Mint Essential Oil Research Articles

Essential oils content, composition and antioxidant activity of lemon balm, mint and sweet basil from Serbia

Lemon balm, mint, and basil were used to determine whether light modification (plants grown under pearl shade nets with 40 % shaded index or in un-shaded open field) could improve the quantity and quality of essential oils (EOs) and antioxidant activity. The yield of EOs of lemon balm, mint and sweet basil obtained after 120 min of hydrodistillation was 0.18, 2.00, and 1.12 mL/100 g, respectively. At the same time under shading conditions plants obtained more levels of EOs (0.22, 2.23, and 1.32 mL/100 g). The main components of the lemon balm essential oil are geranial (6.84–7.78 %); neral (3.02–3.52 %) and piperitenone oxide (1.67–5.36 %). The main components of mint essential oil are piperitenone oxide (12–14 %) and 1,8 cineole (1.32–2.27 %), while basil essential oil consists of the following components: linalool (9.06–10.2 %); 1,8 cineole (1.26–8.06 %) and α-trans bergamotene (1.21–1.47 %). The essential oil obtained from basil leaves grown under shading has shown the highest antioxidant activity (EC50 value after 20 min of incubation = 0.68 mg/mL). Medicinal plants are a good source of natural antioxidants with potential application in the food and pharmaceutical industries. Medicinal plants can be recommended to grow in shading conditions for achieving optimal quality parameters.

Chemical Composition of Essential Oils of Peppermint and Spearmint Dry Leaves and Their Allelopathic Effects on Wheat Species

This study was carried out to determine the chemical composition of essential oils of the spearmint and the peppermint dry leaves and their allelopathic effects on seed germination and seedling growth of different wheat species. The ratios of essential oil isolated by hydrodistillation were found to be 2.5 % and 2.0 % (w/w), respectively. The GC/MS analysis revealed that the peppermint essential oil contained 20 compounds, while spearmint essential oil incorporated 17 compounds. The main components in the spearmint essential oil were identified to be carvone (62.9 %) and limonene (8.2 %), while those of the peppermint essential oil was to be menthone (34.5 %) and menthol (41.4 %). The seed germination started to be negatively affected by 0.2 μL of essential oil and the negative effect increased in parallel with the increase in essential oil dose. The reducing effect of the mint essential oils on seed germination was the lowest for Triticum spelta and the highest for T. aestivum. In the pot trial, the negative effect began to appear with 0.8 μL of essential oil and increased with the higher doses. The effect of mint essential oils on root lengths and dry weights of single seedlings was the lowest for T. spelta and the highest for T. dicoccum. The estimated field application dose of the peppermint essential oil for the investigated wheat species was determined to be approximately 208 mL da−1.

In Vitro Antimicrobial Activity of Lavender, Mint, and Rosemary Essential Oils and the Effect of Their Vapours on Growth of Penicillium spp. in a Bread Model System.

The chemical composition, antioxidant activity, and antimicrobial properties of three commercially available essential oils: rosemary (REO), lavender (LEO), and mint (MEO), were determined in the current study. Our data revealed that the major components of REO, MEO, and LEO were 1,8-cineole (40.4%), menthol (40.1%), and linalool acetate (35.0%), respectively. The highest DPPH radical-scavenging activity was identified in MEO (36.85 ± 0.49%) among the investigated EOs. Regarding antimicrobial activities, we found that LEO had the strongest inhibitory efficiencies against the growth of Pseudomonas aeruginosa and Candida (C.) tropicalis, MEO against Salmonella (S.) enterica, and REO against Staphylococcus (S.) aureus. The strongest antifungal activity was displayed by mint EO, which totally inhibited the growth of Penicillium (P.) expansum and P. crustosum in all concentrations; the growth of P. citrinum was completely suppressed only by the lowest MEO concentration. The lowest minimal inhibitory concentrations (MICs) against S. enterica, S. aureus, and C. krusei were assessed for MEO. In situ analysis on the bread model showed that 125 µL/L of REO exhibited the lowest mycelial growth inhibition (MGI) of P. citrinum, and 500 µL/L of MEO caused the highest MGI of P. crustosum. Our results allow us to make conclusion that the analysed EOs have promising potential for use as innovative agents in the storage of bakery products in order to extend their shelf-life.

