphologically, C. maculatus chitin displayed a flat lamellar surface with pores, while S. oryzae and T. castaneum exhibited densely arranged microfibrils based surfaces. Fumigant toxicity assays revealed varied susceptibility levels, C. maculatus exhibited higher susceptibility (0.27 μL/L air of LC50) compared to S. oryzae and T. castaneum (14.35 and 3.74 μL/L air of LC50, respectively) to garlic essential oil. The higher chitin content, greater crystallinity, and densely arranged structures in S. oryzae might contribute to its tolerance towards fumigant. Additionally, physico-chemical properties and penetration potentiality of the bioactive constituents might be linked to the toxicity in insects. Understanding these relations can enrich knowledge of chitin's role in fumigant toxicity mechanism.

Volatiles from French and Croatian Sea Fennel Ecotypes: Chemical Profiles and the Antioxidant, Antimicrobial and Antiageing Activity of Essential Oils and Hydrolates

Sea fennel is a halophytic plant rich in valuable nutritional components and is characterized by pleasant organoleptic properties. While its essential oils (EOs) are well investigated, there are no reports on the volatiles from their corresponding hydrolates, which are the main by-products of EO isolation, as well as on their biological activity. Therefore, the composition and biological activities of EOs and corresponding hydrolates of sea fennel from Atlantic (French, FRA) and Mediterranean (Croatian, CRO) ecotypes were investigated and compared. The EO from the CRO sample was characterized by an abundance of sabinene and limonene, while that from the FRA ecotype was rich in dillapiol and carvacryl methyl ether. The CRO hydrolate was rich in terpinen-4-ol and 10-(acetylmethyl)-3-carene, while dillapiol, thymyl methyl ether and γ-terpinene were the main compounds in the FRA sea fennel hydrolate. The biological activities of the EOs and hydrolates were evaluated for their antioxidant (with DPPH, NO, FRAP and ORAC bioassays), antimicrobial (against some Gram+ and Gram- spoilage bacteria) and antiageing (tyrosinase, elastase and collagenase inhibition) activities. Both EOs showed low reducing powers and antiradical activities while the ability of both hydrolates to quench NO was slightly higher (35-39% if inhibition). The FRA EO showed low activity against Staphylococcus aureus (8 mm), while CRO moderately inhibited the growth of P. aeruginosa (8 mm), but strongly inhibited the other two bacterial strains. While the French EO showed no antityrosinase and anticollagenase activity, the Croatian oil significantly inhibited both enzymes (IC50 of 650 µg/mL and IC50 of 2570 µg/mL, respectively) probably due to the dominance of limonene and sabinene. Neither EO exhibited antielastase properties, while the hydrolates from both ecotypes showed no antiageing activity, regardless of the enzyme tested. The EOs from the aerial parts of sea fennel from FRA and CRO differed greatly in composition, resulting in different activities. The Croatian samples appeared to have better biological properties and are therefore good candidates for applications as preservatives or antiageing agents.

Chitosan-Based Nanoencapsulated Essential Oils: Potential Leads against Breast Cancer Cells in Preclinical Studies

Since ancient times, essential oils (EOs) derived from aromatic plants have played a significant role in promoting human health. EOs are widely used in biomedical applications due to their medicinal properties. EOs and their constituents have been extensively studied for treating various health-related disorders, including cancer. Nonetheless, their biomedical applications are limited due to several drawbacks. Recent advances in nanotechnology offer the potential for utilising EO-loaded nanoparticles in the treatment of various diseases. In this aspect, chitosan (CS) appears as an exceptional encapsulating agent owing to its beneficial attributes. This review highlights the use of bioactive EOs and their constituents against breast cancer cells. Challenges associated with the use of EOs in biomedical applications are addressed. Essential information on the benefits of CS as an encapsulant, the advantages of nanoencapsulated EOs, and the cytotoxic actions of CS-based nanoencapsulated EOs against breast cancer cells is emphasised. Overall, the nanodelivery of bioactive EOs employing polymeric CS represents a promising avenue against breast cancer cells in preclinical studies.

Antimycobacterial potential of Trachyspermum ammi seed essential oil via fume contact and determination of major compounds

Trachyspermum ammi (L.), commonly known as carrom seeds or Ajwain, has been extensively studied for its medicinal properties. In this study, anti-mycobacterial effect of AEO in liquid and fume form was investigated against Mycobacterium smegmatis and Mycobacterium tuberculosis (M. tb). Results showed that AEO inhibits the growth of M. smegmatis at 0.03 mg/mL and becomes bactericidal at 0.125 mg/mL. MICs were observed at 0.03, 0.125 and 0.06 mg/mL against M. tb (H37Rv), isoniazid- and rifampicin-resistant (RIF-R) strains. Inverted disc-fume assay revealed AEO and Thymol efficiently inhibit the growth of M. smegmatis and M. tb. Similarly, in fume contact AEO and Thymol demonstrated antibiofilm activity at a dose of 1.25 mg/mL air and 40 mg/mL air against M.smegmatis effectively. GC-MS analysis showed that Thymol was the dominant compound. These findings suggest that the use of AEO in fume form may serve as a promising strategy as an anti-mycobacterial activity against M. tb.

