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

Aqueous extract of Teucrium polium ameliorates diabetes and induced-prostatic complication

PURPOSE

Prostatic complications are common among diabetic patients. Previous research demonstrates that Teucrium polium (T. polium) has beneficial effects in diabetic cases. This study, therefore, aimed to evaluate the impacts of T. polium aqueous extract on the prostate of diabetic rats.

METHODS

Diabetes was induced in male Wistar rats by intraperitoneal injection of streptozotocin (50 mg/kg). a total of 40 Rats were randomly divided into the following groups: Control, Control + TP100 (TP100), Diabetic, Diabetic + TP100 (DTP100) and Diabetic + TP200 (DTP200). The intervention was done orally once per day for 56 days (8 weeks). An oral glucose tolerance test was conducted, glucose and insulin levels were assessed. Microscopic features of the ventral prostatic lobe were evaluated pathologically.

RESULTS

T. polium at both doses significantly reduced glucose levels in an insulin-independent pathway. T. polium at both doses significantly improved prostate weight, prostate epithelium height, and prostate secretory activity in comparison with the diabetic group. Interestingly, treatment of T. polium to healthy rats led to decreased epithelial height.

CONCLUSION

It could be deduced that T. polium has useful impacts on glucose control and may prevent prostatic complications.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s40200-022-00979-4.

GC, GC/MS Analysis, and Biological Effects of Essential Oils from Thymus mastchina and Elettaria cardamomum

Spanish marjoram (Thymus mastichina) and cardamom (Elettaria cardamomum) are traditional aromatic plants with which several pharmacological properties have been associated. In this study, the volatile composition, antioxidative and antimigratory effects on human breast cancer (MDA-MB-468 cell line), antimicrobial activity, and antibiofilm effect were evaluated. Results obtained via treatment of human breast cancer cells generally indicated an inhibitory effect of both essential oils (EOs) on cell viability (after long-term treatment) and antioxidative potential, as well as the reduction of nitric oxide levels. Antimigratory effects were revealed, suggesting that these EOs could possess significant antimetastatic properties and stop tumor progression and growth. The antimicrobial activities of both EOs were determined using the disc diffusion method and minimal inhibition concentration, while antibiofilm activity was evaluated by means of mass spectrometry. The best antimicrobial effects of T. mastichina EO were found against the yeast Candida glabrata and the G⁺ bacterium Listeria monocytogenes using the disc diffusion and minimal inhibitory concentration methods. E. cardamomum EO was found to be most effective against Pseudomas fluorescens biofilm using both methods. Similarly, better effects of this oil were observed on G^- compared to G⁺ bacterial strains. Our study confirms that T. mastichina and E. cardamomum EOs act to change the protein structure of older P. fluorescens biofilms. The results underline the potential use of these EOs in manufactured products, such as foodstuffs, cosmetics, and pharmaceuticals.

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.

Comparative Study of Useful Compounds Extracted from Lophanthus anisatus by Green Extraction

Essential oils were obtained from different parts of Agastache foeniculum (Lophanthus anisatus) plants by means of extraction: green extraction using hydro-distillation (HD) and bio-solvent distillation, BiAD, discontinuous distillation, and supercritical fluid extraction, in two stages: (1) with CO₂, and (2) with CO₂ and ethanol co-solvent. The extraction yields were determined. The yield values varied for different parts of the plant, as well as the method of extraction. Thus, they had the values of 0.62 ± 0.020 and 0.92 ± 0.015 g/100 g for the samples from the whole aerial plant, 0.75 ± 0.008 and 1.06 ± 0.005 g/100 g for the samples of leaves, and 1.22 ± 0.011 and 1.60 ± 0.049 g/100 g for the samples of flowers for HD and BiAD, respectively. The yield values for supercritical fluid extraction were of 0.94 ± 0.010 and 0.32 ± 0.007 g/100 g for the samples of whole aerial plant, 0.9 ± 0.010 and 1.14 ± 0.008 g/100 g for the samples of leaves, and 1.94 ± 0.030 and 0.57 ± 0.003 g/100 g for the samples of flowers, in the first and second stages, respectively. The main components of Lophanthus anisatus were identified as: estragon, limonene, eugenol, chavicol, benzaldehyde, and pentanol. The essential oil from Agatache foeniculum has antimicrobial effects against Staphylococcus aureus, the Escherichia coli and Pseudomonas aeruginosa. Acclimatization of Lophantus anisatus in Romania gives it special qualities by concentrating components such as: estragole over 93%, limonene over 8%, especially in flowers; and chavicol over 14%, estragole over 30%, eugenol and derivatives (methoxy eugenol, methyl eugenol, etc.) over 30% and phenyl ether alcohol over 20% in leaves. As a result of the research carried out, it was proven that Lophanthus anisatus can be used as a medicinal plant for many diseases, it can be used as a spice and preservative for various foods, etc.

