Correlative metabolite profiling approach to understand antioxidant and antimicrobial activities from citrus essential oils

The objective of this study was to investigate the chemical composition of the essential oils from citrus species, as well as their antioxidant and antimicrobial activities. By gas chromatography-mass spectrometry, we identified thirty-seven metabolites and a range of unique compounds, contributing to the discrimination of the species. Different biological potentialities were detected depending on the species supported the significant effect of the genetic factor. C. aurantium and C. limon exhibited the highest antioxidant activities which make them a potential source of natural preservative. C. limon exhibited the highest antibacterial activities and C. reticulata the highest antifungal activities. Essential oils extracted from these agro-wastes could serve as natural food preservatives to prevent food pathogens and then extending the shelf life. A set of potential metabolites could be implicated in the observed biological activity, underlying that the antimicrobial activity is a complex trait.     

Biological activity of Boswellia serrata Roxb. oleo gum resin essential oil: effects of extraction by supercritical carbon dioxide and traditional methods

The findings of this study suggests that chemical composition, essential oil yield, antioxidant and antimicrobial activity of Boswellia serrata oleo gum resin essential oils extracted by hydro distillation, steam distillation and supercritical fluid carbon dioxide methods vary greatly from each other. The optimum essential oil yield was obtained using hydro distillation method (8.18 ± 0.15 %). The essential oils isolated through different extraction methods contained remarkable amounts of total phenolics and total flavonoids. Essential oil isolated through supercritical fluid carbon dioxide extraction exhibited better antioxidant activity with highest free radical scavenging potential (96.16 ± 1.57 %), inhibition of linoleic acid oxidation (94.18 ± 1.47 %) and hydrogen peroxide free radical scavenging potential (68.25 ± 1.02 %). Moreover, the antimicrobial activity of essential oils was performed through well diffusion, resazurin microtiter plate and micro dilution broth assay assays. The essential oil isolated through steam distillation method revealed highest antimicrobial activity with maximum inhibition zone (24.21 ± 0.34 to12.08 ± 0.30 mm) and least MIC values (35.18 ± 0.77 to 281.46 ± 7.03 µg/mL). The comparison of chemical composition of essential oils isolated at different extraction methods have shown that the concentration of α-thujene, camphene, β-pinene, myrcene, limonene, m-cymene and cis-verbenol was higher in steam distilled essential oil as compared to hydro and supercritical fluid carbon dioxide extracted essential oils. These compounds may be responsible for the higher antimicrobial activity of Boswellia serrata oleo gum resin steam distilled essential oil.     

Determination of Chemical Composition,Total Phenolic,Antimicrobial, and Antioxidant Activities of Echinophora tenuifolia Essential Oil

In this study, the antioxidant and antimicrobial activities, total phenolic content, and essential oil composition of Echinophora tenuifolia L. subsp. sibthorpiana were investigated. The antioxidant activity of investigated essential oil was assessed by ABTS and DPPH assays. DPPH radical scavenging activity expressed by IC₅₀ was 2.84 g/L, whereas the TEAC value determined by ABTS assay was 0.032 g TEAC/kg plant. Total phenol content of essential oil determined by Folin-Ciocalteu method was calculated as 1.32 g GAE/kg plant. The essential oil extracted by hydrodistillation (Clevenger apparatus) was investigated by GC-MS technique and 78 compounds were identified. The main components of essential oils were found to be δ-3-carene (17.93%), p-cymene (8.99%), methyleugenol (16.41%), and α-phellandrene (9.33%). The antimicrobial activity of investigated essential oil was tested using a broth dilution method against 13 bacterial and 2 fungal microorganisms. The lowest minimum inhibitory concentration of essential oil against Bacillus cereus was 62.5 μg/mL while the antifungal activity was greater than 1000 μg/mL for both Candida albicans and Saccharomyces cereviciae. Investigated essential oil has a certain level of antioxidant and antimicrobial effects, which may be attributed to their chemical compounds. The antimicrobial efficiency of essential oil, especially against Bacillus cereus and Staphylocoocus spp., offers its effectiveness to treatment of wound or disease caused by Gram positive bacteria.     