Network pharmacology integrated with molecular docking reveals the anticancer mechanism of Jasminum sambac Linn. essential oil against human breast cancer and experimental validation by in vitro and in vivo studies

Jasminum sambac L. (J. sambac) belongs to the family Oleaceae and it is an ornamental subtropical evergreen shrub used in traditional treatments of certain ailments and diseases. This study aimed at devising an integrated strategy attempts to evaluate the bioactive components in the J. sambac essential oil (JEO) against human breast cancer. JEO extracted by distillation process and analyzed by GC-MS was subjected to screening of therapeutic components in their allegiance to the drug-likeness index. The utility and efficacy of its molecular mechanism relating to anticancer potential were probed with network pharmacology analysis. Gene ontology, pathway enrichment, and compound-target-pathway network by Cytoscape helped to harp on hub targets and pathways involved in curative action. Drawing from the network data, molecular docking analysis of selected compounds on breast cancer targets was approached. The anti-proliferative study was carried out in MCF-7 and MDA-MB-231 to evaluate the cytotoxicity of JEO. Finally, in vivo anticancer activity was verified using rat models. The results showed MDA-MB-231 cell growth was highly inhibited than the MCF-7 cell line. Alongside this in vitro trial, in situ effectiveness of JEO was evaluated using female Sprague-Dawley rat animal models. In vivo experiments and histopathological analysis showed convincing results in DMBA tumor-induced rats. The larger aim of this study is to identify the potential ingredients of the JEO in cancer apoptosis by integrating network pharmacology and experimental validation achieved to certain extent confers credence to the concept of hiring J. sambac as floral therapy in dealing with the disastrous disease.

Essential Oils in Cervical Cancer: Narrative Review on Current Insights and Future Prospects

Cervical cancer is a prevalent and often devastating disease affecting women worldwide. Traditional treatment modalities such as surgery, chemotherapy, and radiation therapy have significantly improved survival rates, but they are often accompanied by side effects and challenges that can impact a patient's quality of life. In recent years, the integration of essential oils into the management of cervical cancer has gained attention. This review provides an in-depth exploration of the role of various essential oils in cervical cancer, offering insights into their potential benefits and the existing body of research. The review also delves into future directions and challenges in this emerging field, emphasizing promising research areas and advanced delivery systems. The encapsulation of essential oils with solid lipid nanoparticles, nanoemulsification of essential oils, or the combination of essential oils with conventional treatments showed promising results by increasing the anticancer properties of essential oils. As the use of essential oils in cervical cancer treatment or management evolves, this review aims to provide a comprehensive perspective, balancing the potential of these natural remedies with the challenges and considerations that need to be addressed.

Chemical Composition and Antimicrobial Activity against the Listeria monocytogenes of Essential Oils from Seven Salvia Species

In recent years, essential oils (EOs) have received interest due to their antibacterial properties. Accordingly, the present study aimed to investigate the effectiveness of the EOs obtained from seven species of Salvia on three strains of Listeria monocytogenes (two serotyped wild strains and one ATCC strain), a bacterium able to contaminate food products and cause foodborne disease in humans. The Salvia species analysed in the present study were cultivated at the Botanic Garden and Museum of the University of Pisa, and their air-dried aerial parts were subjected to hydrodistillation using a Clevenger apparatus. The obtained EOs were analysed via gas chromatography coupled with mass spectrometry for the evaluation of their chemical composition, and they were tested for their inhibitory and bactericidal activities by means of MIC and MBC. The tested Eos showed promising results, and the best outcomes were reached by S. chamaedryoides EO, showing an MIC of 1:256 and an MBC of 1:64. The predominant compounds of this EO were the sesquiterpenes caryophyllene oxide and β-caryophyllene, together with the monoterpenes bornyl acetate and borneol. These results suggest that these EOs may possibly be used in the food industry as preservatives of natural origins.

HPLC-DAD Analysis, SFE-CO2 Extraction, and Antibacterial Activity on Bioactive Compounds from Mosla chinensis Maxim

Mosla chinensis Maxim is an annual herb with many potential purposes in agricultural, industrial, and pharmaceutical fields. At present, the extract of the whole plant from M. chinensis has been proven to demonstrate antifungal, antioxidant, and anti-inflammatory activities. Previous studies focused on the enzyme pretreatment in hydrodistillation from M. chinensis. However, organic solvent or supercritical fluid carbon dioxide extraction (SFE-CO2) methods, which are commonly utilized in industry, have seldom been studied and cannot provide multiple evaluations of yield. In this work, we analysed compounds from M. chinensis by HPLC-DAD, discussed n-hexane extraction, and conducted further investigations on SFE-CO2 through the design of response surface methodology (RSM). The sample obtained from pilot-scale SFE-CO2 was also tested against nine kinds of microorganisms. Single-factor results revealed that the extraction rates from M. chinensis by steam distillation, n-hexane extraction, and SFE-CO2 were 1%, 2.09%, and 3.26%, respectively. RSM results showed a significant improvement in extraction rate through optimising pressure and time, and the interaction of both factors was more important than that of temperature-pressure and temperature-time. A pilot-scale test with an extraction rate of 3.34% indicated that the predicted RSM condition was operable. In addition, samples from the pilot-scale SFE-CO2 showed antibacterial effects against three previously unreported bacteria (Gardnerella vaginalis, methicillin-resistant Staphylococcus aureus, and Propionibacterium acnes). These results fill the gap in previous research and provide more information for the application and development of M. chinensis in the future.

Chemical composition and antimicrobial activity of essential oils made from Lavandula x intermedia from Hvar (Croatia)

The aim of the study was to investigate the essential oil (EO) of Lavandula x intermedia cv. Bila, which has not been studied before. The EOs were distilled from plants collected in two consecutive years on the island of Hvar (Croatia) and in the Karst (Slovenia) and analysed for chemical composition and antimicrobial activity. The main component of EOs was linalool, but the EOs from Hvar had higher contents of Z-β-ocimene and borneol + lavandulol than the EOs from Karst, in which camphor, linalyl acetate and 1,8-cineole predominated. The antimicrobial activity was evaluated using the minimum inhibitory concentration and proved that the EOs were effective against Candida spp. Studies have shown that the composition of L. x intermedia EO depends on the variety and the climatic and geographical characteristics of the plant growth. The antimicrobial activity of EO is also influenced by the type and strain of microorganisms involved in the research.