Essential oil of Magnolia denudata is an effective anesthetic for spotted seabass (Lateolabrax maculatus): a test of its effect on blood biochemistry, physiology, and gill morphology

Magnolia denudata is a well-known ornamental tree in China due to its beautiful blossoms, and it has been used as an analgesic to treat human headaches. This study investigated the anesthetic potential and physiological response of the essential oil of M. denudata flowers on spotted seabass Lateolabrax maculatus. Fish (mean ± SD, 164.16 ± 15.40 g) were individually exposed to different concentrations of M. denudata essential oil (MDO, 10, 20, 40, 60, 80, 100, and 120 mg/L) and eugenol (10, 20, 30, 40, 50, 60, and 70 mg/L) to investigate anesthetic efficacy. Based on the ideal time criterion for anesthetic induction (< 3 min) and recovery (< 10 min), the lowest effective concentration for spotted seabass was 100 mg/L for MDO and 60 mg/L for eugenol. The physiological and histopathological damage in the gill of L. maculatus after using MDO and eugenol was also evaluated at the minimum dose inducing deep anesthesia, and at 0, 6, and 24 h after recovery. The results showed that MDO and eugenol anesthesia alleviated the levels of cortisol and glucose and the lactic dehydrogenase activity induced by handling. Compared with eugenol, MDO also caused secondary stress to the body, but MDO caused minor physiological responses and histological changes in the gills. This study suggests that MDO is an effective anesthetic for spotted seabass.

Chemical Composition, Antitumor Potential, and Impact on Redox Homeostasis of the Essential Oils of Orlaya grandiflora from Two Climate Localities

It is well known that abiotic components can affect biosynthetic pathways in the production of certain volatile compounds. The aim of this study was to compare the chemical composition of essential oils obtained from Orlaya grandiflora (L.) Hoffm. collected from two localities in Serbia (continental climate, OG1) and Montenegro (Mediterranean climate, OG2) and to assess their antitumor potential on the human colon cancer HCT-116 and breast cancer MDA-MB-231 cell lines. EOs obtained by hydrodistillation were analyzed using GC-MS and GC-FID methods. The results indicate considerable differences in the chemical compositions of the two samples. Although in both samples the main class of volatiles observed was sesquiterpenes (47.5% for OG1 and 70.1% for OG2), the OG1 sample was characterized by a high amount of monoterpene hydrocarbons (29.3%), and sesquiterpene germacrene D (29.5%) as the most abundant compound. On the other hand, the OG2 sample contained a high quantity of oxygenated sesquiterpenes (20.6%), and β-elemene (22.7%) was the major constituent. The possible antitumor mechanisms of these EOs in the HCT-116 and MDA-MB-231 cell lines were examined by means of cell viability, apoptosis, redox potential, and migratory capacity. The antiviability potential appeared to be dose dependent, since the results showed that both EOs decreased the viability of the tested cells. Stronger antitumor effects were shown in MDA-MB-231 cells after short-term treatment, especially at the highest applied concentration, where the percentage of viability was reduced by over 40%. All tested concentrations of EOs exhibited proapoptotic activity and elevated activity of caspase-3 in a dose- and time-dependent manner. The results also showed decreased concentrations of superoxide anion radical in the treated cells, which indicates their significant antioxidative role. Long-term treatments showed mild recovery effects on cell viability in both cell lines, probably caused by the balancing of redox homeostasis. Elevated levels of nitrites indicate high levels of nitric oxide (NO) production and suggest its higher bioavailability due to the antioxidative environment. The tested EOs also induced a drop in migratory capacity, especially after short-time treatments. Taken together, these results suggest considerable antitumor activity of both EOs, which could have potential therapeutic applications.

Essential oils for healing and/or preventing infection of surgical wounds: a systematic review

OBJECTIVE

To analyze the evidence available in the literature on the use of essential oils for healing and/or preventing infection in surgical wounds.

METHOD

Systematic review according to the JBI model and PRISMA statement. The search was carried out in November/2020 and updated in December/2021, using descriptors and keywords, in the CINAHL, LILACS, CENTRAL, EMBASE, PUBMED, Scopus, and Web of Science databases. The quality of the evidence was assessed using the JBI critical appraisal tool for randomized controlled trials.

RESULTS

Five publications were included. Three studies evaluated healing and the presence of infection after episiotomy using the Redness-Edema-Ecchymosis-Discharge-Approximation (REEDA) scale; one study evaluated healing after periodontal surgery using the plaque index and Modified Gingival Index; the other four studies considered the presence of infection after episiotomy. Most studies used lavender oil, associated or not with other oils (80%). Two studies showed an improvement in healing. The infection outcome, although mentioned by 60% of studies, was not assessed as a primary outcome.

CONCLUSION

The promising efficacy of essential oils, especially lavender, was verified in the healing of surgical wounds, especially in episiotomies.

Photoprotective Agents Obtained from Aromatic Plants Grown in Colombia: Total Phenolic Content, Antioxidant Activity, and Assessment of Cytotoxic Potential in Cancer Cell Lines of Cymbopogon flexuosus L. and Tagetes lucida Cav. Essential Oils

Photoprotective agents obtained from plants provide benefits for the health of the skin. The present study aims to assess the total phenolic content (TPC) and in vitro UV-protective properties of twelve essential oils (EOs) from plants grown in Colombia and to evaluate the antioxidant and cytotoxic potential of two species identified as photoprotective potentials: Cymbopogon flexuosus and Tagetes lucida. The composition of EOs was studied by GC/MS. The cytotoxicity of both EOs was examined using an MTT assay, and an H2-DCFDA probe was employed to estimate the intracellular production of ROS in HepG2 and Calu-1 cells. Major constituents (≥10%) were neral, geranial, geranyl acetate in C. flexuosus and estragole in T. lucida. The TPC for C. flexuosus and T. lucida EOs were ≥10 mg GAE/g of byproduct. Both EOs showed photoprotective properties (SPFin vitro: 13−14), and long-wavelength UVA protection (λc > 370 nm). HepG2 and Calu-1 cells exposed to C. flexuosus exhibited antiproliferative activity (˂50%) at 125 µg/mL, while T. lucida was at 250 and 500 µg/mL. The IC50 values for C. flexuosus were 75 and 100 µg/mL in HepG2 and Calu-1 cells, respectively, whereas those for T. lucida were >250 µg/mL. These EOs achieved significant inhibitory effects (between 15.6 and 40.4%) against H2O2-induced oxidative stress. The results showed that EO compounds recognized as antioxidants could counteract the effects elicited by H2O2.