Antimicrobial synergism and antibiofilm activities of Pelargonium graveolens, Rosemary officinalis, and Mentha piperita essential oils against extreme drug-resistant Acinetobacter baumannii clinical isolates.

Rosemary officinalis L., Pelargonium graveolens L., and Mentha piperita L., essential oils are used by complementary medicine specialists simultaneously with traditional antibiotics for treatment purposes. The chemical composition of essential oils was analyzed by the gas chromatography-mass spectrometry method. In vitro antibacterial and antibiofilm activities of the essential oils were tested against extreme drug-resistant (XDR) colistin-resistant and colistin susceptible Acinetobacter baumannii clinical strains. The synergistic activities between essential oils and colistin antibiotics were investigated by the checkerboard method. The highest antibacterial effect was detected in mint essential oil (2.5-5μl/ml), followed by pelargonium essential oil (5-20μl/ml) and rosemary essential oil (5-20μl/ml). The combination of rosemary essential oil or pelargonium essential oil with colistin showed strong synergistic activity in most of the bacterial strains tested (fractional inhibitory concentration index≤0.5; synergy). As a result of the combination of mint essential oil and colistin, an indifferent effect was observed in only two bacterial strains, and other strains could not be evaluated. No antagonistic effects were observed in any of the tested essential oils. As a result of the effectiveness of the combination, the minimum inhibitory concentration (MIC) values of colistin in XDR-A.baumannii clinical isolates decreased 2-32 fold. Additionally, the sub-MIC concentration of essential oils exhibited an inhibitory effect (48-90%) against the biofilm layer of tested A.baumannii strains.

Biopesticide Trunk Injection Into Apple Trees: A Proof of Concept for the Systemic Movement of Mint and Cinnamon Essential Oils.

The use of conventional pesticides is debated because of their multiple potential adverse effects on non-target organisms, human health, pest resistance development and environmental contaminations. In this setting, this study focused on developing alternatives, such as trunk-injected essential oil (EO)-based biopesticides. We analysed the ecophysiology of apple trees (Malus domestica) following the injection of Cinnamomum cassia and Mentha spicata nanoemulsions in the tree’s vascular system. Targeted and untargeted volatile organic compounds (VOCs) analyses were performed on leaf-contained and leaf-emitted VOCs and analysed through dynamic headspace–gas chromatography–mass spectrometry (DHS-GC-MS) and thermal desorption unit (TDU)-GC-MS. Our results showed that carvone, as a major constituent of the M. spicata EO, was contained in the leaves (mean concentrations ranging from 3.39 to 19.7 ng gDW–1) and emitted at a constant rate of approximately 0.2 ng gDW–1 h–1. Trans-cinnamaldehyde, C. cassia’s major component, accumulated in the leaves (mean concentrations of 83.46 and 350.54 ng gDW–1) without being emitted. Furthermore, our results highlighted the increase in various VOCs following EO injection, both in terms of leaf-contained VOCs, such as methyl salicylate, and in terms of leaf-emitted VOCs, such as caryophyllene. Principal component analysis (PCA) highlighted differences in terms of VOC profiles. In addition, an analysis of similarity (ANOSIM) and permutational multivariate analysis of variance (PERMANOVA) revealed that the VOC profiles were significantly impacted by the treatment. Maximum yields of photosystem II (Fv/Fm) were within the range of 0.80–0.85, indicating that the trees remained healthy throughout the experiment. Our targeted analysis demonstrated the systemic translocation of EOs through the plant’s vascular system. The untargeted analysis, on the other hand, highlighted the potential systemic acquired resistance (SAR) induction by these EOs. Lastly, C. cassia and M. spicata EOs did not appear phytotoxic to the treated trees, as demonstrated through chlorophyll fluorescence measurements. Hence, this work can be seen as a proof of concept for the use of trunk-injected EOs given the systemic translocation, increased production and release of biogenic VOCs (BVOCs) and absence of phytotoxicity. Further works should focus on the ecological impact of such treatments in orchards, as well as apple quality and production yields.

