Biological activities of the essential oils and methanol extract of Origanum vulgare ssp. vulgare in the Eastern Anatolia region of Turkey

Chemical Composition, Biological Activity, and Potential Uses of Oregano (Origanum vulgare L.) and Oregano Essential Oil

Medicinal aromatic plants (MAPs) are a rich and diverse source of traditional and modern medicines. Aromatic plants contain valuable essential oils that exhibit numerous biological activities. Essential oils are used in pharmaceutical production, cosmetics, and food preservation to ensure the microbiological stability of products. Plants from the Lamiaceae family, including Origanum vulgare L., are a source of raw materials with antimicrobial and antioxidant properties, and they can be utilized in the production of new drugs and other bioproducts. Oregano is an example of a plant with great potential, known for its traditional health-related and culinary applications and its growing significance in the production of medicines, cosmetics, antiseptics, and preservatives. This work aims to consolidate the current research results on the occurrence, acquisition, use, and medicinal and dietary value of common oregano and oregano essential oil. The obtained results indicate that oregano is a valuable medicinal and culinary plant, serving as a source of natural antiseptics and protective agents. Oregano essential oil, rich in thymol and carvacrol, has a number of health-promoting properties. These compounds (also present in extracts) exhibit significant antioxidant, anti-inflammatory, antiangiogenic, anticancer, and antimicrobial activities. The research findings highlight the promising role of these compounds as potential structures in the search for new antimicrobial and antibiofilm agents.

Antioxidant, insecticidal, antifeedant, and repellent activities of oregano (Origanum vulgare)

This study aimed to assess the antioxidant capacity, the insecticidal, feeding deterrence, repellent effects against Tribolium confusum of the essential oil (EO) and the organic extracts (ME) of Origanum vulgare. The chemical composition of the EO revealed the presence thirty-nine components dominated by carvacrol (81%). With respect to the EO, the ME acted as a potent free radical scavenger with IC50 values of 0.127 and 0.058 mg/mL, respectively. The EO exhibited the most significant toxicity compared to the ME with a mortality of 62 and 20% at 0.08 µL/insect after 24h whereas the EO expressed the highest repellency compared to the ME with a PR of 70 and 38% after 24h. As for feeding deterrence, both samples influenced all nutritional indexes. The findings found in this work might help in the promotion of oregano as natural antioxidant, antifeedant, repellent and insecticide as an alternative to conventional harmful ones.

GC-MS Characterization and Bioactivity Study of Eucalyptus globulus Labill. (Myrtaceae) Essential Oils and Their Fractions: Antibacterial and Antioxidant Properties and Molecular Docking Modeling

BACKGROUND/OBJECTIVES

Eucalyptus globulus is a medicinal plant extensively used by the Moroccan population for treating a range of illnesses, especially respiratory conditions.

METHODS

This study aimed to assess the antioxidant and antibacterial properties of E. globulus essential oil and its individual fractions (F1, F2, and F3). Antioxidant activity was evaluated through iron-reducing power, 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assays. Antibacterial activity was tested using disk diffusion and dilution methods, supported by molecular docking studies. Furthermore, GC-MS analysis was conducted on the essential oil and its individual fractions.

RESULTS

GC-MS analysis identified the major compounds in the essential oil and its fractions as eucalyptol (62.32-42.60%), globulol (5.9-26.24%), o-cymene (6.89-24.35%), cryptone (7.10-15.95%), terpinen-4-ol (2.43-15.24%), and α-pinene (2.46-7.89%). Fraction F3 displayed the highest antioxidant activity in DPPH (IC50 = 3.329 ± 0.054 mg/mL) and ABTS assays (IC50 = 3.721 ± 0.027 mg/mL), while fraction F2 was most effective in the FRAP assay (IC50 = 1.054 ± 0.008 mg/mL). The essential oil and its fractions also showed antibacterial activity against Staphylococcus aureus, Staphylococcus epidermidis, Klebsiella pneumoniae, Enterobacter cloacae, Escherichia coli, and Acinetobacter baumannii. Molecular docking further corroborated these findings, supporting both antioxidant and antibacterial activities.

CONCLUSIONS

The present findings demonstrate the antioxidant and antimicrobial properties of Eucalyptus globulus essential oil and its fractions, underscoring the need for further research to confirm their medicinal potential and explore pharmaceutical applications.

In vivo evaluation by oral administration of chitosan combined with bioactive glass against cadmium-induced toxicity in rats

Bioactive glass and chitosan are biomaterials widely used for orthopedic applications, notably as bone grafts. Although these biomaterials show promising therapeutic properties, no research has yet examined their potential for oral administration in soft tissue protection, particularly against metal toxicity. The aim of our study was to evaluate the potential of chitosan from cuttlefish (CHS) bone combined with bioactive glass (BG) against Cadmium-induced toxicity in rats. Cadmium (Cd), a heavy metal that accumulates in tissues, causes various disorders. Experiments were carried out on rats intoxicated acutely by oral administration of Cd (20 mg/kg body weight) and/or concomitantly with oral administration of CHS/BG (100 mg/kg body weight) for 7 days. Using pathophysiological and biochemical tests, we evaluated the detoxifying effect of orally administered CHS/BG against Cd toxicity. Our results showed, for the first time, a significant detoxifying effect of CHS/BG against Cd-induced toxicity in rats. Treatment with CHS/BG protected rats against the harmful effects of Cd by reducing lipid peroxidation levels and enhancing antioxidant enzyme activities. In addition, it helped restore phosphocalcic balance and protect liver, kidney and brain function. Remarkably, it also reduced Cd levels in the liver, kidneys and brain, as well as in the bones of rats. These results show that oral administration of CHS/BG has a strong therapeutic potential on tissues through detoxification of cadmium-exposed rats.

Influence of the Extraction Method on the Biological Potential of Solidago virgaurea L. Essential Oil and Hydrolates

Solidago virgaurea L., or European goldenrod, has a long tradition in folk medicine due to the wide range of its biological activity. This paper aimed to investigate the antimicrobial and antioxidative potential of S. virgaurea essential oil and hydrolates obtained by traditional and novel extraction techniques. For that purpose, hydrodistillation, microwave-assisted hydrodistillation and solvent-free extraction were performed. Analysis of the composition of essential oils indicated the presence of 59 different compounds with cyclocolorenone, germacrene D and spathulenol being the dominant in all essential oil samples. Antimicrobial activity was detected in all the analyzed samples, with higher effect on Gram-positive microorganisms compared to Gram-negative. Regarding the type of performed extraction process, the introduction of microwaves induced higher antimicrobial and antioxidative potential in both essential oils and hydrolates. Hydrolates obtained in microwave-assisted processes had pronounced antioxidative activity, which creates a good basis for further investigation of this side product's potential use in the food, cosmetic and pharmaceutical industries.

The chemical composition and the preservative, antimicrobial, and antioxidant effects of Thymus broussonetii Boiss. essential oil: an in vitro and in silico approach

Introduction

The aim of this study was to evaluate the antioxidant, antimicrobial, and preservative efficacy of Thymus broussonetii Boiss. essential oil (EO) in a topically applied formulation using a challenge test.

Methods

The essential oil was extracted from the aerial part of T. broussonetii using hydrodistillation, and the obtained EO was further analyzed by gas chromatography/mass spectrometry (GC/MS). The antioxidant effect of the EO was evaluated using three methods: the inhibition of free radical 2,2-diphenyl-1-picrylhydrazyl (DPPH), β-carotene-linoleic acid, and the ferric reducing antioxidant power (FRAP) methods. The antimicrobial activity and the minimum inhibitory concentration (MIC) of this EO were assayed by the disk-diffusion method and the broth microdilution method, respectively. The preservative efficacy of T. broussonetii EO was assayed at 1% and 2% (v/w) in a topical cream formulation using a challenge test against standard-specific microorganisms recommended by the European Pharmacopoeia. Furthermore, the identified phytochemical compounds were docked for their effect on nicotinamide adenine dinucleotide phosphate oxidase, human casein kinase 1 alpha 1 (CSNK1A1), glycogen synthase kinase 3, Staphylococcus aureus nucleoside diphosphate kinase, Escherichia coli beta-ketoacyl-[acyl-carrier protein] synthase, Pseudomonas aeruginosa LasR ligand-binding domain, and sterol 14-alpha demethylase (CYP51) from Candida albicans. The ADME/toxicity was predicted by analyzing the absorption, distribution, metabolism, and excretion parameters.