Chemical Composition and Antibacterial Activity of Liquid and Volatile Phase of Essential Oils against Planktonic and Biofilm-Forming Cells of Pseudomonas aeruginosa

Pseudomonas aeruginosa is an opportunistic pathogen causing life-threatening, hard-to-heal infections associated with the presence of a biofilm. Essential oils (EOs) are promising agents to combat pseudomonal infections because of the alleged antimicrobial activity of their volatile fractions and liquid forms. Therefore, the purpose of this paper was to evaluate the antibacterial efficacy of both volatile and liquid phases of seven EOs (thyme, tea tree, basil, rosemary, eucalyptus, menthol mint, lavender) against P. aeruginosa biofilm and planktonic cells with the use of a broad spectrum of analytical in vitro methods. According to the study results, the antibacterial activity of EOs in their liquid forms varied from that of the volatile fractions. Overall, liquid and volatile forms of rosemary EO and tea tree EO displayed significant antibiofilm effectiveness. The outcomes indicate that these particular EOs possess the potential to be used in the therapy of P. aeruginosa infections.

Insights into the Composition and Antibacterial Activity of Amomum tsao-ko Essential Oils from Different Regions Based on GC-MS and GC-IMS

Chemical components are one of the most significant traits and attributes of plant tissues, and lead to their different functions. In this study, the composition of Amomun tsao-ko essential oils (AEOs) from different regions was first determined by a combination of gas chromatography–mass spectrometry (GC-MS) and gas chromatography–ion mobility spectrometry (GC-IMS). In total, 141 compounds were identified, of which terpenes and aldehydes were the main groups. Orthogonal partial least square discriminant analysis (OPLS-DA) distinguished the samples from different regions clearly, and the main differences were terpenes, aldehydes, and esters. Meanwhile, AEOs showed strong antibacterial activity against Staphylococcus aureus (S. aureus), and the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) reached 0.20 mg/mL and 0.39–0.78 mg/mL, respectively. From correlation analysis, 1,8-cineole, (E)-dec-2-enal, citral, α-pinene, and α-terpineol were determined to be the potential antibacterial compounds. This study provides the basis for the variety optimization of A. tsao-ko and its application as a natural food preservative.

Nanodelivery of essential oils as efficient tools against antimicrobial resistance: a review of the type and physical-chemical properties of the delivery systems and applications

This review provides a synthesis of the last ten years of research on nanodelivery systems used for the delivery of essential oils (EOs), as well as their potential as a viable alternative to antibiotics in human and veterinary therapy. The use of essential oils alone in therapy is not always possible due to several limitations but nanodelivery systems seem to be able to overcome these issues. The choice of the essential oil, as well as the choice of the nanodelivery system influences the therapeutic efficacy obtained. While several studies on the characterization of EOs exist, this review assesses the characteristics of the nanomaterials used for the delivery of essential oils, as well as impact on the functionality of nanodelivered essential oils, and successful applications. Two classes of delivery systems stand out: polymeric nanoparticles (NPs) including chitosan, cellulose, zein, sodium alginate, and poly(lactic-co-glycolic) acid (PLGA), and lipidic NPs including nanostructured lipid carriers, solid lipid NPs, nanoemulsions, liposomes, and niosomes. While the advantages and disadvantages of these delivery systems and information on stability, release, and efficacy of the nanodelivered EOs are covered in the literature as presented in this review, essential information, such as the speed of emergence of a potential bacteria resistance to these new systems, or dosages for each type of infection and for each animal species or humans is still missing today. Therefore, more quantitative and in vivo studies should be conducted before the adoption of EOs loaded NPs as an alternative to antibiotics, where appropriate.

Óleos essenciais para a cicatrização e/ou prevenção de infecção de feridas cirúrgicas: revisão sistemática

RESUMO Objetivo: Analisar as evidências disponíveis na literatura sobre o uso de óleos essenciais para a cicatrização e/ou prevenção de infecção em feridas cirúrgicas. Método: Revisão sistemática segundo modelo JBI e declaração PRISMA. Busca realizada em novembro/2020 e atualizada em dezembro/2021, utilizando-se descritores e palavras-chave, nas bases CINAHL, LILACS, CENTRAL, EMBASE, PUBMED, Scopus e Web of Science. A qualidade das evidências foi avaliada usando a ferramenta JBI critical appraisal para ensaios clínicos randomizados. Resultados: Cinco publicações foram incluídas. Três estudos avaliaram a cicatrização e presença de infecção após episiotomia por meio da escala REEDA (Redness-Edema-Ecchymosis-Discharge-Approximation); um avaliou cicatrização após cirurgia periodontal por meio do índice de placa e Índice Gengival Modificado; o restante considerou a presença de infecção após episiotomia. A maioria dos estudos utilizou o óleo de lavanda, associado ou não a outros óleos (80%). Em dois estudos houve melhora da cicatrização. O desfecho infecção, embora mencionado por 60% estudos, não foi avaliado como primário. Conclusão: Verificou-se a eficácia promissora de óleos essenciais, sobretudo do de lavanda, na cicatrização de feridas cirúrgicas, especialmente em episiotomias.

