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The present study was carried out to determine some biochemical characteristics, in particular the total polyphenol content and the free radical scavenging activity, of the extracts recovered from bulbs and aerial parts (these last often considered as by-products) of two landraces of A. ampeloprasum var. holmense cultivated in Southern Italy. For the first time, the capacity of the extracts of these landraces to inhibit the formation of biofilm of different Gram-negative and Gram-positive bacteria and to affect the metabolism of the cells present within the bacterial biofilm was evaluated. All extracts exhibited an amount of total polyphenols not lower than 2.86 mg/g of dried product and revealed a noteworthy antioxidant activity, with EC 50 values not exceeding 4.95 mg. In both cases, the aerial parts extracts were more effective than the bulb extracts, which also showed a minor amount of total polyphenols. The extracts inhibited mainly the adhesive capability of Pseudomonas aeruginosa and Staphylococcus aureus , by 95.78% and 85.01%, respectively. The extracts demonstrated to inhibit also the metabolism of the bacterial cells reaching levels up to 90%. Finally, as assessed by the assays performed on the 24-h preformed biofilms, all the extracts were also capable to cause a reduction in bacterial biomass and to affect their metabolism.

Essential oils (EOs) are one of the most important groups of plant metabolites responsible for their biological activities. This study was carried out to study the chemical composition and the antimicrobial effects of Artemisia herba-alba and Origanum majorana essential oils against some Gram-positive and Gram-negative bacteria, and a fungal strain isolated from spoiled butter. The plants were collected in the region Azzemour of South West Morocco and the EOs, extracted by hydrodistillation, were analyzed by GC-MS. The antimicrobial activity was determined using the agar paper disc method. The main components of A. herba-alba EO were cis-thujone, trans-thujone and vanillyl alcohol; in O. majorana EO terpinen-4-ol, isopulegol and β-phellandrene predominated. Both essential oils exhibited growth inhibiting activities in a concentration-dependent manner on several microorganism species. Our results demonstrated that O. majorana and A. herba-alba EOs could be effective natural antibacterial agents in foods., Competing Interests: The authors declare no conflict of interest.

There is a growing interest in a potential use of essential oils (EOs) as a replacement for traditional pesticides and herbicides. The aims of this study were to: (i) Identify the chemical composition of the two EOs derived from Origanum heracleoticum L. and O. majorana L., (ii) evaluate the in vitro antifungal activity of the EOs against some postharvest phytopathogens ( Botrytis cinerea , Penicillium expansum , Aspergillus niger and Monilinia fructicola ), (iii) evaluate the in vitro antibacterial activity against Bacillus megaterium , Clavibacter michiganensis , Xanthomonas campestris , Pseudomonas fluorescens and P. syringae pv. phaseolicola , (iv) evaluate the effect of both studied EOs on the spore germination percentage and their minimum inhibitory concentration (MIC) against M. fructicola , and (v) study the possible phytotoxicity of the two EOs and their major constituents, carvacrol for O. heracleoticum and terpinen-4-ol for O. majorana , against tha germination and initial radicle growth of radish, lettuce, garden cress and tomato. The two EOs demonstrated promising in vitro antimicrobial and antifungal activities against all tested microorganisms. EOs showed high inhibition of spore germination percentage at the minimal inhibitory concentration of 500 and 2000 µg/mL, respectively. Moreover, both germination and radical elongation of selected plant species were sensitive to the oils.

Plant essential oils (EOs) are one of the most relevant natural products due to their biological, medicinal, and nutritional properties. The promising biological effects of many plants EOs encourage researchers to study their biochemical properties to be used as possible natural alternatives for commercial pesticides and not only as herbal medicines. The current research has been conducted to study the microbicide effect of Solidago canadensis L. EO to control some common plant diseases caused by several postharvest phytopathogenic fungi (Monilinia fructicola, Botrytis cinerea, Aspergillus niger, and Penicillium expansum) in comparison with Azoxystrobin as a large spectrum fungicide. The antibacterial activity has been carried out against some phytopathogenic bacteria (Bacillus megaterium and Clavibacter michiganensis (G+ve) and Xanthomonas campestris, Pseudomonas fluorescens, and Pseudomonas syringae pv. phaseolicola (G-ve)) compared to the synthetic antibiotic Tetracycline. Minimum inhibitory concentration was carried out to determine the lowest effective EO dose using a 96-well microplate. The cell membrane permeability was also evaluated by measuring the electric conductivity (EC) to examine the possible mechanisms of action of S. canadensis EO. Chemical characterization of EO has been carried out using gas chromatography and mass spectrometry (GC-MS). Thirty-two identified components in S. canadensis EO presented 97.7% of total compounds in EO. The principal compounds were identified as germacrene D (34.9%), limonene (12.5%), α-pinene (11.6%), β-elemene (7.1%), and bornyl acetate (6.3%). In addition, S. canadensis EO demonstrated promising in vitro antimicrobial activities against the majority of tested phytopathogens at all tested concentrations., Competing Interests: The authors declare no conflict of interest.