Results and discussion

chemical composition of the EO revealed the presence of thymol (63.09%), p-cymene (11%), and γ-terpinene (8.99%) as the major components. The antioxidant assays revealed that the essential oil exhibited strong antioxidant activity, as indicated by the minimum inhibitory concentration IC50 (IC50 = 210 ± 0.3 μg/mL for the DPPH assay, IC50 = 145 ± 0.1 μg/mL for the β-carotene assay, and IC50 = 84 ± 0.21 μg/mL for the FRAP assay) when compared to quercetin and butylated hydroxytoluene (BHT) as controls. The investigated essential oil exhibited important antimicrobial activity against all the tested microorganisms, and the MICs of the EO against bacteria and fungi were 0.02%-1%. Moreover, the EO of T. broussonetii evaluated at 2% (v/w) in a cream formulation succeeded in satisfying the A criteria for preservation efficacy against S. aureus, E. coli, and Aspergillus brasiliensis but exhibited less efficacy against P. aeruginosa (1.78 log reduction in the number of CFU/g after 7 days of evaluation) and C. albicans (1.09 log reduction in the number of CFU/g after 14 days of evaluation) when compared to the synthetic preservative phenoxyethanol 1% (v/w). In silico results showed that the antimicrobial activity of T. broussonetii EO is mostly attributed to thymol, terpinen-4-ol, and aromadendrene, while the antioxidant activity is attributed to thymol. These results indicate that the EO of T. broussonetii possesses important antimicrobial and antioxidant properties and can, therefore, be used as a natural preservative ingredient in the cosmetic industry.

Multiplicative Effects of Essential Oils and Other Active Components on Skin Tissue and Skin Cancers

Naturally derived essential oils and their active components are known to possess various properties, ranging from anti-oxidant, anti-inflammatory, anti-bacterial, anti-fungal, and anti-cancer activities. Numerous types of essential oils and active components have been discovered, and their permissive roles have been addressed in various fields. In this comprehensive review, we focused on the roles of essential oils and active components in skin diseases and cancers as discovered over the past three decades. In particular, we opted to highlight the effectiveness of essential oils and their active components in developing strategies against various skin diseases and skin cancers and to describe the effects of the identified essential-oil-derived major components from physiological and pathological perspectives. Overall, this review provides a basis for the development of novel therapies for skin diseases and cancers, especially melanoma.

Development, characterization, and evaluation of the antioxidant activity of nanocarriers based on surfactant swollen micelles that encapsulate essential oils

This work aimed to compare the performance of two relatively underexplored methods for the swollen micelles (SMs) production as nanocarriers for essential oils (EOs). Origanum vulgare and Thymus vulgaris EOs were examined. The first method (SMs-1), involved a self-assembly process, while the second one (SMs-2), employed titration operation of an emulsion into a surfactant solution for SMs formation. Tween 80 and ethanol were used as surfactant and co-surfactant, respectively. The solubilization kinetics and the saturation concentration of EOs were determined. Particle size (measured by DLS) and encapsulation efficiency (EE) were the control parameters assessed, along with the EOs-loaded SMs' stability during 30 days of storage. Additionally, the EOs-loaded SMs' morphology was analyzed using atomic force microscopy (AFM). Finally, the antioxidant activity through the ABTS+ radical scavenging and the reducing power of EOs encapsulated in SMs was determined. The results showed that the solubilization of EOs in SMs was a rapid process with high EE. EOs-loaded SMs-2 systems exhibited greater colloidal stability and higher EE compared to EOs-loaded SMs-1 systems, showing smaller and more homogeneous particle sizes. Moreover, EOs-loaded SMs-2 systems maintained constant EE throughout the storage period. AFM imaging confirmed the rounded and heterogeneous morphology of EOs-loaded SMs-1 and the smaller, more homogeneous, and spherical morphology of EOs-loaded SMs-2. EOs-loaded SMs-2 showed high ABTS+ radical scavenging and reducing power when encapsulated in SMs. In conclusion, the SMs-2 method emerged as an effective approach for producing efficient nanocarriers for EOs, signifying a promising path for future developments in antioxidant delivery systems.

Essential Oil from the Leaves, Fruits and Twigs of Schinus terebinthifolius: Chemical Composition, Antioxidant and Antibacterial Potential

Schinus terebinthifolius Raddi, popularly known as "Pink pepper", is a plant native to Brazil. The objective of this work was to analyze the chemical composition and the antioxidant and antibacterial potential of essential oils (EOs) from the leaves, fruits and twigs of S. terebinthifolius, aiming for their application in food safety. EOs were obtained by hydrodistillation and the chemical composition was determined by gas chromatography coupled to mass spectrometry. Phenolic compounds were quantified and antioxidant activity was evaluated using three different methods. The antibacterial activity was determined by the broth microdilution method against foodborne bacteria. In the chemical analysis, 22 compounds were identified in the leaves, 13 compounds in the fruits and 37 compounds in the twigs, revealing the presence of the main compounds germacrene D (12.04%, 15.78%, 20,41%), caryophyllene (15.97%, 3.12%, 11.73%), α-pinene (11.6%, 17.16%, 2.99%), β-pinene (5.68%, 43.34%, 5.60%) and γ-gurjunene (16,85%, 3,15%) respectively. EOs showed better antioxidant potential using the β-carotene/linoleic acid method with 40.74, 61.52 and 63.65% oxidation inhibition for leaves, fruits and twigs, respectively. The EO from the leaves showed greater antibacterial potential against Escherichia coli and Staphylococcus aureus with a minimum inhibitory concentration (MIC) of 0.62 mg mL-1, a value lower than the MIC of sodium nitrite (5.00 mg mL-1), the antimicrobial standard synthetic. The activities of pink pepper EOs suggest their potential as a biopreservative in foods.

Antimicrobial and Antibiofilm Efficacy and Mechanism of Oregano Essential Oil Against Shigella flexneri

The aim of this study was to assess the antimicrobial activity of oregano essential oil (OEO) against Shigella flexneri and eradication efficacy of OEO on biofilm. The results showed that the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) of OEO against S. flexneri were 0.02% (v/v) and 0.04% (v/v), respectively. OEO effectively killed S. flexneri in Luria-Bertani (LB) broth and contaminated minced pork (the initial population of S. flexneri was about 7.0 log CFU/mL or 7.2 log CFU/g), and after treatment with OEO at 2 MIC in LB broth or at 15 MIC in minced pork, the population of S. flexneri decreased to an undetectable level after 2 or 9 h, respectively. OEO increased intracellular reactive oxygen species concentration, destroyed cell membrane, changed cell morphology, decreased intracellular ATP concentration, caused cell membrane depolarization, and destroyed proteins or inhibited proteins synthesis of S. flexneri. In addition, OEO effectively eradicated the biofilm of S. flexneri by effectively inactivating S. flexneri in mature biofilm, destroying the three-dimensional structure, and reducing exopolysaccharide biomass of S. flexneri. In conclusion, OEO exerts its antimicrobial action effectively and also has a valid scavenging effect on the biofilm of S. flexneri. These findings suggest that OEO has the potential to be used as a natural antibacterial and antibiofilm material in the control of S. flexneri in meat product supply chain, thereby preventing meat-associated infections.