In Vivo Evaluation of the Potential of Thyme and Lemon Hydrolates as Processing Aids to Reduce Norovirus Concentration during Oyster Depuration

In this study, we evaluated the use of hydrolates, co-products of essential oil distillation, as processing aids to improve the depuration process of Pacific oysters (Crassostrea gigas) as a post-harvest method aimed at reducing the norovirus (NoV) viral load. Live oysters were kept in water to which hydrolates of Thymus serpyllum and Citrus limon at 1% were added for 24 h. The concentration of NoV was quantified using the ISO 15216-1 quantitative real-time RT-PCR method in the oyster digestive tissue both before and after the treatment. The results showed a significant reduction of 0.2 log in the NoV GII concentration after 24 h of treatment with 1% C. limon hydrolate. Conversely, treatment with T. serpyllum did not appear to reduce the concentration of NoV compared to the control. Additionally, a sensory analysis was conducted through a blind survey comparing untreated and treated oysters. No changes in the sensory and physical characteristics of the oysters were observed, except for a decrease in the marine flavour intensity, which was positively perceived by consumers. These results indicate that the addition of hydrolates of C. limon at 1% during depuration might represent a promising processing aid for enhancing both the safety and acceptability of live oysters.

Preparation and Characterization of Eugenol Incorporated Pullulan-Gelatin Based Edible Film of Pickering Emulsion and Its Application in Chilled Beef Preservation

The purpose of this study was to develop a composite film composed of eugenol Pickering emulsion and pullulan-gelatin, and to evaluate its preservation effect on chilled beef. The prepared composite film was comprehensively evaluated in terms of the stability of emulsion, the physical properties of the film, and an analysis of freshness preservation for chilled beef. The emulsion size (296.0 ± 10.2 nm), polydispersity index (0.457 ± 0.039), and potential (20.1 ± 0.9 mV) proved the success of emulsion. At the same time, the films displayed good mechanical and barrier properties. The index of beef preservation also indicated that eugenol was a better active ingredient than clove essence oil, which led to the rise of potential of hydrogen, chroma and water content, and effectively inhibited microbial propagation, protein degradation and lipid oxidation. These results suggest that the prepared composites can be used as promising materials for chilled beef preservation.

Chemical Composition and In Vitro Evaluation of Antioxidant and Antiproliferative Effects of Volatile Oils Hydrodistilled from Onobrychis carduchorum C.C. Towns., a Kurdish Traditional Plant

The volatile oils hydrodistilled from the aerial parts and roots of O. carduchorum C.C Towns. (Fabaceae) have been chemically characterized for the first time. A total of 43 constituents with an abundance >0.03% were identified and quantified in the two oils by GC/MS and GC/FID analyses. They comprise 38 components (98.58%) of the oil isolated from the aerial parts (OCA) and 34 components (93.33%) of the oil from the roots (OCR). Six constituents, α-pinene (23.11 ± 0.1%), β-elemene (17.33 ± 0.1%), 1,8-cineole (12.15 ± 0.2%), furfural (7.91 ± 0.1%), terpineol-4-ol (6.32 ± 0.2%), and limonene (4.13 ± 0.1%), accounted for about 75% of the total OCA oil. On the other hand, 1,8-cineole (15.79 ± 0.1%), furfural (10.44 ± 0.1%), β-elemene (10.14 ± 0.2%), α-terpineol (7.74 ± 0.1%), linalool (7.45 ± 0.1%), and α-pinene (4.76 ± 0.1%) made up about 60% of the OCR oil. The IC50 values of the scavenging activities of the OCA and OCR oils towards the DPPH radical and H2O2 were 79.8 ± 0.5 and 153.3 ± 0.6 μg/mL and 394.09 ± 0.2 and 311.67 ± 0.4 μg/mL, respectively. In addition, in the MTS assay, the OCA and OCR oils showed significant antiproliferative effects against T47D, MDA-MB-453, BG-1, and A549 human cancer cells that were more powerful than those against two normal human cell lines, HEK-293 and HFF-1. The abundant presence of β-elemene as an antiproliferative component of the two oils suggested the existence of a new chemotype of O. carduchorum.

Sanitizing Hatching Eggs with Essential Oils: Avian and Microbiological Safety

Increased meat and egg production leads to concomitant changes in poultry practices, including the indiscriminate use of formaldehyde to sanitize hatching eggs. Although this sanitizer aids in the increase in poultry production, its toxic potential for man and for avian embryos represents an obstacle to its long-term use. This review assesses whether essential oils fit into the context of hatching egg contamination, reviewing their antimicrobial efficiency, toxicity to poultry embryos and chicks, and their sanitizing effects on poultry production parameters. Studies have indicated that, because they are safer, most of the essential oils studied can be a potential substitute for formaldehyde for minimizing microbial exposure of hatching eggs and embryos. However, complementary studies on the microbiological profile of embryos and chicks hatched from eggs sanitized with essential oils need to be carried out and the economic feasibility of the candidate products should also be considered.