To highlight the importance of the spices in the Mediterranean diet, the aim of the paper was to study the essential oil compositions and to clarify the potential differences in the biological activities of the three cardamom species. In the study, we compared the phytochemical profiles and biological activities of essential oils from Elettaria cardamomum , Aframomum corrorima and Amomum subulatum . The oils were analyzed using the GC and GC/MS techniques and were mainly constituted of the oxygenated monoterpenes which represents 71.4%, 63.0%, and 51.0% of all compounds detected in E. cardamomum , A. corrorima and A. subulatum essential oils, respectively, 1,8-cineole was the main common compound between the tree tested volatile oil. The essential oils showed significant antimicrobial activity against Gram-positive and Gram-negative microorganisms tested especially the fungal strains. The Ethiopian cardamom was the most active essential oil with fungal growth inhibition zone ranging from 12.67 to 34.33 mm, MICs values ranging from 0.048 to 0.19 mg/mL, and MBCs values from 0.19 to 1.75 mg/mL. The three tested essential oils and their main component (1,8-cineole) significantly increased the production of elastase and protease production, and motility in P. aeruginosa PAO1 in a dose dependent manner. In fact, at 10 mg/mL concentration, the three essential oils showed more than 50% of inhibition of elastolytic and proteolytic activities in P. aeruginosa PAO1. The same oils inhibited also the violacein production in C. violaceum strain. It was also noticed that at high concentrations, the A. corrorima essential oil significantly inhibited the germination of radish. A thorough knowledge of the biological and safety profiles of essential oils can produce applications of economic importance.

There is a growing interest in essential oils (EOs) as possible alternatives for traditional chemical pesticides. This study was carried out to characterize the chemical composition of the three EOs extracted from Verbena officinalis, Majorana hortensis, and Salvia officinalis using gas chromatography (GC) and GC-mass spectrometry (GC-MS) and to evaluate in vitro their efficacy against some phyto or human pathogens. The antifungal activity was investigated against Colletotrichum acutatum and Botrytis cinerea in comparison with Azoxystrobin as a large spectrum fungicide. Antibacterial activity was evaluated against Bacillus megaterium, Bacillus mojavensis, and Clavibacter michiganensis (G+ve) and Escherichia coli, Xanthomonas campestris, Pseudomonas savastanoi, and P. syringae pv. phaseolicola (G-ve) compared to a synthetic antibiotic tetracycline. Minimum inhibitory concentration was evaluated against the above tested fungi using 96-well microplate method. Results showed that the chemical structure of the three studied EOs was mainly composed of monoterpene compounds and all oils belong to the chemotype carvacrol/thymol. Results of GC analysis identified 64 compounds, which were identified based on their mass to charge ratio. Furthermore, the different concentrations of studied EOs inhibited the growth of tested microorganism in a dose-dependent manner.

Citrus medica cv. 'liscia' and C. medica cv. 'rugosa' are two taxa of citron, belonging to the biodiversity of South Italy, in particular of Amalfi Coast, in the Campania region. The chemical composition of the essential oils (EOs) from fruit peels of both C. medica cultivars was studied by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) analyses. In all, 100 compounds were identified, 82 for C. medica cv. 'liscia', accounting for 91.4% of the total oil, and 88 for C. medica cv. 'rugosa', accounting for 92.0% of the total oil. Monoterpene hydrocarbons are the main constituents in both oils of C. medica cv. 'liscia' (79.1%) and C. medica cv. 'rugosa' (80.2%). In both oils, limonene (67.2%-62.8%) and camphene (8.5%-10.9%) are the main constituents. The antimicrobial activity of the EOs was assayed against some bacterial strains: Bacillus cereus (DSM 4313), Bacillus cereus (DSM 4384), Staphylococcus aureus (DSM 25693), Pseudomonas aeruginosa (ATCC 50071), and Escherichia coli (DSM 8579). Low concentrations of C. medica cv. 'rugosa' EO showed an inhibitory effect on P. aeruginosa and higher concentrations inhibited more B. cereus (4384) and E. coli than S. aureus. The cytotoxicity of the EO was evaluated against SH-SY5Y cell line. The influence of the EO on the expression of adenylate cyclase 1 (ADCY1) was also studied. The antimicrobial activity registered confirm their traditional uses as food preserving agents and led us to hypothesize the possible use of these oils as antimicrobials. The alterations in ADCY1 expression suggested a role for limonene in effects on the central nervous system.