Antioxidant activity, analgesic activity, and phytochemical analysis of Ammi majus (L.) extracts

Ammi majus (L.) is commonly used to cure many diseases in Moroccan folk medicine, especially vitiligo. This research tries to evaluate the phytochemical constituents of two aqueous extracts (E1; Maceration; 48 h) and (E2: Infusion; 1h) and three organic fractions (F1: Cyclohexane), (F2: Ethyl acetate (EtOAc)) and (F3: Ethanolic (EtOH)) of A. majus (L.) seeds, as well as to study the antioxidant and analgesic activity of the species. Phytochemical analysis, antioxidant activity (DPPH, FRAP, ABTS, and TAC tests), and analgesic activity (writhing and tail immersion were induced by Acetic acid tests) were analyzed according to the literature. A quantitative phytochemical study indicate that the E1 had the highest content of total polyphenols (26.95 ± 0.53 mg GAE/g extract) and flavonoids (37.92 ± 0.46 mg QE/g extract), while F3 showed a promising flavonol content (24.26±0.08 mg QE/g extract). Tannins were found to be high in F1 (59.27 ± 0.16 mg CE/g extract) and F2 (57.65 ± 1.18 mg CE/g extract). Antioxidant results reveals that DPPH (IC50 = 179.68 ± 0.47 μg/mL) and FRAP (EC50 = 367.03 ± 0.12 μg/mL) show to E1 a high antioxidant activity. Regarding the analgesic activity of the different studied extracts, it was found that E1 has a high peripheral analgesic effect with 62.32 % and a high central analgesic potential throughout the experimentation at 500 mg/kg. Our studies demonstrated for the first time that A. majus seeds extracts have high antioxidant and analgesic activities through different analysis techniques.

Extracts of Brocchia cinerea (Delile) Vis Exhibit In Vivo Wound Healing, Anti-Inflammatory and Analgesic Activities, and Other In Vitro Therapeutic Effects

The plant Brocchia cinerea (Delile) (B. cinerea) has many uses in traditional pharmacology. Aqueous (BCAE) and ethanolic extracts (BCEE) obtained from the aerial parts can be used as an alternative to some synthetic drugs. In vitro, DPPH, FRAP and TAC are three tests used to measure antioxidant efficacy. Antibacterial activities were determined against one Gram positive and two Gram negative strains of bacteria. The analgesic power was evaluated in vivo using the abdominal contortion model in mice, while carrageenan-induced edema in rats was the model chosen for the anti-inflammatory test; wound healing was evaluated in an experimental second degree burn model. The results of the phytochemical analysis showed that BCEE had the greatest content of polyphenols (21.06 mg AGE/g extract), flavonoids (10.43 mg QE/g extract) and tannins (24.05 mg TAE/g extract). HPLC-DAD reveals the high content of gallic acid, quercetin and caffeic acid in extracts. BCEE has a strong antiradical potency against DPPH (IC50 = 0.14 mg/mL) and a medium iron reducing activity (EC50 = 0.24 mg/mL), while BCAE inhibited the growth of the antibiotic resistant bacterium, P. aeruginosa (MIC = 10 mg/mL). BCAE also exhibited significant pharmacological effects and analgesic efficacy (55.81% inhibition 55.64% for the standard used) and the re-epithelialization of wounds, with 96.91% against 98.60% for the standard. These results confirm the validity of the traditional applications of this plant and its potential as a model to develop analogous drugs.

Eco-physiological response of secondary metabolites of teas: Review of quality attributes of herbal tea

Herbal tea is a rich source of secondary metabolites which are reputed to have medicinal and nutritional efficacy. These secondary metabolites are influenced by the abiotic and biotic stresses that improve the production of herbal teas in terms of biomass production, accumulation and partitioning of assimilates of compounds. In this study, various examples of herbal teas have been shown to respond differently to secondary metabolites affected by environmental factors. Thus, the meta-analysis of this study confirms that different herbal teas' response to environmental factors depends on the type of species, cultivar, and the degree of shade that the plant is exposed. It is also evident that the metabolic processes are also known to optimize the production of secondary metabolites which can thus be achieved by manipulating agronomic practices on herbal teas. The different phenolic compound in herbal teas possesses the antioxidant, antimicrobial, antiatherosclerosis, anti-inflammatory, antimutagenic, antitumor, antidiabetic and antiviral activities that are important in managing chronic diseases associated with lifestyle. It can be precluded that more studies should be conducted to establish interactive responses of biotic and abiotic environmental factors on quality attributes of herbal teas.

Potential use of essential oils from Origanum vulgare and Syzygium aromaticum to control Tetranychus urticae Koch (Acari: Tetranychidae) on two host plant species

Plant extracts and essential oils are considered alternatives to synthetic chemicals with toxic effects on insects and mites. Acaricidal, repellent, and oviposition effects of commercially available essential oils of Origanum vulgare L. (Lamiaceae) and Syzygium aromaticum (L.) (Myrtaceae) were investigated in this study on Tetranychus urticae Koch (Acari: Tetranychidae), one of the main pests in agriculture, on two host plant species using leaf disc bioassays. O. vulgare essential oil showed higher toxicity to T. urticae protonymphs and adult females inhabiting both bean and tomato leaves than S. aromaticum essential oil. The LC₅₀ values of O. vulgare essential oil were found to be 1.67 and 2.05 µl L^-1 air for the bean populations in protonymphs and adult females and 1.87 and 3.07 µl L^-1 air for the tomato populations, respectively. Five percent concentration of S. aromaticum essential oil had the highest repellent effect on the bean population of T. urticae after 1, 24, and 48 h, resulting in 61.22%, 40.81%, and 18% repellence, respectively. Although O. vulgare showed higher toxic effects, S. aromaticum was a better repellent against the bean population of T. urticae. The mortality rates of adult females of T. urticae treated with either O. vulgare or S. aromaticum essential oil increased with the increasing concentration and time on both host plants. Both essential oils caused a decrease in egg number and larvae hatching in both bean and tomato populations of T. urticae. In the light of the results obtained, O. vulgare and S. aromatium essential oils have the potential to be used in the control programs against T. urticae in both host plants.

In vitro antioxidant activities of Carissa edulis ((Forssk) Vahl) and Pappea capensis (Eckyl. & Zeyh) extracts

Herbal medications are gaining popularity due to their long history of use in traditional medicine. They serve as a reservoir for a diverse array of phytocompounds linked to amelioration of oxidative stress. Oxidative stress is a disturbance in the balance between generation and elimination of reactive species in human body. Moreover, reactive species are implicated in the onset and progression of chronic disorders. The current therapeutic approaches despite showing efficacy are characterized by several limitations such as adverse effects and prohibitive costs. This drives the need to explore alternatives that can inhibit, ameliorate or reverse conditions caused by oxidative stress. Several studies have evaluated antioxidant effects of diverse plant extracts. C. edulis and P. capensis are used as traditional therapy among the African communities to manage oxidative stress-related ailments. However, there is limited research on the antioxidant effects of these medicinal plants. The current study, therefore, sought to evaluate the antioxidant and phytochemical profile, of C. edulis and P. capensis extracts. Samples were collected from Embu County, Kenya. In vitro antioxidant properties of the extracts were evaluated through ferric reduction, Iron chelating, hydroxyl radical, and DPPH radical scavenging activities. Activities of catalase, superoxide dismutase and glutathione reductases of the extracts were further determined. Phytochemical profiles were determined using Liquid Chromatography Mass Spectrophotometer (LC-MS) and Gas Chromatography Mass Spectrophotometer (GC-MS) analyses. The extracts displayed concentration dependent antioxidant activities. Phytochemical analyses revealed presence compounds which are associated with antioxidant activities including flavonoids, phenolics, tocopherols and terpenoids. The findings provide a scientific validation for the folklore use of C. edulis and P. capensis in management of oxidative stress. Nevertheless, there is a need for further purification and characterization of phytochemicals associated with antioxidant activities.

