Lemon Balm Essential Oil Research Articles

Ecological pre-treatment of cell wall degrading enzymes from Pleurotus djamor for optimized essential oil extraction from Melissa officinalis L.

Melissa officinalis L. is a plant with different medicinal and culinary uses, which is considered one of the essential oils with the highest market value, mainly because of its low yield. The use of technologies that improve the extraction of this essential oil is justified. The study evaluated the use of cell wall degrading enzymes (CWDE) obtained from Pleorotus djamor to extract essential oil of Melissa officinalis L.. For the optimization of the enzymatic pre-treatment, the independent variables time and CWDE/H2O ratio were evaluated through central composite rotational design (CCRD). The essential oil extraction was carried out by hydrodistillation after pre-treatment. The results showed that the pre-treatment was able to increase the essential oil yield by 71 % and reduced energy consumption and CO2 emissions by 42 %, when applied for 60 minutes and CWDE/H2O ratio (25/450 mL.mL−1). Gas chromatography-mass spectrometry (GC/MS) was used to evaluate the essential oil composition. The majority of compounds were citral (Neral +Geranial). In addition, the increase of this compound was observed at about 24 %. The lemon balm plant cell wall was degraded. Considering the production and energy costs and increase yield as well as the quality of lemon balm essential oil, the application of CWDE was efficient.

The Effect of Inhalation Aromatherapy with Lemon Balm (Melissa officinalis) Essential Oil on Sleep Quality in Mothers of Preterm Infants in the Neonatal Intensive Care Unit (A Randomized Clinical Trial Study)

Aim The present study was to investigate the effect of inhalation aromatherapy with the lemon balm (Melissa officinalis) essential oil on sleep quality in the mothers of preterm infants admitted to the neonatal intensive care unit (NICU). Background Preterm infants and their hospital care are among the stressful events encountered by mothers. As maternal sleep disturbances are one of the frequent disorders at this stage, developing some measures to support mothers has been high on the list. Methods This two-group randomized clinical trial (RCT) was conducted on 50 mothers of preterm infants at the 28-32 weeks of pregnancy, completing the Pittsburgh Sleep Quality Index (PSQI) as the data collection tool. The study samples were initially randomized into two groups, viz., intervention and control. Afterward, the mothers in the intervention group received inhalation aromatherapy with the lemon balm essential oil by 5-7 drops on their face masks twice a day for two weeks. Then, sleep quantity and quality were assessed during the one- and two-week intervals following the intervention. The data were further analyzed using descriptive and inferential statistics. Results In total, 50 mothers of preterm infants were investigated in this study. The overall score of sleep quality in the mothers in the intervention group within the one- and two-week intervals at the post-intervention stage indicated a significant decrease, as compared with those in the controls (p<0.001). Moreover, the overall score of sleep quality for two weeks after the intervention compared with the one-week interval significantly dropped in the intervention group, as compared with the control one (p<0.001). Conclusion It was concluded that inhalation aromatherapy with lemon balm essential oil as a complementary medicine could be effective in improving sleep quality in mothers of preterm infants.

Effect of lemon balm (Melissa officinalis L.) essential oil on some characteristics of oil/water food emulsions

Food emulsions are used on a daily basis by people, therefore it is of great importance to study the factors that can influence their stability. The aim of this work is to track the influence of lemon balm essential oil (Melissa officinalis L.) on the change of some physical and chemical indicators, kinetic (turbidity) and thermodynamic (Gibbs free energy, enthalpy and entropy) parameters, which are related to their stability. 24 food emulsions were developed with oleic type sunflower oil acting as an oil phase in concentrations of 20 and 30%, soybean protein emulsifier in concentrations of 1, 2, and 3% and lemon balm essential oil in concentrations of 0.1, 0.2 and 0.3%. The pH of the emulsions was determined, microscopic photographs were taken to measure the sizes of the colloidal particles, turbidity was observed for 15 days, their absorbance was determined, Gibbs energy, enthalpy and entropy were calculated. The most stable is the emulsion with 30% oil phase, 3% soybean protein emulsifier and 0.3% lemon balm essential oil.