A variety of novel 5-aryl thiophenes 4a-g containing sulphonylacetamide (sulfacetamide) groups were synthesized in appreciable yields via Pd[0] Suzuki cross coupling reactions. The structures of these newly synthesized compounds were determined using spectral data and elemental analysis. Density functional theory (DFT) studies were performed using the B3LYP/6-31G (d, p) basis set to gain insight into their structural properties. Frontier molecular orbital (FMOs) analysis of all compounds 4a-g was computed at the same level of theory to get an idea about their kinetic stability. The molecular electrostatic potential (MEP) mapping over the entire stabilized geometries of the molecules indicated the reactive sites. First hyperpolarizability analysis (nonlinear optical response) were simulated at the B3LYP/6-31G (d, p) level of theory as well. The compounds were further evaluated for their promising antibacterial and anti-urease activities. In this case, the antibacterial activities were estimated by the agar well diffusion method, whereas the anti-urease activities of these compounds were determined using the indophenol method by quantifying the evolved ammonia produced. The results revealed that all the sulfacetamide derivatives displayed antibacterial activity against Bacillus subtiles, Escherichia coli, Staphylococcus aureus, Shigella dysenteriae, Salmonella typhae, Pseudomonas aeruginosa at various concentrations. Furthermore, the compound 4g N-((5-(4-chlorophenyl)thiophen-2-yl)sulfonyl) acetamide showed excellent urease inhibition with percentage inhibition activity ~46.23 ± 0.11 at 15 µg/mL with IC50 17.1 µg/mL. Moreover, some other compounds 4a-f also exhibited very good inhibition against urease enzyme.

This study is aimed at assessing the essential oil composition, total phenolic content, antimicrobial and antioxidant activities of Thymus vulgaris collected in five different area of the Campania Region, Southern Italy. The chemical composition of the essential oils was studied by GC-flame ionization detector (FID) and GC/MS; the biological activities were evaluated through determination of MIC and minimum bactericidal concentration (MBC) and evaluation of antioxidant activity. In total, 134 compounds were identified. The oils were mainly composed of phenolic compounds, and all oils belonged to the chemotype thymol. The antimicrobial activity of the five oils was assayed against ten bacterial strains. The oils showed different inhibitory activity against some Gram-positive pathogens. The total phenol content in the essential oils ranged from 77.6-165.1 mg gallic acid equivalents (GAE)/g. The results reported here may help to shed light on the complex chemotaxonomy of the genus Thymus. These oils could be used in many fields as natural preservatives of food and as nutraceuticals.

Deeper knowledge of the potentiality of aromatic plants can provide results of economic importance for food and pharmacological industry. The essential oils of seven Lamiaceae species were analyzed by gas chromatography-mass spectrometry and assayed for their antibacterial, antifungal and mutagenic activities. Monoterpenes in the oils ranged between 82.47% (hyssop oil) and 97.48% (thyme oil), being mainly represented by oxygenated compounds. The antibacterial activity was evaluated against six pathogenic and five non-pathogenic bacterial strains. Oregano and thyme oils showed the strongest antibacterial activity against the pathogenic ones. The antifungal activity was evaluated against six fungal strains of agrifood interest: the oils tested exhibited variable degrees of activity. Two Salmonella typhimurium strains were used to assess the possible mutagenic activity. No oil showed mutagenic activity. Data obtained let us hypothesise that the use of essential oils could be a viable and safe way to decrease the utilisation of synthetic food preservatives. Further research is needed to obtain information regarding the practical effectiveness of essential oils to prevent the growth of food borne and spoiling microbes under specific application conditions.

