Search

Tulsi (Holi Basil, Ocimum tenuiflorum) is extensively used in herbal medicine, and it includes two distinct subtypes; namely green Tulsi and purple Tulsi. Both types have similar medicinal properties. However, purple Tulsi contains a significantly higher amount of methyleugenol, which is genotoxic, and its daily intake is restricted. We developed a polymerase chain reaction-restriction fragment length polymorphism (PCR–RFLP) method to identify purple Tulsi. For this purpose, we selected a C > T single nucleotide polymorphism (SNP) in the ycf1 gene of the chloroplast genome that overlapped with a DdeI restriction site. The primers and PCR conditions were optimized to amplify a 797 bp DNA encompassing the C > T SNP, specifically from O. tenuiflorum. After restriction digestion of the PCR product with DdeI, green Tulsi was identified by two fragments (539 bp and 258 bp), and purple Tulsi was recognized by a single fragment (797 bp). Analysis of 40 Tulsi market samples revealed that only 36 (90%) were derived from O. tenuiflorum. The majority of the market samples were purple Tulsi (60%) or a mixture of green and purple Tulsi (27.5%), with some mixed samples containing up to 50% purple Tulsi. [ABSTRACT FROM AUTHOR]

Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the safety and efficacy of a tincture from the leaves of Eucalyptus globulus Labill. (eucalyptus tincture) when used as a sensory additive for all animal species. The product is a ■■■■■ solution, with a dry matter content of ~ 1.86%, which contains on average 0.454% phenolic acids and flavonoids (of which 0.280% was gallic acid), 0.0030% 1,8‐cineole and 0.00012% methyleugenol. In the absence of analytical data on the occurrence of mono‐ or diformylated adducts of acylphloroglucinols with terpenes in the tincture and in the absence of toxicity data, the Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) could not conclude on the use of eucalyptus tincture for long‐living and reproductive animals. For short‐living animals (species for fattening), the additive was considered of no concern at 4 mg/kg complete feed for chickens for fattening, 5 mg/kg for turkeys for fattening, 6 mg/kg for piglets and rabbits for meat production, 7 mg/kg for pigs for fattening, 16 mg/kg for veal calves (milk replacer), 14 mg/kg for cattle for fattening, sheep/goats and horses for fattening, and 15 mg/kg for salmonids. These levels were extrapolated to physiologically related minor species. No safety concern would arise for the consumer from the use of eucalyptus tincture up to the levels in feed considered of no concern. Eucalyptus tincture should be considered as irritant to skin and eyes, and as a dermal and respiratory sensitiser. The use of eucalyptus tincture as a flavour in animal feed was not expected to pose a risk for the environment. Since the leaves of E. globulus and their preparations were recognised to flavour food and their function in feed would be essentially the same, no demonstration of efficacy was considered necessary. [ABSTRACT FROM AUTHOR]

Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the safety and efficacy of a tincture from the dried flower bud of Syzygium aromaticum (L.) Merr. & L.M. Perry (clove tincture) when used as a sensory additive in feed and water for drinking for all animal species. The product is a ■■■■■) solution, with a dry matter content of ~ 1.66%. The product contains on average 0.511% phenolic acids (of which 0.0344% were flavonoids), 0.039% eugenol, 0.00019% methyleugenol and 0.00008% estragole. The Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) concluded that the use of clove tincture is very unlikely to be of safety concern for the target species up to the maximum proposed use level of 50 mg clove tincture/kg complete feed for all animal species, except for horses, for which the proposed use level is 200 mg/kg complete feed. The FEEDAP Panel considers that the use in water for drinking alone or in combination with use in feed should not exceed the daily amount that is considered very unlikely to be of safety concern when consumed via feed alone. No safety concern would arise for the consumer and the environment from the use of clove tincture up to the maximum proposed use levels in feed. The additive under assessment should be considered as irritant to skin and eyes, and as a dermal and respiratory sensitiser. When handling the additive, exposure of unprotected users to methyleugenol and estragole may occur. Therefore, to reduce the risk, the exposure of the users should be minimised. Since the flower buds of S. aromaticum and their preparations were recognised to flavour food and their function in feed would be essentially the same, no demonstration of efficacy was considered necessary. [ABSTRACT FROM AUTHOR]

Phenylpropenes are a class of natural products that are synthesised by a vast range of plant species and hold considerable promise in the flavour and fragrance industries. Many in vitro studies have been carried out to elucidate and characterise the enzymes responsible for the production of these volatile compounds. However, there is a scarcity of studies demonstrating the in vivo production of phenylpropenes in microbial cell factories. In this study, we engineered Escherichia coli to produce methylchavicol, methyleugenol and isoeugenol from their respective phenylacrylic acid precursors. We achieved this by extending and modifying a previously optimised heterologous pathway for the biosynthesis of chavicol and eugenol. We explored the potential of six S-adenosyl l-methionine (SAM)-dependent O-methyltransferases to produce methylchavicol and methyleugenol from chavicol and eugenol, respectively. Additionally, we examined two isoeugenol synthases for the production of isoeugenol from coniferyl acetate. The best-performing strains in this study were able to achieve titres of 13 mg L−1 methylchavicol, 59 mg L−1 methyleugenol and 361 mg L−1 isoeugenol after feeding with their appropriate phenylacrylic acid substrates. We were able to further increase the methyleugenol titre to 117 mg L−1 by supplementation with methionine to facilitate SAM recycling. Moreover, we report the biosynthesis of methylchavicol and methyleugenol from l-tyrosine through pathways involving six and eight enzymatic steps, respectively.

Alkenylbenzenes are naturally occurring secondary plant metabolites. While some of them are proven genotoxic carcinogens, other derivatives need further evaluation to clarify their toxicological properties. Furthermore, data on the occurrence of various alkenylbenzenes in plants, and especially in food products, are still limited. In this review, we tempt to give an overview of the occurrence of potentially toxic alkenylbenzenes in essential oils and extracts from plants used for flavoring purposes of foods. A focus is layed on widely known genotoxic alkenylbenzenes, such as safrole, methyleugenol, and estragole. However, essential oils and extracts that contain other alkenylbenzenes and are also often used for flavoring purposes are considered. This review may re-raise awareness of the need for quantitative occurrence data for alkenylbenzenes in certain plants but especially in final plant food supplements, processed foods, and flavored beverages as the basis for a more reliable exposure assessment of alkenylbenzenes in the future. [ABSTRACT FROM AUTHOR]

Following a request from the European Commission, the EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on the safety and efficacy of an essential oil from the leaves of Laurus nobilis L. (laurel leaf oil), when used as a sensory additive for all animal species. The additive contains up to 4% methyleugenol. The use of the additive at 2 mg/kg complete feed in dogs and cats was considered of low concern. For other long‐living and reproductive animals, the use of the additive at 10 mg/kg was considered of concern. For short‐living animals, the Panel had no safety concern when the additive is used at 10 mg/kg complete feed for turkeys for fattening, piglets and other growing Suidae, pigs for fattening, veal calves (milk replacer), cattle for fattening and other growing ruminants, horses and rabbits for meat production, salmonids and other fin fish; and at 8.5 mg/kg for chickens for fattening, other growing poultry and other minor species for fattening. The use of laurel leaf oil up to the highest level in feed which was considered of no concern for target animals was also expected to be of no concern for consumers. The additive should be considered as irritant to skin and eyes and the respiratory tract. Due to the high concentration of methyleugenol (≥ 1%), the additive was classified by the applicant as suspected of causing genetic defects and of causing cancer and should be handled accordingly. The use of the additive under the proposed conditions of use was not expected to pose a risk for the environment. Since the leaves of L. nobilis and their preparations were recognised to flavour food and their function in feed would be the same, no further demonstration of efficacy was considered necessary. [ABSTRACT FROM AUTHOR]