Shade-Induced Effects on Essential Oil Yield, Chemical Profiling, and Biological Activity in Some Lamiaceae Plants Cultivated in Serbia

Thyme, mint, and lemon balm were used to determine whether shading conditions could improve the yield, composition, antioxidant, and antimicrobial activity in plant essential oils (EOs) in comparison with non-shaded plants from an open field. The yield of the EOs of non-shaded thyme, mint, and lemon balm, was 3.44, 3.96, and 0.21 mL/100 g, respectively. Plants covered by nets produced different levels of EOs (3.46, 2.20, and 0.45 mL/100 g) after 120 min of hydrodistillation. The main components of the thyme essential oil are thymol (44.2–43.9%), γ-terpinene (18.3–16.8%), and p-cymene (16.5–17.4%). The predominant components of mint essential oil are piperitenone oxide (52.6–64.8%) and 1,8 cineole (25.9–16.3%), while lemon balm essential oil consists of the following main components: geranial (34.0–32.8%); neral (21.3–24.9%); and piperitenone oxide (17.2–16.7%). The EOs from non-shaded thyme and mint plants have the highest antioxidant activity (EC50 value 0.54 mg/mL and 3.03 mg/mL). However, shaded lemon balm showed a stronger antioxidant activity (EC50 3.43 mg/mL) than non-shaded plants (12.85 mg/mL) after 60 min of incubation. The EOs from all plants showed significant effects against Escherichia coli, Proteus vulgaris, Bacillus subtilis, Staphylococcus aureus, and Candida albicans. The most active EOs against most of the isolates originated from Thymus vulgaris L., plants. Adequate cultivation techniques, such as shading for Lamiaceae plants, has positive effects, especially in Melissa officinalis L. Shading can achieve a higher content and components in terms of the specific biological activity (antioxidant and microbial) of EOs.

Lemon Balm (Melissa officinalis) Essential Oil Moderately Affects Strychnine-Induced and Pentylenetetrazol-Induced Convulsions —In Silico and In Vivo Studies

Epileptic seizures are a consequence of uncontrolled neuronal discharge and demand urgent and prolonged treatment. Due to a lack of potent and low-risk drugs that could prevent seizures, efforts are underway to discover new drugs, and plant metabolites are often considered valuable candidates in this search. Lemon balm ( Melissa officinalis L., Lamiaceae) is a world-renowned medicinal plant affecting central nervous system function. In this study, we aimed to examine whether the results from in silico modeling of the interactions of major lemon balm essential oil constituents with GABAA and glycine receptors correspond to in vivo results of the convulsions in mice induced by the application of either pentylenetetrazol (GABAA antagonistic) or strychnine (glycine receptor antagonist). While molecular docking experiments of essential oil constituents to the two receptors demonstrated the possibility of ligand–receptor interactions, no binding poses were scored highly, and as the in vivo effect of the essential oil on convulsions seems to be only moderate, the results of the in silico study seem not to contradict results obtained by in vivo models. Thus, we can say that molecular docking might be a useful tool in initial screening for active constituents of natural product mixtures and the potential prediction of their activity in models in vivo.

Bioactive Collagen Hydrolysate-Chitosan/Essential Oil Electrospun Nanofibers Designed for Medical Wound Dressings.

In this study, lemon balm (Melissa officinalis L.) and dill (Anethum graveolens L.) essential oils (EOs) were encapsulated into collagen hydrolysates extracted from bovine tendons and rabbit skins, both mixed with chitosan (CS) by using the coaxial electrospinning technique for potential wound dressing applications. The morphology and chemical composition of the electrospun nanofibers were investigated using scanning electron microscopy (SEM) and attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR). The antimicrobial activity of the dill EO and lemon EO, as well as the electrospun samples loaded with essential oils was determined by disk diffusion assay against Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922, Enterococcus faecalis ATCC 29212, and Salmonella typhimurium ATCC 14028 bacterial strains; Candida albicans ATCC 10231 and Candida glabrata ATCC 90028 yeast strains; and Aspergillus brasiliensis ATCC 9642 fungal strain. In vivo biocompatibility testing of the collagen hydrolysate-chitosan/essential oil electrospun nanofibers was based on the determination of the hematological, biochemical, and immunological profile and the evaluation of the influence produced on the oxidative stress in white Swiss mice. The synergetic effect of dill and lemon balm EOs can improve the antimicrobial activity of collagen hydrolysate-chitosan nanofibers against the most important bacterial strains. The in vivo test results suggested a good biocompatibility of electrospun samples based on collagen hydrolysate extracted from bovine tendons or rabbit skin mixed with chitosan and containing dill and/or lemon balm essential oils as encapsulated bioactive compounds.