Mycotoxins and consumers' awareness: Recent progress and future challenges

While food shortages have become an important challenge, providing safe food resources is a point of interest on a global scale. Mycotoxins are secondary metabolites that are formed through various fungi species. They are mainly spread through diets such as food or beverages. About one quarter of the world's food is spoiled with mycotoxins. As this problem is not resolved, it represents a significant threat to global food security. Besides the current concerns regarding the contamination of food items by these metabolites, the lack of knowledge by consumers and their possible growth and toxin production attracted considerable attention. While globalization provides a favorite condition for some countries, food security still is challenging for most countries. There are various approaches to reducing the mycotoxigenic fungi growth and formation of mycotoxins in food, include as physical, chemical, and biological processes. The current article will focus on collecting data regarding consumers' awareness of mycotoxins. Furthermore, a critical overview and comparison among different preventative approaches to reduce risk by consumers will be discussed. Finally, the current effect of mycotoxins on global trade, besides future challenges faced by mycotoxin contamination on food security, will be discussed briefly.

Essential Oils for the Conservation of Paper Items

Archival documents and artworks stored in libraries frequently undergo degradative processes promoted by the so-called "biodeteriogens" that inhabit these places. A renewed interest in plant-derived products has arisen in those research groups focusing on cultural heritage preservation and looking for new and safe disinfection techniques. In this view, essential oils (EOs) and their volatile organic constituents are very appealing thanks to their versatility of action. A literature survey of the scientific publications involving EOs and/or their major constituents related to the conservation of paper items of cultural heritage interest is presented here, aiming to reveal benefits and limitations of such peculiar plant-derived compounds.

Essential oils and essential oil compounds in animal production as antimicrobials and anthelmintics: an updated review

Several countries have shown an increased prevalence of drug resistance in animal production due to the indiscriminate use of antibiotics and antiparasitics in human and veterinary medicine. This article aims to review existing methods using naturally occurring essential oils (EOs) and their isolated compounds (EOCs) as alternatives to antimicrobials and antiparasitic compounds in animal production and, consequently, to avoid resistance. The most-reported mechanism of action of EOs and EOCs was cell membrane damage, which leads to the leakage of cytoplasmic content, increased membrane permeability, inhibition of metabolic and genetic pathways, morphologic changes, antibiofilm effects, and damage to the genetic material of infections. In parasites, anticoccidial effects, reduced motility, growth inhibition, and morphologic changes have been reported. Although these compounds regularly show a similar effect to those promoted by traditional drugs, the elucidation of their mechanisms of action is still scarce. The use of EOs and EOCs can also positively influence crucial parameters in animal production, such as body weight gain, feed conversion rate, and cholesterol reduction, which also positively impact meat quality. The application of EOs and EOCs is enhanced by their association with other natural compounds or even by the association with synthetic chemicals, which has been found to cause synergism in their antimicrobial effect. By reducing the effective therapeutical/prophylactic dose, the chances of off-flavors – the most common issue in EO and EOC application – is greatly mitigated. However, there is very little work on the combination of EOs and EOCs in large in vivo studies. In addition, research must apply the correct methodology to properly understand the observed effects; for example, the use of only high concentrations may mask potential results obtained at lower dosages. Such corrections will also allow the elucidation of finer mechanisms and promote better biotechnologic use of EOs and EOCs. This manuscript presents several information gaps to be filled before the use of EOs and EOCs are fully applicable in animal production.

Potential of Essential Oils in the Control of Listeria monocytogenes

Listeria monocytogenes is a foodborne pathogen, the causative agent of listeriosis. Infections typically occur through consumption of foods, such as meats, fisheries, milk, vegetables, and fruits. Today, chemical preservatives are used in foods; however, due to their effects on human health, attention is increasingly turning to natural decontamination practices. One option is the application of essential oils (EOs) with antibacterial features, since EOs are considered by many authorities as being safe. In this review, we aimed to summarize the results of recent research focusing on EOs with antilisterial activity. We review different methods via which the antilisterial effect and the antimicrobial mode of action of EOs or their compounds can be investigated. In the second part of the review, results of those studies from the last 10 years are summarized, in which EOs with antilisterial effects were applied in and on different food matrices. This section only included those studies in which EOs or their pure compounds were tested alone, without combining them with any additional physical or chemical procedure or additive. Tests were performed at different temperatures and, in certain cases, by applying different coating materials. Although certain coatings can enhance the antilisterial effect of an EO, the most effective way is to mix the EO into the food matrix. In conclusion, the application of EOs is justified in the food industry as food preservatives and could help to eliminate this zoonotic bacterium from the food chain.

Fortification of polysaccharide-based packaging films and coatings with essential oils: A review of their preparation and use in meat preservation

As the demand for botanical food additives and eco-friendly food packaging materials grows, the use of essential oils, edible biodegradable films and coatings are becoming more popular in packaging. In this review, we discussed the recent research trends in the use of natural essential oils, as well as polysaccharide-based coatings and films: from the composition of the substrates to preparing formulations for the production of film-forming technologies. Our review emphasized the functional properties of polysaccharide-based edible films that contain plant essential oils. The interactions between essential oils and other ingredients in edible films and coatings including polysaccharides, lipids, and proteins were discussed along with effects on film physical properties, essential oil release, their active role in meat preservation. We presented the opportunities and challenges related to edible films and coatings including essential oils to increase their industrial value and inform the development of edible biodegradable packaging, bio-based functional materials, and innovative food preservation technologies.