Many aromatic plant volatile compounds contain methyleugenol, which is an attractant for insect pollination and has antibacterial, antioxidant, and other properties. The essential oil of Melaleuca bracteata leaves contains 90.46% methyleugenol, which is an ideal material for studying the biosynthetic pathway of methyleugenol. Eugenol synthase (EGS) is one of the key enzymes involved in the synthesis of methyleugenol. We recently reported two eugenol synthase genes (MbEGS1 and MbEGS2) present in M. bracteata, where MbEGS1 and MbEGS2 were mainly expressed in flowers, followed by leaves, and had the lowest expression levels in stems. In this study, the functions of MbEGS1 and MbEGS2 in the biosynthesis of methyleugenol were investigated using transient gene expression technology and virus-induced gene silencing (VIGS) technology in M. bracteata. Here, in the MbEGSs genes overexpression group, the transcription levels of the MbEGS1 gene and MbEGS2 gene were increased 13.46 times and 12.47 times, respectively, while the methyleugenol levels increased 18.68% and 16.48%. We further verified the function of the MbEGSs genes by using VIGS, as the transcript levels of the MbEGS1 and MbEGS2 genes were downregulated by 79.48% and 90.35%, respectively, and the methyleugenol content in M. bracteata decreased by 28.04% and 19.45%, respectively. The results indicated that the MbEGS1 and MbEGS2 genes were involved in the biosynthesis of methyleugenol, and the transcript levels of the MbEGS1 and MbEGS2 genes correlated with the methyleugenol content in M. bracteata. [ABSTRACT FROM AUTHOR]

Asarum sieboldii Miq., a perennial herb of the family Aristolochiaceae, is widely used in China to treat cold, fever, aphthous stomatitis, toothache, gingivitis, and rheumatoid arthritis. Methyleugenol is the most representative pharmacological constituent of this medicinal herb. Cinnamoyl‐CoA reductase (CCR), which has been well known for occupying a critical position in the lignin biosynthesis pathway, is also shared with the biosynthesis of methyleugenol. To better understand the regulatory mechanisms of methyleugenol biosynthesis, a 1530‐bp long promoter region of the AsCCR1 gene was isolated. PLACE and PlantCARE analysis affirmed the existence of the core promoter elements such as TATA and CAAT boxes, abiotic stress‐responsive cis‐regulation elements like abscisic acid‐responsive element, G‐box, and MBS in the isolated sequence. The histochemical assay suggested that it was a constitutive promoter, highly expressed in the root tissue. Moreover, the region of −200 bp to ATG (start codon) was enough to drive the expression of It GUS gene. Treatments with low temperature and high concentration of gibberellin or abscisic acid demonstrated the abiotic stress‐induced expression of the AsCCR1 promoter. Overall, this study revealed the isolation and characterization of the AsCCR1 promoter. Moreover, it also provided a candidate gene for molecular breeding in A. sieboldii to enhance its pharmacological potential. [ABSTRACT FROM AUTHOR]

Methyleugenol (ME) has been classified as a "group 2B carcinogen" by IARC. Its positional isomer methylisoeugenol (MIE) has been considered to be of "generally recognized as safe'' status by FDA. ME was more cytotoxic than MIE in cultured mouse primary hepatocytes. The underlying mechanism of this difference is unclear. Our metabolism study revealed ME and MIE were oxidized to epoxides ME-E/MIE-E as well as to phase I metabolites ME-1'-OH (MEOH)/MIE-3'-OH (MIEOH). MEOH was further dehydrogenated to α,β-unsaturated ketone (Michael acceptor, ME-M) by P450 enzymes and was biotransformed to sulfate (ME-S) by sulfotransferases. However, MIEOH was mainly oxidized to α,β-unsaturated aldehyde (Michael acceptor, MIE-M) by P450s subsequently, while MIE-M was rapidly oxidized to cinnamic acid (MIE-C) catalyzed by aldehyde dehydrogenases. Furthermore, cinnamic acid (MIE-C) was found to be a very weak electrophilic metabolite. In vitro and in vivo studies showed that ME possesses higher metabolic activation efficiencies than MIE across three pathways, while MIE shows a higher efficiency in generating MIE-C compared to ME. Taken together, the observed difference in cytotoxicity between ME and MIE may stem from their difference in metabolic pathways due to the difference in the position of their double bonds.

Quorum sensing (QS) is a cell-to-cell communication in bacteria that couples gene expression through the accumulation of signaling molecules, which finally induce the production of several virulence factors and modulate bacterial behaviors. Plants have evolved an array of quorum sensing inhibitors (QSIs) to inhibit the pathogens, of which aromatic compounds are widely recognized. The essential oil of Melaleuca bracteata was found to exhibit anti-quorum sensing activity, and its principal bioactive component, methyleugenol (ME), had been isolated in our previous study. Here, ME interfered effectively with the QS-regulated processes of toxin secretion in Chomobacterium violaceum ATCC31532, resulting in strong inhibition of QS genes, cviR, cviI, vioA-E, hmsHNR, lasA-B, pilE1-3, and hcnABC, leading to impaired virulence, including violacein production, biofilm biomass, and swarming motility. The accumulation of the signal molecule (N-hexanoyl-DL-homoserine lactone, C6-HSL) in C. violaceum declined upon treatment with ME, suggesting an inhibition effect on the C6-HSL production, and the ME was also capable of degrading the C6-HSL in vitro assay. Molecular docking technique and the consumption change of exogenous C6-HSL in C. violaceum CV026 revealed the anti-QS mechanism of ME consisted of inhibition of C6-HSL production, potentially via interaction with CviR and/or CviI protein. Collectively, the isolated ME, the principal active components of M. bracteata EO, exhibited a wide range of inhibition processes targeting C. violaceum QS system, which supports the potential anti-pathogenic use of M. bracteata EO and ME for treatment of pathogen contamination caused by bacterial pathogens. [ABSTRACT FROM AUTHOR]

This study aimed to determine the chemical composition, antibacterial and anti-inflammatory activities of Melaleuca leucadendra leaf essential oils. Ten samples of leaves from M. leucadendra were collected on the salt zone of Fatick (Senegal). The corresponding oils were obtained by hydrodistillation and analyzed by GC/FID and GC/MS. Oil yields from dried leaves were ranged from 1.64% to 2.75%. The almost exclusive compound in all samples of M. leucadendra oils was methyleugenol (98.4–99.5%). The oil exhibited moderate activity against S. aureus and E. coli and no activity against E. faecalis and P. aeruginosa. Anti-inflammatory properties of oil (25, 100 and 150 mg/kg, bw) showed significant inhibition of rat paw oedema induced by carrageenan at the 3rd and 5th h (p < 0.001 and 0.0001, respectively) when compared with control and standard drug (acetylsalicylic acid). The experimental study revealed that M. leucadendra oil, a natural source of methyleugenol, displayed remarkable anti-inflammatory activity. [ABSTRACT FROM AUTHOR]