Optimizing the Distillation of Greek Oregano-Do Process Parameters Affect Bioactive Aroma Constituents and In Vitro Antioxidant Activity?

The aim of the present work was to optimize the conditions of the distillation process at a pilot scale to maximize the yield of specific bioactive compounds of the essential oil of oregano cultivated in Greece, and subsequently to study the in vitro antioxidant activity of these oils. Steam distillation was conducted at an industrial distillery and a Face-Centered Composite (FCC) experimental design was applied by utilizing three distillation factors: time, steam pressure and temperature. Essential oil composition was determined by static headspace gas chromatography-mass spectrometry (HS-GC/MS). To obtain a comprehensive profile of the essential oils, instrumental parameters were optimized, including sample preparation, incubation conditions, sampling process, injection parameters, column thermal gradient and MS conditions. With the applied GC-MS method, more than 20 volatile compounds were identified in the headspace of the oregano essential oils and their relative percentages were recorded. Carvacrol was the most prominent constituent under all distillation conditions applied. Data processing revealed time as the main factor which most affected the yield. The Desired Space (DSc) was determined by conducting a three-dimensional response surface analysis of the independent and dependent variables, choosing yields of thymol and carvacrol as optimization criteria. The in vitro antioxidant activity of the essential oils of all samples was measured in terms of the interaction with the stable free radical 2,2-diphenyl-1-picrylhydrazyl (DPPH) after 20 and 60 min. The most prominent essential oils at different distillation conditions were also tested as inhibitors of lipid peroxidation. Higher % values of carvacrol and thymol were correlated to higher antioxidant activity. Evaluating the impact of the distillation conditions on the in vitro results, it seems that lower pressure, less time and higher temperature are crucial for enhanced antioxidant activities.

Bacterial Communities of Lamiacea L. Medicinal Plants: Structural Features and Rhizosphere Effect

Bacterial communities associated with medicinal plants are an essential part of ecosystems. The rhizosphere effect is rather important in the cultivation process. The purpose of the study was to analyze the rhizosphere effect of oregano (Origanum vulgare L.), peppermint (Mentha piperita L.), thyme (Thymus vulgaris L.), creeping thyme (Thymus serpillum L.) and sage (Salvia officinalis L.). To estimate the quantity of 16S bacteria ribosomal genes, qPCR assays were used. To compare bacterial communities' structure of medicinal plants rhizosphere with bulk soil high-throughput sequencing of the 16S rRNA targeting variable regions V3-V4 of bacteria was carried out. The highest bacterial abundance was associated with T. vulgaris L., M. piperita L. and S. officinalis L., and the lowest was associated with the O. vulgare L. rhizosphere. Phylum Actinobacteriota was predominant in all rhizosphere samples. The maximum bacterial α-diversity was found in S. officinalis L. rhizosphere. According to bacterial β-diversity calculated by the Bray-Curtis metric, T. vulgaris L. root zone significantly differed from bulk soil. The rhizosphere effect was positive to the Myxococcota, Bacteroidota, Verrucomicrobiota, Proteobacteria and Gemmatimonadota.

Optimizing the extraction of phenolic antioxidants from date palm fruit by simplex-centroid solvent mixture design

Date palm (Phoenix dactylifera L.) fruits are rich in various bioactive compounds, such as phenolic acids, hydroxycinnamates, flavonoid glycosides, coumarins, alkaloids, and proanthocyanidin oligomers. The focus of this study was to develop a simplex-centroid mix design method to identify the most suitable mixture of solvents (water, acetone, and methanol) to extract bioactive compounds from date fruits. Three extraction solvents (water, methanol, and acetone) were investigated during this study to determine, total phenolic content (TPC), total flavonoid content (TFC), antioxidant activity (free radical DPPH) and ferric reduction ability (FRAP). The results showed that polar mixtures were effective in extracting antioxidant phenolics. The optimum solvent for extraction was Binary mixture water-acetone (50%) presenting TPC, TFC, DPPH and FRAP values of 502.88 mg GAE.100 g^-1 DW, 206.23 mg QE.100 g^-1 DW, 77 0.01% and 1688.66 μmol.100 g^-1 respectively. The results also confirmed a strong correlation between the amount of polyphenols in a given extract and the antioxidant activities observed in the DPPH and FRAP assays. This study presents a pragmatic and efficient way to choose a solvent combination to extract polyphenols from date palm fruits.

Quality Control, Phytochemical Profile, and Antibacterial Effect of Origanum compactum Benth. Essential Oil from Morocco

Origanum compactum Benth (O. compactum) is widely used traditionally in Morocco to treat a broad range of illnesses, including infectious diseases. The aim of this study was to evaluate the phytochemical composition, quality control, and antibacterial activity of O. compactum leaf and flower essential oil. First, a quality control study on soil and irrigation water was performed to determine whether there was any risk of heavy metals endangering human health or causing stress to the plants studied. Laboratory examination of the environmental quality of the researched species revealed an almost absolute absence of metals that could endanger human health or any abiotic stressor. The essential oil was extracted by hydrodistillation. Chemical characterization was performed using gas chromatography-mass spectrometry (GC/MS). The yield of essential oil (EO) obtained by hydrodistillation of O. compactum leaves and flowers and moisture content were 4.27% and 12.20%, respectively. GC/MS identified 35 volatile compounds in the studied EO majorly composed of thymol (38.59%) followed by carvacrol (26.65%), o-cymene (14.33), and γ-terpinene (11.22%). The antibacterial activity of O. compactum leaf and flower essential oil was evaluated using the solid-state diffusion method against five Gram-negative bacterial strains and a Gram-positive strain. The results show that the essential oil of O. compactum leaves and flowers has a considerable inhibitory effect against E. coli with an MIC = 0.35 µg/mL, E. pseudocoloides (MIC = 0.35 µg/mL), E. vekanda (MIC = 0.35 µg/mL), K. pneumoniae (MIC = 0.7 µg/mL), P. aeruginosa (MIC = 0.35 µg/mL), and S. aureus (MIC = 0.35 µg/mL).

Investigation on wound healing effect of Mediterranean medicinal plants and some related phenolic compounds: A review

ETHNOPHARMACOLOGICAL RELEVANCE

The human skin constitutes a biological barrier against external stress and wounds can reduce the role of its physiological structure. In medical sciences, wounds are considered a major problem that requires urgent intervention. For centuries, medicinal plants have been used in the Mediterranean countries for many purposes and against wounds.

AIM OF THIS REVIEW

Provides an outlook on the Mediterranean medicinal plants used in wound healing. Furthermore, the wound healing effect of polyphenolic compounds and their chemical structures are also summarized. Moreover, we discussed the wound healing process, the structure of the skin, and the current therapies in wound healing.

MATERIALS AND METHODS

The search was performed in several databases such as ScienceDirect, PubMed, Google Scholar, Scopus, and Web of Science. The following Keywords were used individually and/or in combination: the Mediterranean, wound healing, medicinal plants, phenolic compounds, composition, flavonoid, tannin.

RESULTS

The wound healing process is distinguished by four phases, which are respectively, hemostasis, inflammation, proliferation, and remodeling. The Mediterranean medicinal plants are widely used in the treatment of wounds. The finding showed that eighty-nine species belonging to forty families were evaluated for their wound-healing effect in this area. The Asteraceae family was the most reported family with 12 species followed by Lamiaceae (11 species). Tunisia, Egypt, Morocco, and Algeria were the countries where these plants are frequently used in wound healing. In addition to medicinal plants, results showed that nineteen phenolic compounds from different classes are used in wound treatment. Tyrosol, hydroxytyrosol, curcumin, luteolin, chrysin, rutin, kaempferol, quercetin, icariin, morin, epigallocatechin gallate, taxifolin, silymarin, hesperidin, naringin, isoliquiritin, puerarin, genistein, and daidzein were the main compounds that showed wound-healing effect.

