Bark Essential Oil Research Articles

Evaluation of Modified Atmosphere Packaging in Combination with Active Packaging to Increase Shelf Life of High-in Beta-Glucan Gluten Free Cake.

Modified atmosphere packaging and active packaging were combined to prolong the shelf life and quality of the clean label, gluten-free (GF), yeast-leavened cakes enriched in oat fiber preparation. Star anise, cinnamon bark, and clove essential oils were used as emitters of active substances. The following concentrations of gases were chosen: 0% CO2/100%/N2 (MAP1), 60% CO2/40% N2 (MAP2), and approx. 78% N2/21% O2/0.04% CO2 (ATM). Microbiological and physicochemical analyses were conducted. GF cakes were stored for 14 days (analysis in 0, 7, and 14 days). The results showed a decrease in moisture content and lightness of crumb and an increase in hardness. EOs significantly (p ≤ 0.05) slowed down the growth of microorganisms regardless of the type of gas mixture. However, the best bacteriostatic effect was in MAP2. The content of beta-glucan did not change throughout the storage time. Generally, the best results were obtained with the combination of MAP and active packaging—60% of CO2 and 40% of N2—where cinnamon or clove essential oils were used.

Antimicrobial activities of plant essential oil vapours against Acidovorax citrulli and Xanthomonas campestris on Cucurbitaceae, Brassicaceae and Solanaceae seeds.

This study was done to develop a seed decontamination treatment for organic seeds against plant pathogens (Acidovorax citrulli and Xanthomonas campestris) using essential oil (EO) vapours without affecting the seeds' germination rate. By using a diffusion assay and determining minimum inhibitory and lethal concentrations, we screened two EO vapours which were most inhibitory to A. citrulli (cinnamon bark and garlic EO vapours) and X. campestris (onion and garlic EO vapours). After 48h of exposure to EO vapours at 25°C and 43% or 85% relative humidity (RH), no significant decrease (p>0.05) in germination rates was observed compared with those of control seeds. It was observed that EO vapour treatment at 25°C and 43% or 85% RH for 48h caused significant population reductions (p≤0.05) (ca. 0.3-2.6log colony forming unit/g) compared to those of untreated seeds. Applications of EO vapours showed significant (p≤0.05) antimicrobial effects against A. citrulli and X. campestris on both laboratory mediums and plant seeds without decreasing the germination rate of seeds. This study provides useful information for the development of natural seed sterilization treatments using EO vapours.

Agathis robusta Bark Essential Oil Effectiveness against COVID-19: Chemical Composition, In Silico and In Vitro Approaches.

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV2), the causative agent of Coronavirus Disease 2019 (COVID-19), has seriously threatened global health. Alongside the approved vaccines, the discovery of prospective anti-COVID-19 drugs has been progressively targeted. Essential oils (EOs) provide a rich source of compounds with valuable antiviral activities that may contribute as effective agents against COVID-19. In this study, the EO of Agathus robusta bark was investigated for its chemical composition and its antiviral activity against SARS-CoV2. Overall, 26 constituents were identified by gas chromatography-mass spectrometry (GC-MS) analysis. α-Pinene, tricyclene, α-terpineol, limonene, d-camphene, trans-pinocarveol, α-phellandren-8-ol, L-β-pinene and borneol were the major components. In silico docking of these constituents against viral key enzymes, spike receptor-binding domain (RBD), main protease (Mpro) and RNA-dependent RNA polymerase (RdRp), using Molecular Operating Environment (MOE) software revealed good binding affinities of the components to the active site of the selected targets, especially, the RBD. In Vitro antiviral MTT and cytopathic effect inhibition assays demonstrated a promising anti SARS-CoV2 for A. robusta bark EO, with a significant selectivity index of 17.5. The results suggested using this EO or its individual components for the protection against or treatment of COVID-19.