Enhanced Bioactivity of Rosemary, Sage, Lavender, and Chamomile Essential Oils by Fractionation, Combination, and Emulsification

This study aimed to increase the bioactivity of essential oils by fractionation, combination, and emulsification. In this regard, pharmaceutical quality Rosmarinus officinalis L. (rosemary), Salvia sclarea L. (clary sage), Lavandula latifolia Medik. (spike lavender), and Matricaria chamomilla L. (chamomile) essential oils were fractionated by vacuum-column chromatography. The main components of the essential oils were verified, and their fractions were characterized by thin layer chromatography, gas chromatography-flame ionization detector, and gas chromatography/mass spectrometry. Besides, oil-in-water (O/W) emulsions of essential oils and diethyl ether fractions were obtained by the self-emulsification method, followed by droplet size, polydispersity index, and zeta potential value measurements. The in vitro antibacterial effects of the emulsions and binary combinations (10:90, 20:80, 30:70, 40:60, 50:50, 60:40, 70:30, 80:20, 90:10, v:v) against Staphylococcus aureus were determined by microdilution. In addition, the in vitro anti-biofilm, antioxidant, and anti-inflammatory effects of emulsion formulations were evaluated. According to the experimental results, fractionation and emulsification enhanced essential oil in vitro antibacterial, anti-inflammatory, and antioxidant effects due to increased solubility and nano-sized droplets. Among 22 different emulsion combinations, 1584 test concentrations resulted in 21 cases of synergistic effects. The mechanism of the increase in biological activities was hypothesized to be higher solubility and stability of the essential oil fractions. Food and pharmaceutical industries may benefit from the procedure proposed in this study.

Exploring the Mechanism of Bergamot Essential Oil against Asthma Based on Network Pharmacology and Experimental Verification

Asthma is a chronic respiratory disease. Bergamot essential oil (BEO) is extracted from the bergamot peel, which is widely used as a medicinal and food plant in China. Modern pharmacological studies have confirmed that BEO has anti-inflammatory properties, suggesting potential in treating asthma. First, the main active ingredients of BEO were detected and analyzed by gas chromatography-mass spectrometry (GC-MS). Network pharmacology methods were used to explore the possible core targets and main pathways of BEO in asthma treatment. Then ovalbumin (OVA)-induced in vivo and lipopolysaccharide (LPS)-induced in vitro models were established to investigate the antiasthmatic effects of BEO. BEO showed a good antiasthmatic effect by improving lung inflammation and inhibiting collagen deposition. Then, enzyme-linked immunosorbent assay (ELISA) and quantitative real-time polymerase chain reaction (qPCR) were used to explore the possible mechanism of BEO in asthma treatment. Furthermore, experimental verification showed that BEO could suppress the release of inflammatory factors in vitro and inhibit the activation of MAPK and JAK-STAT signaling pathways. This study demonstrated the anti-inflammatory effects of BEO against asthma. Moreover, it supplies a theoretical basis for the clinical application of BEO.

Advances in the Role and Mechanisms of Essential Oils and Plant Extracts as Natural Preservatives to Extend the Postharvest Shelf Life of Edible Mushrooms

China has a large variety of edible mushrooms and ranks first in the world in terms of production and variety. Nevertheless, due to their high moisture content and rapid respiration rate, they experience constant quality deterioration, browning of color, loss of moisture, changes in texture, increases in microbial populations, and loss of nutrition and flavor during postharvest storage. Therefore, this paper reviews the effects of essential oils and plant extracts on the preservation of edible mushrooms and summarizes their mechanisms of action to better understand their effects during the storage of mushrooms. The quality degradation process of edible mushrooms is complex and influenced by internal and external factors. Essential oils and plant extracts are considered environmentally friendly preservation methods for better postharvest quality. This review aims to provide a reference for the development of new green and safe preservation and provides research directions for the postharvest processing and product development of edible mushrooms.

The Assessment of Antimicrobial and Anti-Biofilm Activity of Essential Oils against Staphylococcus aureus Strains

The increase in antimicrobial resistance and tolerance over the years has become a serious public health problem, leading to the inevitable development of alternative antimicrobial agents as substitutes for industrial pharmaceutical antibiotics targeting humans and animals under the concept of one health. Essential oils (EOs) extracted from aromatic and pharmaceutical plants incorporate several bioactive compounds (phytochemicals) that positively affect human and animal health. Herein, this work aimed to examine a standardized chemical composition and screen the antimicrobial and anti-biofilm activity of Thymus sibthorpii, Origanum vulgare, Salvia fruticosa, and Crithmum maritimum EOs against three different Staphylococcus aureus strains by gold-standard disc diffusion, broth microdilution, and microtiter plate biofilm assays. Therefore, the evaluation of the above-mentioned EOs were considered as substitutes for antibiotics to combat the ever-mounting antimicrobial resistance problem. The observed bacterial growth inhibition varied significantly depending on the type and concentration of the antimicrobials. Thymus sibthorpii was determined as the strongest antimicrobial, with 0.091 mg/mL minimum inhibitory concentration (MIC) and a 14-33 mm diameter inhibition zone at 5% (v/v) concentration. All tested EOs indicated almost 95% inhibition of biofilm formation at their half MIC, while gentamicin sulfate did not show sufficient anti-biofilm activity. None of the methicillin-resistant strains showed resistance to the EOs compared to methicillin-sensitive strains. Thymus sibthorpii and Origanum vulgare could be potential alternatives as antimicrobial agents to overcome the problem of microbial resistance. The tested EOs might be incorporated into antimicrobial products as safe and potent antimicrobial and anti-biofilm agents.

Bioactivities and green advanced extraction technologies of ginger oleoresin extracts: A review

Zingiber officinale Roscoe is an excellent source of bioactive compounds, mainly gingerols and shogaols compounds, that associated with various bioactivities including antioxidant, anticancer, anti-inflammatory, antimicrobial, and antibiofilm. Zingiber officinale Roscoe found its application in the food, pharmaceutical, and cosmeceutical industries. The demand for a high quality of ginger oleoresin extracts based on the contents of gingerols and shogaols compounds for a health-benefit has dramatically increased. Various extraction techniques, including the conventional and advanced extraction techniques for gingerols and shogaols have been reported based on the literature data from 2012 to 2022. The present review examines the functional composition and bioactivities of Zingiber officinale Roscoe and the advanced green extraction technologies. Some variations in the quantity and quality of gingerols and shogaols compounds are because of the extraction method employed. This review provides a depth discussion of the various green advanced extraction technologies and the influences of process variables on the performance of the extraction process. Lower temperature with a short exposure time such as ultrasound-assisted and enzyme-assisted extraction, will lead to high quality of extracts with high content of 6-gingerol. High thermal processing, such as microwave-assisted and pressurized liquid extraction, will produce higher 6-shogaol. Meanwhile, supercritical fluid extraction promotes high quality and the safety of extracts by using non-toxic CO2. In addition, challenges and future prospects of the extraction of ginger oleoresin have been identified and discussed. The emerging green extraction methods and technologies show promising results with less energy input and higher quality extracts than conventional extraction methods.