Low energy nanoemulsions as carriers of thyme and lemon balm essential oils

The aim of this work was to produce monomodal and stable thyme and lemon balm-loaded nanoemulsions (NE), through a low energy approach. NEs were prepared by the emulsion phase inversion method using sunflower oil as carrier and Tween 80 as surfactant. Different surfactant-to-oil ratios (SOR) and essential oil (EO) loadings were evaluated. Nanoemulsions presented a monomodal diameter distribution below 200 nm and high negative zeta potential (>−40 mV). Nanoemulsions loaded with EOs were physically stable for 3 months at 4 °C and 20 °C. Nanoemulsions with thyme EO presented the highest radical scavenging activity by DPPH and ABTS tests. Loaded nanoemulsions were not effective against Escherichia coli but could inhibit Staphylococcus aureus. Cytotoxicity studies using cell counting kit-8 and resazurin assays revealed a dose-responsive effect of nanoemulsions on Caco-2 cells after incubation for 24 h. A concentration of 100 μg oil/mL of NE for unloaded and thyme loaded and 50 μg oil/mL of NE for lemon balm loaded showed to be safe to use.

The Inhibition of Non-albicans Candida Species and Uncommon Yeast Pathogens by Selected Essential Oils and Their Major Compounds.

The epidemiology of yeast infections and resistance to available antifungal drugs are rapidly increasing, and non-albicans Candida species and rare yeast species are increasingly emerging as major opportunistic pathogens. In order to identify new strategies to counter the threat of antimicrobial resistant microorganisms, essential oils (EOs) have become an important potential in the treatment of fungal infections. EOs and their bioactive pure compounds have been found to exhibit a wide range of remarkable biological activities. We investigated the in vitro antifungal activity of nine commercial EOs such as Thymus vulgaris (thyme red), Origanum vulgare (oregano), Lavandula vera (lavender), Pinus sylvestris (pine), Foeniculum vulgare (fennel), Melissa officinalis (lemon balm), Salvia officinalis (sage), Eugenia caryophyllata (clove) and Pelargonium asperum (geranium), and some of their main components (α-pinene, carvacrol, citronellal, eugenol, γ-terpinene, linalool, linalylacetate, terpinen-4-ol, thymol) against non-albicans Candida strains and uncommon yeasts. The EOs were analyzed by GC-MS, and their antifungal properties were evaluated by minimum inhibitory concentration and minimum fungicidal concentration parameters, in accordance with CLSI guidelines, with some modifications for EOs. Pine exhibited strong antifungal activity against the selected non-albicans Candida isolates and uncommon yeasts. In addition, lemon balm EOs and α-pinene exhibited strong antifungal activity against the selected non-albicans Candida yeasts. Thymol inhibited the growth of all uncommon yeasts. These data showed a promising potential application of EOs as natural adjuvant for management of infections by emerging non-albicans Candida species and uncommon pathogenic yeasts.

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.

Nematocidni efekat esencijalnih ulja biljaka familije Lamiaceae NA Panagrolaimus sp. (Nematoda:Panagrolaimidae)

The long-term presence of conventional pesticides changes the ecological balance in nature, causing the disappearance of many beneficial organisms, while their residues in food and water pose a global threat to humans. The consequences of the application of large quantities of pesticides have resulted in the banning of many highly toxic compounds. In search for more environmentally friendly solutions, essential oils are being investigated. Essential oils have been used for centuries in folk medicine and today show great potential in controlling a wide range of pathogens, pests and parasites. The family Lamiaceae is one of the most important plant families in the production of essential oils. The aim of this study was to investigate the nematicidal effect of essential oils of some plants of the family Lamiaceae on free-living nematodes of the genus Panagrolaimus. A low nematicidal effect was shown by pachouli, while moderate nematicidal effects performed wild mint, wild sage, lavender, oregano, thyme and basil. The lemon balm essential oil had the strongest nematicidal impact. The aldehyde and phenolic components of terpenoids are the main constituents of the essential oils of thyme, basil and lemon balm which have shown the strongest nematicidal action and the chemicals potentially responsible for their toxicity.