Characterization of essential oil composition of Juglans regia bark, comparison of secondary metabolites and biological activities of its extracts

Aromatic and medicinal plants form a reservoir of active molecules; among them, Juglans regia is a plant of the Juglandaceae family, and it is used thanks to its medicinal properties. The present study was conducted to investigate the secondary metabolite content and biological activities of the infusion, methanolic extracts, and essential oil of the bark essential oil (EO) of Juglans regia harvested from North Tunisia, as well as its chemical composition. Essential oil, infusion, and methanolic extracts were prepared. Identification of essential oil composition was determined using GC-MS. Phenolic content, antioxidant, and antimicrobial activities were evaluated with the colorimetric method. The obtained data indicate that J. regia is very abundant in bioactive compounds. The infusion extract of J. regia bark has been found to contain elevated amounts of phenolic compounds. The infusion extract showed stronger antioxidants and radical scavenging action than methanol. The studied methanolic extract displayed antimicrobial activity against all ten tested microbial strains but with variable degrees according to the microbial strain. The infusion extract, instead, was inactive. The use of gas chromatography coupled with mass spectrometry (GC-MS) revealed the existence of 34 components in the bark (EO). The main compounds were: carvacrol (13.82%), isoeugenol (13.71%), β-caryophyllene (7.81%), 1,8-cineole (8.60%), and bornyl acetate (7.13%). Our results suggest that Juglans regia is a natural source of potent antioxidants and antimicrobials and may be useful as preventive agents in some diseases.

Research Note: Preservative effect of compound spices extracts on marinated chicken

The antimicrobial effect of 21 nature spices essential oils (EOs) on marinated chicken was investigated and response surface analysis was applied to obtain the optimal combination. Cassia bark EO, cinnamon EO, tea tree EO, and angelica EO had the best antibacterial effect. Their inhibition zone diameters (IZD) were 23 mm, 21 mm, 15 mm, and 12 mm, and their minimal bactericidal concentrations (MBC) were 1.25 μL/mL, 1.25 μL/mL, 10.00 μL/mL, 20.00 μL/mL. Using the Box-Behnken Design model, with the minimum total number of spoilage bacteria as the evaluation index, the optimal mixture was cassia bark EO 2.40 μL/mL, cinnamon EO 1.00 μL/mL, tea tree EO 3.50 μL/mL, and angelica EO 9.00 μL/mL. Compared with the control group, the total number of colonies was reduced by 1.3 log unites at the 12th sampling day, and the protein degradation process was slowed down owing to the preservative addition. These results indicate the potential application of nature extracts in chicken and other meat preservation.

Cytotoxicity and Apoptosis Induction of 6,7-Dehydroroyleanone from Taiwania cryptomerioides Bark Essential Oil in Hepatocellular Carcinoma Cells.

The objective of the present study is to evaluate the cytotoxicity of Taiwania cryptomerioides essential oil and its phytochemical on the Hep G2 cell line (human hepatocellular carcinoma). Bark essential oil has significant cytotoxicity to Hep G2 cells, and S3 fraction is the most active fraction in cytotoxicity to Hep G2 cells among the six fractions. The diterpenoid quinone, 6,7-dehydroroyleanone, was isolated from the active S3 fraction by bioassay-guided isolation. 6,7-Dehydroroyleanone exhibited significant cytotoxicity in Hep G2 cells, and the efficacy of 6,7-dehydroroyleanone was better than the positive control, etoposide. Apoptosis analysis of Hep G2 cells with different treatments was characterized via flow cytometry to confirm the cell death situation. Etoposide and 6,7-dehydroroyleanone could induce the apoptosis in Hep G2 cells using flow cytometric assay. Results revealed 6,7-dehydroroyleanone from T. cryptomerioides bark essential oil can be a potential phytochemical to develop the anticancer chemotherapeutic agent for the treatment of the human hepatocellular carcinoma.

Anti-Mold Effectiveness of a Green Emulsion Based on Citrus aurantium Hydrolate and Cinnamomum zeylanicum Essential Oil for the Modern Paintings Restoration.

