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Parasitic diseases caused by gastrointestinal nematodes (GIN) are responsible for a major impact on ruminant welfare. Although the available anthelmintics have a safe margin of toxicity to the animals, their indiscriminate use has increased the selection of resistant parasite populations. In this scenario, essential oils (EO) stand out as a promising ecofriendly therapeutic alternative against GIN. The objective of this work was to determine the effect of the EO of Mentha villosa Hubs (MVEO) collected in 2017 and 2018, M. x piperita (MPEO) and their main components, carvone and limonene, against the third stage larvae (L3) of Haemonchus spp. and Trichostrongylus spp. The solutions, including in nanoemulsion preparations, were tested in a range of concentrations using the larval migration inhibition test (LMIT). The EO and carvone were also tested in combination with nitroxynil (NTX) to determine their effect as drug enhancers (additive or synergy). MVEO/2017, MVEO/2018, MPEO and carvone showed 70.6 (73.4 mg/mL), 86.3 (74.9 mL/mL), 95.5 (143.6 mg/mL), and 88.2 % (38.3 mg/mL) efficacy against L3, respectively. Carvone alone had approximately a 3-fold higher efficacy when compared to its concentration in each EO: 68.8 % in MVEO/2017 and 83.9 % in MVEO/2018. Limonene did not show any significant effect on inhibiting L3 migration. The combination of MPEO and NTX, and carvone and NTX showed a statistically significantly (P <  0.05) synergic and additive effect, respectively, when compared to the isolated treatment. The nanoemulsion of MVEO/2017 at 0.367 mg/mL, inhibited L3 migration by 83.1 %, demonstrating to be highly effective (concentration ratio of 1:0.004), when compared to the MVEO/2017 (70.6 % at 73.4 mg/mL) extraction. The in vitro data from the combination of MPEO or carvone plus NTX suggest that these products can be considered for in vivo experiments against the most important GIN of ruminants as drug enhancers, possibly reducing the final concentration of NTX`. The efficacy of carvone was higher (EC 50  = 1.96 mg/mL) than its expected efficacy, based on its concentrations on both EO. Therefore, this component does not need the entire EO composition to exert its L3 motility action. The remarkable efficacy demonstrated by the MVEO/2017/nanoemulsion (EC 50  = 0.10 mg/mL), supports its potential to be a candidate to the next-generation therapy to alleviate clinical parasite infections and combat GIN resistant populations., (Copyright © 2020 Elsevier B.V. All rights reserved.)

The chemical composition and acaricidal activity of plant-derived essential oils was assessed against Rhipicephalus microplus ticks. The essential oils of Mentha arvensis, Cymbopogon citratus and C. nardus were assessed for acaricidal activity against Rhipicephalus microplus. Essential oils (EO) of plants were separated by hydrodistillation (three times) and analyzed using gas chromatography - mass spectrometer (GC-MS). For bioassays, engorged females of R. microplus were exposed to C. citratus and C. nardus EO at 2%, 3%, 4% and 5% concentrations; and to M. arvensis EO at 1%, 3%, and 5% for 5 min. The weight egg mass, nutrient index (N.I), egg production index (E.P.I), hatching and control rate were evaluated. Non-feed larvae of R. microplus were exposed to essential oils with 0.25%, 0.5%; 1%; 1.5% and 2% concentrations; the mortality rate was measured after 48 h. Only engorged females presented reduced biological activities (oviposition, E.P.I) after exposure to M. arvensis at 3%, when in comparison to both positive and negative controls. The hatchability of R. microplus larvae ranged from 66.9% (after exposure to C. nardus EO at 5%) to 99.2% (positive control). The nutrition index was lower (46.6%) for the exposure to M. arvensis EO at 5%. M. arvensis at 3% and 5% concentrations was significantly efficient for engorged females when compared to control (53.7% and 47.5%, respectively). C. citratus EO at 1%, 1.5% and 2% concentrations yielded better results in the larval packet test, causing 100% mortality. Nonetheless, C. nardus and M. arvensis EO at 2% yielded 66% and 39% mortality, respectively. The study showed that M. arvensis presented potential for the control of R. microplus engorged females while C. citratus and C. nardus presented potential as a larvicide., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Colletotrichum nymphaeae is the causal agent of strawberry anthracnose, which is one of the most important disease affecting strawberry plant in Iran. This research aimed to apply the selected plant essential oils (EOs) such as Achillea millefolium, Mentha longifolia, and Ferula kuma to the management of strawberry anthracnose disease under in vitro, in vivo, and greenhouse conditions. In vitro tests indicated that all the EOs and fungicide were able to inhibit mycelial growth and conidial germination of the pathogen. Scanning electron microscopy (SEM) revealed that EOs significantly suppressed the mycelia growth and caused a change in morphology of fungal mycelia. The severity of strawberry anthracnose disease was significantly (p ≤ 0.05) reduced by all EOs under in vivo and greenhouse conditions. Results of all experiments showed that M. longifolia EO was the best EO to control C. nymphaeae. Also, EOs almost reduced weight loss and preserved firmness, ascorbic acid, total phenol, antioxidant activity (DPPH), and enzyme peroxidase activity in treated fruit. Moreover, EOs preserved the sensory quality of strawberry fruit during the storage period so that there were no significant differences between treatments (EOs) in their appearance, flavor, odor attributes, and overall evaluation compared to the control. Our results indicate that EOs are excellent bio-fungicides for the management of strawberry anthracnose.