[Developement and biological activity evaluation of clove essential oil based emulsion]

INTRODUCTION

Clove essential oil is isolated from the dried flower buds of Syzygium aromaticum from which many biological activities have been reported. The aim of this work was to develop a cream for topical use containing clove essential oil (HE) as an active ingredient and to test its biological activity.

MATERIAL AND METHODS

Clove EO was extracted by hydrodistillation, its chemical composition was analysed by Gas chromatography-mass spectrometry (CG-SM). The EO was then incorporated into a cream where its stability was studied. The antifungal activity was evaluated by disc-diffusion method. The in vivo anti-inflammatory activity of EO and the cream was assessed y by carrageenan-induced rat paw edema model.

RESULTS

Clove EO contains two major constituents: eugenol (69.14%) and β-Caryophyllene (18.8%). The cream had good organoleptic and physicochemical properties. Both EO and the cream showed growth inhibitory effects on the two studied dermatophytes strains.The incorporation of EO in the cream provided a good anti-inflammatory activity, similar to the reference drug.

CONCLUSION

the developed creme was stable, had good anti-inflammatory properties and moderate antifungal activity. Long-term stability studies and in vivo tests would lead to the use of clove essential oil in the development of new pharmaceutical forms.

In Vitro Antimicrobial Activity of Medicinal Plant Extracts against Some Bacterial Pathogens Isolated from Raw and Processed Meat

BACKGROUND AND AIM

The poultry meat and its products are considered ideal media for bacterial growth and spoilage, as they are highly nutritive with a favorable pH. The food industry has focused its attention on a great diversity of plant species as food preservatives. The aim of this study was to investigate the presence of Staphylococcus aureus, Escherichia coli O157: H7, and Klebsiella pneumonia in food samples and to evaluate of the antibacterial activity of some medicinal plant extracts against these bacteria.

METHODS

Raw and processed meat samples (n = 60) were collected from abattoirs and local markets. S. aureus, E. coli O157: H7, and K. pneumonia were isolated, identified by phenotypic methods, and then confirmed by 16S rRNA gene sequencing. The antibacterial activity and spectrum of essential oils and spices powder of cumin, black seeds, cloves, cinnamon, and marjoram was determined against the isolated strains in this study by microbial count and well-diffusion techniques.

RESULTS

A total of 33 isolates have been identified as S. aureus, 30 isolates were identified as E. coli O157: H7, and 15 isolates were identified as K. pneumonia. S. aureus, E. coli O157: H7, and K. pneumonia could be detected in both fresh and processed food with higher prevalence in the processed meat. There was a significant decrease in microbial count in treated samples either with the spices powder or essential oils of the tested medicinal plants compared to control samples during storage time period. Furthermore, while the microbial count increased in the control samples, the microbial count decreased to reach zero in almost all treated samples with essential oils after 15 days of storage.

CONCLUSION

S. aureus, E. coli O157: H7, and K. pneumonia are associated with food from animal sources, in either fresh or processed meat samples. The prevalence of them was higher in the processed meat than in fresh meat. The essential oils and spices powder of cumin, black seeds, cloves, cinnamon, and marjoram have an in vitro wide spectrum antibacterial activity with the highest antibacterial activity for the black seeds.

Encapsulation of Natural Bioactive Compounds by Electrospinning-Applications in Food Storage and Safety

Packaging is used to protect foods from environmental influences and microbial contamination to maintain the quality and safety of commercial food products, to avoid their spoilage and to extend their shelf life. In this respect, bioactive packaging is developing to additionally provides antibacterial and antioxidant activity with the same goals i.e., extending the shelf life while ensuring safety of the food products. New solutions are designed using natural antimicrobial and antioxidant agents such as essential oils, some polysaccharides, natural inorganic nanoparticles (nanoclays, oxides, metals as silver) incorporated/encapsulated into appropriate carriers in order to be used in food packaging. Electrospinning/electrospraying are receiving attention as encapsulation methods due to their cost-effectiveness, versatility and scalability. The electrospun nanofibers and electro-sprayed nanoparticles can preserve the functionality and protect the encapsulated bioactive compounds (BC). In this review are summarized recent results regarding applications of nanostructured suitable materials containing essential oils for food safety.

The Antimicrobial and Antibiofilm In Vitro Activity of Liquid and Vapour Phases of Selected Essential Oils against Staphylococcus aureus

The high resistance of staphylococcal biofilm against antibiotics and developing resistance against antiseptics induces a search for novel antimicrobial compounds. Due to acknowledged and/or alleged antimicrobial activity of EOs, their application seems to be a promising direction to follow. Nevertheless, the high complexity of EOs composition and differences in laboratory protocols of the antimicrobial activity assessment hinders the exact estimation of EOs effectiveness. To overcome these disadvantages, in the present work we analysed the effectiveness of volatile and liquid forms of seven EOs (derived from thyme, tea tree, basil, rosemary, eucalyptus, lavender, and menthol mint) against 16 staphylococcal biofilm-forming strains using cohesive set of in vitro techniques, including gas chromatography–mass spectrometry, inverted Petri dish, modified disk-diffusion assay, microdilution techniques, antibiofilm dressing activity measurement, AntiBioVol protocol, fluorescence/confocal microscopy, and dynamic light scattering. Depending on the requirements of the technique, EOs were applied in emulsified or non-emulsified form. The obtained results revealed that application of different in vitro techniques allows us to get a comprehensive set of data and to gain insight into the analysed phenomena. In the course of our investigation, liquid and volatile fractions of thyme EO displayed the highest antibiofilm activity. Liquid fractions of rosemary oil were the second most active against S. aureus. Vapour phases of tea tree and lavender oils exhibited the weakest anti-staphylococcal activity. The size of emulsified droplets was the lowest for T-EO and the highest for L-EO. Bearing in mind the limitations of the in vitro study, results from presented analysis may be of pivotal meaning for the potential application of thymol as a antimicrobial agent used to fight against staphylococcal biofilm-based infections.