A modern painting is characterized by multi-material bases extremely exposed to biodeteriogenic attacks. The aim of this work was to test the antifungal effectiveness of a natural, eco-friendly, and safe emulsion based on Citrus aurantium L. var. amara hydrolate and Cinnamomum zeylanicum Blume (from bark) essential oil, named “Zeylantium green emulsion” (Zege), on modern paintings. Colored unaged and aged canvas samples, performed with modern techniques (acrylic, vinylic and alkyd), were used to test in vitro both the antifungal effectiveness of Zege and its impact on the chemical–physical characteristics. Microbiological tests were performed according to the EUCAST international guidelines. pH measurements and colorimetric analysis were performed on unaged and aged canvases before and after Zege spray treatment. Finally, in situ tests were performed using the spray emulsion on canvas samples obtained from Ilaria Margutti’s modern artwork, which had been colonized by molds. Microbiological tests on canvas prototypes showed a time- and dose-dependent effectiveness of the Zege spray. None of the techniques underwent relevant changes in pH. Only the acrylic colors were unaffected in the colorimetric analysis, among all colored unaged or aged canvases. Tests made with modern artwork samples confirmed the in situ antifungal effectiveness. The Zege spray showed encouraging results in regard to the use of this formulation in the restoration of modern paintings.

FORMULATION OF CINNAMON BARK ESSENTIAL OIL GEL AS MOSQUITO REPELLENT

Objective: The purpose of this research is to prepare a cinnamon bark essential oil gel preparation, determines the physical characteristic and physical stability during storage, and examines the activity of mosquito repellent from the best gel preparation. Methods: The formulations of gel were made with variations in the concentration of Carbopol 940 (0.5%, 1.5%, and 2%) contain 1% of cinnamon bark essential oil. The gel evaluated physical characteristics and physical stability. The parameters of organoleptic, homogeneity, and pH are analyzed descriptive, while the viscosity, the spreadability, and the gel adhesion were analyzed using one-way ANOVA at the level of confidence of 95%. The best gel tested its effectiveness as compared to the negative control and product innovator (which used DEET as an active compound) as a positive control. The activity of repellent was determined by an Aedes aegypti mosquito for 6 h with 2 hands respondents. The effectiveness of repellent protection is calculated by the percentage of protection power. Results: The studies showed that all the gel preparations qualified the organoleptic, homogeneity, and pH parameters. The viscosity, gel adhesion, and spreadability are also stable during storage. Conclusion: Based on the results, the best gel is the formula I which has mosquito repellent activity effective for 6 h like DEET.

THE CHARACTERIZATION OF PAPER COATED WITH ESSENTIAL OILS AND THE EVALUATION OF ITS USE IN THE PACKAGING OF BEEF

Background. Active packaging improves the microbial safety and sensory properties of food, extending shelf life of the stored product. Raw beef is an example of food prone to microbial contamination. Listeria monocytogenes and Escherichia coli are commonly found in raw meat, and their presence can lead to food poisoning of consumers worldwide. Cellulose paper is commonly used to wrap raw meat. Active paper can be obtained by coating the paper with antimicrobial agents. Plant-derived essential oils can act as a natural preservative. The aim of the study is the characterization of paper coated with cinnamon bark essential oil, cinnamon leaf essential oil and clove essential oil, as well as the evaluation of its use in packing raw beef. Results and conclusion. Coating paper with cinnamon bark essential oil and clove essential oil changed the color of paper to yellow and white compared to the blue and white colors of the control sample and paper enriched with cinnamon leaf essential oil. Coating the paper affected its structure. Essential oils penetrated the voids in the paper and filled the pores. Wrapping raw beef in the coated paper reduced the growth of Listeria innocua and E. coli during refrigerated storage. Wrapping beef in the coated paper did not affect the beef color during 72-hour storage. The results obtained indicate the possibility of using paper coated with essential oils as active packaging for raw beef

Antifungal and Antitoxigenic Effects of Selected Essential Oils in Vapors on Green Coffee Beans with Impact on Consumer Acceptability.