Alkenylbenzenes represent a group of naturally occurring substances that are synthesized as secondary metabolites in various plants, including nutmeg and basil. Many of the alkenylbenzene-containing plants are common spice plants and preparations thereof are used for flavoring purposes. However, many alkenylbenzenes are known toxicants. For example, safrole and methyleugenol were classified as genotoxic carcinogens based on extensive toxicological evidence. In contrast, reliable toxicological data, in particular regarding genotoxicity, carcinogenicity, and reproductive toxicity is missing for several other structurally closely related alkenylbenzenes, such as myristicin and elemicin. Moreover, existing data on the occurrence of these substances in various foods suffer from several limitations. Together, the existing data gaps regarding exposure and toxicity cause difficulty in evaluating health risks for humans. This review gives an overview on available occurrence data of myristicin, elemicin, and other selected alkenylbenzenes in certain foods. Moreover, the current knowledge on the toxicity of myristicin and elemicin in comparison to their structurally related and well-characterized derivatives safrole and methyleugenol, especially with respect to their genotoxic and carcinogenic potential, is discussed. Finally, this article focuses on existing data gaps regarding exposure and toxicity currently impeding the evaluation of adverse health effects potentially caused by myristicin and elemicin. [ABSTRACT FROM AUTHOR]

Following a request from the European Commission, the EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on the safety and efficacy of an essential oil from the leaves of Agathosma betulina (P.J. Bergius) Pillans (buchu leaf oil), when used as a sensory additive (flavouring) in feed and water for drinking for all animal species. The FEEDAP Panel concluded that the essential oil under assessment is safe up to the maximum proposed use levels in complete feed of 0.1 mg/kg for chickens for fattening, 0.15 mg/kg for laying hens, turkeys for fattening and rabbits, 0.20 mg/kg for piglets, 0.25 mg/kg for pigs for fattening, 0.30 mg/kg for sows and dairy cows, 0.45 mg/kg for cattle for fattening, sheep, goats and horses, 0.5 for veal calves (milk replacer), fish, ornamental fish and dogs. For cats, the calculated maximum safe level in feed is 0.2 mg/kg complete feed. The FEEDAP Panel considered that the use in water for drinking is safe provided that the total daily intake of the additive does not exceed the daily amount that is considered safe when consumed via feed. No concerns for consumer safety were identified following the use of the additive up to the highest safe levels in feed. The essential oil under assessment should be considered as irritant to skin and eyes, and as a skin and respiratory sensitiser. The use of the additive in animal feed under the proposed conditions was not expected to pose a risk for the environment. Buchu leaf oil was recognised to flavour food. Since its function in feed would be essentially the same as that in food, no further demonstration of efficacy was considered necessary. [ABSTRACT FROM AUTHOR]

Following a request from the European Commission, the EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on the safety and efficacy of olibanum extract from Boswellia serrata Roxb. ex Colebr., when used as a sensory additive (flavouring) in feed for all dogs and horses. The FEEDAP Panel concluded that the additive under assessment is safe for horses at the maximum proposed use level of 100 mg/kg in complete feed. For dogs, the calculated safe concentration in feed is 330 mg/kg complete feed. The additive is considered safe for consumers when used at the proposed conditions of use in horses. The additive under assessment should be considered as non‐irritant to skin and eyes, but in the absence of data, no conclusion can be drawn on its potential to be a dermal and respiratory sensitiser. The use of the additive under the proposed conditions of use in feed for horses was not expected to pose a risk for the environment. Boswellia species and their preparations were recognised to flavour food. Since their function in feed would be essentially the same as that in food, no further demonstration of efficacy was considered necessary. [ABSTRACT FROM AUTHOR]

Alkenylbenzenes are naturally occurring secondary plant metabolites. While some of them are proven genotoxic carcinogens, other derivatives need further evaluation to clarify their toxicological properties. Furthermore, data on the occurrence of various alkenylbenzenes in plants, and especially in food products, are still limited. In this review, we tempt to give an overview of the occurrence of potentially toxic alkenylbenzenes in essential oils and extracts from plants used for flavoring purposes of foods. A focus is layed on widely known genotoxic alkenylbenzenes, such as safrole, methyleugenol, and estragole. However, essential oils and extracts that contain other alkenylbenzenes and are also often used for flavoring purposes are considered. This review may re-raise awareness of the need for quantitative occurrence data for alkenylbenzenes in certain plants but especially in final plant food supplements, processed foods, and flavored beverages as the basis for a more reliable exposure assessment of alkenylbenzenes in the future.

Following a request from the European Commission, the EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on the safety and efficacy of a tincture from the bark of Cinnamomum verum J. Presl (cinnamon tincture) when used as a sensory additive in feed and water for drinking for all animal species. The product is a water/ethanol ■■■■■ solution, with a dry matter content of approximately 0.9%. The product contains on average 0.344% polyphenols (of which 0.001% are flavonoids) and 0.001% cinnamaldehyde. Methyleugenol was present at the limit of detection in one out of the five batches examined. The FEEDAP Panel concluded that cinnamon tincture is safe at the maximum proposed use level of 50 mg/kg complete feed for all animal species except horses. For horses, the maximum proposed use level of 60 mg/kg complete feed is considered safe. No safety concern would arise for the consumer from the use of cinnamon tincture up to the highest proposed use levels in feed. The additive under assessment should be considered as irritant to skin and eyes, and as a skin and respiratory sensitiser. The use of the cinnamon tincture as a flavour in animal feed is not expected to pose a risk for the environment. Since C. verum and cinnamon bark extracts are recognised to flavour food and their function in feed would be essentially the same as that in food, no further demonstration of efficacy is considered necessary for the tincture under application. [ABSTRACT FROM AUTHOR]

Many aromatic plant volatile compounds contain methyleugenol, which is an attractant for insect pollination and has antibacterial, antioxidant, and other properties. The essential oil of Melaleuca bracteata leaves contains 90.46% methyleugenol, which is an ideal material for studying the biosynthetic pathway of methyleugenol. Eugenol synthase (EGS) is one of the key enzymes involved in the synthesis of methyleugenol. We recently reported two eugenol synthase genes (MbEGS1 and MbEGS2) present in M. bracteata, where MbEGS1 and MbEGS2 were mainly expressed in flowers, followed by leaves, and had the lowest expression levels in stems. In this study, the functions of MbEGS1 and MbEGS2 in the biosynthesis of methyleugenol were investigated using transient gene expression technology and virus-induced gene silencing (VIGS) technology in M. bracteata. Here, in the MbEGSs genes overexpression group, the transcription levels of the MbEGS1 gene and MbEGS2 gene were increased 13.46 times and 12.47 times, respectively, while the methyleugenol levels increased 18.68% and 16.48%. We further verified the function of the MbEGSs genes by using VIGS, as the transcript levels of the MbEGS1 and MbEGS2 genes were downregulated by 79.48% and 90.35%, respectively, and the methyleugenol content in M. bracteata decreased by 28.04% and 19.45%, respectively. The results indicated that the MbEGS1 and MbEGS2 genes were involved in the biosynthesis of methyleugenol, and the transcript levels of the MbEGS1 and MbEGS2 genes correlated with the methyleugenol content in M. bracteata.