Antibacterial and antioxidant activity of cinnamon essential oil-laden 45S5 bioactive glass/soy protein composite scaffolds for the treatment of bone infections and oxidative stress

This study aimed to fabricate cinnamon essential oil (CO)-laden 45S5 bioactive glass (BG)/soy protein (SP) scaffolds exhibiting antioxidant and antibacterial activity. In this regard, 45S5 BG-based scaffolds were produced by the foam replica method, and subsequently the scaffolds were coated with various concentrations of CO (2.5, 5 and 7 (v/v) %) incorporated SP solution. Scanning electron microscopy images revealed that the CO-laden SP effectively attached to the 45S5 BG scaffold struts. The presence of 45S5 BG, SP and CO was confirmed using Fourier transform infrared spectroscopy. Compressive strength results indicated that SP based coatings improved the scaffolds' mechanical properties compared to uncoated BG scaffolds. The loading efficiency and releasing behaviour of the different CO concentrations were tested by gas chromatography-mass spectroscopy and UV-Vis spectroscopy. The results showed that CO incorporated scaffolds have controlled releasing behaviour over seven days. Furthermore, the coating on the scaffold surfaces slightly retarded, but it did not inhibit, the in vitro bioactivity of the scaffolds. Moreover, the antioxidant and antibacterial activity of CO was studied. The free radical scavenging activity measured by DPPH was 5 ± 1, 41 ± 3, 44 ± 1 and 43 ± 1 % for BGSP, CO2.5, CO5 and CO7, respectively. The antioxidant activity was thus enhanced by incorporating CO. Agar diffusion and colony counting results indicated that the incorporation of CO increased the antibacterial activity of scaffolds against S. aureus and E. coli. In addition, cytotoxicity of the scaffolds was investigated using MG-63 osteoblast-like cells. The results showed that the BG-SP scaffold was non-toxic under the investigated conditions, whereas dose-dependent toxicity was observed in CO-laden scaffolds. Considered together, the developed phytotherapeutic agent laden 45S5 BG-based scaffolds are promising for bone tissue engineering exhibiting capability to combat bone infections and to protect against oxidative stress damage.

ATR-FTIR-MIR Spectrometry and Pattern Recognition of Bioactive Volatiles in Oily versus Microencapsulated Food Supplements: Authenticity, Quality, and Stability

Fourier transform infrared spectroscopy on the middle infrared region (ATR-FTIR-MIR) proved to be a convenient and reliable technique to evaluate foods' quality and authenticity. Plants' essential oils are bioactive mixtures used as such or in different oily or microencapsulated formulations, beneficial to human health. Six essential oils (thyme, oregano, juniperus, tea tree, clove, and cinnamon) were introduced in three oily formulations (Biomicin, Biomicin Forte, and Biomicin urinary) and these formulations were microencapsulated on fructose and maltodextrin matrices. To study their stability, the microencapsulated powders were kept under light irradiation for 14 days at 25 °C or introduced in biopolymer capsules. All variants were analysed by ATR-FTIR-MIR, recording wavenumbers and peak intensities (3600-650 cm^-1). The data were processed by Unscrambler and Metaboanalyst software, with specific algorithms (PCA, PLSDA, heatmaps, and random forest analysis). The results demonstrated that ATR-FTIR-MIR can be successfully applied for fingerprinting and finding essential oil biomarkers as well as to recognize this pattern in final microencapsulated food supplements. This study offers an improved ATR-FTIR-MIR procedure coupled with an adequate chemometric analysis and accurate data interpretation, to be applied for the evaluation of authenticity, quality, traceability, and stability during storage of essential oils incorporated in different matrices.

Chemical Composition and Biological Activities of the Essential Oils of Chrysophyllum albidum G. Don (African Star Apple)

The volatile compounds of the fruit and leaf essential oils of the African star fruit, Chrysophyllum albidum G. Don, were characterized by gas chromatography-mass spectrometry in this study. The antimicrobial, antibiofilm, and antioxidant activities of the essential oils were also investigated. Thirty-five and thirty-four compounds, representing 97.84% and 97.87%, were identified in the leaf and fruit essential oils, respectively. The antimicrobial activity of the oils was evaluated in vitro against eight pathogens using the broth microdilution method. The fruit essential oil exhibited broad-spectrum antimicrobial activity in the antimicrobial susceptibility test, with minimum inhibitory concentrations (MICs) ranging from 0.195 to 6.250 mg/mL, while the leaf essential oils showed antimicrobial activity with MICs in the range of 6.875–13.750 mg/mL. The antibiofilm activity was assessed via the crystal violet staining assay, with Pseudomonas aeruginosa as the model organism. The concentrations of the leaf and fruit essential oil required for half-maximal inhibition of biofilm formation (BIC₅₀) were 6.97 ± 0.56 and 4.78 ± 0.21 mg/mL, respectively. In evaluating antioxidant activity, the total antioxidant capacity obtained from the phosphomolybdenum assay was 104.8 ± 2.4 and 101.6 ± 0.8 μg/g AAE for leaf and fruit essential oils, respectively. The IC₅₀ values obtained from the hydrogen peroxide scavenging, 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging, and inhibition of lipid peroxidation assays were 301.8 ± 0.7 and 669.2 ± 2.1 μg/mL, 1048.0 ± 0.3 and 1454.0 ± 0.3 μg/mL, and 460.1 ± 2.7 and 457.4 ± 0.3 μg/mL for both leaf and fruit essential oils, respectively. The results obtained in this study suggest that the leaf and fruit essential oil of Chrysophyllum albidum G. Don could find potential use in the food, cosmetic, and pharmaceutical industries as preservative and pharmaceutical agents.