CONCLUSION

In conclusion, medicinal plants and polyphenolic compounds provide therapeutic evidence in wound healing and for the development of new drugs in this field.

Phytochemical Characterization and Biological Evaluation of Origanum vulgare L. Essential Oil Formulated as Polymeric Micelles Drug Delivery Systems

This study presents phytochemical characterization and biological evaluation of Origanum vulgare L. essential oil (OEO) formulated as polymeric micelles drug delivery systems as a possible non-invasive approach for the management of skin tags. GC-MS analysis of Romanian OEO revealed the identification and quantification of 43 volatile compounds (thymol and carvacrol being the main ones). The antioxidant activity was shown by four consecrated methods: CUPRAC, ABTS, ORAC and DPPH. OEO was incorporated by micellar solubilization into a binary hydrogel based on a Pluronic F 127/L 31 block-copolymers mixture. The pH, consistency, spreadability, particle size, polydispersity index and zeta potential of the OEO-loaded poloxamer-based binary hydrogel (OEO-PbH) were investigated. OEO-PbH was skin compatible in terms of pH and exhibited adequate spreadability and consistency. The minimal inhibitory concentrations of the tested OEO were similar to those obtained for the formulation, lower (2.5 µg/mL) for yeast and higher (40-80 µg/mL) for Gram-negative bacilli. As keratinocytes are among main components of skin tags, an in vitro evaluation was conducted in order to see the effect of the formulation against HaCaT human keratinocytes. OEO-PbH decreased HaCaT cells migration and proliferation and elicited a cytotoxic and pro-apoptotic effect in a dose- and time-dependent manner. No harmful effect on the viability of dendritic cells (DCs) was detected following the incubation with different concentrations (0-200 µg/mL) of the 5% formulation. Treatment in inflammatory DCs (+LPS) indicated a decrease in cytokine production of IL-6, TNF-α and IL-23 but no significant effect on IL-10 in any of the tested concentrations.

The Antioxidant, Analgesic, Anti-Inflammatory, and Wound Healing Activities of Haplophyllum tuberculatum (Forsskal) A. Juss Aqueous and Ethanolic Extract

Herbal extracts are part of the solution to the increased demand for organic health care products. Traditionally, the different extracts prepared from Haplophyllum tuberculatum (Forsskal) A. Juss (H. tuberculatum) have been widely used to treat a wide range of illnesses. The aim of this study is to evaluate the antioxidant, analgesic, anti-inflammatory, and wound healing potential of the aqueous (HTAE) and ethanolic (HTEE) extracts of this plant as well as identify its major phytochemical components using LC-MS. Phytochemical analysis of both extracts revealed a rich composition and especially high amounts of glycosylic flavonols, 65.37% and 68.77% for the HTEE and HTAE, respectively. The antioxidant assays performed (DPPH, FRAP and TAC) indicated the excellent activity of the ethanolic extract while the in vivo activities (analgesic, anti-inflammatory, and healing potential) indicated the excellent activity of the aqueous extract. These findings support the therapeutic use of this plant by preventing pain and inflammation and promoting wound healing. To uncover, identify, and isolate compounds of potential medicinal and therapeutic significance, more studies on this species are required.

Inhibitory Effect of GRAS Essential Oils and Plant Extracts on the Growth of Aspergillus westerdijkiae and Aspergillus carbonarius Strains

The effect of essential oils (obtained using hydrodistillation) and plant extracts (ethanolic, aqueous, and hexanic extractions) of 10 different plants cultivated in Brazil were tested using the diffusion agar method, with the objective of evaluating the inhibitory effect of the oils and extracts on the mycelial growth of Aspergillus westerdijkiae NRRL 3174 and A. carbonarius RC 2054 (UNRC). Of the 40 essential oils and plant extracts analyzed, oregano essential oil and plant extract, rosemary essential oil, and the clove ethanolic extract were the best choice to obtain the growth parameters (radial growth rates (mm day−1) and lag phase (h)) due the good results presented and the volume of oil/extract obtained. Comparing all the essential oils and plant extracts that were tested for growth parameters, the best results were obtained for the clove ethanolic extract for both strains assayed. These results demonstrated an outstanding potential use of some of these products in prevention of fungal contamination in food. However, further studies need to be conducted to determine the ability of these oils and extracts to inhibit or reduce ochratoxin A production.

Corchorus olitorius L. (Jute) leaf and seed extracts exerted high antibacterial activity against food and plant pathogenic bacteria

Aim of this study was to comparatively evaluate antibacterial activities of methanol (MetOH), acetone (Ace), petroleum ether (PE) and aqueous (dw) leaf (L), root (R), and seed (S) extracts of Corchorus olitorius L. on both food- and plant-borne pathogens, with DPPH radical scavenging activities (DRSA), and quantitative and qualitative constituent analysis. Leaf PE has the highest strain susceptibility on both food- and plant-borne pathogens. Clavibacter michiganensis, Pseudomonas tomato, and Erwinia caratovora were susceptible to nearly all the leaf and seed extracts. Very low minimum inhibitory concentration (8-128 μg mL−1) and minimum bactericidal concentration (32-2048 μg mL−1) were determined for both leaf and seed extracts against C. michiganensis. Total phenolic contents were correlated to DRSA. The phenolic compounds tested were higher in the leaf MetOH, cholorogenic acid being the most abundant one. Palmitic acid was determined in leaf PE and seed PE extracts. Results presented here demonstrate high antibacterial activity of C. olitorius leaf seed extracts against phytopathogens for the first time, and provide the most comprehensive data on the antibacterial activity screening against food-borne pathogens. Considering limitations in plant disease control, antibacterial activities of these extracts would be important in plant disease control.

Effect of Germacrene-Rich Essential Oil of Parentucellia latifolia (L.) Caruel Collected in Central Sicily on the Growth of Microorganisms Inhabiting Historical Textiles

In the present study, the chemical composition of the essential oil from aerial parts of Parentucellia latifolia (L.) Caruel collected in Central Sicily was analyzed by gas chromatography and gas chromatography–mass spectrometry. The results showed the presence of sesquiterpene hydrocarbons, with germacrene D and germacrene B accounting, respectively, for 59.2% and 24.3% of the total oil. Different colonies of bacteria and fungi frequently affect cellulosic objects such as books stored in libraries and museums. The antibacterial and antifungal activity against some microorganisms infesting historical-artistic craftsmanship was determined, demonstrating that the essential oil was particularly active against Bacillus subtilis, Staphylococcus aureus, and Proteus vulgaris.

Protective Impact of Chitosan Film Loaded Oregano and Thyme Essential Oil on the Microbial Profile and Quality Attributes of Beef Meat

Edible films and essential oil (EO) systems have the potency to enhance the microbial quality and shelf life of food. This investigation aimed to evaluate the efficacy of chitosan films including essential oils against spoilage bacteria and foodborne pathogens associated with meat. Antimicrobial activity (in vitro and in vivo) of chitosan films (CH) incorporated with oregano oil (OO) and thyme oil (TO) at 0.5 and 1% was done against spoilage bacteria and foodborne pathogens, compared to the control sample and CH alone. Preliminary experiments (in vitro) showed that the 1% OO and TO were more active against Staphylococcus aureus compared to Escherichia coli O157:H7 and Salmonella Typhimurium. In in vivo studies, CH containing OO and TO effectively inhibited the three foodborne pathogens and spoilage bacteria linked with packed beef meat which was kept at 4 °C/30 days compared to the control. The total phenolic content of the EOs was 201.52 mg GAE L-1 in thyme and 187.64 mg GAE L-1 in oregano. The antioxidant activity of thyme oil was higher than oregano oil. The results demonstrated that the shelf life of meat including CH with EOs was prolonged ~10 days compared to CH alone. Additionally, CH-OO and CH-TO have improved the sensory acceptability until 25 days, compared to the control. Results revealed that edible films made of chitosan and containing EOs improved the quality parameters and safety attributes of refrigerated or fresh meat.