Subcritical extraction of Rosa damascena Mill. was performed with Freon 143a. The pressure and duration of the process were studied to obtain the yield. It was found that a short-time triple extraction at low pressures of 5-6 bar resulted in the highest yield - 0.151%. The chemical composition of the product revealed a high scent content: β-phenylethyl alcohol (25.6 - 54.1%), citronellol (1.5 - 2.3%), geraniol (1.0 - 3.9%) and nerol (1.9 - 2.9%). The distribution of paraffins' content was: nonadecane (2.7 - 4.9%), nonadecene (3.1 - 5.6%), eicosane (4.4 - 11.6%) and heneicosane (4.4 - 9.8%). The deviations in the constituents of the day product and the year batch production were discussed. The yield and composition were compared with other rose aromatic products. The content of methyleugenol, potential genotoxic and carcinogenic agent was regular low (0.4 - 0.8%), comparing the essential oil (up to 4%). [ABSTRACT FROM AUTHOR]

Copyright of ScienceRise: Pharmaceutical Science is the property of PC TECHNOLOGY CENTER and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Alkenylbenzenes represent a group of naturally occurring substances that are synthesized as secondary metabolites in various plants, including nutmeg and basil. Many of the alkenylbenzene-containing plants are common spice plants and preparations thereof are used for flavoring purposes. However, many alkenylbenzenes are known toxicants. For example, safrole and methyleugenol were classified as genotoxic carcinogens based on extensive toxicological evidence. In contrast, reliable toxicological data, in particular regarding genotoxicity, carcinogenicity, and reproductive toxicity is missing for several other structurally closely related alkenylbenzenes, such as myristicin and elemicin. Moreover, existing data on the occurrence of these substances in various foods suffer from several limitations. Together, the existing data gaps regarding exposure and toxicity cause difficulty in evaluating health risks for humans. This review gives an overview on available occurrence data of myristicin, elemicin, and other selected alkenylbenzenes in certain foods. Moreover, the current knowledge on the toxicity of myristicin and elemicin in comparison to their structurally related and well-characterized derivatives safrole and methyleugenol, especially with respect to their genotoxic and carcinogenic potential, is discussed. Finally, this article focuses on existing data gaps regarding exposure and toxicity currently impeding the evaluation of adverse health effects potentially caused by myristicin and elemicin.

Copyright of Tobacco Science & Technology is the property of Tobacco Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Aniba canelilla (Kunth) Mez, popularly known as “casca preciosa” (precious bark), falsa canela (cinnamon-scented) Casca-do-maranhão (bark of maranhão), and Folha-preciosa (precious leaf), is an aromatic species of the Lauraceae family, widely distributed in the Amazon region. In traditional medicine, it is indicated for the treatment of a great diversity of diseases, including digestive, respiratory, inflam]matory, painful, and central nervous system disorders, it is administered mainly in the form of tea or decoction orally. Its essential oil is referred to as a natural antioxidant for food preservation and disease control, showing great potential for use in the cosmetics, perfumery, and pharmaceutical products sector. The present review aimed to discuss critically and comprehensively the ethnobotanical characteristics, phytochemical constitution, and scientifically tested biological properties of A. canelilla, systematizing the knowledge about the species and proposing new perspectives for research and development. The chemical composition of A. canelilla includes 1-nitro-2-phenylethane, metyleugenol, eugenol, safrol, anabasin, anbin, tannin, α-pinene, b-pinene, b-felandren, b-caryophyllene, b-sesquifelandren, p-cymene, linalool, α-copaene, and spatulenol. Researches with ethanolic extracts, essential oils, and major constituents (1-nitro-2-phenylethane and metyleugenol) have revealed antioxidant, antinociceptive, anti-inflammatory, cardio-modulating, hypotensive (vasorelaxant), hypnotic, anxiolytic, anticholinesterase, and antibiotic properties (trypanomicidal, leishmanicidal, and antifungal). Some of these effects are potentially beneficial for aging-related diseases treatment, such as cardio and cerebrovascular, chronic inflammatory, neurological, and degenerative diseases. However, it is necessary to advance in the research of its clinical use and development of therapeutic products.

A new strain of Cymbopogon khasianus rich in methyl eugenol was identified and named Jor Lab L-9. It is stable for production of essential oil yield (average 0.81%; σ 2 di = 0.00) and methyl eugenol (average 74.56%; σ 2 di = 0.06). This variety was registered with ICAR-NBPGR, New Delhi, India, under registration number INGR-18037. [ABSTRACT FROM AUTHOR]

Aniba canelilla (Kunth) Mez, popularly known as "casca preciosa" (precious bark), falsa canela (cinnamon-scented) Casca-do-maranhão (bark of maranhão), and Folha-preciosa (precious leaf), is an aromatic species of the Lauraceae family, widely distributed in the Amazon region. In traditional medicine, it is indicated for the treatment of a great diversity of diseases, including digestive, respiratory, inflam]matory, painful, and central nervous system disorders, it is administered mainly in the form of tea or decoction orally. Its essential oil is referred to as a natural antioxidant for food preservation and disease control, showing great potential for use in the cosmetics, perfumery, and pharmaceutical products sector. The present review aimed to discuss critically and comprehensively the ethnobotanical characteristics, phytochemical constitution, and scientifically tested biological properties of A. canelilla , systematizing the knowledge about the species and proposing new perspectives for research and development. The chemical composition of A. canelilla includes 1-nitro-2-phenylethane, metyleugenol, eugenol, safrol, anabasin, anbin, tannin, α-pinene, b-pinene, b-felandren, b-caryophyllene, b-sesquifelandren, p-cymene, linalool, α-copaene, and spatulenol. Researches with ethanolic extracts, essential oils, and major constituents (1-nitro-2-phenylethane and metyleugenol) have revealed antioxidant, antinociceptive, anti-inflammatory, cardio-modulating, hypotensive (vasorelaxant), hypnotic, anxiolytic, anticholinesterase, and antibiotic properties (trypanomicidal, leishmanicidal, and antifungal). Some of these effects are potentially beneficial for aging-related diseases treatment, such as cardio and cerebrovascular, chronic inflammatory, neurological, and degenerative diseases. However, it is necessary to advance in the research of its clinical use and development of therapeutic products. [ABSTRACT FROM AUTHOR]

Asarum sieboldii Miq., a perennial herb in the family Aristolochiaceae, is widely used to treat colds, fever, headache and toothache in China. However, little is known about the drought-tolerance characteristics of A. sieboldii. In this study, to elucidate the molecular–genetic mechanisms of drought-stress tolerance of A. sieboldii, RNA-seq was conducted. In total, 53,344 unigenes were assembled, and 28,715 unigenes were annotated. A total of 6444 differential-expression unigenes (DEGs) were found, which were mainly enriched in phenylpropanoid, starch and sucrose metabolic pathways. Drought stress revealed significant up-regulation of the unigenes encoding PAL, C4H, HCT, C3H, CCR and IGS in the methyleugenol-biosynthesis pathway. Under the condition of maintaining drought for 15 days and 30 days, drought stress reduced the biosynthesis of volatile oil by 24% and 38%, respectively, while the production of key medicinal ingredients (such as methyl eugenol) was increased. These results provide valuable information about the diverse mechanisms of drought resistance in the A. sieboldii, and the changes in the expression of the genes involved in methyleugenol biosynthesis in response to drought stress.