Bioactivities of Achillea millefolium Essential Oil and Its Main Terpenes from Iran

Achillea millefolium L. comprises several relevant species for the food, cosmetic, perfumery, and pharmaceutical industries. Gas chromatography/mass spectrometry analysis revealed borneol to be a major component of A. millefolium, with its contribution to the essential oil being 36.35%. Borneol exhibited significant lipid peroxidation inhibition and antimicrobial activity against all tested bacterial strains. In addition, borneol had the highest antioxidant activity in all conducted assays. The borneol had significantly greater radical scavenging activity than other component essential oil and the reference antioxidant Trolox. In addition, a correlation between antioxidant activity and the total phenolic content was found. The borneol significantly inhibited nitric oxide production in lipopolysaccharide-activated macrophages (an in vitro model of inflammation). These results clearly show the antimicrobial, antioxidant, and anti-inflammatory effects of the plant essential oils.     

The influence of organ,season and drying method on chemical composition and antioxidant and antimicrobial activities of Juniperus phoenicea L. essential oils

BACKGROUND: Juniperus phoenicea is an important medicinal plant. In the present study, essential oils (18 samples) from leaves and berries of Juniperus phoenicea L. (Cupressaceae), obtained by various drying methods and in different collection months, were analysed by gas chromatography–mass spectrometry and also evaluated for in vitro antimicrobial and antioxidant activities. Correlations were studied between antimicrobial activity and the chemical composition of essential oils. RESULTS: Sixty‐seven compounds were identified in essential oils, representing 97.7–100%. Essential oils were dominated by monoterpenes and sesquiterpenes, which presented 35.0–93.3% and 6.7–62.0%, respectively, depending of organ, season and drying method. Antimicrobial tests showed that essential oils strongly inhibited the growth of Gram‐positive microorganisms and Mucor ramamnianus, but was inactive against Gram‐negative strains. Antioxidant activity was tested using the ABTS radical‐scavenging assay. Most samples showed good activity (the best IC₅₀ = 41.7 ± 1.5 mg L^?1). CONCLUSIONS: It could be concluded that drying of leaves of J. phoenicea in the sun and berries in oven‐drying was more suitable and was recommended for obtaining higher essential oil yield, but for a higher percentage of some special components such as α‐pinene and δ‐3‐carene shade‐drying was more suitable. Copyright © 2009 Society of Chemical Industry     

Salvia spp. plants-from farm to food applications and phytopharmacotherapy

Salvia is one of the largest genera of the family Lamiaceae. It is widely distributed in the temperate, subtropical, and tropical regions all over the world. Besides its ethnobotanical importance, some species such as S. officinalis (sage, common sage), S. sclarea (clary sage), S. lavandulifolia (Spanish sage), S. miltiorrhiza (danshen), and S. hispanica (chia) are traded on the market as a food and because of the interest in their essential oils and/or popularity in traditional medicine. The high diversity of the Salvia genus and phytochemical richness generate great interest for discovering new biological active compounds, including those found in essential oils. Salvia plant essential oils exhibit broad-spectrum pharmacological activities and represent great interest for food preservation as potential natural products. Thus, this review describes the phytochemical composition of essential oils from different Salvia spp. according to the geographic regions, plant organ, and phenological stage. Moreover, the cultivation and growing conditions of Salvia plants have been also revised. Finally, the interest on Salvia plants for food and pharmaceutical applications has been covered, through reporting their biological properties, including as antioxidant, antimicrobial, anti-alzheimer, hypotensive, anti-hyperglycemia, anti-hyperlipidemia, anti-cancer, and skin curative agents.     

Seasonal variation in content,chemical composition and antimicrobial and cytotoxic activities of essential oils from four Mentha species