Efficacy of Topical Essential Oils in Musculoskeletal Disorders: Systematic Review and Meta-Analysis of Randomized Controlled Trials

Essential oils (EOs) are widely used topically in musculoskeletal disorders (MSDs); however, their clinical efficacy is controversial. Our aim was to find evidence that topical EOs are beneficial as an add-on treatment in MSDs. We performed a systematic review and meta-analysis to summarize the evidence on the available data of randomized controlled trials (RCTs). The protocol of this work was registered on PROSPERO. We used Web of Science, EMBASE, PubMed, Central Cochrane Library and Scopus electronic databases for systematic search. Eight RCTs were included in the quantitative analysis. In conclusion, EO therapy had a favorable effect on pain intensity (primary outcome) compared to placebo. The greatest pain-relieving effect of EO therapy was calculated immediately after the intervention (MD of pain intensity = −0.87; p = 0.014). EO therapy had a slightly better analgesic effect than placebo one week after the intervention (MD of pain intensity = −0.58; p = 0.077) and at the four-week follow-up as well (MD of pain intensity = −0.52; p = 0.049). EO therapy had a beneficial effect on stiffness (a secondary outcome) compared to the no intervention group (MD = −0.77; p = 0.061). This systematic review and meta-analysis showed that topical EOs are beneficial as an add-on treatment in reducing pain and stiffness in the investigated MSDs.

Survival, growth, and biogenic amine production of Enterococcus faecium FC12 in response to extracts and essential oils of Rubus fruticosus and Juniperus oxycedrus

Introduction

Enterococci are lactic acid bacteria (LAB) usually found as food contaminants in fermented products such as cheeses and fermented sausages. Due to their antibiotic resistance, the presence of virulence factors, and the ability to produce biogenic amines (BAs), the determination of these bacteria is crucial to assure food quality and safety. BAs production and consequent accumulation in foods can cause toxicological effects on human health. Plant phenolic compounds are promising alternatives to chemical preservatives and reflect consumers' demand for "green" solutions. In this study, the antimicrobial effect of blackberry (Rubus fruticosus) leaves and prickly juniper (Juniperus oxycedrus) needles, both as phenolic extracts (PE) and essential oils (EO), were evaluated against Enterococcus faecium FC12, a known tyramine-producing strain.

Methods

The growth kinetics in the presence of sub-lethal concentrations of such plant derivatives were modeled (Gompertz equation) and BA production was monitored over time by HPLC. Moreover, flow cytometry (FCM) was used to study the effects of EOs and PEs on cell viability.

Results

The EOs showed a higher antimicrobial effect (especially R. fruticosus added at 0.75 mg/ml), determining an initial decrease of culturable cells followed by a recovery, even if with lower growth rates and final cell loads. Different rates of BA formation were observed, with tyramine concentrations ranging from 120 to 160 mg/l after 96 h of incubation, and 2-phenylethylamine was produced in lower amounts, usually after reaching the peak of tyramine. FCM confirmed the higher efficacy of R. fruticosus EO that induced cell membrane injury in 93% of the total population. However, complete recovery occurred in the following incubation, demonstrating transient damage.

Discussion

Although further research is required to better investigate this recovery and to assess the suitability of this approach in a real food system, the present study showed the potential antimicrobial activity of plant derivatives, especially R. fruticosus EO, against the tyramine-producing E. faecium FC12.

Chemical Characterization, Antioxidant, Antimicrobial, and Antibiofilm Activities of Essential Oils of Plumeria alba (Forget-Me-Not)

Essential oils are known to possess many biological properties such as antimicrobial and antioxidant activities. Plumeria alba flowers are used in traditional remedies for diarrhea, cough, fever, and asthma treatment. This work evaluated the chemical composition and the biological activities of essential oils obtained from the flowers and leaves of Plumeria alba. The essential oils were extracted using the Clevenger-type apparatus and characterized using GC-MS. In the flower essential oil, a total of 17 compounds were identified, with linalool (23.91%), α-terpineol (10.97%), geraniol (10.47%), and phenyl ethyl alcohol (8.65%) being abundant. In the leaf essential oil, a total of 24 compounds were identified, with benzofuran, 2,3-di, hydro-(3.24%), and muurolol (1.40%) being present. Antioxidant activities were assessed using hydrogen peroxide scavenging, phosphomolybdenum, and 2, 2-diphenyl-1-picrylhydrazyl (DPPH) free radical-scavenging assays. Antimicrobial activities were assessed through a microdilution assay. The essential oil showed antimicrobial activity against test microorganisms with minimum inhibitory concentrations ranging from 25.0 to 50.0 mg/mL. Biofilm inhibition ranged from 27.14 ± 1.0 to 58.99 ± 0.6 mg/mL. The essential oil exhibited total antioxidant capacities which ranged from 17.5 μg/g AAE to 83 μg/g AAE in the phosphomolybdenum assay. The IC₅₀ values in the DPPH and hydrogen peroxide radical scavenging assays for both flowers and leaves ranged from 18.66 μg/mL to 38.28 μg/mL. Both essential oils also displayed good antibiofilm activities, with the concentration required for half-maximal inhibition of biofilm formation being ∼60 mg/mL for both oils. This study shows that essential oils of Plumeria alba possess good antioxidant and antimicrobial activities and could be used as a source of natural antioxidants and antimicrobial agents.