This study investigated the anaesthetic potential of the essential oil from the leaves of Piper divaricatum (EOPD) through evaluation of the behaviour and electromyographic (EMG) recordings from the fish Colossoma macropomum which was used as an animal model. Initially, fish (3.9 ± 0.3 g; 6.4 ± 0.49 cm, total length) were subjected to short-term anaesthetic baths in five different concentrations of the EOPD: 25, 30, 35, 40 and 45 μL.L−1 to record the latencies for deep anaesthesia and recovery. Ten fish per concentration were used (n = 10) and each animal was considered a replicate and used only once. Thereafter, for the evaluation of EMG, fish (5.6 ± 1.8 g; 8.7 ± 0.52 cm, total length) were assigned to the following groups: a) sham control (basal recordings) and b) fish exposed to the EOPD at 40 μL.L−1 and subsequent recovery in anaesthetic-free water. Nine fish per analysis (n = 9) were used. The EOPD presented a high concentration of methyleugenol (71.36%) and prompted immediate behavioural changes in fish. Initially, hyperactivity was observed, followed by loss of the righting reflex and full body immobilization. All concentrations tested were capable to promote an anaesthetic-like state in tambaqui, with 40 μL.L−1 being the minimal concentration necessary to induce a rapid immobilization, i.e. < 3 min. The EMG showed a marked and reversible myorelaxation effect, confirming this oil as an indisputable muscle relaxant agent. The EOPD was capable of promoting a general anaesthesia-like state, with complete body immobilization of Colossoma macropomum at all concentrations tested. Gradual increases in frequency and amplitude of EMG tracings confirm the reversibility and uneventful resumption of normal swimming behaviour observed during recovery. Our results underscore the anaesthetic potential and myorelaxant effects of Piper divaricatum essential oil. • This is the first study to report the Piper divaricatum essential oil as an anaesthetic for fish. • All concentrations tested induced full body immobilization and loss of the righting reflex in Colossoma macropomum. • P. divaricatum essential oil dampened skeletal muscle contraction power in C. macropomum. [ABSTRACT FROM AUTHOR]

Eugenia samanensis Alain is an endangered species of Myrtaceae unique to the Samaná Peninsula, Dominican Republic. We investigated its foliar essential oil (EO) composition from dried leaves, extracted via hydrodistillation, by gas chromatography-mass spectrometry (GC-MS) for identification and gas chromatography-flame ionization detection (GC-FID) for quantification. E. samanensis leaves produced an average of 1.6 ± 0.1% (w/w) EO and 23 compounds were identified, representing 98.4% of the EO composition. The EO composition consisted of 84.4% phenylpropenes, 8.9% oxygenated monoterpenes, 4.0% oxygenated sesquiterpenes, 0.4 % monoterpenes, 0.4% sesquiterpenes, and 0.25% other. The EO was richest in the phenylpropene, methyleugenol. The abundance of phenylpropenes in the EO of E. samanensis may be unique to Eugenia, suggesting the need for further research to elucidate the biological function of these compounds, to review the taxonomic status of this species, and to perform further studies to explain the high phenylpropene content of this species. [ABSTRACT FROM AUTHOR]

Abstract The presence and accompanying risks of methyleugenol and eugenol in herbal beverages available on the Indonesian market were evaluated. Methyleugenol was detected in 49 out of 114 samples, at levels amounting to 2.6–443.7 μg/g, while 4 samples contained eugenol at 21.4–101.2 μg/g. The EDI resulting from drinking these preparations amounted to 0.1–51.2 μg/kg bw/day and 1.1–3.3 μg/kg bw/day, respectively for samples targeted at adults and children. A BMDL 10 value of 22.2 mg/kg bw/day for methyleugenol was defined using literature data and model averaging. MOE values were below 10,000 for 46 samples (40.4%), indicating a priority for risk management when assuming daily lifelong consumption, while the EDI for 4 samples containing eugenol did not exceed the ADI of 2.5 mg/kg bw thus did not raise a concern for human health. Using Haber's rule to correct for less than lifetime exposure, consumption of methyleugenol via these beverages would be of low concern when consumed for less than 2 weeks/year during a lifetime. This conclusion holds for herbal beverages collected by targeted sampling, not for all herbal beverages on the Indonesian market. The study provides data that can support establishment of a maximum permitted level (MPL) for methyleugenol in herbal beverages in Indonesia. Graphical abstract Image 1 Highlights • Methyleugenol and eugenol were quantified in Indonesian herbal beverages. • An exposure and risk assessment was performed. • Lifetime daily consumption of 46 out of 114 samples indicate a priority for risk management. • To be of low concern consumption should be less than 2 weeks a year during a lifetime. • The level of eugenol in most of the beverages did not raise a concern. [ABSTRACT FROM AUTHOR]

Abstract Carrot (Daucus carota subsp. sativus) is a widely cultivated root vegetable of high economic importance. The aroma of carrot roots and aboveground organs is mainly defined by terpenes. We found that leaves of orange carrot cultivar also produce considerable amounts of the phenylpropenes methyleugenol and methylisoeugenol. Notably, methyleugenol is most abundant in young leaves, while methylisoeugenol is the dominant phenylpropene in mature leaf tissue. The goal of the present study was to shed light on the biochemistry and molecular biology of these compounds' biosynthesis and accumulation. Using the available genomic and transcriptomic data, we isolated a cDNA encoding eugenol/isoeugenol synthase (DcE(I)GS1), an NADPH-dependent enzyme that converts coniferyl acetate to eugenol. This enzyme exhibits dual product specificity and yields propenylphenol isoeugenol alongside allylphenol eugenol. Furthermore, we identified a cDNA encoding S -adenosyl-L-methionine:eugenol/isoeugenol O -methyltransferase 1 (DcE(I)OMT1) that produces methyleugenol and methylisoeugenol via methylation of the para -OH-group of their respective precursors. Both DcE(I)GS1 and DcE(I)OMT1 were expressed in seeds, roots, young and mature leaves, and the DcE(I)OMT1 transcript levels were the highest in leaves. The DcE(I)GS1 protein is 67% identical to anise t -anol/isoeugenol synthase and displays an apparent K m of 247 μM for coniferyl acetate. The catalytic efficiency of DcEOMT1 with eugenol is more than five-fold higher than that with isoeugenol, with K m values of 40 μM for eugenol, and of 115 μM for isoeugenol. This work expands the current knowledge of the enzymes involved in phenylpropene biosynthesis and would enable studies into structural elements defining the regioselectivity of phenylpropene synthases. Graphical abstract The enzyme reaction leading to eugenol and isoeugenol formation catalyzed by Daucus carota (iso)eugenol synthase. Image 1 Highlights • Eugenol/isoeugenol synthase and O -methyltransferase were identified from carrot. • The recombinant phenylpropene synthase catalyzes the formation of both eugenol and isoeugenol. • The recombinant eugenol/isoeugenol O -methyltransferase shows specificity towards phenylpropenes. • Expression analysis suggests that the enzymes may play a role in eugenol/isoeugenol derivatives biosynthesis. • Expression analysis suggests that the isolated genes are involved in phenylpropene biosynthesis in carrot. [ABSTRACT FROM AUTHOR]