In Silico and In Vitro Evaluation of the Antimicrobial and Antioxidant Potential of Mentha × smithiana R. GRAHAM Essential Oil from Western Romania.

This study was conducted to identify the volatile compounds of Mentha × smithiana essential oil (MSEO) and evaluate its antioxidant and antibacterial potential. The essential oil (EO) content was assessed by gas chromatography–mass spectrometry (GC-MS). Carvone (55.71%), limonene (18.83%), trans-carveol (3.54%), cis-carveol (2.72%), beta-bourbonene (1.94%), and caryophyllene oxide (1.59%) were the main identified compounds. The MSEO displayed broad-spectrum antibacterial effects and was also found to be the most effective antifungal agent against Candida albicans and Candida parapsilosis. The antioxidant activity of MSEO was tested against cold-pressed sunflower oil by peroxide, thiobarbituric acid, 1,1-diphenyl-2-picrylhydrazyl radical (DPPH), and β-carotene/linoleic acid bleaching methods. The EO showed strong antioxidant effects as reflected by IC50 values of 0.83 ± 0.01 mg/mL and relative antioxidative activity of 87.32 ± 0.03% in DPPH and β-carotene/linoleic acid bleaching assays, respectively. Moreover, in the first 8 days of the incubation period, the inhibition of primary and secondary oxidation compounds induced by the MSEO (0.3 mg/mL) was significantly stronger (p < 0.05) than that of butylated hydroxyanisole. In silico molecular docking studies were conducted to highlight the underlying antimicrobial mechanism as well as the in vitro antioxidant potential. Recorded data showed that the antimicrobial activity of MSEO compounds could be exerted through the D-Alanine-d-alanine ligase (DDl) inhibition and may be attributed to a cumulative effect. The most active compounds are minor components of the MSEO. Docking results also revealed that several mint EO components could exert their in vitro antioxidant activity by employing xanthine oxidase inhibition. Consequently, MSEO could be a new natural source of antioxidants and antiseptics, with potential applications in the food and pharmaceutical industries as an alternative to the utilization of synthetic additives.

A novel vortex assisted dispersive solid phase extraction of some trace elements in essential oils and fish oil

In this paper, a novel vortex assisted solid phase extraction procedure combined with inductively coupled plasma optic emission spectrometry was presented for determination of Mn, Cu, Ni, Cr, Cd and Pb directly in oily matrix. The suggested separation and preconcentration method was based on simultaneous sorption of the target analytes from real essential oil matrix onto γ-Al2O3 functionalized with fluorescein (Al-Flr) and transfer to aqueous eluent prior to quantification. The effect of different parameters including sorption and elution time, sample volume, eluent type and concentration and interfering ions were investigated. The working conditions were given as follows, vortex agitation for sorption and elution 40 s, sample volume 20 mL, eluent type HCl, eluent concentration 0.3 mol L−1. The detection limits were found to be 0.7 μg L−1 for Mn, 4.1 μg L−1 for Cu, 1.0 μg L−1 for Ni, 1.6 μg L−1 for Cr, 0.7 μg L−1 Cd and 1.0 μg L−1 Pb. The evaluation of the accuracy and precision of the method was tested via metallo-organic certified reference material. The recovery values have warranted the accuracy and found between 98.4 and 103.3% with 2.6–6.4% relative standard deviation (RSD, %). The sampling frequency of the procedure was calculated as 11.25 h−1.Finally, the proposed analytical method was successfully applied on analyte spiked and unspiked apricot, black cumin, pine turpentine, thyme, mint essential oils and fish oil samples without any need of performing mineralization pretreatments.