The main objective of this study is to evaluate the effect of selected essential oils thyme chemotype linalool (Thymus zygis L.), thyme chemotype tymol (Thymus vulgaris L.), eucalyptus (Eucalyptus globulus Labill.), lavender (Lavandula angustifolia Mill.), mint (Mentha piperita L.), almond (Prunbus dulcis Mill.), cinnamon bark (Cinnamomum zeylanicum Nees), litsea (Litsea cubeba Lour. Pers), lemongrass (Cympogon citrati L. Stapf), and ginger (Zingiber officinalis Rosc.) in the vapor phase on growth, sporulation, and mycotoxins production of two Aspergillus strains (Aspergillus parasiticus CGC34 and Aspergillus ochraceus CGC87), important postharvest pathogens of green and roasted coffee beans. Moreover, the effect of the essential oils (EOs) on the sensory profile of the coffee samples treated with EOs was evaluated. The major components of tested EOs were determined by gas chromatography and mass spectrometry (GC–MS) and gas chromatography with flame ionization detector (GC-FID). The results showed that almond, cinnamon bark, lemongrass, and litsea EOs are able to significantly inhibit the growth, sporulation, and mycotoxins production by toxigenic fungi. Sensory evaluation of coffee beans treated with EOs before and after roasting showed that some EOs (except lemongrass and litsea) do not adversely affect the taste and aroma of coffee beverages. Thus, application of the vapors of almond and cinnamon EOs appears to be an effective way that could serve to protect coffee during its transport and storage from toxigenic fungi.

The variation in essential oils composition, phenolic acids and flavonoids is correlated with changes in antioxidant activity during Cinnamomum loureirii bark growth

Cinnamomum loureirii is one of the most important medicinal and aromatic plants. It is used by the food, perfumery, cosmetic, and pharmaceutical industries. The objective of this study was to examine the relationships between the chemical composition and antioxidant activity of essential oil (EOs) and ethanol extracts from 10 samples of the bark from C. loureirii trees (6–15 years old). Obtained results showed that C. loureirii bark EO content at 12–15 years old had high oil yields (4.52–5.48%). The major components in the EOs were trans-cinnamaldehyde (50.2–92.9%) and α-copaene (0.5–21.3%). The highest content of trans-cinnamaldehyde in bark EOs was obtained from 10 to 12-year-old trees, while the highest content of α-copaene was obtained at 13–15 years. The highest total phenolic (429.85 and 474.45 mg TAE /g DW) and total flavonoid contents (85.54 and 102.80 mg RE /g e DW) were obtained from the 13- to 14-year-old trees. Our results indicated that the EO and ethanol extract of 13- to 14-year-old bark showed the strongest antioxidant properties. Moreover, GC–MS, PCA and correlation analysis indicated that the changes in α-copaene, beta-caryophyllene, τ-muurolene, γ-muurolene, δ-cadinene and τ-muurolol were positively correlated with the changes in antioxidant activity in oils. Meanwhile, procyanidin B2 and hyperoside were the main contributors to the antioxidant activity of the ethanol extract from C. loureirii bark. This study is the first one that report the antioxidant potential and phenolic profile of C. loureirii plant. These results provide reference information for the rational utilization of C. loureirii resources and the harvest of C. loureirii bark as medicinal materials during the optimal period.

The Chemical Composition and Biological Activities of Essential Oils from Zanthoxylum rhetsa Grown in Son La, Northwest Vietnam