Applications of Essential Oils as Antibacterial Agents in Minimally Processed Fruits and Vegetables—A Review

Microbial foodborne diseases are a major health concern. In this regard, one of the major risk factors is related to consumer preferences for “ready-to-eat” or minimally processed (MP) fruits and vegetables. Essential oil (EO) is a viable alternative used to reduce pathogenic bacteria and increase the shelf-life of MP foods, due to the health risks associated with food chlorine. Indeed, there has been increased interest in using EO in fresh produce. However, more information about EO applications in MP foods is necessary. For instance, although in vitro tests have defined EO as a valuable antimicrobial agent, its practical use in MP foods can be hampered by unrealistic concentrations, as most studies focus on growth reductions instead of bactericidal activity, which, in the case of MP foods, is of utmost importance. The present review focuses on the effects of EO in MP food pathogens, including the more realistic applications. Overall, due to this type of information, EO could be better regarded as an “added value” to the food industry.

Origanum vulgare ssp. hirtum (Lamiaceae) Essential Oil Prevents Behavioral and Oxidative Stress Changes in the Scopolamine Zebrafish Model

Origanum vulgare ssp. hirtum has been used as medicinal herbs promoting antioxidant, anti-inflammatory, antimicrobial, and neuroprotective activities. We investigated the protective effects and the mechanism of O. vulgare ssp. hirtum essential oil (OEO) on cognitive impairment and brain oxidative stress in a scopolamine (Sco)-induced zebrafish (Danio rerio) model of cognitive impairment. Our results show that exposure to Sco (100 µM) leads to anxiety, spatial memory, and response to novelty dysfunctions, whereas the administration of OEO (25, 150, and 300 µL/L, once daily for 13 days) reduced anxiety-like behavior and improved cognitive ability, which was confirmed by behavioral tests, such as the novel tank-diving test (NTT), Y-maze test, and novel object recognition test (NOR) in zebrafish. Additionally, Sco-induced brain oxidative stress and increasing of acetylcholinesterase (AChE) activity were attenuated by the administration of OEO. The gas chromatography-mass spectrometry (GC-MS) analyses were used to elucidate the OEO composition, comprising thymol (38.82%), p-cymene (20.28%), and γ-terpinene (19.58%) as the main identified components. These findings suggest the ability of OEO to revert the Sco-induced cognitive deficits by restoring the cholinergic system activity and brain antioxidant status. Thus, OEO could be used as perspective sources of bioactive compounds, displaying valuable biological activities, with potential pharmaceutical applications.

Principal Metabolites in Extracts of Different Plants Responsible for Antibacterial Effects

The increase in bacterial resistance and decreased effectiveness of antibacterial agents has forced researchers to look for new antibacterial agents from environmentally friendly sources such as essential oils and oil extracts. The functional group of the metabolites present in the essential oils or plant extract and the synergy effects between them play an important role in the biological activity and can be the principal factor affecting the antibacterial effect. All of these bioactive oils showed the same action mechanism, and the best way to implement them is by extracting them without changing their original properties, whereby the characterization and evaluation of the compounds are important steps. All of these themes are extensively reviewed, analyzed, and discussed in this work.

Chemical Constituents of the Essential Oil from Ecuadorian Endemic Species Croton ferrugineus and Its Antimicrobial, Antioxidant and α-Glucosidase Inhibitory Activity

Croton ferrugineus Kunth is an endemic species of Ecuador used in traditional medicine both for wound healing and as an antiseptic. In this study, fresh Croton ferrugineus leaves were collected and subjected to hydrodistillation for extraction of the essential oil. The chemical composition of the essential oil was determined by gas chromatography equipped with a flame ionization detector and gas chromatography coupled to a mass spectrometer using a non-polar and a polar chromatographic column. The antibacterial activity was assayed against three Gram-positive bacteria, one Gram-negative bacterium and one dermatophyte fungus. The radical scavenging properties of the essential oil was evaluated by means of DPPH and ABTS assays. The chemical analysis allowed us to identify thirty-five compounds representing more than 99.95% of the total composition. Aliphatic sesquiterpene hydrocarbon trans-caryophyllene was the main constituent with 20.47 ± 1.25%. Other main compounds were myrcene (11.47 ± 1.56%), β-phellandrene (10.55 ± 0.02%), germacrene D (7.60 ± 0.60%), and α-humulene (5.49 ± 0.38%). The essential oil from Croton ferrugineus presented moderate activity against Candida albicans (ATCC 10231) with an MIC of 1000 μg/mL, a scavenging capacity SC₅₀ of 901 ± 20 µg/mL with the ABTS method, and very strong antiglucosidase activity with an IC₅₀ of 146 ± 20 µg/mL.

Herbal extracts and essential oils microencapsulation studies for different applications

Studies on bioactivities of numerous essential oils (EOs) and herbal extracts compounds against diseases are crucial. Microencapsulation methods development might be an alternative to obtain bioactive compounds for cosmetics and pharmaceutical uses. In this study, we carried out a literature review of 219 503 data articles using ScienceDirect, Redalyc, Web of Science, Scopus, SciELO, and Google Scholar databases in English and Spanish, after with inclusion (original articles, book chapters, and theoretical references) and exclusion criteria (frameworks description), we found 1854 restricting the publication years between 2004 and August 2020 and 35 relevant articles with our scope research. References found contained a collection of methods that could be utilized to create microcapsules, including coacervation, extrusion, polymerization, and spray drying. This article analyzed the most recent and advanced microencapsulation techniques and their applications in the food, cosmetic, and pharmaceutical industries. Herbal extracts and EOs have many applications, depending on the wall materials and microencapsulation methods that could help know about selective release and efficacy to ensure optimal dosing and other advantages; thus, improving the profitability of these product manufacturers.

New insight into antimicrobial activities of Linaria ventricosa essential oil and its synergetic effect with conventional antibiotics

The purpose of the present study was to determine for the first time the volatile constituents, the antioxidant and antimicrobial activities of the essential oil (EO) of the endemic Moroccan Linaria ventricosa, alone or in combination with four known antibiotics. The major constituents were 2-methoxy-4-vinylphenol (17.4%), α-terpinene (13.64%) and 3,5-dimethylphenyl isocyanate (12.21%). The EO had moderate antioxidant potency, as measured by DPPH free radical scavenging (1.233 ± 0.031 mg/mL), ferric reducing antioxidant power assay (0.373 ± 0.019 mg/mL) and β-carotene/linoleic acid (0.922 ± 0.026 mg/mL). EO showed microbicidal activity against all microorganisms tested. The highest effectiveness was recorded against Candida albicans (IZ = 24 mm, MIC = 4.87 mg/mL and MMC = 9.75 mg/mL) and Candida glabrata (IZ = 22 mm, MIC = MMC = 4.87 mg/mL). Gram negative bacteria were the most resistant (MIC = MMC = 39 mg/mL). The combination of EO at sub-inhibitory concentrations with antibiotics showed a significant decrease in their individual MICs from 2 to 128 fold, being the best for ciprofloxacin and fluconazole against E. coli and C. albicans and C. glabrata, respectively.