This review article discusses the active constituents and potential of two menthol mint oils, Mentha piperita (MPEO) and Mentha arvensis (MAEO), as natural sources for botanical pesticides. The biological activities of these menthol mint oils, which can be useful in agriculture, have been broadly researched, especially toward phytotoxic microorganisms. To a lesser extent, the insecticidal and herbicidal activities of mint EOs have also been studied. It is apparent that the prospect of using menthol mint oils in agriculture is increasing in popularity. A number of investigations showed that the in vitro efficacy of MPEO and MAEO, as well as that of their main constituent, menthol, is pronounced. The results of in vitro research are useful for choosing EOs for further investigations. However, it is clear that in situ experiments are crucial and should be more extensively developed. At the same time, known techniques are to be applied to this area and new methods should be worked out, aiming at the improvement of EOs' pesticidal efficacy and cost-effectiveness, for future implementation in agricultural pest control.

Chemical composition and antifungal activity of essential oils of Algerian Mentha species were studied. Chemical compositions of different Mentha species oils (Mentha rotundifolia, M. spicata, M. pulegium, and M. piperita) were investigated by capillary GC and GC/MS, and their antifungal activities were evaluated by means of paper disc diffusion method and minimum inhibitory concentration (MIC) assays. In total, 98 components from all Mentha species were identified. All oils were rich in monoterpene-oxygenated components. In addition, we reported fumigant antifungal activity of Algerian Mentha essential oils against four fungi: Botrytis cinerea, Penicillium expansum, Monilinia laxa, and M. fructigena. All oils demonstrated very good inhibition especially against B. cinerea, M. laxa, and M. fructigena. Both Monilinia fungi were extremely sensitive to all Algerian Mentha oils, which suggests that Mentha essential oils have the potential to be used as bio-pesticides to protect fruit trees, such as apple and pear trees, and provides an alternative to chemical pesticides.

The antifungal activity of seven essential oils (eucalyptus, clove, mint, oregano, savory, tea tree, and thyme) was studied on Venturia inaequalis, the fungus responsible for apple scab. The composition of the essential oils was checked by gas chromatography-mass spectrometry. Each essential oil had its main compound. Liquid tests were performed to calculate the IC 50 of essential oils as well as their majority compounds. The tests were made on two strains with different sensitivities to tebuconazole: S755, the sensitive strain, and rs552, the strain with reduced sensitivity. Copper sulfate was selected as the reference mineral fungicidal substance. IC 50 with confidence intervals were calculated after three independent experiments. The results showed that all essential oils and all major compounds had in vitro antifungal activities. Moreover, it was highlighted that the effectiveness of four essential oils (clove, eucalyptus, mint, and savory) was higher than copper sulfate on both strains. For each strain, the best activity was obtained using clove and eucalyptus essential oils. For clove, the IC 50 obtained on the sensitive strain (5.2 mg/L [4.0-6.7 mg/L]) was statistically lower than the IC 50 of reduced sensitivity strain (14 mg/L [11.1-17.5 mg/L]). In contrast, for eucalyptus essential oil, the IC 50 were not different with respectively 9.4-13.0 and 12.2-17.9 mg/L for S755 and rs552 strains. For mint, origano, savory, tea tree, and thyme, IC 50 were always the best on rs552 strain. The majority compounds were not necessarily more efficient than their corresponding oils; only eugenol (for clove) and carvacrol (for oregano and savory) seemed to be more effective on S755 strain. On the other hand, rs552 strain seemed to be more sensitive to essential oils than S755 strain. In overall, it was shown that essential oils have different antifungal activities but do not have the same antifungal activities depending on the fungus strain used.

A comparative investigation of hydro-distilled essential oils from aerial parts of Mentha longifolia L. (ML), Mentha microphylla K.Koch (MM), Mentha australis R.Br. (MA), and Teucrium polium L. (TP) growing in Al Madinah Al Munawwarah, Saudi Arabia, was carried out. The total numbers of identified constituents were 22, 23, 14, and 20 in ML, MM, MA, and TP oils, representing 93.0, 99.3, 78.1, and 81.1% of the total oil composition, respectively. Pulegone (40.7%) and cineole (33.4%) were the major components in ML, whereas carvone (64.6%) was the major one in MM. Furthermore, β-linalool (22.9%) and α-terpineol (12%) were the major components in MA, whereas, (E)-3-caren-2-ol accounted for 12.1% in TP. The essential oils of TP and MA exhibited promising activities against Leishmania donovani promastigotes with IC50 values of 2.3 and 3.7 μg/mL, respectively. In contrast, MA essential oils exhibited antifungal activities towards Candida krusei and C. glabrata with IC50 values of 1 and 1.2 μg/mL, respectively.