Essential oils (EOs) from the stem barks, leaf petioles, fruit petioles, fresh leaves, and fresh and dried fruits of Zanthoxylum rhetsa were extracted by hydrodistillation. The volatile compounds of the products were analyzed by gas chromatography (GC-FID) and gas chromatography/mass spectrometry (GC/MSD). Monoterpene hydrocarbons formed the predominant fraction of all six EO samples, of which sabinene is one of the major components (from 12.37% to 41.13%). For the leaf petiole EO, limonene (25.01%), sabinene (14.56%), and linalool (12.63%) are the major constituents, while the main constituents of fruit petiole EO were terpinolene (19.66%), terpinen-4-ol (19.07%), and sabinene (17.83%). The major components of stem bark EO are terpinen-4-ol (18.23%), sabinene (12.37%), α-phellandrene (7.34%), β-phellandrene (6.32%), and γ-terpinene (6.12%), while sabinene (38.35%), terpinen-4-ol (13.71%), γ-terpinene (6.47%), and limonene (6.02%) are the major constituents of fresh leaf EO. For the EOs of dried fruits and fresh fruits, sabinene, terpinolene, limonene, and terpinen-4-ol are the major constituents. The essential oils were also tested for their cytotoxic and antimicrobial activities. The results revealed that six EOs at concentrations of 50 μg/mL exhibited inhibitory activity against at least one tested cancer cell line but were nontoxic on Vero normal cells. Most EOs showed moderate antimicrobial activity against F. oxysporum; however, there were no obvious activity against B. subtilis and S. aureus.

Volatile Oil Profiles of Aerial and Underground Plant Parts of Annona muricata L. (Annonaceae) Grown in Goa, India

Annona muricata Linn illustrates an extensive spectrum of ethno-pharmacological applications. The biogenic occurrence of essential oils along with other active metabolites is responsible for the bio-active functionalities offered by various plant parts of A. muricata. Owing to considerable intra-species and intra-organ diversity in essential oil compositions; the objective of this study was to validate and assess the volatile oil profiles of A. muricata plant parts cultivated in Goa, India. The essential oils were derived by hydro-distilling pulverized dried-plant samples namely rind, pulp, seed, leaf, bark and roots using glass Clevenger- type device. The quantity of essential oil yield varied substantially, depending on the plant organs from which the samples were isolated. GC/MS chemical profiling of plant organs revealed largest proportion of γ-sitosterol (28.76 %), (Z)-11-hexadecenal, 1-chlorononadecane and α-gurjunene in pulp, seed, bark and root essential oils respectively. Phytol, on the other hand, was the most prevalent essential oil component in both the rind (47.16 %) and the leaf (37.7 %). Whereas, the sole volatile found in all plant parts analysed was β-caryophyllene with greatest proportion in roots trailed by leaf and lowest in seed. Essential oils were found in significantly diverse amounts and sorts in various parts of A. muricata, including the rind, pulp, seed, leaf, bark, and root. Cluster analysis of essential oil composition from six different plant sections revealed major chemical heterogeneity, with rind-leaf and pulp-root developing a comparatively good relationship. Thus, the present study indicates that the essential oils isolated from various organs of A. muricata form a unique amalgam of bioactive metabolites that could be used as a potential medicinal source.

Comparative Evaluation of Apoptosis Induction Using Needles, Bark, and Pollen Extracts and Essential Oils of Pinus eldarica in Lung Cancer Cells

Lung cancer is one of the leading causes of cancer-related mortality worldwide. Although effective clinical drugs for treating advanced stages are available, interest in alternative herbal medicines has gained momentum. Herbal extracts are potent antioxidants that reportedly inhibit the growth of various cancer cell lines. In the present study, we investigated the effects of essential oils and hexane, methanolic, and aqueous extracts, obtained from various parts (bark, needles, and pollen) of Pinus eldarica against human lung cancer (A549) cells. First, the DPPH radical scavenging activities of P. eldarica extracts and essential oils were examined, which revealed that methanolic extracts presented higher antioxidant activity than the other extracts and essential oils. Next, A549 cells were exposed to various concentrations of the extracts and essential oils for 48 h. P. eldarica extracts/essential oil-treated lung cancer cells demonstrated a significant decrease in cell proliferation, along with an induction of apoptotic cell death, particularly, the pollen hexane extract, bark essential oil, and methanolic needle extract showed superior results, with IC50 values of 31.7, 17.9, and 0.3 μg/mL, respectively. In the cell cycle analysis, treatment of A549 cells with the methanolic needle and pollen hexane extracts led to apoptosis and accumulation of cells in the sub-G1 phase. Further, exposure to the bark essential oil and methanolic needle extract decreased the cell population in the G2/M phase. Notably, treatment with the pollen hexane extract, bark essential oil, and methanolic needle extract resulted in caspase-3 activation, poly (ADP-ribose) polymerase cleavage, Bcl-2 downregulation, and Bax and p53 regulation in A549 cells. Furthermore, these extracts and essential oils decreased the migration, and colony formation of A549 cells. These findings provide experimental evidence for a new therapeutic effect of P. eldarica against human lung cancer and suggest P. eldarica as a potential chemopreventive natural resource for developing novel cancer therapeutics.