Aniba canelilla (Kunth) Mez is an aromatic tree from Amazon region whose essential oil presents 1-nitro-2-phenylethane (NP) and methyleugenol (ME) as major compounds. Several properties are attributed to Aniba canelilla essential oil (ACEO), such as antifungal. Onychomycoses are fungal nail infections that require novel therapeutic alternatives, especially topical ones. However, to ensure the success of topical therapy, the active compound should be able to penetrate/permeate the nail plate, which is challenging due to the highly keratinized composition of this structure. Thus, the aims of this article were to develop, validate and apply a high-performance liquid chromatography method (HPLC-UV) to quantify NP and ME in porcine hoof extract (PHE) and receptor fluid (RF) during in vitro permeation/retention studies in nail model, for which porcine hoof membranes were used. For method development, two Designs of Experiment (DoE) were adopted: 23 Full Factorial and Box-Behnken. Retention times of 5.65 and 7.49 min were achieved for NP and ME, respectively. The method was full validated for NP and ME quantification in receptor fluid, in accordance with the recommended parameters by ICH Q2(R1) Guideline. In addition, the method was full validated for NP and ME quantification in porcine hoof extract, considering the parameters and criteria of ICH M10 Guideline. In vitro permeation/retention studies were carried out in nail model, and promising results were obtained. NP reached the receptor fluid in the order of 441.1 ± 92.1 µg/cm2 at 72 h. The amount of NP and ME retained into porcine hoof membrane was 1272.6 ± 225.7 µg/cm2 and 84.7 ± 20.4 µg/cm2, respectively, at 72 h. Our findings open perspective to develop topical formulations containing ACEO as active compound aiming the management of onychomycosis. [Display omitted] • A fast HPLC-UV method to simultaneous quantify NP and ME was developed by DoE. • The method was validated for NP and ME quantification in receptor fluid. • The method was validated for NP and ME quantification in porcine hoof extract. • NP and ME penetrated porcine hoof membrane and NP permeated to receptor fluid. • ACEO is a potential compound to for the management of onychomycosis. [ABSTRACT FROM AUTHOR]

Although nonsteroidal anti-inflammatory drugs (NSAIDs) are one of the main types of drugs used to treat pain, they have several adverse effects, and such effects can be reduced by combining two analgesic drugs. The aim of this study was to evaluate the nociceptive activity of methyleugenol combined with either diclofenac or ketorolac, and determine certain parameters of pharmacokinetics. For the isobolographic analysis, the experimental effective dose 30 (ED30) was calculated for the drugs applied individually. With these effective doses, the peak plasma concentration (Cmax) was found and the other parameters of pharmacokinetics were established. Methyleugenol plus diclofenac and methyleugenol plus ketorolac decreased licking behavior in a dose-dependent manner in phase II, with an efficacy of 32.9 ± 9.3 and 39.8 ± 9.6%, respectively. According to the isobolographic analysis, the experimental and theoretical ED30 values were similar for methyleugenol plus diclofenac, suggesting an additive effect, but significantly different for methyleugenol plus ketorolac (3.6 ± 0.5 vs. 7.7 ± 0.6 mg/kg, respectively), indicating a probable synergistic interaction. Regarding pharmacokinetics, the only parameter showing a significant difference was Cmax for the methyleugenol plus diclofenac combination. Even with this difference, the combinations studied may be advantageous for treating inflammatory pain, especially for the combination methyleugenol plus ketorolac.

Climate plays an important role in crop production, and it is the main factor limiting the success of crop production in specific area. Medicinal plants are characterized by its contents of biological active substances. Among those, essential oil is considered as one of the most important natural substances. This field experiment was conducted during the two successive seasons 2016-2017 and 2017-2018 in order to evaluate the growth, yield and essential oil constituents of chervil plants at four different locations across Egypt (El-Fayoum, El-Minya, El-Sharkia, and El-Baharia Oasis). Plants cultivated in El-Fayoum showed the highest growth rate (plant height) and the highest yield (fresh and dry herb) followed by El-Sharkia. Also, the highest quality (0.180 and 0.185 % essential oil with 0.158 and 0.120 ml/plant in first and second season, respectively) was observed on plant cultivated in El-Fayoum and the lowest observed in El-Baharia Oasis plants. Thirteen main compounds were detected in GC/MS analysis of essential oil. There were obvious differences in chemical constituents of essential oil of plants cultivated under different locations. The lowest Methyleugenol, Estragoleand 2-Allyl-1,4-dimethoxybenzenecontents were observed in plant cultivated in El-Minya location. The highest Methyleugenol content (47.21 %) was observed in El-Sharkia, the highest Estragole content (18.04) were observed in El-Fayoum, and the highest 2-Allyl-1,4-dimethoxybenzene content (7.89) was observed in El-Baharia Oasis. The results of this study suggested that agro-climatic zone and suitable location selection could be as important strategies for maximizing the content and composition of essential oils. [ABSTRACT FROM AUTHOR]

Abstract Feeding can be inhibited by satiety, sickness, or food unpalatability. The central nucleus of the amygdala (CeA) has been considered the key region for processing multiple anorexigenic signals, although the detailed cellular and molecular mechanisms remain largely unclear. Here we identify that methyleugenol (ME), a novel agonist of A type ionotropic γ-aminobutyric acid receptors (GABA A Rs), significantly counteracts the anorexigenic effects caused by satiety or sickness in association with GABAergic inhibition in the CeA. Electrophysiologically, ME enhanced GABAergic transmission and repressed neuronal excitability of the CeA. Behaviorally, ME increased feeding but not affect locomotor activity and basal anxiety in naïve mice. Notably, both systemic and CeA-specific delivery of ME significantly rescued satiety- or sickness-induced inhibition of feeding. The effects of ME were mainly dependent on the GABA A Rs in the CeA. Indeed, viral-mediated, the CeA region-specific genetic knockdown of the γ2 subunit of GABA A Rs largely abolished the above pharmacological effects, while its re-expression in a subpopulation of GABAergic neurons in the CeA, that produce protein kinase C-δ (PKC-δ), recovered the effects of ME on anorexigenic signals. Taken together, these results reveal a novel molecular mechanism for counter-anorexigenic signals dependent on GABAergic inhibition in the CeA, suggesting the possibility of ME as a leading compound for anorexia treatment. Graphical abstract Image 1 Highlights • Methyleugenol enhances GABAergic transmission and represses neuronal excitability of the CeA. • Methyleugenol increases feeding but does not affect basal activity in mice. • Methyleugenol counteracts anorexigenic signals of satiety or sickness. • Effect of methyleugenol is associated with GABAergic inhibition in CeA. [ABSTRACT FROM AUTHOR]