The major purpose of this study was to determine the chemical relationships between the essential oils (EO) obtained form 18 mint samples of different species and its cultivrs. GC/MS analysis of all essential oils showed that oxygenated monoterpenoids are the major components of these oils, with the exception of Mentha arvensis 'Banana'. Based on the. chemical composition of the essential oils, the analyzed mints can be divided into five groups. Group I was characterized by the-presence of menthol and menthone, piperitenone oxide is the major constituent of group II, linalool of group III, carvone characterizes group IV, while 3-octanone is the most characteristic compound for group V. A reference strain of biofilm forming Staphylococcus epidermidis ATTC 35984 was tested against the obtained essential oils. Two of them, M suaveolens 'Variegata' and M x piperita 'Almira' exhibited significant bacteriostatic activity. The MIC values of these EOs were 0.25% and 0.5% respectively in comparison with an average MIC of 4% of the other tested mint EOs. Both active EOs are characterized by the presence of piperitenone oxide as the major component.

Mentha spicata L. var. viridis oil (MVO) is a potent antifungal agent, but its application in the topical treatment is limited due to its irritancy and volatility. It was aimed to develop more efficient, chitosan-incrusted MVO microspheres with reduced volatility and lesser irritancy and to dispense it in the form of ointment. Simple coacervation technique was employed to microencapsulate MVO in chitosan matrix. Morphological properties and polymer cross-linking were characterized by scanning electron microscopy and differential scanning calorimetry, respectively. Optimization was carried out on the basis of entrapment efficiency (EE) using response surface methodology. Well-designed microspheres having smooth surface and spherical shape were observed. EE (81.20%) of optimum batch (R21) was found at 1.62% w/v of cross-linker, 5.4:5 of MVO to chitosan ratio and at 1000 rpm. R21 showed 69.38 ± 1.29% in vitro MVO release in 12 h and 96.92% retention of MVO in microspheres even after 8 week. Ointments of PEG 4000 and PEG 400 comprising MVO (F1) and R21 (F2) were developed separately. F2 showed comparatively broader zone of growth inhibition (13.33 ± 1.76-18.67 ± 0.88 mm) and less irritancy (PII 0.5833, irritation barely perceptible) than that of F1. F2 was able to avoid the direct contact of mild irritant MVO with the skin and to reduce its rapid volatility. Controlled release of MVO helped in lengthening the duration of availability of MVO in agar media and hence improved its therapeutic efficacy. In conclusion, a stable and non-irritant formulation with improved therapeutic potential was developed.

Our TLC study of the volatile oil isolated from Mentha longifolia showed a major UV active spot with higher Rf value than menthol. Based on the fact that the components of the oil from same plant differ quantitatively due to environmental conditions, the major spot was isolated using different chromatographic techniques and identified by spectroscopic means as pulegone. The presence of pulegone in M. longifolia, a plant widely used in Saudi Arabia, raised a hot debate due to its known toxicity. The Scientific Committee on Food, Health & Consumer Protection Directorate General, European Commission set a limit for the presence of pulegone in foodstuffs and beverages. In this paper we attempted to determine the exact amount of pulegone in different extracts, volatile oil as well as tea flavoured with M. longifolia (Habak) by densitometric HPTLC validated methods using normal phase (Method I) and reverse phase (Method II) TLC plates. The study indicated that the style of use of Habak in Saudi Arabia resulted in much less amount of pulegone than the allowed limit.

The present study is the first investigation of the volatile-oil variability and insecticidal properties of the endemic Moroccan mint Mentha suaveolens subsp. timija (mint timija). The yield of essential oils (EOs) obtained from different wild mint timija populations ranged from 0.20±0.02 to 1.17±0.25% (v/w). GC/MS Analysis revealed the presence of 44 oil constituents, comprising 97.3-99.9% of the total oil compositions. The main constituents were found to be menthone (1.2-62.6%), pulegone (0.8-26.6%), cis-piperitone epoxide (2.9-25.5%), piperitone (0.3-35.5%), trans-piperitone epoxide (8.1-15.7%), piperitenone (0.2-9.6%), piperitenone oxide (0.5-28.6%), (E)-caryophyllene (1.5-11.0%), germacrene D (1.0-15.7%), isomenthone (0.3-7.7%), and borneol (0.2-7.3%). Hierarchical-cluster analysis allowed the classification of the EOs of the different mint timija populations into four main groups according to the contents of their major components. This variability within the species showed to be linked to the altitude variation of the mint timija growing sites. The results of the insecticidal tests showed that all samples exhibited interesting activity against adults of Tribolium castaneum, but with different degrees. The highest toxicity was observed for the EOs belonging to Group IV, which were rich in menthone and pulegone, with LC50 and LC90 values of 19.0-23.4 and 54.9-58.0 μl/l air in the fumigation assay and LC50 and LC90 values of 0.17-0.18 and 0.40-0.52 μl/cm(2) in the contact assay., (Copyright © 2015 Verlag Helvetica Chimica Acta AG, Zürich.)