The role of essential oils in maintaining the postharvest quality and preservation of peach and other fruits

Fruits are highly susceptible to postharvest losses induced majorly by postharvest diseases. Peach are favored by consumers because of their high nutritional value and delicious taste. However, it was easy to be affected by fungal infection. The current effective method to control postharvest diseases of fruits is to use chemical fungicides, but these chemicals may cause adverse effects on human health and the residual was potentially harmful to nature and the environment. So, it is especially important to develop safe, non-toxic, and highly effective strategies for the preservation of the fruits. Essential oil, as a class of the natural bacterial inhibitor, has been proven to exhibit strong antibacterial activity, low toxicity, environmental friendliness, and induce fruit resistance to microorganism, which could be recognized as one of the alternatives to chemical fungicides. This paper reviews the research progress of essential oils (Eos) in the storage and preservation of fruits, especially the application in peach, as well as the application in active packaging such as edible coatings, microcapsules, and electrospinning loading. Electrospinning can prepare a variety of nanofibers from different viscoelastic polymer solutions, and has broad application prospects. The paper especially summarizes the application of the new Eos technology on peach. The essential oil with thymol, eugenol, and carvacrol as the main components has a better inhibitory effect on the postharvest disease of peaches, and can be further applied. PRACTICAL APPLICATIONS: As an environmentally friendly natural antibacterial agent, essential oil can be used as a substitute for chemical preservatives to keep fruits fresh. This paper summarizes the different preservation methods of essential oils for fruits, and especially summarizes the different preservation methods of essential oils for peaches after harvesting, as well as their inhibitory effects on pathogenic fungi. It could provide ideas for preservation of fruits and vegetables by essential oils.

Carvacrol and HP-β-Cyclodextrin Complexes: Extensive Characterization and Potential Cytotoxic Effect in Human Colorectal Carcinoma Cells

The aim of this study was to obtain solid carvacrol-cyclodextrin (CD) complexes for use in the pharmaceutical industry. To this end, the complexation of carvacrol at different pH values was studied in detail, to determine the type of CD and the reaction environment that supported the highest amount of encapsulated carvacrol. Evidence of the capability of hydroxypropyl-β-cyclodextrins (HP-β-CD) to form inclusion complexes with carvacrol (K_C = 5042 ± 176 L mol^-1) and more high complexation efficiency (2.824) was demonstrated for HP-β-CDs using two different energy sources, ultrasound (US) (K_C = 8129 ± 194 L mol^-1 24 h) and microwave irradiation (MWI) (K_C = 6909 ± 161 L mol^-1), followed by spraying the resulting solution in a spray dryer. To confirm complex formation, the complexes were characterized using various instrumental methods to corroborate the carvacrol incorporation into the hydrophobic cavity of HP-β-CD. The obtained carvacrol solid complexes were analyzed by 1H nuclear magnetic resonance (¹H-NMR) and 2D nuclear magnetic resonance (ROSEY), differential scanning calorimetry (DSC), thermogravimetric analysis (TG) and Fourier transform infrared spectroscopy (FTIR) characterization. The structures of the resulting complexes were also characterized by molecular modeling. Furthermore, 1 mM HP-β-CD-carvacrol complex has been shown to reduce cell proliferation in HCT-116 colorectal cancer cells by 43%, much more than in a healthy lung fibroblast MRC-5 cell line (11%).

Biobased polymer resources and essential oils: a green combination for antibacterial applications

To fight nosocomial infections, the excessive use of antibiotics has led to the emergence of multidrug-resistant microorganisms, which are now considered a relevant public health threat by the World Health Organization. To date, most antibacterial systems are based on the use of petro-sourced polymers, but the global supplies of these resources are depleting. Besides, silver NPs are widely accepted as the most active biocide against a wide range of bacterial strains but their toxicity is an issue. The growing interest in natural products has gained increasing interest in the last decade. Therefore, the design of functional antibacterial materials derived from biomass remains a significant challenge for the scientific community. Consequently, attention has shifted to naturally occurring substances such as essential oils (EOs), which are classified as Generally Recognized as Safe (GRAS). EOs can offer an alternative to the common antimicrobial agents as an inner solution or biocide agent to inhibit the resistance mechanism. Herein, this review not only aims at providing developments in the antibacterial modes of action of EOs against various bacterial strains and the recent advances in genomic and proteomic techniques for the elucidation of these mechanisms but also presents examples of biobased polymer resource-based EO materials and their antibacterial activities. Especially, we describe the antibacterial properties of biobased polymers, e.g. cellulose, starch, chitosan, PLA PHAs and proteins, associated with EOs (cinnamon (CEO), clove (CLEO), bergamot (BEO), ginger (GEO), lemongrass (LEO), caraway (CAEO), rosemary (REO), Eucalyptus globulus (EGEO), tea tree (TTEO), orange peel (OPEO) and apricot (Prunus armeniaca) kernel (AKEO) essential oils). Finally, we discuss the influence of EOs on the mechanical strength of bio-based materials.