Back to the Roots-An Overview of the Chemical Composition and Bioactivity of Selected Root-Essential Oils

Since ancient times, plant roots have been widely used in traditional medicine for treating various ailments and diseases due to their beneficial effects. A large number of studies have demonstrated that-besides their aromatic properties-their biological activity can often be attributed to volatile constituents. This review provides a comprehensive overview of investigations into the chemical composition of essential oils and volatile components obtained from selected aromatic roots, including Angelica archangelica, Armoracia rusticana, Carlina sp., Chrysopogon zizanioides, Coleus forskohlii, Inula helenium, Sassafras albidum, Saussurea costus, and Valeriana officinalis. Additionally, their most important associated biological impacts are reported, such as anticarcinogenic, antimicrobial, antioxidant, pesticidal, and other miscellaneous properties. Various literature and electronic databases-including PubMed, ScienceDirect, Springer, Scopus, Google Scholar, and Wiley-were screened and data was obtained accordingly. The results indicate the promising properties of root-essential oils and their potential as a source for natural biologically active products for flavor, pharmaceutical, agricultural, and fragrance industries. However, more research is required to further establish the mechanism of action mediating these bioactivities as well as essential oil standardization because the chemical composition often strongly varies depending on external factors.

Microemulsification of essential oils for the development of antimicrobial and mosquito repellent functional coatings for textiles

AIMS

To develop an essential oil (EO)-loaded textile coating using an environmentally friendly microemulsion technique to achieve both antimicrobial and mosquito repellent functionalities.

METHODS AND RESULTS

Minimum inhibitory concentrations and fractional inhibitory concentrations of litsea, lemon and rosemary EOs were determined against Staphylococcus aureus, Escherichia coli, Staphylococcus epidermidis, Pseudomonas aeruginosa and Trichophyton rubrum. A 1 : 2 mixture of litsea and lemon EOs inhibited all the microorganisms tested and was incorporated into a chitosan-sodium alginate assembly by a microemulsification process. The EO-loaded microemulsions were applied to cotton and polyester fabrics using a soak-pad-dry method. The textile challenge tests demonstrated 7-8 log₁₀ reductions of S. epidermidis, S. aureus and E. coli after 24 h and T. rubrum after 48 h. Aedes aegypti mosquito repellency was also assessed which demonstrated 71·43% repellency compared to 52·94% by neat EO-impregnated cotton.

CONCLUSIONS

Textiles treated with the litsea and lemon EO microemulsion showed strong antimicrobial activity against the skin associated microorganisms E. coli, S. aureus, S. epidermidis and T. rubrum and potential mosquito repellent properties.

SIGNIFICANCE AND IMPACT OF THE STUDY

EOs could be useful for the development of natural, environmentally friendly functional textiles to protect textiles and users from microbial contamination in addition to possessing other beneficial properties such as mosquito repellency.

Antiviral Essential Oil Components Against SARS-CoV-2 in Pre-procedural Mouth Rinses for Dental Settings During COVID-19: A Computational Study

COVID-19 mainly spreads through cough or sneeze droplets produced by an infected person. The viral particles are mostly present in the oral cavity. The risk of contracting COVID-19 is high in the dental profession due to the nature of procedures involved that produce aerosols. Along with other measures to limit the risk of infection, pre-procedural mouth rinses are beneficial in reducing the viral particles in the oral cavity. In this study, the antiviral efficacy of essential oil components has been determined specifically against SARS-CoV-2 by molecular docking and conceptual DFT approach. Based on the binding affinities of the components against the receptor binding domain of the S1 glycoprotein, cuminal, carvacrol, myrtanol, and pinocarveol were found to be highly active. The molecular descriptor values obtained through conceptual DFT also indicated the above-mentioned components to be active based on the correlation between the structure and the activity of the compounds. Therefore, pre-procedural mouth rinses with these components included may be specifically suitable for dental procedures during the COVID-19 period.

Antibacterial effect of essential oils of two plants Eucalyptus camaldulensis and Artemisia herba alba on some bacterial strains

Essential oils are secondary plant metabolites and have many therapeutic properties. The aim of our study is to determine the antibacterial effect of the essential oils of two plants cultivated in a semi-arid region located in the Northeast of Algeria (Tebessa), Eucalyptus camaldulensis (Myrtaceae) and Artemisia herba alba (Asteraceae). The yield of essential oils of the two plants were 1.45 ± 0.026 and 1.21 ± 0.061 g/100 g of the dry matter of the aerial part respectively. The test of the antibacterial effect is based on the diffusion method on solid medium (sensitivity), this method allows us to determine the susceptibility or resistance of an organism vis-à-vis the sample studied. Our study reveals that E. camaldulensis essential oil had very strong activity on all bacterial strains tested, except on Pseudomonas aeruginosa and Enterococcus faecalis for which there was no inhibitory effect. However, A. herba alba essential oil had very strong activity on all bacterial strains tested except on Pseudomonas aeruginosa. The MIC of Artemisia essential oil ranged between 0.08 and 1.57 µL/mL, with the lowest activity for S. aureus and P. mirabilis (1.57 µL/mL) and the highest activity was observed against E. feacalis, E. coli, and K. pneumonia (0.09 µL/mL). The MIC of the second plant EO ranged between 0.08 and 0.36 µL/mL, with the lowest activity for P. mirabilis (0.36 µL/mL) and the highest one was observed against S. saprophyticus and E. coli (0.08 µL/mL). Statistical analysis shows that the two plants have the same efficacy against S. saprophyticus while E. faecalis, K. pneumoniae and P. mirabilis species are affected more by the essential oil of A. herba alba. While, E. camaldulensis has a higher efficiency than that of A. herba alba on the species: S. aureus and E. coli. Therefore, the essential oils of E. camaldulensis and A. herba alba suggests avenues for further non clinical and clinical studies.