The chemical characterization of the essential oil of the endemic Moroccan species, Calendula maroccana, was achieved by GC and GC-MS methods. The antioxidant, antimicrobial and antibiofilm activities of this essential oil were also studied. Eighty-one compounds were identified in the essential oil, representing 94.82% of the total. Sesquiterpenes predominate in the essential oil; 2-Methoxy-4-vinylphenol (16.13%), δ-amorphene (13.56%), α-cedrene (6.23%), γ-curcumene (5.10%) and α-bisabolol (4.94%) were the main constituents. The antioxidant potential was evaluated by DPPH, FRAP and ABTS assays: the essential oil exhibited antioxidant effectiveness with IC50 values of 0.92, 0.3 and 1.7 mg/mL, respectively. Moreover, the essential oil showed potent antimicrobial activity as revealed by inhibition zone values against selected clinically important pathogenic microorganisms. Inhibition zone values of 15.33 ± 0.19, 23 ± 0.05 and 15.33 ± 0.33 mm were observed against Staphylococcus aureus, Candida albicans and C. tropicalis, respectively. The maximal and minimal inhibition concentration values were in the range of 0.25 ± 0.17 - 4.68 ± 0.10 mg/mL for bacteria and 0.06 ± 0.03 - 0.12 ± 0.14 mg/mL, for Candida. The essential oil showed potent anti-biofilm activity with dual actions, inhibiting (69 - 88%) and eradicating (75 - 92%) the biofilms formed by the three tested bacteria strains. Based on these results, this essential oil can be considered as a natural antioxidant, antibacterial and antibiofilm agent that could be applied in phytotherapy, pharmaceutical and food sectors. [ABSTRACT FROM AUTHOR]

The use of natural products to control several phytopathogens is now gaining a great interest because of the environmental risks deriving from the use of synthetic drugs in controlling pathogens. Salvia hispanica L., commonly known as chia, is a traditional food in Central and Southern America. The current research is focusing on the chemical characterization of the essential oil extracted from the aerial parts of chia plant (stem and leaves) using GC-MS analysis, evaluating its antimicrobial effects. The essential oil is constituted mainly of sesquiterpenes, with caryophyllenes as main constituents. Results of antimicrobial tests proved that the essential oil could be potentially utilized in controlling some phytopathogenic fungi and bacteria. [ABSTRACT FROM AUTHOR]

Laurus nobilis is native to the southern Mediterranean region and cultivated mainly in Europe and the USA as an ornamental and medicinal plant. The chemical composition of the essential oil (EO) from leaves of L. nobilis, collected in Southern Italy, was studied by GC and GC-MS. In all, 55 compounds were identified, accounting for 91.6% of the total essential oil. 1,8-Cineole (31.9%), sabinene (12.2%), and linalool (10.2%) were the main components. Antimicrobial and antifungal activities of EO and 1,8-cineole were determined in vitro. The cytotoxicity of the EO was evaluated against SH-SY5Y cell line, as well as the influence of the EO on the expression of adenylate cyclase 1 (ADCY1), suggesting possible essential oil effects on the Central Nervous System. [ABSTRACT FROM AUTHOR]

Peganum harmala L., also known as Syrian rue or Pègano, is a herbaceous plant belonging to the Zygohpyllaceae family, and is widely used in traditional medicine. The chemical composition of essential oils of P. harmala seeds from five different regions of Northern Africa (Algeria, Egypt, Libya, Morocco and Tunisia) was studied by GC and GC-MS analyses. A total of 105 compounds were identified, the main components being oxygenated monoterpenes and oxygenated sesquiterpenes. Eugenol is the main component in all oils. The antimicrobial activity of the essential oils was assayed against some bacterial strains: Staphylococcus aureus (DSM 25693), Bacillus cereus (DSM 4313), Bacillus cereus (DSM4384), Escherichia coli (DMS 857) and Pseudomonas aeruginosa (ATCC 50071). All the oils showed different inhibitory activity. In the twentieth century this is an important result; we need possible new botanical drugs because the problem of resistance to antimicrobial drugs has become apparent. Moreover, the essential oils were evaluated for their possible in vitro phytotoxic activity against germination and initial radicle growth of Raphanus sativus L., Lepidium sativum L., and Ruta graveolens L. The results showed that both germination and radical elongation were sensitive to the oils. [ABSTRACT FROM AUTHOR]

Chemical composition, antioxidant and anti-Vibrio spp. activities of the essential oil isolated from the aerial parts of Mentha spicata L. (spearmint) are investigated in the present study. The effect of the essential oil on Vibrio spp. biofilm inhibition and eradication was tested using the XTT assay. A total of 63 chemical constituents were identified in spearmint oil using GC/MS, constituting 99.9% of the total identified compounds. The main components were carvone (40.8% ± 1.23%) and limonene (20.8% ± 1.12%). The antimicrobial activity against 30 Vibrio spp. strains (16 species) was evaluated by disc diffusion and microdilution assays. All microorganisms were strongly affected, indicating an appreciable antimicrobial potential of the oil. Moreover, the investigated oil exhibited high antioxidant potency, as assessed by four different tests in comparison with BHT. The ability of the oil, belonging to the carvone chemotype, to inhibit or reduce Vibrio spp. biofilm warrants further investigation to explore the use of natural products in antibiofilm adhesion and reinforce the possibility of its use in the pharmaceutical or food industry as a natural antibiotic and seafood preservative against Vibrio contamination. [ABSTRACT FROM AUTHOR]