The chemical composition of the essential oil obtained by hydrodistillation from the aerial parts of Mentha haplocalyx was investigated by GC-FID and GC/MS analyses. In sum, 23 components, representing 92.88% of the total oil composition, were identified, and the main compounds were found to be menthol (59.71%), menthyl acetate (7.83%), limonene (6.98%), and menthone (4.44%). By bioassay-guided fractionation (contact toxicity), three compounds were obtained from the essential oil and identified as menthol, menthyl acetate, and limonene. The essential oil and the three isolated compounds exhibited potent contact toxicity against Lasioderma serricorne adults, with LD50 values of 16.5, 7.91, 5.96, and 13.7 μg/adult, respectively. Moreover, the oil and its isolated compounds also exhibited strong repellency against L. serricorne adults. At the lower concentrations tested and at 2 h after exposure, menthol showed even significantly stronger repellency than the positive control DEET. The study revealed that the bioactivity properties of the essential oil can be attributed to the synergistic effects of its diverse major and minor components, which indicates that the M. haplocalyx oil and its isolated compounds have potential for the development as natural insecticides and/or repellents to control insects in stored grains and traditional Chinese medicinal materials., (Copyright © 2015 Verlag Helvetica Chimica Acta AG, Zürich.)

This study evaluated effects of dietary supplementation of sage (Salvia officinalis), mint (Mentha spicata) and thyme (Thymus vulgaris) oils on growth performance, lipid peroxidation level (melondialdehyde, MDA) and liver antioxidant enzyme activities (superoxide dismutase, SOD; catalase, CAT; glucose-6-phosphate dehydrogenase, G6PD; glutathione reductase, GR; glutathione-S-transferase, GST and glutathione peroxidase, GPx) in rainbow trout (Oncorhynchus mykiss) juveniles. For this purpose, triplicate groups of rainbow trout were fed daily ad libitum with diets containing sage, mint and thyme oils at 500, 1,000 and 1,500 mg kg(-1) for 60 days. While weight gain percentage of fish fed the diets containing sage and thyme oils was significantly higher than the control group, that of fish fed mint oil was the lowest. Similarly, specific growth rate was found to be the highest in all groups of the sage and thyme oil feeding and the lowest in the mint groups. Moreover, feed conversion ratio was significantly higher in the mint oil administered groups. Survival rate was also significantly reduced in the fish fed the diet containing mint oil. It was observed that SOD, G6PD and GPx activities were significantly increased in liver tissues of all the treated fish groups compared to that of control diet-fed group. However, CAT, GST and GR activities were significantly decreased in experimental diet-fed fish groups at the end of the experiment. On the other hand, a significant reduction was found in MDA levels in the fish fed the diets with sage and thyme oils compared to control and mint diets on the 30th and 60th days of experiment. Overall, dietary inclusion of sage and thyme oils is effective in enhancing rainbow trout growth, reduction in MDA and least changing antioxidant enzyme activities at a low level of 500 mg kg(-1) diet, and they can be used as important feed supplements for rainbow trout production.

The objective in this study was to evaluate the antifungal activity of essential oils from native and commercial aromatic plants grown in Argentina against corn postharvest fungi and to link the essential oil bioactivity with lipid oxidation and morphological changes in fungus cell membrane. Essential oil (EO) of oregano variety Mendocino (OMen), Cordobes (OCor), and Compacto (OCom), mint variety Inglesa (Mi), and Pehaujo (Mp), Suico (Sui); rosemary (Ro), and Aguaribay (Ag) were tested in vitro against 4 corn fungi: A. flavus (CCC116-83 and BXC01), P. oxalicum (083296), and P. minioluteum (BXC03). The minimum fungicidal concentration (MFC) and the minimum inhibitory concentration (MIC) were determined. The chemical profiles of the EOs were analyzed by GC-MS. Lipid oxidation in cell membrane of fungi was determined by hydroperoxides and related with essential oil antifungal activity. The major compounds were Thymol in OCor (18.66%), Omen (12.18%), and OCom (9.44%); menthol in Mi and Mp; verbenone in Sui; dehydroxy-isocalamendiol in Ag; and eucaliptol in Ro. OCor, Omen, and OCom showed the best antifungal activity. No antifungal activity was observed in Ag and Ro EO. The hydroperoxide value depended on the fungi (P < 0.001) and the antimicrobial agent (P < 0.001).Membrane lipids were oxidized by Sui EO in A. flavus BXC01 and A. flavus CCC116-83 (0.021 and 0.027 meqO2 /kg, respectively). The results suggest that the EOs of OCor, OMen, OCom, Mi, Mp, and Sui grown in Argentina can be used as natural alternatives to control fungi that produce mycotoxin in maize., (© 2014 Institute of Food Technologists®)