Aniba canelilla (H.B.K.) Mez is an aromatic plant from the Amazon region whose essential oil has 1-nitro-2-phenylethane (NP) and methyleugenol (ME) as major compounds. Despite of the scientifically proven antifungal and anti-inflammatory activities for these compounds, there is no report up to date about the topical permeation or quantification of NP and ME on skin samples. The aim of this study was the validation of an optimized bioanalytical method by solid-phase microextraction in headspace mode in gas chromatograph with flame ionization detector (HS-SPME-GC-FID) for the determination of NP and ME from the oil in different samples from permeation study, such as porcine ear skin (PES) layers (stratum corneum, epidermis and dermis) and receptor fluid (RF). For this propose polydimethylsiloxane fibers (100 μm) were used and HS-SPME extraction condition consisted of 53 °C, 21 min, and 5% w.v −1 NaCl addition. The wide range of the calibration curve (2.08–207.87 μg mL −1 for NP and 0.40–40.41 μg mL −1 for ME), the presence of matrix interferences and the intrinsic characteristics of HS-SPME required a data linearization using Log 10 . Thereby, data and the gained results presented homoscedasticity, normalization of residues and adequate linearity (r 2  > 0.99) and accuracy for both compounds. In order to verify the applicability of the validated method, the HS-SPME-GC-FID procedure was performed to determine the amount of NP and ME permeated and retained in samples after Franz diffusion cell study from different dosages (20, 100 and 200 μL) of A. canelilla oil. Compounds permeation showed a progressive increase and penetration dependence based on the dosage applied. Furthermore, retention was in order receptor fluid >> dermis >> epidermis >> stratum corneum for both compounds, suggesting NP and ME could penetrate deep tissue, probably due to the partition coefficient, mass, size, and solubility of these compounds. In conclusion, the proposed method by HS-SPME-GC-FID to quantify 1-nitro-2-phenylethane and methyleugenol from Aniba canelilla essential oil was able to determine selectively, precisely and accurately these main compounds in skin permeation samples. [ABSTRACT FROM AUTHOR]

The method for simultaneous determination of 4 eugenol derivatives anesthetics residues in aquatic products was developed by solid phase extraction coupled with ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The influences of extraction procedures, chromatographic conditions and mass spectrometry conditions were investigated. The optimal solid phase extraction experiment conditions were as follows: the aquatic samples were extracted with 5 mL hexane twice, supernatant was combined and centrifuged at 6 000 r/min, enriched by nitrogen blowing at 35 ℃, mixed with 3 mL 40% methanol, cleaned up by solid phase column of hydrophilic-lipophilic balance (HLB) cartridge, then rinsed by 3 mL 40% methanol, eluted by 2 mL methanol, dried with nitrogen gas at 35 ℃. The chromatographic separation was performed within 13.0 min on an Agilent ZORBAX Eclipse Plus C18 column （50 mm×2.1 mm×1.8 μm）. Formic acid played a key role in mobile phase as modifier to improve the ionization efficiency of methyleugenol and methylisoeugenol. The flow rate was 0.30 mL/min. An Agilent 6470 Triple Quadrupole mass spectrometer (QQQ-MS) was operated in the positive and negative ion modes at the same time using multiple reaction monitoring （MRM） for qualitative and quantitative analysis of 4 eugenol derivatives which were quantitated with an external standard method. The QQQ-MS conditions were optimized including ionization mode, precursor ion, product ion, fragmentor voltage, and collision energy. The limits of quantitation for eugenol and isoeugenol are 2.5 μg/kg while the limits of quantitation for methyleugenol and methylisoeugenol are 1.0 μg/kg. The linear correlation coefficient (R2) is over 0.996 in the range of 1.200 μg/L for eugenol derivatives’ concentrations. The average recoveries for eugenol derivatives are 77.6%-111.4% with RSDs of 2.7%-9.1%. This method is precise, selective and reliable, and has been successfully applied for detection and determination of eugenol, isoeugenol, methyleugenol and methylisoeugenol simultaneously in batch sample of aquatic products. [ABSTRACT FROM AUTHOR]

Abstract: BACKGROUND: Methyleugenol is a common phenylpropanoid compound found in many plants and has been widely used as a flavoring agent in people's daily life. In this study, a stable isotope dilution assay‐coupled gas chromatography/triple quadrupole mass spectrometry (SIDA‐GC/MS/MS) method was developed for the quantitative determination of methyleugenol in food samples. Methyleugenol‐D3 was synthesized and used as an isotope internal standard for the determination of methyleugenol. The QuEChERS (quick, easy, cheap, effective, rugged and safe) method was applied to the clean‐up of food sample extracts. Confirmation and quantification were carried out by GC/MS/MS. RESULTS: The analytical performance of the method was validated. The determination range of methyleugenol was linear from 4 to 500 µg L−1. Method detection limits for solid food samples, semi‐solid food samples and liquid beverages were 50, 50 and 1 µg kg−1 respectively. Satisfactory recoveries in the range 94.29–100.27% were obtained. Intra‐ and inter‐day precision was also validated and the values were all lower than 9%. The method was successfully applied to quantify methyleugenol in different kinds of food samples. CONCLUSION: This article describes a new method for the accurate quantification of methyleugenol in food samples based on a stable isotope labeling‐assisted GC/MS/MS method. Methyleugenol‐D3 was synthesized and used as an isotope internal standard for the determination of methyleugenol. Excellent results were generated with the method, and the detection sensitivity and accuracy of the method were good. © 2018 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Levels of eugenol, isoeugenol and methyleugenol were investigated in 216 seawater fish and 321 freshwater fish from wholesale markets. Eugenol was detected in 55 samples with concentrations ranging from 3.11 to 30,690 μg/kg. Isoeugenol was detected only in two samples of grouper at concentrations of 1032 μg/kg and 86.2 μg/kg. Methyleugenol was not detected in any samples. The incidence of anesthetic residue in all the samples was 10.6%. The frequencies of species found with anesthetic residue were higher in seawater fish than in freshwater fish, with rates of 19.4% and 4.7%, respectively. The warm seawater fish such as grouper, sea bass, sea bream, pompano, and red drum should be monitored more closely in the future due to the higher detection frequencies and values of these compounds. Although the results indicate that eugenol or isoeugenol have been used as fish anesthetic to assist with fish handling and fish transport in some species, the human health risk is negligible. [ABSTRACT FROM AUTHOR]

Here, for the first time, the accumulation ratio of methylchavicol and methyleugenoland compounds together with the expression profiles of five critical genes (i.e., 4Cl , C3H , COMT , CVOMT and EOMT ) in three Iranian cultivars of basil were assessed under water deficit stress at flowering stage. The highest value of methylchavicol was detected for Cul. 3 under severe stress ( S3 ; 7.695 μg/mg) alongside Cul. 2 under similar circumstances ( S3 ; 4.133 μg/mg), while regarding Cul. 1, no detectable amounts were acquired. Considering methyleugenol, Cul. 3 (0.396 μg/mg; S0 ) followed by Cul. 1 (S3; 0.160 μg/mg) were the capable plant samples in producing some detectable amounts of methyleugenol. Apart from some expectations, all the genes under study exhibited also different transcription ratios under deficit stress. Our results, overall, demonstrated that the regulation of the above-mentioned genes and production of methychavicol and methyleugenol seems to be a cultivar- and drought stress-dependent mechanism. [ABSTRACT FROM AUTHOR]