BACKGROUND: The aim of the present study was to appraise variation in the chemical composition, and antimicrobial and cytotoxic activities of essential oils from the leaves of four Mentha species—M. arvensis, M. piperita, M. longifolia and M. spicata—as affected by harvesting season. Disc diffusion and broth microdilution susceptibility assays were used to evaluate the antimicrobial activity of Mentha essential oils against a panel of microorganisms. The cytotoxicity of essential oils was tested on breast cancer (MCF‐7) and prostate cancer (LNCaP) cell lines using the MTT assay. RESULTS: The essential oil contents of M. arvensis, M. piperita, M. longifolia and M. spicata were 17.0, 12.2, 10.8 and 12.0 g kg^?1 from the summer and 9.20, 10.5, 7.00 and 9.50 g kg^?1 from the winter crops, respectively. Gas chromatographic–mass spectrometric analysis revealed that mostly quantitative rather than qualitative variation was observed in the oil composition of each species. The principal chemical constituents determined in M. arvensis, M. piperita, M. longifolia and M. spicata essential oils from both seasons were menthol, menthone, piperitenone oxide and carvone, respectively. The tested essential oils and their major components exhibited notable antimicrobial activity against most of the plant and human pathogens tested. The tested essential oils also exhibited good cytotoxicity potential. CONCLUSION: Of the Mentha essential oils tested, M. arvensis essential oil showed relatively better antimicrobial and cytotoxic activities. A significant variation in the content of most of the chemical components and biological activities of seasonally collected samples was documented. Copyright © 2010 Society of Chemical Industry     

Chemical Composition,Antimicrobial, and Antioxidant Activities of Essential Oil and Ethanol Extract of Coriandrum sativum L. Leaves from Turkey

This study reports the chemical composition, antioxidant, and antimicrobial activity of the essential oil and ethanol extract of Coriandrum sativum L. leaves. Gas chromatography/mass spectrometry analysis identified 19 compounds representing 95.30% of the oil. (E)-2-decenal (29.87%), linalool (21.61%), (E)-2-dodecenal (7.03%), dodecanal (5.78%), (E)-2-undecenal (3.84%), (E)-2-tridecenal (3.56%), (E)-2-hexadecenal (2.47%), tetradecenal (2.35%), and α-pinene (1.64%) were the main components identified in the essential oil. The samples were screened for their antioxidant activities using 2,2-diphenyl-1-picrylhydrazyl radical scavenging and β-caroten bleaching assay. IC₅₀ value for ethanol extract of C. sativum was determined as 74.87 ± 0.03 μg/mL. Total antioxidant activity value for C. sativum ethanol extract was 85.85 ± 0.04%. Total phenolic content for ethanol extract of the plant was determined as 14.97 ± 0.05 mg gallic acid equivalents/g dry weight. The essential oil and ethanol extract were also tested for antimicrobial activity against 28 different foodborne microorganisms, including 19 bacteria, 7 fungi, and 2 yeast species. The ethanol extract of the plant showed weak antimicrobial activities against microbial strains in both disc diffusion and minimal inhibition concentration tests. This study suggested that Coriandrum sativum L. leaves may be used as a potential source of food flavoring, and for their antioxidants and antimicrobial properties.     

Liposomal incorporation of carvacrol and thymol isolated from the essential oil of Origanum dictamnus L. and in vitro antimicrobial activity

The chemical composition of the essential oils from Origanum dictamnus L. (wild and organic cultivated plant) was analysed by GC–MS. Carvacrol, thymol, p-cymene, and γ-terpinene were identified as major constituents and isolated from both samples. The above components were successfully encapsulated in phosphatidyl choline-based liposomes and the possible improvement of their antioxidant and antimicrobial activities was tested against selected microbia. The antimicrobial properties of the oils were tested by a diffusion technique against four Gram positive and four Gram negative bacteria and three human pathogenic fungi, as well as the food-borne pathogen, Listeria monocytogenes. The percentage of the encapsulated carvacrol, the major component of the oil, was determined by GC–FID. In order to investigate any possible synergistic or antagonistic effect between carvacrol/thymol and carvacrol/γ-terpinene, the antimicrobial activities of the mixtures, were also determined before and after encapsulation in liposomes. All tested compounds presented enhanced antimicrobial activities after the encapsulation. Finally, in all cases, their antioxidant activity using differential scanning calorimetry was studied, in order to gain knowledge about their oxidation stability.     

Designing novel industrial and functional foods using the bioactive compounds from Nigella sativa L. (black cumin): Biochemical and biological prospects toward health implications

Nigella sativa is one of the nutraceuticals that has gained popularity and studied extensively in recent decades as it is considered a safe medicinal plant for use as a dietary supplement. N. sativa contains a wide variety of bioactive substances, which include polyphenols, volatile oils (thymoquinone and p-cymene), proteins, and peptides. The biological attributes of N. sativa include antioxidant, antimicrobial, antifungal, anti-inflammatory, anticancer, antidiabetic, antihypertensive, hypolipidemic, and antioxidant activities, which have potential applications for the prevention of a variety of chronic diseases. In the food industry, N. sativa improves the sensory qualities, shelf life, strength, and freshness of foods, such as bread, pizza, biscuits, cookies, and cakes. This review discusses the industrial use of N. sativa, which includes processing technologies to enhance its health-promoting properties as well as the isolation of nutraceutical components.     