A rapid and fully automated screening of chiral compounds in essential oils, aimed to the selection of natural sources of pure enantiomers of limonene and carvone, is performed by using on-line coupled reversed phase liquid chromatography with gas chromatography and mass spectrometry (RPLC-GC-MS). Essential oils obtained from Mentha spicata and Mentha piperita were analysed by direct injection into RPLC. The reported procedure includes fractionation and clean-up in RPLC, selection of the fraction to be transferred from RPLC to GC, trapping and concentration of the target compounds in the interface, thermal desorption and, finally, enantiomeric resolution and identification of chiral compounds by GC-MS. The presence of (S)-limonene and (R)-carvone as the unique enantiomeric forms existing for both compounds could be unambiguously established by transferring different volume fractions from RPLC to GC. Data obtained demonstrate high separation efficiency and well tunable selectivity in the on-line coupled RPLC-GC-MS analysis of chiral compounds., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Dynamic changes in the content of acetylsalicylic acid and the output and qualitative composition of essential oil have been studied in mint plants (Mentha spicata L. and cultivar Medichka) during their ontogenesis with allowance for changes in weather conditions. Ontogenetic changes in the level of acetylsalicylic acid in leaf tissues are found to be similar in both cv. Medichka and M. spicata. In the case of cv. Medichka, this change is connected with the dynamics of the production and the qualitative composition of essential oil; in the case of M. spicata, this connection is less expressed. The role of acetylsalicylic acid and essential oil in plant adaptation to the environment is discussed.

The anti-yeast activity of mentha oil and vapours was evaluated against 8 food spoiling yeasts through disc diffusion, disc volatilisation and micro broth dilution method. The minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) varied from 0.28 to 2.25 and 1.13 to 4.5 mg/ml, respectively. Furthermore, the anti-yeast efficacy of mentha oil alone and in combination with thermal treatment was evaluated in a real food system i.e. mixed fruit juices. The samples treated with a combination of mentha oil at the MIC, ½ MIC and ¼ MIC levels and thermal treatment enhanced the reduction viability. Chemical characterisation of mentha oil by gas chromatography-mass spectrometry (GC-MS) revealed that the dominant compounds were cis-menthone (27.43%), menthol (24.3%), trans-menthone (9.23%), limonene (5.84%), menthofuran (4.44%) and isomenthol (3.21%). Present results established the superior performance of integrated treatment over individual exposure for fruit juice preservation., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Spray dried microcapsules of mint oil were prepared using gum Arabic alone and its blends with radiation or enzymatically depolymerized guar gum as wall materials. Microcapsules were evaluated for retention of mint oil during 8-week storage during which qualitative changes in encapsulated mint oil was monitored using principal component analysis. The microcapsules with radiation depolymerized guar gum as wall material component could better retain major mint oil compounds such as menthol and isomenthol. The t(1/2) calculated for mint oil in microcapsules of gum Arabic, gum Arabic:radiation depolymerized guar gum (90:10), gum Arabic:enzyme depolymerized guar gum (90:10) was 25.66, 38.50, and 17.11 weeks, respectively. The results suggested a combination of radiation depolymerized guar gum and gum Arabic to show better retention of encapsulated flavour than gum Arabic alone as wall material., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Unlabelled: ABSBACKGROUND: Thymus algeriensis is an endemic aromatic plant to Tunisia largely used in folk medicine and as a culinary herb. The bulks aromatic plants come from wild populations whose essential oils compositions as well as their biological properties are severely affected by the geographical location and the phase of the plant development. Therefore, the aim of the present work is to provide more information on the variation of essential oil composition of T. algeriensis collected during the vegetative and the flowering phases and from eight different geographical regions. Besides, influence of population location and phenological stage on yield and metal chelating activity of essential oils is also assessed., Methods: The essential oil composition of Thymus algeriensis was determined mainly by GC/FID and GC/MS. The chemical differentiation among populations performed on all compounds was assessed by linear discriminate analysis and cluster analysis based on Euclidean distance., Results: A total of 71 compounds, representing 88.99 to 99.76% of the total oil, were identified. A significant effect of the population location on the chemical composition variability of T. algeriensis oil was observed. Only 18 out of 71 compounds showed a statistically significant variation among population locations and phenological stages. Chemical differentiation among populations was high. Minor compounds play an important role to distinguish between chemical groups. Five chemotypes according to the major compounds have been distinguished. Chemotypes distribution is linked to the population location and not to bioclimate, indicating that local selective environmental factors acted on the chemotype diversity., Conclusions: The major compounds at the species level were α-pinene (7.41-13.94%), 1,8-cineole (7.55-22.07%), cis-sabinene hydrate (0.10-12.95%), camphor (6.8-19.93%), 4-terpineol (1.55-11.86%), terpenyl acetate (0-14.92%) and viridiflorol (0-11.49%). Based on major compounds, the populations were represented by (α-pinene/1,8-cineole/cis-sabinene hydrate/camphor/viridiflorol), (1,8-cineole/camphor/terpenyl acetate), (α-pinene/1,8-cineole/camphor), (1,8-cineole/camphor/4-terpineol) and (α-pinene/1,8-cineole/cis-sabinene hydrate/camphor/4-terpineol) chemotypes. Variation of phenological stage did not have a statistically significant effect on the yield and metal chelating activity of the essential oil. These results can be used to investigate the geographical location and the harvesting time of this plant for relevant industries.