The increasing resistance of microorganisms to conventional chemicals and drugs is a serious and evident worldwide problem that has prompted research into the identification of new biocides with broad activity. Plants and their derivatives, such as essential oils, are often used in folk medicine. In nature, essential oils play an important role in the protection of plants. Essential oils contain a wide variety of secondary metabolites that are capable of inhibiting or slowing the growth of bacteria, yeasts and moulds. Essential oils and their components have activity against a variety of targets, particularly the membrane and cytoplasm, and in some cases, they completely change the morphology of the cells. This brief review describes the activity of essential oils against pathogenic bacteria. [ABSTRACT FROM AUTHOR]

Grewia asiatica L., is a species native to south Asia from Pakistan, east to Cambodia, cultivated primarily for its edible fruit and well-reputed for its diverse medicinal uses. Fruits are a rich source of nutrients such as proteins, amino acids, vitamins, and minerals and contain various bioactive compounds, like anthocyanins, tannins, phenolics and flavonoids. Different parts of this plant possess different pharmacological properties. Leaves have antimicrobial, anticancer, antiplatelet and antiemetic activities; fruit possess anticancer, antioxidant, radioprotective and antihyperglycemic properties; while stem bark possesses analgesic and anti-inflammatory activities. This review focuses on the botanical description, phytochemistry, nutritional studies and pharmacological properties of this plant. [ABSTRACT FROM AUTHOR]

The chemical composition of the essential oils of Melaleuca armillaris Sm., Melaleuca styphelioides Sm. and Melaleuca acuminata F. Muell., collected in Tunisia, was studied by means of GC and GC-MS analysis. In all, 46 compounds were identified, 38 for M. armillaris, 20 for M. acuminata and eight for M. styphelioides, respectively. The presence of a sesquiterpenic fraction (52.2%) characterized the oil from M. armillaris; M. sthypheliodes oil was rich in methyl eugenol, a phenolic compound (91.1%), while M. acuminata oil is mainly constituted by oxygenated monoterpenoids (95.6%). The essential oils were evaluated for their in vitro potentially phytotoxic activity against germination and initial radicle growth of Raphanus sativus L., Lepidium sativum L., Sinapis arvensis L., Triticum durum L. and Phalaris canariensis L. seeds. The radicle elongation of five seeds was inhibited at the highest doses tested, while germination of all seeds was not affected. Moreover, the essential oils showed low antimicrobial activity against eight selected microorganisms. [ABSTRACT FROM AUTHOR]

The present study evaluated the effects of thyme and balm essential oils on the 3-wk storage of fresh chicken breast meat at 4 °C. Thyme and, to a lesser extent, balm essential oils reduced DPPH (2,2-diphenyl-1-picrylhydrazyl) radical formation in the meat (25% to 30% and 20%, respectively). Treatment with the 2 essential oils also limited lipid peroxidation and the deterioration of sarcoplasmic proteins, helping to preserve the meat even after 2 wk of storage. Thyme and balm essential oils decreased the natural microflora present in the meat; total microbial content decreased down to 50% in comparison to the control samples. In addition, a clear effect on lactic acid bacterial growth was recorded. Balm essential oil significantly limited the growth of Salmonella sp., whereas thyme essential oil effectively inhibited the growth of Escherichia coli. Our data demonstrate that these 2 essential oils effectively reduced deteriorative processes in chicken meat and extended the shelf life of this fresh product. Practical Application: The essential oils of thyme and balm can protect the chicken meat from decomposition during the storage time. [ABSTRACT FROM AUTHOR]

Essential oils obtained from inflorescences of three Origanum vulgare L. ssp. hirtum (Link) Ietswaart samples, growing wild in different locations in Campania (Southern Italy), were analysed. Three chemotypes were found: the first, with a prevalence of carvacrol/thymol; the second, characterized by the prevalence of thymol/α-terpineol; the third, featuring a prevalence of linalyl acetate and linalool. This chemical study attempts to provide a contribution in shedding light on the relationship between chemical composition and biotypes and/or chemotypes in Origanum vulgare ssp. hirtum. The essential oils were also evaluated for their antibacterial activity against 10 selected microorganisms. The data obtained contribute to the future view to use the essential oils as natural preservatives for food products, due to their positive effect on their safety and shelf life. [ABSTRACT FROM AUTHOR]