Synergistic Antimicrobial Activities of Combinations of Vanillin and Essential Oils of Cinnamon Bark, Cinnamon Leaves, and Cloves.

Plant bioactive compounds have antimicrobial and antioxidant activities that allow them to be used as a substitute for synthetic chemical additives in both food and food packaging. To improve its sensory and bactericidal effects, its use in the form of effective combinations has emerged as an interesting possibility in the food industry. In this study, the antimicrobial activities of essential oils (EOs) of cinnamon bark, cinnamon leaves, and clove and the pure compounds vanillin, eugenol, and cinnamaldehyde were investigated individually and in combination against Listeria monocytogenes and Escherichia coli O157:H7. The possible interactions of combinations of pure compounds and EOs were performed by the two-dimensional checkerboard assay and isobologram methods. Vanillin exhibited the lowest antimicrobial activity (MIC of 3002 ppm against L. monocytogenes and 2795 ppm against E. coli O157:H7), while clove and cinnamon bark EOs exhibited the highest antimicrobial activity (402–404 against L. monocytogenes and 778–721 against E. coli O157:H7). For L. monocytogenes, pure compound eugenol, the main component of cinnamon leaves and clove, showed lower antimicrobial activity than EOs, which was attributed to the influence of the minor components of the EOs. The same was observed with cinnamaldehyde, the main component of cinnamon bark EO. The combinations of vanillin/clove EO and vanillin/cinnamon bark EO showed the most synergistic antimicrobial effect. The combination of the EOs of cinnamon bark/clove and cinnamon bark/cinnamon leaves showed additive effect against L. monocytogenes but indifferent effect against E. coli O157:H7. For L. monocytogenes, the best inhibitory effects were achieved by cinnamon bark EO (85 ppm)/vanillin (910 ppm) and clove EO (121 ppm)/vanillin (691 ppm) combinations. For E. coli, the inhibitory effects of clove EO (104 ppm)/vanillin (1006 ppm) and cinnamon leaves EO (118 ppm)/vanillin (979 ppm) combinations were noteworthy. Some of the tested combinations increased the antimicrobial effect and would allow the effective doses to be reduced, thereby offering possible new applications for food and active food packaging.

Chemical Composition, Antioxidant, Anti-inflammatory and Anticancer Activities of Bark Essential Oil of Cryptocarya amygdalina from India

Several species of Cryptocarya (Lauraceae) are traditionally used in folk medicines for the treatment of various diseases and disorders in tropical and subtropical countries. The essential oil extracted from the leaves and barks of Cryptocarya species are reported to possess antimicrobial, insecticidal, antioxidant, and antitumoral activities. However, there are no scientific reports on the biological activity of essential oil extracted from the tropical Asiatic species Cryptocarya amygdalina. The present study was undertaken to determine the chemical composition and evaluate the antioxidant, anticancer, and anti-inflammatory activities of bark essential oil of C. amygdalina. A total of 57 constituents accounting for 99.05 % of the total essential oil content were identified by GC/MS. The bark essential oil was dominated by sesquiterpene hydrocarbons (78.71 %) with β- caryophyllene (34.77 %), α-copaene (14.26 %), bicyclogermacrene (7.65 %), and δ-cadinene (4.42 %) as the major constituents. The essential oil exhibited good radical scavenging activity against DPPH, ABTS, and Reducing power assay with half-maximal inhibitory concentration (IC50) values of 6.97 ± 0.24, 1.28 ± 0.07, and 9.23 ± 0.34 μg/mL, respectively compared to ascorbic acid and BHT. The Pearson’s coefficient analysis showed a significant correlation between TPC, TFC, and an antioxidant assay of C. amygdalina essential oil. The essential oil also showed potent cytotoxicity against human colon (HCT-116) and ovarian (PA-1) cancer cell lines with IC50 values lesser than 50 μg/mL in both cases. Besides, this bark essential oil at 50 μg/mL concentration exhibited significant anti-inflammatory activity in lipopolysaccharide-activated RAW 264.7 macrophages by inhibiting nitric oxide production.