Origanum vulgare ssp. hirtum Essential Oil as a Natural Intrinsic Hurdle against Common Spoilage and Pathogenic Microbes of Concern in Tomato Juice

The aim of the present study was to assess the commercial potential of the Origanum vulgare ssp. hirtum essential oil (OEO) as a natural intrinsic hurdle against common spoilage and pathogenic microbes in tomato juice. The main volatile compounds of the OEO identified by gas chromatography mass spectrometry (GC/MS) analysis were thymol and carvacrol, accounting for approximately 48% and 27%, respectively. Its activity against common food spoilage and pathogenic microbes was confirmed and the minimum inhibitory concentration (MIC), non-inhibitory concentration (NIC), and minimum lethal concentration (MLC) values were determined. OEO effectiveness was further validated in commercial tomato juice. Supplementation of tomato juice with OEO at concentrations lower than the MIC (350 ppm) resulted in significant delay of food spoilage and extension of the product’s shelf-life, as well as in inhibition of Listeria monocytogenes, Clostridium difficile, Saccharomyces cerevisiae, and Aspergillus niger growth after deliberate inoculation in both room and refrigerated temperatures. In conclusion, the results suggested that OEO may be used as an efficient intrinsic inhibitor of food spoilage and growth of pathogenic microbes in tomato juice.

Antioxidant and Antibacterial Activity of Essential Oils and Hydroethanolic Extracts of Greek Oregano (O. vulgare L. subsp. hirtum (Link) Ietswaart) and Common Oregano (O. vulgare L. subsp. vulgare)

Greek oregano and common oregano were compared in respect of the antioxidant and antibacterial activity of the corresponding essential oils and hydroethanolic extracts in relation with their chemical profile. The chemical composition of essential oils was determined by GC-MS and GC-FID, while extracts (phenolic acids and flavonoids fractions) were analyzed by HPLC-DAD. Based on given volatiles, the investigated subspecies represented two chemotypes: a carvacrol/γ-terpinene/p-cymene type in the case of Greek oregano and a sabinyl/cymyl type rich in terpinen-4-ol in common oregano. Within non-volatile phenolic compounds, rosmarinic acid appeared to dominate in both subspecies. Lithospermic acid B, chlorogenic acid and isovitexin were present only in Greek oregano extracts. However, the total content of flavonoids was higher in common oregano extracts. The essential oil and extract of Greek oregano revealed visibly stronger antibacterial activity (expressed as MIC and MBC) than common oregano, whereas the antioxidant potential (determined by DPPH, ABTS and FRAP) of these extracts was almost equal for both subspecies. In the case of Origanum plants, the potential application of essential oils and extracts as antiseptic and antioxidant agents in the food industry should be preceded by subspecies identification followed by recognition of their chemotype concerning both terpene and phenolics composition.

Evaluation of the inhibitory activity of essential oils against spoilage yeasts and their potential application in yogurt

Yeasts are the leading cause of spoilage in yogurt. Considering the high demand from consumers to use natural products as an alternative to additives, essential oils (EOs) could be a promising solution to guarantee high microbiological standards. The present study highlighted the in vitro antifungal potential of cinnamon, ginger, lemongrass, mandarin, orange, lemon and lime EOs against spoilage yeasts isolated from yogurts prepared with pasteurized buffalo milk. A total of 74 isolates represented by 14 different species of Candida, Rhodotorula, Debaryomyces, Kluyveromyces and Yarrowia genera were subjected to a disc diffusion assay, showing lemongrass EO to have the highest antifungal activity (40.97 ± 9.86 mm), followed by cinnamon (38.46 ± 6.59 mm) and orange (12.00 ± 4.52 mm) EOs. Yarrowia lipolytica was less susceptible to lemongrass EO than Candida sake and Yarrowia deformans isolates. Ginger EO exhibited the lowest efficacy. A minimum inhibitory concentration (MIC) assay showed the ability of lemongrass and cinnamon EOs to inhibit the growth of all selected isolates at concentrations between ≤0.31 and 1.25 μL/mL. Therefore, for the first time, the two best-performing EOs (lemongrass and cinnamon) based on in vitro assays were assessed for their potential roles as preservatives in an in vivo yogurt model prepared at the laboratory scale. Since some limitations, such as the inhibition of lactic acid bacteria by cinnamon EO, consequently leading to fermentation failure as well as species-specific antifungal activity of lemongrass EO, were observed, further studies are needed to explore the possibility of using a slightly higher concentration of lemongrass EO and/or combinations of different EOs and/or their components. Finally, since yogurt spoilage could also be prevented by correct sanitation procedures of the production environment, the sanitizers commonly used in the food industry were tested against all isolates, showing the high efficiency of alcohol-based sanitizers and the ineffectiveness of chlorine-based sanitizers.

Bioactivity of Different Chemotypes of Oregano Essential Oil against the Blowfly Calliphora vomitoria Vector of Foodborne Pathogens

Simple Summary

Calliphora vomitoria L. is a very common synanthropic blowfly. Since it is attracted by human food, it plays a main role in the transmission of foodborne diseases. Among aromatic plant essential oils (EOs), those of spices are the most suitable to protect food from insect pests. In the present work, we determined the bioactivity of three oregano EOs against C. vomitoria. The chemical analyses showed that the EOs belonged to three chemotypes, one with a prevalence of carvacrol and two with a prevalence of thymol. The bioassays showed that the bioactivity of the EOs significantly varies among chemotypes, with the thymol chemotype showing an overall higher efficacy compared to the carvacrol one.

Abstract

Blowflies play a substantial role as vectors of microorganisms, including human pathogens. The control of these insect pests is an important aspect of the prevention of foodborne diseases, which represent a significant public health threat worldwide. Among aromatic plants, spices essential oils (EOs) are the most suitable to protect food from insect pests. In this study, we determined the chemical composition of three oregano EOs and assessed their toxicity and deterrence to oviposition against the blowfly Calliphora vomitoria L. The chemical analyses showed that the EOs belonged to three chemotypes: one with a prevalence of carvacrol, the carvacrol chemotype (CC; carvacrol, 81.5%), and two with a prevalence of thymol, the thymol/p-cymene and thymol/γ-terpinene chemotypes (TCC and TTC; thymol, 43.8, and 36.7%, respectively). The bioassays showed that although all the three EOs chemotypes are able to exert a toxic activity against C. vomitoria adults (LD₅₀ from 0.14 to 0.31 μL insect⁻¹) and eggs (LC₅₀ from 0.008 to 0.038 μL cm⁻²) as well as deter the oviposition (Oviposition Activity Index, OAI, from 0.40 ± 0.04 to 0.87 ± 0.02), the bioactivity of oregano EOs significantly varies among the chemotypes, with the thymol-rich EOs (TCC and TTC) overall demonstrating more effectiveness than the carvacrol-rich (CC) EO.

Antimicrobial Effects of Essential Oils on Oral Microbiota Biofilms: The Toothbrush In Vitro Model

The present investigation intended to evaluate the bacteriostatic and bactericidal abilities of clove, oregano and thyme essential oils against oral bacteria in planktonic and biofilm states. Furthermore, aiming to mimic everyday conditions, a toothbrush in vitro model was developed. Determination of the minimum inhibitory concentration, minimum bactericidal concentration, minimum biofilm inhibitory concentration and minimum biofilm eradication concentration were achieved using the microdilution procedure. To simulate the toothbrush environment, nylon fibers were inoculated with oral bacteria, which, after incubation to allow biofilm development, were submitted to contact with the essential oils under study. Thyme and oregano essential oils revealed promising antimicrobial effects, both in growth inhibition and the destruction of cells in planktonic and biofilm states, while clove essential oil showed a weaker potential. Regarding the toothbrush in vitro model, observation of the nylon fibers under a magnifying glass proved the essential oil anti-biofilm properties. Considering the effects observed using the in vitro toothbrush model, a realistic approximation to oral biofilm establishment in an everyday use object, a putative application of essential oils as toothbrush sanitizers to help prevent the establishment of bacterial biofilm can be verified.