Assessing and integrating the transcriptome analysis with plant development, trichomes, and secondary metabolites yield potential in Mentha arvensisL

Mentha arvensisL. (corn mint) is well known for the production of menthol, a used commodity in flavouring industries, and provides natural fragrances. Glandular trichomes are responsible for producing specific secondary metabolites in vascular plants having species chemistry. Ten cultivars/varieties of M. arvensis, namely, Saksham, Kosi, Himalaya, Gomti, Sambhav, Kalka, Damroo, Kushal, and Shivalik, were used to study the developmental regulation of trichomes, essential oil yield, chemical constituents of essential oil and morphological parameters were estimated with gene expression using a randomized block design. Simultaneously, RNA sequence-based transcriptome analysis was done to reveal the transcription factors and differential gene analysis, which are responsible for the biosynthesis of essential oil as well as trichome development. Plant growth showed the maximum transition between 35 and 50 days stage, while essential oil and its metabolite bioconversion was observed in between 70 and 100 days stage. Glandular trichomes were maximally increased between 50, 70 days, and 100 days stage in var. Kosi followed by var. Saryu which has rapid growth in oil content. Menthol reductase activity was found to be a regulatory element during development, as it follows the inverse trend of menthol content and leads to menthol accumulation in subcuticular spaces. Transcriptional factors, cog, and nonredundant novel genes were identified. The composition of mintessential oils is regulated at multiple levels, including transcript abundance, catalytic properties of enzyme catalysts, and cell type-specific epigenetic processes.

The Wonderful Activities of the Genus Mentha: Not Only Antioxidant Properties.

Medicinal plants and their derived compounds have drawn the attention of researchers due to their considerable impact on human health. Among medicinal plants, mint (Mentha species) exhibits multiple health beneficial properties, such as prevention from cancer development and anti-obesity, antimicrobial, anti-inflammatory, anti-diabetic, and cardioprotective effects, as a result of its antioxidant potential, combined with low toxicity and high efficacy. Mentha species are widely used in savory dishes, food, beverages, and confectionary products. Phytochemicals derived from mint also showed anticancer activity against different types of human cancers such as cervix, lung, breast and many others. Mint essential oils show a great cytotoxicity potential, by modulating MAPK and PI3k/Akt pathways; they also induce apoptosis, suppress invasion and migration potential of cancer cells lines along with cell cycle arrest, upregulation of Bax and p53 genes, modulation of TNF, IL-6, IFN-γ, IL-8, and induction of senescence phenotype. Essential oils from mint have also been found to exert antibacterial activities against Bacillus subtilis, Streptococcus aureus, Pseudomonas aeruginosa, and many others. The current review highlights the antimicrobial role of mint-derived compounds and essential oils with a special emphasis on anticancer activities, clinical data and adverse effects displayed by such versatile plants.

Atividade antifúngica de óleos essenciais em sementes de Enterolobium contortisiliquum

&lt;p&gt;&lt;span class="fontstyle0"&gt;The objective of this work was to evaluate the efficiency of essential oils in sanitary and physiological quality in seeds of Enterolobium contortisiliquum. The experiment was carried out at Universidade Federal da Paraíba. The monkfish seeds were manually benefited and scarified to overcome dormancy. Ten treatments were used: control, dicarboximide fungicide and essential oils of Andiroba, eucalyptus, camphor, mint, fennel, basil, rosemary and Copaiba. A health test was performed, with incubation in filter paper, using as a criterion to identify the comparison of characteristics described in the specific literature. The germination test was evaluated up to the fourteenth day, and the variables analyzed were: germination percentage, first count, germination speed index, dead seeds, aerial part length, root and seedling, and fresh and dry matter of seedling. The experimental design used was DIC and the averages were compared using the Scott-Knott test. The essential oils of mint and fennel showed an efficiency equivalent to the conventional method with the use of fungicide and did not cause physiological damage. The essential oil of copaiba should not be used in the treatment of E. Contortisiliquum seeds because they are fungal stimulants and may cause damage to the physiological quality.&lt;/span&gt;&lt;br /&gt;&lt;br /&gt;&lt;/p&gt;