Sanitary and physiological quality of corn seeds (Zea mays) treated with essential oil emulsion

The aim of the present studies were to evaluate the effects of treatments with essential oil emulsion on the sanitary and physiological quality of creole corn seeds. In the studies were evaluated the essential oils of neem (Azadirachta indica), citronella (Cymbopogon nardus), lemon balm (Cymbopogon citratus), melissa (Melissa officinalis L.), and the combinations neem-citronella, neem-lemon balm, neem-melissa, citronella-lemon balm, citronella-melissa and lemon balm-melissa. The tests carried out were germination, length of seedlings (aerial part and root), dry mass and pathology for Fusarium sp and Aspergillus sp, in seeds of creole corn produced without the use of synthetic pesticides. The studies were carried out in vitro and consisted of the preparation of water emulsion, 5,000 ppm of essential oil and 1% of triton X100 and direct application on the seeds of creole corn, following the protocol of Rules of Seed Analysis (RSA). The results showed a significant decrease in the occurrence of fungi Fusarium sp and Aspergillus sp with treatment with essential oils of citronella, lemon balm and melissa, while the oil of neither reduced the occurrence of Fusarium sp, but increased the occurrence of Aspergillus sp in almost four times. All binary combinations of essential oils reduced the occurrence of both fungi. On the other hand, the physiological quality was strongly affected by the death of creole corn seeds, except for the treatment with lemon balm essential oil. Therefore, these studies allow to affirm that essential oils can be efficient in the control of pathogens, however they can kill the seeds of creole corn.

A randomised controlled trial of Lavender (Lavandula Angustifolia) and Lemon Balm (Melissa Officinalis) essential oils for the treatment of agitated behaviour in older people with and without dementia

ObjectiveLavender and Lemon Balm essential oils are popular in the management of older person agitation due to their ease of application, minimal side effects and low interaction with concurrent medications. This study addressed limitations in the literature to evaluate and compare effectiveness of Lavender and Lemon Balm essential oils on the agitated behaviour of older people with and without dementia living in residential aged care facilities [RACFs]. MethodsForty-nine nursing home residents with dementia (n=39) and without dementia (n=10) exhibiting agitation participated in this study. Participants were randomised to a counterbalanced, repeated measures design experiment that tests the treatments Lavender, Lemon Balm, and Placebo (Sunflower oil). Treatments were administered once daily for two-weeks followed by a two-week washout period before commencing the subsequent treatment. All participants trialed all three treatments over a 10-week period. Data were collected on the Neuropsychiatric Inventory (NPI) and Cohen-Mansfield Agitation Inventory (CMAI). ResultsA significant difference was shown when essential oils effect were compared between the cognitive groups. Post hoc analysis reports Lemon Balm more effective in reducing NPI agitation (p = .04) and CMAI physical non-aggressive behaviour (PNAB) (p = .02) in residents without dementia. Lemon Balm less effective in reducing NPI irritability (p = 0.01) and Lavender more effective in reducing CMAI PNAB (p = 0.04) in dementia. ConclusionThe findings support an opposing effect of Lemon Balm and Lavender in reducing agitated behaviour between the participant cognitive groups. There was no reduction in agitation with treatments when compared to placebo independent of cognitive groups.

<b>The growth, photosynthetic pigments and essential oil composition of monocropped and intercropped lemon balm with yarrow

The purpose of this study was to assess the influence of lemon balm intercropping with yarrow on the vegetative growth, photosynthetic pigments and essential oil contents as well as the chemical composition of essential oils. Accordingly, the lemon balm and yarrow monocroppings were compared to the intercropping of both species. The plants were cultivated for 120 days under field conditions. The experimental design followed randomized blocks with seven repetitions. Growth was assessed through the accumulation of shoot dry matter and through the leaf area. The photosynthetic pigment content was set based on the fully expanded leaves from five plants in each treatment. The essential oil was extracted through the hydrodistillation of the lemon balm leaves and yarrow leaflets dehydrated in a forced ventilation oven at 40°C. The chemical analyses of the essential oils were performed using GC-FID and GC-MS. Intercropping showed a reduction of vegetative growth. However, intercropping increased the lemon balm essential oil content. On the other hand, these parameters did not change in yarrow. There were variations in the level of chemical constituents in lemon balm and yarrow essential oils, which were more evident in the major constituents.

Essential oil content and its composition in herb of lemon balm (Melissa officinalis L.) breeding strains

The evaluation of essential oil content and its composition in the herb of lemon balm breeding strains was the goal of the research, with the aim of selecting appropriate genotypes for further breeding programs. In 2013–2014, at the beginning of flowering, the herb was collected from ten randomly selected plants of eight strains bred in the nursery. The essential oil content was estimated after hydrodistillation of dried lemon balm herb, in accordance with the method recommended by the European Pharmacopoeia VI; the essential oil was then subjected to gas chromatography. Both the yield of lemon balm essential oil and its composition showed significant differentiation among the investigated strains. These differences were associated with fluctuations in weather conditions in the years of the research. Higher levels of the main components (neral and geranial), though not of essential oil itself, were observed under higher insolation.