Methyleugenol is a rodent hepatocarcinogen occurring in many herbs and spices as well as essential oils used for flavoring. Following metabolic activation by cytochromes P450 (CYPs) and sulfotransferases (SULTs), methyleugenol can form DNA adducts. Previously, we showed that DNA adduct formation by methyleugenol in mouse liver is dependent on SULT1A1 expression and that methyleugenol DNA adducts are abundant in human liver specimens. In humans, SULT1A1 activity is affected by genetic polymorphisms, including single-nucleotide polymorphisms (SNPs) and copy number variations (CNVs). Here we investigated the relationship between individual methyleugenol DNA adduct levels and SULT1A1 in human liver samples. Using isotope-dilution ultraperformance liquid chromatography coupled with tandem mass spectrometry, we quantified methyleugenol DNA adducts in 121 human surgical liver samples. Frequent CNVs, including deletions ( f = 3.3%) and duplications ( f = 36.4%) of SULT1A1, were identified using qPCR and TaqMan assays in the donors' genomic DNA. SULT1A1 mRNA and protein levels were quantified using microarray data and Western blot analysis, respectively. Methyleugenol DNA adducts were detected in all 121 liver samples studied. Their levels varied 122-fold between individuals and were significantly correlated to both mRNA and protein levels of SULT1A1 ( r = 0.43, and r = 0.44, respectively). Univariate and multivariate statistical analysis identified significant associations of SULT1A1 CNVs with mRNA ( p = 1.7 × 10) and protein ( p = 4.4 × 10) levels as well as methyleugenol DNA adduct levels ( p = 0.003). These data establish the importance of SULT1A1 genotype for hepatic methyleugenol DNA adducts in humans, and they confirm a strong impact of SULT1A1 CNVs on SULT1A1 hepatic phenotype. [ABSTRACT FROM AUTHOR]

Intestinal ischemia/reperfusion (I/R) injury is associated with a high risk of mortality in the clinical situation. Many factors are involved in I/R, including reactive oxygen species, cytokine release, and apoptosis. We aimed to determine whether a pure methyl eugenol (ME) given before intestinal ischemia, protects against intestinal I/R injury and the possible mechanism involved in this protection. Rat received ME (100 mg/kg) for 30 days then underwent intestinal I/R with 30 min ischemia and 60 min reperfusion. Serum lactate dehydrogenase (LDH) level, tissue malondialdehyde (MDA), as well as some antioxidant biomarkers were assessed, while the serum level of tumor necrosis factor alpha (TNF-α) was determined by ELISA. The change in TNF-α and interleukin 6 ( IL-6) gene expressions were evaluated and confirmed by assessing protein level of TNF-α in the intestinal tissue by immunohistochemistry. Apoptosis was evaluated using DNA-laddering assay and by detecting caspase-3 immunohistochemically. Administration of ME prior to I/R injury resulted in a modulation of the production of MDA, LDH, and nitric oxide and restoration of the tested oxidative stress biomarkers. Pretreatment with ME downregulated messenger RNA of TNF-α and IL-6 inflammatory cytokines and their protein expressions in I/R rats. Marked inhibition of the apoptotic DNA and improvement of the architectures of small intestine were observed after pretreatment with ME. ME exhibits a protective effect against intestinal I/R via amelioration of the oxidative stress and inflammatory cytokines gene expression. Therefore, the supplementation of ME prior to intestinal I/R might be helpful in the attenuation of I/R complications. [ABSTRACT FROM AUTHOR]

Malaria is transmitted by infected female Anopheles mosquitoes, and An. arabiensis is a main malaria vector in arid African countries. Like other anophelines, its life cycle comprises of three aquatic stages; egg, larva, and pupa, followed by a free flying adult stage. Current vector control interventions using synthetic insecticides target these stages using adulticides or less commonly, larvicides. With escalating insecticide resistance against almost all conventional insecticides, identification of agents that simultaneously act at multiple stages of Anopheles life cycle presents a cost-effective opportunity. A further cost-effective approach would be the discovery of such insecticides from natural origin. Interestingly, essential oils present as potential sources of cost-effective and eco-friendly bioinsecticides. This study aimed to identify essential oil constituents (EOCs) with potential toxic effects against multiple stages of An. arabiensis life cycle. Five EOCs were assessed for inhibition of Anopheles egg hatching and ability to kill larvae, pupae and adult mosquitoes of An. arabiensis species. One of these EOCs, namely methyleugenol, exhibited potent Anopheles egg hatchability inhibition with an IC 50 value of 0.51 ± 0.03 μM compared to propoxur (IC 50 : 5.13 ± 0.62 μM). Structure-activity relationship study revealed that methyleugenol and propoxur share a 1,2-dimethoxybenze moiety that may be responsible for the observed egg-hatchability inhibition. On the other hand, all five EOCs exhibited potent larvicidal activity with LC 50 values less than 5 μM, with four of them; cis -nerolidol, trans -nerolidol, (−)-α-bisabolol, and farnesol, also possessing potent pupicidal effects (LC 50 < 5 μM). Finally, all EOCs showed only moderate lethality against adult mosquitoes. This study reports for the first time, methyleugenol, (−)-α-bisabolol and farnesol as potent bioinsecticides against early life stages of An. arabiensis. This synchronized activity against Anopheles aquatic stages shows a prospect to integrate EOCs into existing adulticide-based vector control interventions. [Display omitted] • Given the increasing Anopheles resistance, it is crucial to identify novel agents with multi-stage insecticidal activity. • Select essential oil constituents displayed toxic activities against four stages of the An. arabiensis life cycle. • These were highly potent against three aquatic stages of An. Arabiensis; egg, larva, and pupa.. [ABSTRACT FROM AUTHOR]

The aim of this research was to determine the chemical composition and nematicidal activity of essential oil of Agastache rugosa flowering aerial parts against the root knot nematode, Meloidogyne incognita, and to isolate and identify any nematicidal constituents from the essential oil. The essential oil of A. rugosa aerial parts was obtained by hydrodistillation and analyzed by GC-FID and GC-MS. A total of 37 components of the essential oil were identified, with the principal compounds being methyleugenol (50.51%), estragole (8.55%), and eugenol (7.54%), followed by thymol (3.62%), pulegone (2.56%), limonene (2.49%) and caryophyllene (2.38%). Based on bioactivity-guided fractionation, the three active constituents were isolated from the essential oil and identified as methyleugenol, estragole and eugenol. The essential oil of A. rugosa exhibited strong nematicidal activity against M. incognita, with a LC50 value of 47.3 μg/mL. The components eugenol (LC50 = 66.6 μg/mL) and methyleugenol (LC50 = 89.4 μg/mL) exhibited stronger nematicidal activity against M. incognita (LC50 = 185.9 μg/mL). The results indicate that the essential oil of A. rugosa aerial parts and its constituent compounds have potential for development into natural nematicides for control of the root knot nematode.