Synergistic Action of Cinnamomum verum Essential Oil with Sertraline

Cinnamomum verum L. essential oil (CEO), commonly known as Ceylon cinnamon or cinnamon tree, is regarded as one of the most employed essential oils in the field of aromatherapy. It is usually applied externally as astringent, antipruritic, rubefacient, and anti-septic agent. Furthermore, both in vitro and in vivo research have demonstrated its numerous pharmacological effects, including the potentiality for treating neuralgia, myalgia, headache, and migraine. Several pieces of research also corroborated its significant antiviral and antimicrobial properties. Cinnamaldehyde, eugenol, caryophyllene, cinnamyl acetate, and cinnamic acid are the most representative compounds that are generally found in greater quantities in CEO and play a pivotal role in determining its pharmacological activities. Due to the global antibiotic resistance scenario and the dwindling amount of funding dedicated to developing new antibiotics, in recent years research has concentrated on exploring specific economic approaches against microbial infections. In this context, the purpose of this study was the investigation of the synergistic antibacterial activities of commercially available and chemically characterized CEO in combination with sertraline, a selective serotonin reuptake inhibitor (SSRI), whose repositioning as a non-antibiotic drug has been explored over the years with encouraging results. In vitro effects of the titled combination were assessed toward a wide panel of both Gram-positive and Gram-negative bacteria. The antimicrobial efficacy was investigated by using the checkerboard microdilution method. The interesting preliminary results obtained suggested a synergistic effect (fractional inhibitory index, FICI < 0.5) of sertraline in combination with CEO, leading to severe growth inhibition for all bacterial species under investigation.

Effect of Combined Treatment with Cinnamon Oil and petit-High Pressure CO2 against Saccharomyces cerevisiae

This study investigated the effects of the combined treatment with cinnamon oil (CIN) and petit-high pressure CO2 (p-HPCO2) against Saccharomyces cerevisiae. The results showed that CIN and p-HPCO2 exhibited a synergistic antifungal effect against S. cerevisiae. After being treated by CIN at a final concentration of 0.02% and p-HPCO2 under 1.3 MPa at 25 °C for 2 h, the S. cerevisiae population decreased by 3.35 log10 CFU/mL, which was significantly (p < 0.05) higher than that of CIN (1.11 log10 CFU/mL) or p-HPCO2 (0.31 log10 CFU/mL). Through scanning electron microscopy, fluorescence staining, and other approaches, a disorder of the structure and function of the cell membrane was observed after the CIN + p-HPCO2 treatment, such as severe morphological changes, increased membrane permeability, decreased cell membrane potential, and loss of membrane integrity. CIN + p-HPCO2 also induced mitochondrial membrane depolarization in S. cerevisiae cells, which could be associated with the decrease in intracellular ATP observed in this study. Moreover, the expression of genes involved in ergosterol synthesis in S. cerevisiae was up-regulated after exposure to CIN + p-HPCO2, which might be an adaptive response to membrane damage. This work demonstrates the potential of CIN and p-HPCO2 in combination as an alternative pasteurization technique for use in the food industry.

A review of plant antipathogenic constituents: Source, activity and mechanism

Green prevention and control of plant pathogens is a development direction of sustainable and low-carbon agriculture given the limitation of traditional chemicals. Plant-derived antipathogenic constituents (PAPCs) exhibit the advantages of being environmental benign and a broad spectrum of target pathogens over traditional chemicals. Here, we review the research advances on plant sources, chemical compositions, activities of antipathogenic constituents in the past 20 years. Reported PAPCs are classified into categories of phenols, flavonoids, terpenoids, alkaloids and antimicrobial peptides. Angiosperms, gymnosperms and some lower plants are the main plant source of detected PAPCs. The PAPCs act on pathogens through multiple pathways including destroying cell structures, blocking key composition synthesis and inhibiting cell metabolism. The development trends of PAPCs are finally prospected. This review serves as a comprehensive review on the study of plant antipathogenic constituents and a key reference for forecasting the source, characteristic and activity of PAPC.

Cinnamon essential oil and its emulsion as efficient antibiofilm agents to combat Acinetobacter baumannii

Acinetobacter baumannii is an emerging nosocomial pathogen resistant to a wide spectrum of antibiotics, with great potential to form a biofilm, which further aggravates treatment of infections caused by it. Therefore, searching for new potent agents that are efficient against A. baumannii seems to be a necessity. One of them, which has already been proven to possess a wide spectrum of biological activities, including antimicrobial effect, is cinnamon essential oil. Still, further increase of antibacterial efficacy and improvement of bioavailability of cinnamon oil is possible by emulsification process. The aim of this study was comparative analysis of cinnamon essential oil and its emulsion against biofilm forming A. baumannii clinical isolates. Furthermore, the investigation of toxicological aspects of possible applications of essential oil and emulsion was done as well. Gas chromatography–mass spectrometry of essential oil indicated trans-cinnamaldehyde as the most abundant component. The cinnamon emulsion was synthesized from cinnamon essential oil by combining modified low- and high- energy methods. Synthesized emulsion was characterized with Fourier-transform infrared spectroscopy and photon correlation spectroscopy. Both substances exhibited significant antibacterial (minimal inhibitory concentrations in the range 0.125–0.5 mg/ml) and antibiofilm effects (inhibitions of formation and reduction of pre-formed biofilm were 47–81 and 30–62%, respectively). Compared to essential oil, the efficacy of emulsion was even stronger considering the small share of pure oil (20%) in the emulsion. The result of biofilm eradication assay was confirmed by scanning electron microscopy. Even though the cytotoxicity was high especially for the emulsion, genotoxicity was not determined. In conclusion, strong antibacterial/antibiofilm effect against A. baumannii of the cinnamon essential oil and the fact that emulsification even potentiated the activity, seems to be of great significance. Observed cytotoxicity implicated that further analysis is needed in order to clearly determine active principles being responsible for obtained antibacterial/antibiofilm and cytotoxic properties.