Bioactivity of essential oil-based nano-biopesticides toward Rhyzopertha dominica (Coleoptera: Bostrichidae)

Essential oils (EOs) are promising active ingredients to produce biopesticides, although their physicochemical characteristics are a critical issue to develop commercial formulates. Repellent and toxic activity of EOs against crop and stored product pests has been widely investigated in the last decades; however, no information is available on the occurrence of adverse undesirable behavioral responses (i.e. habituation) toward these repellents in target pest species. In this study, stable EO-based nano-emulsions from commercial fennel (Foeniculum vulgare), mint (Mentha x piperita) and sweet orange (Citrus sinensis) EOs were developed, and their repellence was tested against a major stored product pest, the lesser grain borer Rhyzopetha dominica. Besides, the occurrence of habituation in R. dominica adults following successive exposure to the repellent formulations was evaluated, considering the main characteristics of this kind of non-associative learning. Nanometric droplet size was achieved for all developed nano-emulsions (<200 nm). All the tested EO-based nano-formulations were repellent to R. dominica, whereas F. vulgare-based nano-emulsions triggered lower repellence both in area choice and arena bioassays. The occurrence of habituation was validated for the strongest repellents, M. piperita and C. sinensis formulations and the decline of R. dominica responses was frequency-dependent. Furthermore, insects completely recovered their responsiveness toward the biopesticides just after 24 h from the end of exposure. The decline of the responsiveness in R. dominica adults was attributable to real learning process, since motor and sensory fatigue were excluded by testing stimulus specificity and dishabituation. The results demonstrated that habituation could occur for repellent EO-based formulations, thus this behavioral process can reduce the effectiveness of these kind of treatments against R. dominica and should be considered to articulate adequate IPM programs against stored product pests.

Investigation and assessment of the quality of Japanese mint essential oil (Mentha arvensis) originated from various geographical regions in Vietnam

In this study, the effects of distillation methods including hydro-distillation (HD) and microwave hydro-distillation (MHD) on essential oil extractions of Mentha arvensis L. in Lam Dong (LD), Ho Chi Minh City (HCMC), and Ba Ria-Vung Tau (BR) were investigated for the yield and chemical composition of the essential oil. The results showed that the use of MHD (0,075 %) was more effective on oil extraction yield than traditional HD (0.053 %). Optimal Distillation parameters were found distillation times of 20 and 110 minutes and material/water ratio of 1:2,5 and 1:6 g/mL for MHD and HD, respectively. The MHD method was subjected to comparing qualitative chemical compositions from Japanese essential oils in BR, LD, and HCMC, Vietnam. The GC-MS analysis results showed that menthol was a major constituent in the essential oil and was responsible for the distinctive smell and flavor of the Japanese mint. Moreover, the menthol content in oil from LD ound was up to 70.6 % higher than that in HCMC (69.45 %) and BR (67.85 %). In conclusion, the mint essential oil is distilled from ingredients in different regions of Vietnam, such as LD, HCMC, BR-VT, all give essential oil a characteristic scent and a relatively high menthol content of about 60 % - 70 %.