Profile of phenolic compounds in Trifolium pratense L. extracts at different growth stages and their biological activities

Although Trifolium pratense (Red Clover) is considered to be one of the leading crops for livestock grazing, it could also be used as a potential source of bioactive compounds in phytopharmacy. The aim of this study was to investigate the phenolic content and its biological activity at the growth phases (30 cm, 50 cm, and bud) of this plant. The phenolic compounds in methanolic extracts of T. pratense leaves at three growth stages, obtained by Microwave Assisted Extraction, were quantified using the HPLC-ESI-MS/MS technique, and their antioxidant and antimicrobial activity were assessed. Isoflavonoids, genistein, and daidzein, as well as other phenols, p-hydroxybenzoic and caffeic acids, kaempferol 3-O-glucoside, quercetin 3-O-glucoside, and hyperoside were found in all the extracts, but the content of these compounds was the highest in the extract of the plant at the lowest growth stage (30 cm, vegetative). Therefore, this extract showed the best antioxidant potential and it was most effective against bacterial strains such as Escherichia coli and Enterobacter aerogenes. These results indicated that red clover has potential health benefits, and that growth phase contributes to its biological activity. The extract of red clover at the growth stage of 30 cm is a great source of bioactive compounds and could be used in phytotherapy and nutrition.     

Phenol content related to antioxidant and antimicrobial activities of Passiflora spp. extracts

Methanolic extracts were prepared from different organs of plants from five Passiflora species obtained by zygotic embryo culture and evaluated for their capacity to quench DPPH and ABTS^•+ radicals in comparison to that of Trolox, a water soluble vitamin-E analogue. Moreover their antimicrobial activity against E. coli was tested by agar diffusion and turbidity assays. P. nitida, P. foetida, and P. palmeri showed antimicrobial activity. P. nitida and P. palmeri also showed high antioxidant activity. P. tenuifila and P. coriacea demonstrated antioxidant power but not antimicrobial activity. The phenolic content of the different extracts was studied and quantified by spectrophotometric methods, HPLC, and mass spectrometry. High antioxidant activity correlated with high amounts of o-diphenol and catechin. An unknown component, tentatively identified as structural isomer of isoschaftoside, appeared to correlate with antimicrobial activity.     

Antioxidant and antimicrobial activity and potential of heather (Erica spp.) extracts in the control of Listeria monocytogenes

In this work, heather and its flowers were studied regarding their antioxidant and antimicrobial activities. Plants were subjected to ultrasound-assisted methanolic extraction followed by fractionation. A phytochemical characterisation of extracts content in total phenols and flavonoids, and their antioxidant activity was performed. The antimicrobial activity was evaluated through the determination of minimum inhibitory concentration and by bioautography. Following, studies on the antilisterial potential were carried out by: time-kill curves, inhibition of biofilm formation and tolerance of Listeria monocytogenes to adverse conditions. The results evidenced the antioxidant activity in both extracts, as well as, the antimicrobial activity against Gram-positive bacteria. Concerning the evaluation of the antilisterial potential, a bacteriostatic behaviour and inhibition of biofilms formation ability were observed. Listeria monocytogenes showed an increased susceptibility to adverse conditions when preincubated with extracts. Thus, heather and its flowers may be a source of new compounds with antilisterial activity potential.     