Quantitative Analysis of Phenolic Acids and Antiplatelet Activity of Melissa officinalis Leaf Extracts

The contents of total phenolic acids and rosmarinic acid were determined and the antiplatelet potential assessed of extracts of lemon balm (Melissa officinalis L., Lamiaceae) leaf samples collected during 2014 and 2015. The quantity of total phenolic acids ranged from 4.8 to 8.5%, while the rosmarinic acid content ranged from 1.78 to 4.35%. Results of statistical analysis showed that the undiluted extracts have antiplatelet activity in the ADP test (final concentration 31.25 mg/L). While there are reports on antiplatelet activity of lemon balm essential oil, to the best of our knowledge, this is the first report on antiplatelet activity of lemon balm leaf extracts.

Antiviral activity of the oseltamivir and Melissa officinalis L. essential oil against avian influenza A virus (H9N2).

Lemon balm derivatives are going to acquire a novelty as natural and potent remedy for treatment of viral infections since the influenza viruses are developing resistance to the current antivirals widely. Oseltamivir, Melissa officinalis essential oil (MOEO) and their synergistic efficacy against avian influenza virus (AIV) subtype H9N2 were evaluated in vitro in MDCK cells at different time exposure by using TCID50, HA, Real Time PCR and HI assay. The results showed that MOEO could inhibit replication of AVI through the different virus replication phase (P≤0.05). Also the highest antiviral activity of MOEO was seen when AIV incubated with MOEO before cell infection. The TCID50/ml was reduced 1.3-2.1, 2.3-2.8, 3.7-4.5 log 10 than control group (5.6 log 10), HAU/50µl was decreased 85-94, 71.4-94, 71.4-94% and viral genome copy number/µl was brought down 68-95, 90-100, 89.6-99.9% at pre-infection, post-infection and simultaneous stage, respectively. Hemagglutination inhibition result showed the MOEO was not able to inhibit agglutination of the chicken red blood cell (cRBC). Replication of the AVI was suppressed by the different concentration of oseltamivir completely or near 100%. Also oseltamivir showed a synergistic activity with MOEO especially when oseltamivir concentration reduced under 0.005mg/ml. The chemical composition was examined by GC-MS analysis and Its main constituents were identified as monoterpenaldehydes citral a, citral b. In conclusion, the findings of the study showed that lemon balm essential oil could inhibit influenza virus replication through different replication cycle steps especially throughout the direct interaction with the virus particles.

Use of egg white protein powder based films fortified with sage and lemon balm essential oils in the storage of lor cheese

Edible film was produced by adding 3 % sorbitol (w/v) to egg white protein powder (EWPP). The first group of lor cheese samples was coated with a film fortified by sage essential oil (SEO) and the second group of samples was coated with films enriched by adding lemon balm essential oil (BEO) at various concentrations [0.5 %, 1 %, 2 % (v/v)]. The films were labeled as EWPPSEO(0.5), EWPPSEO(1), EWPPSEO(2), EWPPBEO(0.5), EWPPBEO(1), EWPPBEO(2) to indicate the type and the concentration of the additive. The third batch of the lor cheese samples was coated exclusively with non-fortified EWPP and the fourth batch was uncoated. All of the cheese samples were artificially contaminated with Escherichia coli O157:H7 (E. coli O157:H7), Listeria monocytogenes (L. monocytogenes) and Staphylococcus aureus (S. aureus). Viable cell counts of these species, yeasts and moulds were determined after the cheese production. All the samples were stored at +4 °C. Their physicochemical and microbiological properties were examined on the 1st, 7th, 15th and 30th day of the storage. Thereat significant (P<0.05) relationships between the increase in the essential oil concentrations and the increase in film thickness, water vapor permeability, inner and outer hardness, decrease in the weight loss, improvement in fat barrier property, and microbial counts during storage were found. These properties were found to be significantly affected in the 2 % (v/v) SEO and BEO samples, while the effects of other additive concentrations were insignificant (P>0.05). Physicochemical and antibacterial properties were more significant in SEO at all concentrations compared to BEO. However, the antifungal effect of BEO was higher than that of SEO. The antifungal effect of BEO was the same at 1 % (v/v) and 2 % (v/v) concentrations. E. coli O157:H7 was the most resistant microorganism to the essential oils while L. monocytogenes was the most sensitive. EWPP showed a bacteriostatic effect on the microorganisms and bactericidal effects were determined on the 30th day of the storage against L. monocytogenes and yeast-moulds.