Effect of Cyclotrichium niveum Essential Oil on Rumen Microbial Fermentation and in vitro Digestibility of Barley

The digestibility of feed in ruminants and the volatile fatty acids (VFA) resulting from digestion directly affect animal performance. It has long been studied on the use of essential oils as an alternative to antibiotics to ensure optimum conditions for the rumen environment. Cyclotrichium niveum (mountain mint) essential oil is rich in antimicrobial agents. In this study different doses (0, 50, 100 and 150 mg/L of culture fluid) of Cyclotrichium niveum essential oil was incubated 24 hours with barley in diluted ruminal fluid takes from fistulated cows fed with a 40:60 concentrate:forage diet in order to assess the effects on rumen microbial fermentation and in vitro true digestibility of barley. True digestibility of barley was determined in ANKOM Daisy Incubator. All doses of Cyclotrichium niveum significantly (P&amp;lt;0.001) decreased the in vitro dry matter (DM), organic matter (OM), neutral detergent fiber (NDF) digestibility of barley. Cyclotrichium niveum essential oil negatively affected end-products of rumen fermentation; the value of the measured rumen volatile fatty acids (VFA: acetate, propionate, butyrate, isobutyric acid, valerate and isovalerate) significantly decreased compared to the control group (P&amp;lt;0.001). Carbon dioxide and methane gases created as a result of incubation in rumen fluid were calculated using volatile fatty acid values formed in rumen fluid. The addition of Cyclotrichium niveum essential oil significantly reduces the CO2 in rumen fluid (P&amp;lt;0.001). Methane (CH4) gas from rumen fluid was significantly decreased in treatment groups compared the control group (P &amp;lt;0.001) While end-products of rumen fermentation parameters significantly decreased with all doses of Cyclotrichium niveum essential oil, rumen pH has increased (P&amp;lt;0.05). The results show that when the Cyclotrichium niveum essential oil incubated with barley significantly inhibited the rumen microbial activity and overall fermentation process of rumen.

Effect of lemongrass and mint essential oils combined with food additives soaking solution on the quality of Pangasius fillets during cold storage

Pangasius fillet has high demand in the international market due to its tender flesh, delicate taste and as an affordable substitute for cod and other more expensive white fishes. The preliminary study, it was found that the optimized condition for soaking was NaCl 1.32%, STPP 1.88%, and sorbitol 4.68% for 30 mins which give a significant effect (p&lt;0.05) to the yield, water activity, pH, and improvement in the sensory of the treated fillet. However, the soaking itself was not contributed to the extension of shelf life. This study aimed to examine the effects of Pangasius fillet soaked in essential oil on the quality and shelf life with simulated storage similar to retail conditions. Lemongrass essential oil was showing the best result in improving the quality and shelf life of Pangasius fillet stored in refrigerated storage (0-4˚C). The addition of 0.2% lemongrass showed 7 days extension of shelf-life or longer compared to fillet without soaking and fillet soaking without essential oil. In addition, it also reduces the Total Volatile BasedNitrogen (TVB-N) content, improves the sensory quality (raw and cooked) of Pangasius fillet. Mint essential oil was showing the shelf-life extension (7 days longer) and sensory improvement at 0.3% concentration. However, the mint essential oil was not showing better TVB-N reduction in treated fillet compared to fillet soaking without essential oil. Therefore, it is recommended to incorporate 0.2% lemongrass essential oil for the Pangasius industry to extend the shelf life of Pangasius fillet followed with quality improvement

Comparison of chemical composition of essential oils obtained by hydro-distillation and microwave-assisted extraction of Japanese mint (Mentha arvensis L.) grown in Vietnam

The Japanese mint (Mentha arvensis L.) is known as a culinary and medicinal herb widely cultivated in several countries. The mint essential oil is considered as one main source of menthol. In this study, the Japanese mint collected from the Central Highlands of Lam Dong Province (Vietnam) was extracted the essential oil by hydro-distillation (HD) and microwave-assisted extraction (MAE). Different extraction parameters were investigated, involving mint leaf drying periods (30, 60, and 90 mins) at 50 °C, material to water ratios (1:4, 1:6, 1:8, and 1:10 for HD and 1:1, 1:1.5, 1:2, and 1:2.5 for MAE), extraction durations (60-180 for HD and 10-25 mins for MAE), and microwave energy (230, 380, 540, and 700 W) in order to discover the conditions with the highest yields for both HD and MAE. The GC-MS was used to determine the oil chemical constituents. For dried mint leaves (nearly 40 % moisture), the highest oil yield of 0.0832 mL g−1 (dried weight) was recorded, and the content of menthol was up to 70.60 % extracted by MAE whilst 0.0510 mL g−1 of yield (dried weight) and lower menthol (62.80 %) were obtained from HD. Besides, menthol, trans- and cis-menthone were found at relatively high concentrations for both HD and MAE (20.19-16.30 and 4.62-5.01 %, respectively). Compared to HD, MAE exhibited higher oil yields and menthol contents, but lower distillation time, resulting in more effective extraction performance of MAE.