Antimicrobial and antioxidant activity of spice essential oils

Essential oils of anise, bastard cardamom, cinnamon, dill, mace, zedoary, prikhom, and bitter ginger were determined for their antimicrobial and antioxidant activities. Of all, cinnamon oil had the highest antibacterial activity. The most sensitive bacteria was Bacillus cereus (0.5mg/mL minimum inhibitory concentration, MIC). Anise, cinnamon, dill, and prikhom exhibited strong antifungal activity against Rhodotorula glutinis, Aspergillus ochraceus, and Fusarium moniliforme. Two oil combinations: i) cinnamon and mace oils and ii) cinnamon and prikhom oils showed a synergistic effect against Staphylococcus aureus, Pseudomonas fluorescens, and Salmonella Rissen (0.32–0.38 mg/mL fractional inhibitory concentration index, FICI). Cinnamon, mace, and prikhom oils had strong antioxidant activity with 0.29–5.66 mg/mL IC₅₀, 61.46–68.52% antioxidant activity, 0.22–2.19 mM/mg reducing capacity, and 78.28–84.30% inhibition by 2,2-diphenyl-1-picrylhydrazyl (DPPH), β-carotene bleaching, ferric reducing (FRAP), and superoxide anion scavenging activity assays, respectively. These oils contained high amount of total phenolics (51.54–140.9 μg gallic acid equivalents/mg oil).     

An overview of research of essential oils by self-organizing maps: A novel approach for meta-analysis study

Essential oils (EOs) are commercially important products, sources of compounds with antioxidant and antimicrobial activities considered indispensable for several fields, such as the food industry, cosmetics, perfumes, pharmaceuticals, sanitary and agricultural industries. In this context, this systematic review and meta-analysis, a novel approach will be presented using chemometric tools to verify and recognize patterns of antioxidant, antibacterial, and antifungal activities of EOs according to their geographic, botanical, chemical, and microbiological distribution. Scientific papers were selected following the Preferred Reporting Items for Systematic Review and Meta-Analyses statement flow diagram, and the data were evaluated by the self-organizing map and hierarchical cluster analysis. Overall, this novel approach allowed us to draw an overview of antioxidants and antimicrobials activities of EOs reported in 2019, through 585 articles evaluated, obtaining a dataset with more than 10,000 data, distributed in more than 80 countries, 290 plant genera, 150 chemical compounds, 30 genera of bacteria, and 10 genera of fungi. The networks for geographic, botanical, chemical, and microbiological distribution indicated that Brazil, Asia, the botanical genus Thymus, species Thymus vulgaris L. “thyme,” the Lamiaceae family, limonene, and the oxygenated monoterpene class were the most representative in the dataset, while the species Escherichia coli and Candida albicans were the most used to assess the antimicrobial activity of EOs. This work can be seen as a guide for the processing of metadata using a novel approach with non-conventional statistical methods. However, this preliminary approach with EOs can be extended to other sources or areas of food science.     

Phenolic composition,antioxidant, antibacterial,larvacidal against Culex pipiens,and cytotoxic activities of Hyacinthella lineata steudel extracts

This study reports the phenolic composition, antioxidant, antibacterial, larvacidal, and cytotoxic activity of methanol and acetone extracts of Hyacinthella lineata leaves and bulbs. The phenolic composition of H. lineata was determined by HPLC. The most abundant component was gallic acid (421.9µg/g). The β-carotene/DPPH/ABTS/FRAP decoloration method was used to estimate the total antioxidant activity. The total antioxidant activity was the highest for bulb-methanol fraction (65.41 ± 0.05%). The total phenolic content for leaves-methanol extract of the plant was determined as 6.56 ± 4.027mg/mL gallic acid equivalents. Analysis of the antibacterial activity showed that the methanolic-bulb extract are efficient against gram positive and gram negative bacteria. The cytotoxic effect on Artemia salina was assessed by Brine shrimp assay. Brine shrimp lethality assay showed that LC₅₀ values of HBM were obtained as 4.105 ± 2.42μg/ml. The bulb extract of H. lineata showed the highest larvicidal activity against Cx pipiens with value LC₅₀ (64.3275μg/ml). This study suggested that H. lineata may be used as a potential source of antioxidant, and for their biological activity, cytotoxic and antimicrobial properties.     