Harvest stage effects on some yield and quality characteristics of lemon balm (Melissa officinalis L.)

The purpose of this study was to investigate the effects of different harvesting stages on some yield and quality characteristics of lemon balm (Melissa officinalis L.) during the 2013 and 2014 growing seasons in Odemis, Izmir, Western Turkey. The experiment was established as a randomized blocks design with four replications and the plants were harvested at three growth periods such as pre-florescence (in May), during florescence (in August) and post-florescence (in November). Plant height, fresh herb yield, dry herb yield, dry leaf yield, dry stem yield, essential oil content and constituents were determined. Statistical analyses showed that the plant height, fresh herb yield, dry herb yield, dry stem yield and essential oil content were all affected by the harvest stages. Mean value of the plant height ranged between 76.94–91.60cm, fresh herb yield was 21980.9–39941.5kgha−1, dry herb yield was 5955.8–91358.0kgha−1, dry leaf yield was 717.4–1076.8kgha−1 and dry stem yield was 524.3–939.2kgha−1. The total essential oil content ranged between 0.27–0.36% and the highest content was provided from the florescence stage of the plant. The main constituent of the essential oil was determined as E-Citral and ranged between 25.90–37.74% of the total and the highest content was also obtained from the florescence stage. Z-Citral and Caryophyllene oxide were identified as other components of the lemon balm essential oil.

Antifungal activity of essential oils of lemon balm, manuka and tansy to the causative agents of otomycosis

Introduction: Otomycosis is a superficial fungal infection of the external ear canal. One of the therapeutic approaches that became topical in treatment of otomycosis is the application of essential oils, which is shown to have different biological properties, including the antimicrobial effect. Aim: The objective of the research is to examine antimycotic effects of essential oils of lemon balm (Melissa officinalis), manuka (Leptospermum scoparium) and tansy (Tanacetum vulgare) on the causative agents of otomycosis. Materials and Methods: In this study, we investigated the sensitivity of 20 randomly selected strains of Candida spp. and Aspergillus spp. isolated from swabs taken from the external ear canal of patients with signs and symptoms of otitis externa. Antifungal activity of essential oils of lemon balm, manuka and tansy was tested by using the microdilution method by determining the value of the Minimum inhibitory concentration (MIC) and Minimum fungicidal concentration (MFC). Results: MIC values of lemon balm were in the range of 0.39- 50 μl/ml, manuka of 0.39-50 μL/mL and tansy of 1.56-50 μL/mL. The MFC values were 2-4 times higher than the MIC values, except in the case of a strain of Aspergillus niger, which was tolerant of the lemon balm essential oil. Conclusion: The investigation has shown that essential oil activities of lemon balm, manuka and tansy to the strains of Candida spp. and Aspergillus spp, using the microdilution method, have antifungal effect.

Evaluation of essential oil quality of lemon balm (Melissa officinalis L.) grown in two locations of northern India

The essential oil composition of lemon balm (Melissa officinalis L.) produced in two ecological conditions were evaluated using gas chromatography–flame ionization detector (GC–FID) and GC–mass spectrometry (GC–MS). Thirty-three constituents, representing 91.4 ± 1.56% to 98.1 ± 0.60% of the total oil compositions, were identified. The major constituents of the essential oil were geranial (42.3 ± 1.77% to 44.9 ± 3.23%), neral (30.7 ± 1.11% to 32.6 ± 3.57%), (E)-caryophyllene (2.8 ± 1.00% to 3.5 ± 1.27%), geranyl acetate (0.7 ± 0.49% to 3.3 ± 0.15%), geraniol (0.9 ± 0.93% to 2.6 ± 0.35%), piperitone (0.6 ± 0.96% to 2.5 ± 1.81%), nerol (0.8 ± 0.44% to 2.4 ± 0.23%), caryophyllene oxide (0.8 ± 0.81% to 2.3 ± 0.55%), (E)-isocitral (0.5 ± 0.06% to 2.1 ± 0.46%) and citronellal (0.4 ± 0.52% to 2.1 ± 0.06%). The examined lemon balm essential oil was considerably rich in monoterpenoid aldehyde (citral, 73.0–77.5%).