Synergistic antimicrobial activities of plant essential oils against Listeria monocytogenes in organic tomato juice

The objective of this study was to identify combinations of plant essential oils (EOs) that have synergistic antilisterial effects in raw organic tomato juice. Among the EOs approved for addition to organic foods in the Republic of Korea, twenty-four EOs were screened for antilisterial activity using a well diffusion assay. Six EOs (cinnamon bark, lemon, lemongrass, oregano, peppermint, and thyme thymol) showed relatively strong inhibitory activities (diameter of zone of inhibition ≥ 35.0 mm) against Listeria monocytogenes. The minimal inhibitory concentrations (MICs) and minimal lethal concentrations (MLCs) of these EOs against L. monocytogenes in a laboratory medium were determined. Oregano and thyme thymol EOs had the lowest MIC (0.3125 μL/mL), and cinnamon bark, oregano, and thyme thymol EOs had the lowest MLC (0.6250 μL/mL). The synergistic antilisterial activities of combinations of EOs in a laboratory medium were determined using a modified checkerboard assay. Combinations of cinnamon bark and lemongrass EOs, cinnamon bark and thyme thymol EOs, and lemongrass and thyme thymol EOs showed synergistic antilisterial activities (fractional inhibitory concentration index = 0.5). A combination of cinnamon bark and thyme thymol EOs was tested for synergistic antilisterial activity in tomato juice incubated at 10 °C and 25 °C for up to 48 h. The number of L. monocytogenes in juice treated with combined EOs at a total concentration of 0.3125 μL/mL decreased significantly (P ≤ 0.05) compared to numbers in juice treated with 0.3125 μL/mL of either cinnamon bark EO or thyme thymol EO alone. These observations show the potential for using combinations of EOs for controlling L. monocytogenes in juice released from cut or bruised raw organic tomatoes intended for consumption in food service or home settings.

Chemistry of leaves, bark, and essential oils from Ocotea diospyrifolia and anti-inflammatory activity – Dual inhibition of edema and neutrophil recruitment

Species from the Ocotea genus have shown scientific evidence of anti-inflammatory activity through a promising mechanism of action. This study is the first in vivo evaluation of the anti-inflammatory potential and mechanism of action of extracts and essential oils from the leaves and bark of O. diospyrifolia. We isolated and identified compounds from the leaf and bark extracts and chemically characterized these extracts by ultra high-performance liquid chromatography–high-resolution mass spectrometry (UPLC-HRMS). Additionally, the essential oils were characterized by gas chromatography–mass spectrometry (GC–MS). Nine compounds (1-9) were isolated; among them, a new compound (9) was elucidated as 6aS,7S-(-)-11-hydroxy-7-methoxy-1,2-methylenedioxy-aporphine, named as diospirifoline. The aporphine substitution pattern found in diospirifoline, with substitution at C-7, was identified for first time in the Ocotea genus. Mururin A(1) and salsoline (5) were also isolated for the first time in this genus. The biosynthetically linked alkaloids coclaurine (7), reticuline (6), and isoboldine (8) were found to be 6aR-(-) isomers, which is different from the 6aS-(+) isomers that are most often found in other Ocotea spp. UPLC-HRMS analysis detected various classes of compounds in the leaf and bark extracts, such as flavonolignans, flavonoids, chlorogenic acids, alkaloids, and many other unidentified compounds. The GC–MS analysis revealed that both leaf and bark essential oils contained α-phellandrene as the major compound and that the chemotaxonomic marker of the Lauraceae family, the phenylpropanoid safrole, was not detected. Furthermore, some of the compounds identified in the extracts and essential oils have known anti-inflammatory activities, such as 5-caffeoylquinic acid, quercitrin, α-humulene, and (E)-caryophyllene. Indeed, the leaf extract, its ethyl acetate fraction, and the essential oils showed in vivo anti-inflammatory activity through the dual inhibition of edema and neutrophil recruitment, suggesting the inhibition of main inflammatory pathways. This mechanism of action is associated with a better efficacy and safety profile than that of the currently available anti-inflammatory drugs. The extract and essential oils of O. diospyrifolia showed high chemical diversity and a promising anti-inflammatory mechanism of action; thus, clearly indicating that this species should be further investigated.