Antifungal activity screening for mint and thyme essential oils against Rhizopus stolonifer and their application in postharvest preservation of strawberry and peach fruits.

With a goal to identify specific essential oils that can control postharvest Rhizopus rot on strawberry and peach fruits, we performed screening for 26 essential oils based on their antifungal activity against Rhizopus stolonifer in vitro and investigated the underlying mechanism. Mentha spicata (Ms), Mentha piperita (Mp), Thymus vulgaris CT carvacrol (Tc) and Thymus vulgaris CT thymol (Tt) exhibited strong inhibition on R. stolonifer growth in the screening. These essential oils increased plasma membrane permeability of R. stolonifer and resulted in the outflow of intercellular electrolyte, nucleic acid, protein and soluble sugar. Morphology of R. stolonifer mycelia was greatly altered by these essential oils. Hyphae treated by these essential oils exhibited high accumulation of superoxide anion and malonaldehyde. Combination of these essential oils in commercial package reduced Rhizopus rot on strawberry and peach fruits, with Mp showing the strongest efficiency. Ms, Mp, Tc and Tt essential oils inhibited R. stolonifer growth by targeting its plasma membrane and reduced Rhizopus rot on strawberry and peach fruits. This study provides potential applications of natural plant extract, as alternatives to tradition fungicides, to control postharvest decay on fruits and vegetables.

Heavy metals concentration, and antioxidant activity of the essential oil of the wild mint (Mentha longifolia L.) in the Egyptian watercourses

In the present study, we assessed seasonal variation in the accumulation potential of wild mint (Mentha longifolia) to heavy metals as well as the chemical composition and antioxidant activity of the essential oil of mint in polluted and unpolluted watercourses. The results indicated that the wild mint showed seasonal fluctuations in accumulation potential for heavy metals proved by bioaccumulation factor (BF) and translocation factor (TF). The all measured heavy metals, except Pb were retained in the underground parts. Summer plants accumulated the highest concentrations of Al, Cd, Cr and Fe in their root, while the lowest concentration of Ni in their shoot. The bioaccumulation factor for Cd, Cu, Mn, Ni, Zn and Co was greater than one, while the translocation factor of the investigated metals (except Pb) did not exceed one, indicating the potential of wild mint for phytostabilization of these metals in contaminated wetlands. The yield and composition of mint essential oil (MEO) were affected by harvesting season and heavy metals pollution. GC/MS showed that isomenthone, cis-piperitenone oxide, menthone and pulegone, were the main oil constituents. Mint essential oil show promising antioxidant activity by 2,2′-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay under pollution stress. The maximum reducing power of MEO were obtained during autumn and summer seasons (polluted canals).In conclusion, summer is the ideal season for harvesting wild mint plants for the maximum plant biomass, oil yield, high radical scavenging activity of MEO and to monitor pollution in contaminated wetlands.