Essential Oils for Bone Repair and Regeneration-Mechanisms and Applications

Although bone possesses a remarkable capacity for self-remodeling and self-healing of small defects, the continuously increasing growth of bone diseases in the elderly population is becoming a significant burden, affecting individual life quality and society. Conventional treatment options involve surgical procedures for repair and reconstruction, local debridement, autografts or allografts, bone transport, Masquelet's two-stage reconstructions, and vascularized bone transplants. However, as such approaches often lead to disruptions of bone-regeneration processes and microbial contaminations and are often inefficient, researchers focus on developing bone-regenerative strategies and identifying novel therapeutic agents that could aid the bone-healing process. In this regard, plant-derived biocompounds, especially essential oils (EOs), have received great scientific attention in recent years, owing to their antioxidant, anti-inflammatory, and antimicrobial effects. Current studies focus on either the direct application of EOs on bone tissue or the introduction of EOs as bioactive compounds in bone scaffolds or as coatings for bone implants. Some of the EOs investigated involve St. John's wort, rosemary, thyme, ylang, white poplar, eucalyptus, lavender, and grape seed. In this context, the present paper aims to provide an overview of the main mechanisms involved in bone repair and regeneration and the potential of EOs to address and enhance these mechanisms.

Essential Oil of Deverra tortuosa Aerial Parts: Detailed Chemical Profile, Allelopathic, Antimicrobial, and Antioxidant Activities

Essential oils (EOs) are a promising group of natural products of the aromatic plants due to their various biological effects such as allelopathic, antioxidant, antimicrobial activities. The present study aimed to construct the detailed chemical profile of the EO derived from Deverra tortuosa aerial parts along with assessing its allelopathic, antimicrobial, and antioxidant potentialities. The EO was extracted by hydrodistillation and analyzed via gas chromatography-mass spectrometry (GC/MS). The allelopathic activity of the EO was assessed against the germination and seedling growth of the weed Chenopodium murale. Also, the EO was tested against five microbes. The antioxidant activity was determined using the free radical 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS). The GC/MS analysis of EO revealed the presence of 86 compounds with a preponderance of oxygenated sesquiterpenes and monoterpene hydrocarbons. Widdrol, β-phellandrene, piperitol, cubedol, α-terpinene, (E)-10-heptadecen-8-ynoic acid methyl ester, citronellyl tiglate, and m-cymene were the major compounds. A comparative profile was established between the EOs constituents of our study with the documented EOs of D. tortuosa and the other Deverra species around the world via agglomerative hierarchical clustering (AHC) and principal components analysis (PCA). The EO showed a substantial allelopathic activity against C. murale, as well as it showed considerable antimicrobial and antioxidant activities. Thereby, the EO of D. tortuosa could be considered as a promising environmental-friendly bioherbicide against weeds. Also, it could be integrated into food preservation due to its potent antimicrobial and antioxidant activities. However, further study is recommended for more characterization of the major compounds and evaluation of their activities, either singular or synergistic, and assess their efficiency and biosafety.

Polyphenols: A Promising Avenue in Therapeutic Solutions for Wound Care

In chronic wounds, the regeneration process is compromised, which brings complexity to the therapeutic approaches that need to be adopted, while representing an enormous loss in the patients’ quality of life with consequent economical costs. Chronic wounds are highly prone to infection, which can ultimately lead to septicemia and morbidity. Classic therapies are increasing antibiotic resistance, which is becoming a critical problem beyond complex wounds. Therefore, it is essential to study new antimicrobial polymeric systems and compounds that can be effective alternatives to reduce infection, even at lower concentrations. The biological potential of polyphenols allows them to be an efficient alternative to commercial antibiotics, responding to the need to find new options for chronic wound care. Nonetheless, phenolic compounds may have some drawbacks when targeting wound applications, such as low stability and consequent decreased biological performance at the wound site. To overcome these limitations, polymeric-based systems have been developed as carriers of polyphenols for wound healing, improving its stability, controlling the release kinetics, and therefore increasing the performance and effectiveness. This review aims to highlight possible smart and bio-based wound dressings, providing an overview of the biological potential of polyphenolic agents as natural antimicrobial agents and strategies to stabilize and deliver them in the treatment of complex wounds. Polymer-based particulate systems are highlighted here due to their impact as carriers to increase polyphenols bioavailability at the wound site in different types of formulations.