The Plant Sesquiterpene Nootkatone Efficiently Reduces Heterodera schachtii Parasitism by Activating Plant Defense

Plant parasitic nematodes, including the beet cyst nematode Heterodera schachtii, constitute a devastating problem for crops worldwide. The limited availability of sustainable management options illustrates the need for new eco-friendly control means. Plant metabolites represent an invaluable source of active compounds for the discovery of such novel antagonistic agents. Here, we evaluated the impact of eight plant terpenoids on the H. schachtii parasitism of Arabidopsis thaliana. None of the metabolites affected the plant development (5 or 10 ppm). Nootkatone decreased the number of adult nematodes on A. thaliana to 50%, with the female nematodes being smaller compared to the control. In contrast, three other terpenoids increased the parasitism and/or female size. We discovered that nootkatone considerably decreased the number of nematodes that penetrated A. thaliana roots, but neither affected the nematode viability or attraction to plant roots, nor triggered the production of plant reactive oxygen species or changed the plant's sesquiterpene profile. However, we demonstrated that nootkatone led to a significant upregulation of defense-related genes involved in salicylic and jasmonic acid pathways. Our results indicate that nootkatone is a promising candidate to be developed into a novel plant protection agent acting as a stimulator of plant immunity against parasitic nematodes.

Anti-Termitic Activity of Three Plant Extracts, Chlorpyrifos, and a Bioagent Compound (Protecto) against Termite Microcerotermes eugnathus Silvestri (Blattodea: Termitidae) in Egypt

A trend towards environmentally friendly chemicals for use in termite management has been occurring globally. This study examined three naturally occurring plant extracts from Lavandula latifolia (Spike lavender), Origanum vulgare (Marjorum), and Syzygium aromaticum (Clove) against the termite Microcerotermes eugnathus. Plant extract results were compared to two commercially used termite pesticides, the bio-insecticide, Bacillus thuringiensis var. kurstaki (Protecto 9.4% WP) and Dursban (Chlorpyrifos 48%). Gas chromatography-mass spectrometry (GC-MS) analysis was used to identify the main compounds in the three plant extracts. The main compounds in Lavandula Latifolia were linalool (21.49%), lavandulol (12.77%), β-terpinyl acetate (10.49%), and camphor (9.30%). Origanum vulgare extract contained thymol (14.64%), m-cymene (10.63%), linalool (6.75%), and terpinen-4-ol (6.92%) as main compounds. Syzygium aromaticum contained eugenol (99.16%) as the most abundant identified compound. The extract of O. vulgare caused the highest termite death rate, with an LC50 of 770.67 mg/L. Exposure to lavender extract showed a high death rate with an LC50 of 1086.39 mg/L. Clove extract did not show significant insecticidal activity with an LC50 > 2000 mg/L. Significant termiticide effects were found, with LC50 values of 84.09 and 269.98 mg/L for soldiers and workers under the application of Dursban and Protecto, respectively. The LC50 values reported for nymphs were <120, <164.5, and 627.87 mg/L after exposure to Dursban, Protecto, and O. vulgare extract, respectively. The results of the study show that some of the extracts have low toxicity compared to the bioagent and Dursban, and may show promise as natural termiticides, particularly as extracts from O. vulgare.

Antioxidant and Antibacterial Capacities of Origanum vulgare L. Essential Oil from the Arid Andean Region of Chile and its Chemical Characterization by GC-MS

This study aimed to characterize the in vitro antioxidant and antibacterial properties of oregano (Origanum vulgare) essential oil, as well as its chemical composition. To our best knowledge, there are few studies on oregano grown in the arid Andes region, but none on the metabolites produced and their bioactivity. This work identified fifty metabolites by Gas Chromatography–Mass Spectrometry (GC-MS)—monoterpene hydrocarbons, oxygenated monoterpenes, phenolic monoterpenes, sesquiterpene hydrocarbons, and oxygenated sesquiterpenes—present in the essential oil of oregano collected in the Atacama Desert. The main components of essential oregano oil were thymol (15.9%), Z-sabinene hydrate (13.4%), γ-terpinene (10.6%), p-cymene (8.6%), linalyl acetate (7.2%), sabinene (6.5%), and carvacrol methyl ether (5.6%). The antibacterial tests showed that the pathogenic bacteria Staphylococcus aureus and Salmonella enterica and the phytopathogenic bacteria Erwinia rhapontici and Xanthomonas campestris were the most susceptible to oregano oil, with the lowest concentrations of oil necessary to inhibit their bacterial growth. Moreover, oregano oil showed antibacterial activity against bacteria associated with food poisoning. In conclusion, O. vulgare from the arid Andean region possesses an important antibacterial activity with a high potential in the food industry and agriculture.

Extraction Techniques and Analytical Methods for Characterization of Active Compounds in Origanum Species

Phytochemical research based on ethnopharmacology is gaining interest in industries such as functional food, nutraceuticals, cosmetics and pharmaceutical industries. Plants and plant extracts are a rich source of bioactive secondary metabolites. These compounds are often involved in plant protection against biotic or abiotic stresses. The exploitation of available technologies should be oriented and intensified to extend and enhance the continued usefulness of the plants as renewable sources of chemicals, especially medicinal compounds. This current contribution is focused on extraction and analytical techniques for their isolation from the oregano species, their characterization and their potential antioxidative, as well as their antimicrobial, antifungal and anticarcinogenic properties. The work is structured rendering to the different steps involved in the research; starting with extraction and sample preparation, followed by discussing the analytical techniques employed for the isolation and identification of compound/s responsible for the biological activity and methods and techniques for biological activity assessment.

Optimizing the Growth, Health, Reproductive Performance, and Gonadal Histology of Broodstock Fantail Goldfish (Carassius auratus, L.) by Dietary Cacao Bean Meal

Simple Summary

Recently, the use of medicinal herbs for regulating reproduction has received much attention in aquaculture, as they are safe, effective, biodegradable, and locally available. The data on the use of cacao bean meal as a food supplement for fish are extremely scarce. This study assessed the possible effects of cacao bean meal as a feed supplement on the growth, health status, blood biochemical parameters, antioxidant, immune status, physiological parameters, female reproductive performance, and gonadal histological features of fantail goldfish. The experimental treatments consisted of three levels of cacao bean meal 0, 5, and 10 g kg⁻¹ diet with the sex ratio being four females:two males per replicate. The findings suggested that cacao bean meal can be used as a feed supplement in diets of broodstock fantail goldfish for improving the growth, health status, and female reproductive performance, economic efficiency, and gonadal histological structure.

Abstract

The potential effects of cacao bean meal, Theobroma cacao L., (CBM) on the growth, health status, blood biochemical parameters, antioxidant, immune status, physiological parameters, female reproductive performance, and gonadal histological features of fantail goldfish (Carassius auratus, L.) were evaluated using a complete randomized block design with sex as a block. The trial lasted for 60 days. A total of 54 healthy fantail goldfish (36 broodstock females and 18 broodstock males) were randomly allocated into three treatments with supplementation of three levels of cocoa powder 0, 5, and 10 g kg⁻¹ diet, CBM0, CBM5, and CBM10, respectively, with the sex ratio being four females:two males per replicate. The body weight gain and feed conversion ratio of males were increased in the CBM10 treatment (p < 0.05). The CBM10 diet improved relative feed costs (p < 0.05). Females fed on the CBM10 diet had an increase in the serum level of total protein (p = 0.001). Females fed on a diet supplemented with CBM5 showed a decrease in the serum level of triglyceride compared to females fed on CBM0 and CBM10 diets (p = 0.03). CBM10 diet increased the serum superoxide dismutase (SOD) activity of fish compared to CBM0 and CBM5 diets (p = 0.004). Serum levels of testosterone and estradiol were significantly increased in males fed on the CBM10 diet. The female reproductive performance was improved by CBM supplementation (p < 0.05). Ovarian histology exhibited increased granulation and follicle numbers after dietary CBM supplementation compared to the control treatment. Therefore, cacao bean meal can be used as a feed supplement in the diets of fantail goldfish for improving the growth, health status, and female reproductive performance, economic efficiency, and gonadal histological structure.