Cyclodextrin-based Gas Chromatography and GC/MS methods for determination of chiral pair constituents in mint essential oils

ABSTRACT The genus Mentha has been known as culinary source of minty note. Besides, the essential oil imparts value to consumer products like confectionery, cosmetics, and pharmaceutical preparations. A simple and sensitive enantioselective gas chromatographic method is described for the quantitative analysis of terpenoid enantiomers in essential oils using different cyclodextrin coated stationary phases. Limonene, menthone, menthol, and menthyl acetate were identified as pure (-)-enantiomers whereas isomenthone, neomenthol, pulegone, and piperitone as pure (+)-enantiomers in menthol mint, and peppermint oils, respectively. The selectivity of each enantiomer was also demonstrated. A β-cyclodextrin phase with diethyl substitution provides baseline resolution for all target enantiomers with selectivity ranged from 1.004 to 1.050. Moreover, permethylated or diacetylated-β-cyclodextrin showed no selectivity for (+/-)-menthol enantiomers. The current study may facilitate the origin authentication studies of mint oils. Investigation of enantiomers involved in menthol biosynthesis revealed that only (-)-menthol is present in the essential oils of Mentha species.

Essential oils control anthracnose in pepper seeds

Pepper (Capsicum annum) is one of the main vegetables consumed in the Brazilian market, however, an important fungal disease, anthracnose, caused by Colletotrichum gloeosporioides, can decimate all its fruits in the field. Chemical control is the most commonly used measure of control, but, some active ingredients are proving ineffective, and consumers appreciate healthier options such as organic foods. Therefore, studies with natural substances that may help in the management of diseases have been encouraged. Because it is transmitted via seed, seed treatment becomes an essential measure in the management and control of pepper anthracnose. The objective of this study was to evaluate the effect of basil (Ocimum basilicum), citronella (Cymbopogon winterianus), clove (Syzygium aromaticum), copaiba (Copaifera langsdorfii), eucalyptus (Eucalyptus citriodora), mint (Mentha arvensis), rosemary (Rosmarinus officinalis) and tea tree (Melaleuca alternifolia) essential oils on the development of C. gloeosporioides. Citronella, clove, eucalyptus, mint and basil essential oils totally inhibited the pathogen, regardless of the concentration used. These essential oils were then used to treat seeds infected with C. gloeosporioides, evaluating the physiological and health quality of these seeds. Clove essential oil reduced the incidence of fungi in seeds inoculated with the pathogen, without affecting their physiological quality.

Mentha spicata essential oil nanoformulation and its larvicidal application against Culex pipiens and Musca domestica

The extensive use of synthetic insecticides to control vector-borne diseases has caused increased insect resistance, adverse health effects on humans and the ecosystem. Currently, a new nanotechnology strategy is being considered to develop new green-nano-friendly insecticides. This is the first study for the formulation of Mentha spicata essential oil (EO) nanoemulsion and its application against Culex pipiens, and housefly, Musca domestica. Acute oral toxicity of nano and normal emulsions was studied on rats. The results of gas chromatography–mass spectroscopy (GC–MS) analysis showed that the total identified compounds 95.18 % comprised 28 compounds. These included 1,8-Cineole (19.55 %), menthol (14.4 %), 1-p-menthen-8-yl acetate (6.42 %), 4-terpineol (6.28 %), α-terpineol (5.38 %), α-pinene (5.26 %), β-pinene (4.72 %),p-cymene (3.52 %) and delta 3-carene (3.09 %) as the major components. Nanoemulsion with droplet size 97.8 nm was obtained by ultrasonic emulsification for 10 min at ratio 1:1 (v/v) of mint EO and Tween 80. Emulsification conditions and nanoemulsion droplet size are correlated. Mint nanoemulsion showed a high larvicidal activity against C. pipiens (LC50, 43.57 μg/mL) and M. domestica (LC50, 65.13 μg/mL) compared with normal oil and lambda-cyhalothrin insecticide. Nanoformulation increased efficiency by 71.46 % and 52.0 % against C. pipiens and M. domestica, respectively. Nanoformulation had no toxic effects on the treated rats. Mint nanoemulsion is solvent-free, soluble in water, effective, safe, and eco-friendly. Therefore, it can be used to control C. pipiens, and M. domestica larvae as it is or by developing new capsules with controlled-release as a possible product.