Chemical Composition and Cytotoxic Activity of the Fractionated Trunk Bark Essential Oil from Tetraclinis articulata (Vahl) Mast. Growing in Tunisia.

The aim of the present research was to determine the chemical composition and the cytotoxic effects of Tetraclinis articulata trunk bark essential oil (HEE) obtained by steam distillation and five fractions obtained by normal phase silica chromatographic separation. Chemical analysis allowed the identification of 54 known compounds. Relatively high amounts of oxygenated sesquiterpenes (44.4–70.2%) were detected, mainly consisting of caryophyllene oxide (13.1–26.6%), carotol (9.2–21.2%),14-hydroxy-9-epi-(E)-caryophyllene (3.2–15.5%) and humulene epoxide II (2.6–7.2%). The cytotoxic activity against human mammary carcinoma cell lines (MDA-MB-231) and colorectal carcinoma cell lines (SW620) of the essential oil and its fractions were assessed. All the samples displayed moderate to weak activity compared to 5-fluorouracil. The colorectal carcinoma cell line was relatively more sensitive to the essential oil and its fractions compared to the breast cancer cell line, showing IC50 values from 25.7 to 96.5 μg/mL. In addition, the essential oil and its fraction E.2 revealed a cytotoxic activity against colorectal carcinoma cell line, with IC50 values lower than 30 μg/mL. This is the first report on the chemical composition and cytotoxic activity of the trunk bark essential oil of T. articulata.

Essential Oil from Bark of Aniba parviflora (Meisn.) Mez (Lauraceae) Reduces HepG2 Cell Proliferation and Inhibits Tumor Development in a Xenograft Model.

Aniba parviflora (Meisn.) Mez (Lauraceae) is an aromatic plant of the Amazon rainforest, which has a tremendous commercial value in the perfumery industry; it is popularly used as flavoring sachets and aromatic baths. In Brazilian folk medicine, A. parviflora is used to treat victims of snakebites. Herein, we analyzed the chemical composition of A. parviflora bark essential oil (EO) and its effect on the growth of human hepatocellular carcinoma HepG2 cells in vitro and in vivo. EO was obtained by hydrodistillation and characterized by GC-MS and GC-FID. The main constituents of EO were linalool (16.3±3.15), α-humulene (14.5±2.41 %), δ-cadinene (10.2±1.09 %), α-copaene (9.51±1.12 %) and germacrene B (7.58±2.15 %). Initially, EO's cytotoxic effect was evaluated against five cancer cell lines (HepG2, MCF-7, HCT116, HL-60 and B16-F10) and one non-cancerous one (MRC-5), using the Alamar blue method after 72 h of treatment. The calculated IC50 values were 9.05, 22.04, >50, 15.36, 17.57, and 30.46 μg/mL, respectively. The best selectivity was for HepG2 cells with a selective index of 3.4. DNA Fragmentation and cell cycle distribution were quantified in HepG2 cells by flow cytometry after a treatment period of 24 and 48 h. The effect of EO on tumor development in vivo was evaluated in a xenograft model using C.B-17 SCID mice engrafted with HepG2 cells. In vivo tumor growth inhibition of HepG2 xenograft at the doses of 40 and 80 mg/kg were 12.1 and 62.4 %, respectively.