The essential oil (EO) of M. aquatica L. growing wild in Corsica was isolated by dry vapor distillation and submitted to combined analysis by column chromatography over silica gel, GC(RI), GC-MS and 13C NMR spectroscopy. The composition was dominated byoxygenated monoterpenes and characterized by the occurrence of menthofuran (50.7%) as the major component. In parallel, seven laboratory-distilled oil samples isolated from individual plants collected in Corsica were analyzed by GC(RI) and 13C NMR spectroscopy. Onlyquantitative differences were observed between the samples. Beside the usual terpenes, various p-menthane lactones (mintlactone, isomintlactone, hydroxymintlactone, menthofurolactone and epimenthofurolactone) have been identified in all the oil samples.

Objective: A novel green extraction technique of check valve & non-oxygen microwave assisted extraction (CVNO-MAE) for essential oils extraction was established. CVNO-MAE is a combination of microwave heating, vacuum pump and check valve, performed at anaerobic environment without added any solvent or water., Method: CVNO-MAE has been compared with a conventional technique, solvent free microwave extraction (SFME), for the extraction of essential oils from two Chinese herbs: Curcuma phaeocaulis and Mentha haplocalyx., Result: GC-MS analyses of the oils revealed the presence of 36 and 37 compounds in the essential oils of C. phaeocaulis and M. haplocalyx, respectively. There was an obvious difference in the quality of essential oils obtained by the two kinds of extraction methods. The CVNO-MAE method yielded an essential oil of C. phaeocaulis with lower amounts of oxygenated compounds (45.53%) than SFME (62.38%). Higher amounts of oxygenated compounds (89.57%) were present in the M. haplocalyx essential oil of SFME in comparison with CVNO-MAE (82.74%)., Conclusion: CVNO-MAE is a fast low temperature extraction method carried in under pressure, appears as a good alternative for the extraction of essential oils from Chinese herbs and a green technology.

The aim of this study was to investigate the antibacterial activity of essential oil (in liquid as well as in vapour phase) and negative air ions (NAI) against Pseudomonas fluorescens. The combined effect of NAI with essential oil vapour was also investigated to determine kill time and morphological changes in bacterial cells. The MIC of Cymbopogon citratus (0.567 mg/ml), Mentha arvensis (0.567 mg/ml), Mentha piperita (1.125 mg/ml) and Eucalyptus globulus (2.25 mg/ml) was studied via the agar dilution method. To estimate the antibacterial activity of essential oils in the vapour phase, agar plates inoculated with P. fluorescens were incubated with various concentrations of each essential oil vapour and zone of inhibition was recorded. Further, in order to assess the kill time, P. fluorescens inoculated agar plates were exposed to selected bactericidal essential oil vapour and NAI, separately, in an air-tight chamber. A continuous decrease in bacterial count was observed over time. A significant enhancement in the bactericidal action was observed by exposure to the combination of essential oil vapour and NAI as compared to their individual action. Scanning electron microscopy was used to study the alteration in morphology of P. fluorescens cells after exposure to C. citratus oil vapour, NAI, and combination of C. citratus oil vapour and NAI. Maximum morphological deformation was found due to the combined effect of C. citratus oil vapour and NAI. This study demonstrates that the use of essential oils in the vapour phase is more advantageous than the liquid phase. Further the antibacterial effect of the essential oil vapours can be significantly enhanced by the addition of NAI. The work described here offers a novel and efficient approach for control of bacterial contamination that could be applied for food stabilization practices., (Copyright © 2010 Elsevier B.V. All rights reserved.)

The aim of the present study was to evaluate antioxidative activities of the essential oil, methanol and water extracts of Iranian pennyroyal in vegetable oil during storage. Different concentrations (0, 200, 400, 600, 800 and 1000 ppm) of essential oil, water and methanol extracts and beta-hydroxy toluene (BHT; 200 ppm) were added to sunflower oil emulsion in the presence of cupric ions and incubated for 7 days at 60 degrees C. Peroxide values (PVs) and thiobarbituric acid reacting substances (TBARS) levels were measured in each day up to day of seven. Furthermore, antioxidant capacity of the essential oil and extracts were determined using DPPH and beta-carotene-linoleic acid methods. Values were compared among groups in each incubation time points using ANOVA. Results showed that DPPH and beta-carotene-linoleic acid assay findings on the Mentha pulegium extracts were comparable to those found on BHT. Furthermore, in all incubation time points, M. pulegium extracts lowered PVs and TBARS levels when compared to the control (p<0.001). In this respect, water extract was more potent than the methanol extract. Essential oil did not show considerable antioxidative effect. It seems that water extract of M. pulegium is a potent antioxidant which makes it as a potential antioxidant for oil and oily products during storage., (2010 Elsevier Ltd. All rights reserved.)