Comparative study on the antioxidant capacity and cholinesterase inhibitory activity of Citrus aurantifolia Swingle, C. aurantium L., and C. bergamia Risso and Poit. peel essential oils

Abstract: The interest in medicinal plant research and in the aroma‐therapeutic effects of essential oils in humans has increased in recent years, especially for the treatment of pathologies of relevant social impact such as Alzheimer's disease. The present study was taken up to evaluate the antioxidant capacity and the acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activity of the peel essential oils from three Citrus species, C. aurantifolia Swingle, C. aurantium L., and C. bergamia Risso & Poit. Essential oils were analyzed by GC and GC‐MS and they contain mainly limonene, α‐pinene, β‐pinene, γ‐terpinene, and linalyl acetate. C. aurantifolia oil showed the highest radical scavenging activity on ABTS assay (IC₅₀ value of 19.6 μg/mL), while C. bergamia exhibited a good antioxidant activity evaluated by the β‐carotene bleaching test (IC₅₀= 42.6 μg/mL after 60 min of incubation). C. aurantifolia inhibited more selectively AChE. Obtained data suggest a potential use of Citrus oils as a valuable new flavor with functional properties for food or nutraceutical products with particular relevance to supplements for the elderly. Practical Application: The demonstrated antioxidant activity and procholinesterase properties of Citrus essential oils suggested their use as a new potential source of natural antioxidant to added as extra‐nutrient for using in food industries as a valuable new flavor with functional properties for food or nutraceutical products with particular relevance to supplements for the elderly.     

Biological activities of Agave by‐products and their possible applications in food and pharmaceuticals

Agave leaves are considered a by‐product of alcoholic beverage production (tequila, mezcal and bacanora) because they are discarded during the production process, despite accounting for approximately 50% of the total plant weight. These by‐products constitute a potential source of Agave extracts rich in bioactive compounds, such as saponins, phenolic compounds and terpenes, and possess different biological effects, as demonstrated by in vitro and in vivo tests (e.g. antimicrobial, antifungal, antioxidant, anti‐inflammatory, antihypertensive, immunomodulatory, antiparasitic and anticancer activity). Despite their positive results in biological assays, Agave extracts have not been widely evaluated in food systems and pharmaceutical areas, and these fields represent a potential route to improve the usage of Agave plants as food additives and agents for treating medical diseases. © 2017 Society of Chemical Industry     

ANTIOXIDATIVE AND ANTIBACTERIAL POTENTIALS OF ESSENTIAL OILS AND EXTRACTS ISOLATED FROM VARIOUS SPICE MATERIALS†

The antioxidant and antibacterial potentials of essential oils and acetone extracts of black pepper, cumin, black cumin and mace were carried out by different techniques. The antioxidative capacity of the essential oils and acetone extracts were evaluated against mustard oil by measuring peroxide and thibarbituric acid values at fixed intervals. In addition, their antioxidant potential was evaluated by 2, 2′‐diphenyl‐1‐picrylhydracyl radical and conjugated diene assays. Their reducing power was determined with standards, which proved the strong antioxidant capacity of essential oils and extracts. The antioxidant activity of essential oils and extracts exerted by all the antioxidant assays can be compared with synthetic antioxidants such as butylated hydroxyanisole and butylated hydroxytoluene. The antibacterial activity was studied by disk diffusion and poison food methods. Black cumin essential oil showed complete zone of inhibition (P < 0.05) against tested bacterial strains of Staphylococcus aureus, Bacillus cereus and Bacillus subtilis at 2 and 6 µL level by disk diffusion method. Black cumin and black pepper extracts showed complete reduction of colonies against tested bacterial strains of S. aureus, B. cereus and B. subtilisat 5 and 10 µL level by poison food method. Poison food method exhibited good results for the tested essential oils and extracts. Essential oils of black pepper, cumin, black cumin and mace may be used to stabilize mustard oil after screening.     

Biological,medicinal and toxicological significance of Eucalyptus leaf essential oil: a review

The genus Eucalyptus L'Heritier comprises about 900 species, of which more than 300 species contain volatile essential oil in their leaves. About 20 species, within these, have a high content of 1,8‐cineole (more than 70%), commercially used for the production of essential oils in the pharmaceutical and cosmetic industries. However, Eucalyptus is extensively planted for pulp, plywood and solid wood production, but its leaf aromatic oil has astounding widespread biological activities, including antimicrobial, antiseptic, antioxidant, chemotherapeutic, respiratory and gastrointestinal disorder treatment, wound healing, and insecticidal/insect repellent, herbicidal, acaricidal, nematicidal, and perfumes, soap making and grease remover. In the present review, we have made an attempt to congregate the biological ingredients of leaf essential oil, leaf oil as a natural medicine, and pharmacological and toxicological values of the leaf oil of different Eucalyptus species worldwide. © 2017 Society of Chemical Industry