Vapors of Volatile Plant-Derived Products Significantly Affect the Results of Antimicrobial, Antioxidative and Cytotoxicity Microplate-Based Assays

Volatile plant-derived products were observed to exhibit broad spectrum of biological effects. However, due to their volatility, results of conventional microplate-based bioassays can be significantly affected by the vapors. With aim to demonstrate this phenomenon, antimicrobial, antioxidant, and cytotoxic activities of three essential oils (Alpinia elegans, Cinnamomum iners, and Xanthostemon verdugonianus), one supercritical CO2 extract (Nigella sativa), and four plant-derived compounds (capsaicin, caryophyllene oxide, 8-hydroxyquinoline, and thymoquinone) were evaluated in series of experiments including both ethylene vinyl acetate (EVA) Capmat sealed and nonsealed microplates. The results clearly illustrate that vapor transition to adjoining wells causes false-positive results of bioassays performed in nonsealed microtiter plates. The microplate layout and a duration of the assay were demonstrated as the key aspects defining level of the results affection by the vapors of volatile agents. Additionally, we reported biological activities and chemical composition of essential oils from A. elegans seeds and X. verdugonianus leaves, which were, according to our best knowledge, analyzed for the first time. Considering our findings, certain modifications of conventional microplate-based assays are necessary (e.g., using EVA Capmat as vapor barrier) to obtain reliable results when biological properties of volatile agents are evaluated.

Chemical Investigation and Screening of Anti-Proliferative Activity on Human Cell Lines of Pure and Nano-Formulated Lavandin Essential Oil

Lavandin essential oil (LEO), a natural sterile hybrid obtained by crossbreeding L. angustifolia × L. latifolia, is mainly composed by active components belonging to the family of terpenes endowed with relevant anti-proliferative activity, which can be enhanced by proper application of nanotechnology. In particular, this study reports the chemical characterization and the screening of the anti-proliferative activity on different human cell lines of pure and nano-formulated lavandin essential oil (EO). LEO and its formulation (NanoLEO) were analyzed by HS/GC-MS (Headspace/Gas Chromatography-Mass Spectrometry) to describe and compare their chemical volatile composition. The most abundant compounds were linalool and 1,8-cineole (LEO: 28.6%; 27.4%) (NanoLEO: 60.4%; 12.6%) followed by α-pinene (LEO: 9.6%; NanoLEO: 4.5%), camphor (LEO: 6.5%; NanoLEO: 7.0%) and linalyl acetate (LEO: 6.5%; NanoLEO: 3.6%). The cytotoxic effects of LEO and NanoLEO were investigated on human neuroblastoma cells (SHSY5Y), human breast adenocarcinoma cells (MCF-7), human lymphoblastic leukemia cells (CCRF CEM), human colorectal adenocarcinoma cells (Caco-2) and one normal breast epithelial cell (MCF10A) by the MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide)-assay. Caco-2, MCF7 and MCF10A normal cells resulted more resistant to the treatment with LEO, while CCRF-CEM and SHSY5Y cells were more sensitive. The antiproliferative effect of LEO resulted amplified when the essential oil was supplied as nanoformulation, mainly in Caco-2 cells. Scanning and transmission electron microscopy investigations were carried out on Caco-2 cells to outline at ultrastructural level possible affections induced by LEO and NanoLEO treatments.

Chemical composition and antimicrobial activity of essential oils obtained from leaves and flowers of Salvia hydrangea DC. ex Benth

The majority of essential oils obtained from vascular plants have been demonstrated to be effective in treating fungal and bacterial infections. Among others, Salvia hydrangea is an endemic half-shrub belonging to the Lamiaceae family that has been widely used from ancient times in Iranian traditional medicine. The aim of this study was to compare the composition and antimicrobial properties of essential oils obtained from leaves or flowers of this plant, collected from the Daran region of Iran during June 2018. The oils were obtained using Clevenger apparatus, their composition was evaluated by means of gas chromatography/mass spectrometry (GC/MS) and the antimicrobial properties were assayed by measuring inhibition halos, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). The yield of leaf oil was ~ 0.25% and that of flower oil was ~ 0.28%. Oil composition was affected by the part of the plants used: the most abundant bioactives contained in leaf essential oil were (+)-spathulenol (16.07%), 1,8-cineole (13.96%), trans-caryophyllene (9.58%), β-pinene (8.91%) and β-eudesmol (5.33%) and those in flower essential oil were caryophyllene oxide (35.47%), 1,8-cineole (9.54%), trans-caryophyllene (6.36%), β-eudesmol (4.11%), caryophyllenol-II (3.46%) and camphor (3.33%). Both the oils showed a significant inhibitory and lethal effect on the Gram-negative bacteria Pseudomonas aeruginosa (MIC ~ 16 µg/mL), Shigella dysenteriae and Klebsiella pneumoniae (MIC ~ 62 µg/mL). Therefore, the essential oils obtained from both leaves and flowers of S. hydrangea may have potential application as bactericidal agents against some bacteria.

Thymol and Thyme Essential Oil-New Insights into Selected Therapeutic Applications

Thymol (2-isopropyl-5-methylphenol) belongs to the phenolic monoterpenes and mostly occurs in thyme species. It is one of the main compounds of thyme essential oil. Both thymol and thyme essential oil have long been used in traditional medicine as expectorant, anti-inflammatory, antiviral, antibacterial, and antiseptic agents, mainly in the treatment of the upper respiratory system. The current search for new directions of biological or therapeutic activities of natural plant substances with known structures includes thyme essential oil and thymol. Novel studies have demonstrated their antibiofilm, antifungal, antileishmanial, antiviral, and anticancer properties. Also, their new therapeutic formulations, such as nanocapsules containing these constituents, can be beneficial in medicinal practice and create opportunities for their extensive use. Extensive application of thymol and thyme essential oil in the healthcare sector is very promising but requires further research and analysis.