Pulegone constitutes a monoterpene occurring in Mentha species and primarily in Mentha pulegium L. (pennyroyal). A major source of human exposure to pulegone is the use of pennyroyal essential oil in flavorings, confectionery and cosmetics. The rapid quantification of pulegone in hydrodistilled pennyroyal oils (which were also "spiked" to increase the validation range) by Fourier transform infrared spectroscopy (FT-IR) combined with partial least-squares (PLS) regression was evaluated, using the spectral region 1650-1260 cm(-1). Gas chromatography was applied as the reference method for pennyroyal oil samples, which ranged in pulegone content from 157 to 860 mg/mL. The two methods were subjected to statistical tests and proved equivalent in terms of accuracy and reproducibility (99% confidence level). The use of FT-IR spectroscopy could offer a viable alternative to the standard analysis procedures presently applied for quantification of valuable plant substances and could also provide the processing industry with a simple and high-throughput technique for the fast quality check of incoming raw materials such as pennyroyal oils.

Mentha x villosa Huds (Labiatae) is an aromatic herb widely used in folk medicine. Since the essential oil of the herb has many pharmacological activities, including antispasmodic effects, we determined whether the oil and its major constituent, piperitenone oxide (PO), have antinociceptive activity. The essential oil of M. x villosa (EOMV) and PO administered orally at 200 mg/kg (vehicle: 0.1% Tween 80 in water) significantly reduced the writhings induced by acetic acid from control values of 59.5 +/- 3.1 s (N = 10) to 31.9 +/- 2.8 s (N = 10) and 23.8 +/- 3.4 s (N = 10), respectively. When administered at 100 and 200 mg/kg, EOMV reduced the paw licking time for the second phase of the formalin test from the control value of 20.6 +/- 2.1 s (N = 13) to 5.3 +/- 2.2 s (N = 12) and 2.7 +/- 1.2 s (N = 18), respectively. At 100 and 200 mg/kg, PO reduced this second phase to 8.3 +/- 2.7 s (N = 12) and 3.0 +/- 1.2 s (N = 10), respectively. This effect of EOMV and PO was not reversed by naloxone. EOMV and PO had no significant effect on the first phase of the formalin test. As evaluated by the hot-plate and tail immersion test, EOMV and PO, at doses up to 200 mg/kg, showed no analgesic activity. These results show that EOMV and PO have antinociceptive activity and suggest that this effect is probably an indirect anti-inflammatory effect, which does not involve the central nervous system.

Mentha spicata Linn. (mint), a herb well known for its gastroprotective properties in the traditional system of medicine has been shown to protect against radiation-induced lethality, and recently its constituents have been found to possess calcium channel antagonizing properties. The present study examined the behavioral radioprotective efficacy of mint oil (obtained from Mentha spicata), particularly in mitigating radiation-induced conditioned taste aversion (CTA), which has been proposed as a behavioral endpoint that is mediated by the toxic effects of gamma radiation on peripheral systems, primarily the gastrointestinal system in the Sprague-Dawley rat model. Intraperitoneal administration of Mentha spicata oil 10% (v/v), 1 h before 2 Gy gamma radiation, was found to render significant radioprotection against CTA (p < 0.05), by blocking the saccharin avoidance response within 5 post-treatment observational days, with the highest saccharin intake being observed on day 5. This finding clearly demonstrates that gastroprotective and calcium channel antagonizing properties of Mentha spicata can be effectively utilized in preventing radiation-induced behavioral changes., (Copyright (c) 2008 John Wiley & Sons, Ltd.)

The use of mint species in traditional and conventional medicine is mostly due to the presence of two classes of secondary bimolecules: monoterpenoids in essential oils and different structural types of phenolic compounds. Essential oils are known to act as antimicrobial, antispasmodic, carminative, and antiviral agents. In addition, essential oils of several mint species have been recently qualified as natural antioxidants. However, since oil composition is highly variable, the pharmacological activity strongly depends on certain chemorace. On the contrary, composition of phenolic constituents is relatively stable within species. The most important phenolic compounds in Mentha species are flavonoids. Mints are characterized by the presence of specific lipophilic flavonoids. Phenolic compounds of mints are found to poses a wide range of pharmacological activity: antioxidant, antiulcer, cytoprotective, heptoprotective, cholagogue, chemopreventive, anti-inflammatory, antidiabetogenic etc. However, besides healing properties some mint species can exhibit an adverse effect on human health. Here we report on botany, chemistry and activity of Mentha species with special respect to their significance for the modern phytotherapy.

Background: Piperitone from plant essential oils enhancesbactericidal activities of nitrofurantoin and furazolidone against bacteria from the family Enterobacteriaceae. In this study, the essential oils of spearmint (Mentha spicata L.), dill (Anethum graveolens L.) and peppermint (Mentha piperita L.)were screened for augmentation of nitrofurantoin activity and the most active components were determined., Method: The effects of essential oils and their components on the bactericidal activity of nitrofurantoin against Enterobacter cloacae were studied using disk-diffusion and agar-dilution methods. The composition of essential oils was studied using gas chromatography-mass spectrometry., Results: M. spicata and A. graveolens oils exhibited the highest effects. Gas chromatography-mass spectrometry analysis showed that the oils of these two plants contained 40.12 and 20.32% carvone, respectively. Pure carvone and piperitone equally increased the bactericidal activity of nitrofurantoin. Other ingredients of essential oils, including camphor, limonene and menthone, were less effective., (Copyright 2007 S. Karger AG, Basel.)

Inhibitory effect of clove oil on Escherichia coli, Staphylococcus aureus, Salmonella typhimurium, Shigella dysenteriae and Candida albicans was detected. Mint ether oil had the high antibacterial action on S. aureus, however against other microorganisms mint oil had a reliably low effect then clove oil. Fennel oil had high antibacterial effect on C. albicans, and bactericidal action on S. typhimurium and S. dysenteriae.

Repellency and toxicity of 2% mint oil granules were evaluated against worker red imported fire ants. Solenopsis invicta Buren, in a series of laboratory and field experiments. In continuous exposure experiments, LT50 values ranged from 1.2 h with 164.8 mg/cm2 of 2% mint oil granules to 15.3 h with 1.65 mg/cm2 of granules. LT50 values declined exponentially with increasing rate of mint oil granules. Limited exposure to 164.8 mg/cm2 mint oil granules resulted in > 50% knock down (KD) after 30 min; however, there was no KD at 15 min. Twenty-four hour mortality increased linearly with increasing exposure time. Mean repellency of worker red imported fire ants ranged from 49.2 +/- 5.4% for 0 mg/cm2 (untreated control) of mint oil granules at 30 min to 100% for 147.8 mg/cm2 of mint oil granules at 3 h. Repellency increased with increasing milligrams per square centimeter of mint oil granules and exposure time. In field tests, 100% of mounds opened and treated with mint oil granules were abandoned 5 d after treatment and ants had relocated or formed satellite mounds by 2 d after treatment. Unopened mounds treated topically with mint oil granules were not abandoned, but ants formed satellite mounds 2 d after treatment. Mint oil granules could provide another tool for red imported fire ant integrated pest management, particularly in situations in which conventional insecticides would be inappropriate.

Essential oils of 12 medicinal plants were tested for inhibitory activity against Aspergillus flavus, A. parasiticus, A. ochraceus and Fusarium moniliforme. The oils of thyme and cinnamon (< or = 500 ppm), marigold (< or = 2000 ppm), spearmint, basil, quyssum (3000 ppm) completely inhibit all the test fungi. Caraway was inhibitory at 2000 ppm against A. flavus, A. parasiticus and 3000 ppm against A. ochraceaus and F. moniliforme. A. flavus, A. ochraceus, A. parasiticus and F. moniliforme were completely inhibited by anise at< or = 500 ppm. However, chamomile and hazanbul at all concentrations were partially effective against the test toxigenic fungi. The results indicate that the test toxigenic fungi are sensitive to the 12 essential oils, and particularly sensitive to thyme and cinnamon. The results also showed that the essential oils of thyme, cinnamon, anise and spearmint have more effect on fungal development and subsequent mycotoxin production in wheat grains. The extent of inhibition of fungal growth and mycotoxin production was dependent on the concentration of essential oils used.

The essential oil of leaves and flowers of sachalinmint [Mentha sachalinensis (Briq.) Kudô] grown in Norway (Trondheim) has been studied by headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography-mass spectrometry analysis (GC-MS). The essential oil content increased linearly in acropetal direction from 1.08% (0-20 cm plant height) to 1.75% (60-80 cm; young leaves and flowers). The steam-distilled samples showed a minor complex matrix with a very high menthol and a much lower menthone content (87.89 and 4.05%, respectively). From testing of HS-SPME unequilibrated exposure times ranging from 10 s to 5 min, an extraction time of 30 s was found to be sufficient to detect both low- and high-eluting compounds. Comparison of HS-SPME and steam-distilled samples established that the same tendencies of increasing menthol/menthone content in the basipetal/acropetal direction could be detected by both analysis methods. With regard to the extraction efficiency, HS-SPME gave additional detailed information about less important terpenic compounds.

Leaf discs obtained from field grown plants of Mentha arvensis were used to initiate multiple shoots on Murashige and Skoog (MS) medium supplemented with 6-benzylaminopurine (5 mg l(-1)) and naphthaleneacetic acid (0.5 mg l(-1)). Profuse rooting was achieved when the well-grown shoots were cultured on half strength MS medium supplemented with indole-3-acetic acid (2 mg l(-1)). The regenerated plantlets were hardened and successfully transferred to soil and grown to maturity. Tissues at different stages of differentiation were analyzed for their essential oil content and characteristic monoterpene pattern. Tissue culture raised plants show the same essential oil profile as that of the parent plant. However, tissues at early stages of growth show distinct changes in oil composition, such as high levels of pulegone in shoot cultures.

Myiasis is one of the most important parasitic diseases, which affects the human welfare. The volatile oils of three plants were tested against adult Lucilia sericata. The LC50 was 80 ppm by Anethum graveolens, 180 ppm by Conyza dioscoridis and 130 ppm by Mentha microphylla. The slope functions were 1.9, 1.79 and 2.2 respectively. The whole results were discussed.