Search Results (109)

The essential oil (EO) of Mentha spicata L. (spearmint) exhibits pronounced biological activity, making it valuable for applications in agrochemistry as an insecticidal agent, in perfumery and cosmetics, and as a natural preservative in the food industry. However, maintaining the integrity and yield of EO during post-harvest processing and extraction remains a key technological challenge. This study aimed to enhance the vacuum-drying (VD) process of spearmint using calcium chloride as a desiccant and to optimize the conditions of supercritical CO₂ extraction (SC-CO₂), including EO separation and the evaluation of its solubility under dynamic extraction conditions. The incorporation of calcium chloride into the VD process reduced drying duration by 21.1% and processing costs by 31.0%, while increasing EO yield by 11%. A decrease in separator pressure from 70 to 10 bar during SC-CO₂ extraction resulted in nearly a threefold increase in EO yield by minimizing the loss of volatile constituents. The solubility of spearmint EO in supercritical CO₂ was successfully described by the Chrastil model and correlated with carvone solubility. The maximum total phenolic content (72.3 ± 2.2 mg gallic acid equivalent per gram) was observed at a CO₂ density of 353.91 kg/m³. The solubility of EO was studied directly using the plant matrix under dynamic conditions. Full article

Essential oils (EOs) of Mentha spicata var. crispa (Benth.) Danert and M. × piperita var. citrata (Ehrh.) Briq. and EO components are widely used in medicine, pharmaceuticals, cosmetics, hygiene products, the food industry, and other fields, and have a high commercial value. The variety Mentha spicata var. crispa is also used as an ornamental plant due to its distinctive curled leaves. Studying the influence of growing conditions and harvest timing on EO yield and the major compound concentrations is one of the key research directions for Mentha species, aimed at the ascertainment of the ways of increasing EO production and quality. Gas chromatography analysis of the component composition of EOs from leaves of Mentha spicata var. crispa “Kurchavaya” (MscK) showed that it remained stable both in July and September, with carvone predominating (81% and 85%, respectively). In contrast, the EO composition from M. × piperita var. citrata “Apelsinovaya” (MpcA) leaves changed in the course of the vegetation period. In July, menthofuran dominated (30%), while in September, linalool and its acetate were predominant (34% and 47%, respectively), which was typical for this chemotype. At the same time, the content of EOs and the density of glandular trichomes (GTs) (the OE storage sites) in MscK were higher in July and decreased by September, whereas in MpcA, both EO content and the number of GTs increased from July to September. These changes may have been caused by temperature fluctuations. Thus, MscK proved to be more resistant to environmental factors than MpcA. Full article

This study aimed to synthesize silver nanoparticles using alcoholic extract of spearmint (Mentha spicata) leaves as a reducing agent and to evaluate their antimicrobial properties. Extract concentrations of 2–5% were used in media with varying pHs. Techniques such as UV-vis spectroscopy, FTIR, and DLS were used to characterize the nanoparticles. The formation of silver nanoparticles was verified by the appearance of a plasmon resonance peak at 418 nm with 2% extract and pH 9. DLS analysis showed a size of 16.1 nm for the 2% extract, which decreased to 10.8 nm with increasing concentration. These results demonstrated that alkaline pH and low extract concentrations favor the formation of monodisperse silver nanoparticles, while higher concentrations induce polydispersity. Silver nanoparticles exhibited antimicrobial activity against E. coli, S. aureus (complete inhibition) and C. albicans (inhibition halo), highlighting their potential in biomedical applications. Full article

Spearmint phytochemicals exhibit remarkable antidiabetic, antioxidant, and broad pharmacological activities. In vitro organ cultures offer an efficient and sustainable platform for enhancing the production of these bioactive metabolites, although optimized media and cultivation strategies are essential to maximize yields. Here, four Murashige and Skoog (MS) medium variants and three cultivation systems—agar-solidified, static-liquid (L), and agitated-liquid (LA)—were evaluated to assess phenolics, antioxidant capacity, antidiabetic potential, and metabolic biochemical markers in in vitro-grown spearmint shoots. Half-strength MS (MS/2) consistently produced the highest antioxidant activity and accumulation of phenolics and sugars across all systems. The MS/2–L combination markedly boosted antioxidant responses, increasing 2,2-diphenyl-1-picrylhydrazyl (DPPH) values up to 27-fold and ferric reducing antioxidant power (FRAP) values tenfold relative to full-strength MS. Antioxidant capacity strongly correlated with total phenolics, flavonoids, rosmarinic acid, antidiabetic activity, and carbohydrate levels. Lipid peroxidation analysis further revealed that shoots cultured under LA conditions showed the highest level of malondialdehyde (MDA) accumulation, whereas MSN/2 (half-strength nitrogen) consistently yielded the lowest MDA levels across all cultivation systems. Collectively, these results highlight the strong influence of nutrient availability and culture system on the metabolic performance of in vitro-grown spearmint. In conclusion, nutrient limitation combined with liquid cultivation effectively enhances antioxidant metabolite accumulation, providing valuable criteria for the future design and optimization of scalable bioreactor systems. Full article

Background/Objectives: As antimicrobial dental treatments, based on chemical products, long tested for their efficacy, have been lately associated with developing antimicrobial resistance, there is a growing interest to identify and develop efficient alternatives. The aim of this paper is to assess the antimicrobial potential of eight selected essential oils (EOs): Cinnamon (Cinnamomum verum), Tea tree (Melaleuca alternifolia), Spearmint (Mentha spicata), Rosemary (Rosmarinus officinalis), Clove (Eugenia caryophyllata), Eucalyptus (Eucalyptus radiata), Cedarwood (Juniperus virginiana), and Lemongrass (Cymbopogon flexuosus), more or less recognized and investigated for this particular therapeutic effect, on Streptococcus mutans (S. mutans), a key pathogen involved in oral pathology. Materials and methods: The chemical constituents of the EOs were identified and quantified by Gas Chromatography-Mass Spectrometry (CG-MS) method. Saliva samples, collected from nine patients with active dental caries, were tested in vitro. To assess the bacterial susceptibility of the selected EOs against S. mutans, the inhibition zones (IZ), minimum inhibitory concentrations (MIC), and minimum bactericidal concentrations (MBC) were determined. Results: All EOs tested showed antimicrobial activity against S. mutans, with IZs over 20 mm. The highest antimicrobial efficacy was observed for spearmint, followed by Eucalyptus, Tea tree, and Lemongrass. The next in descending order were Cinnamon Bark, Clove, Rosemary, and Cedarwood. Considering the mean MIC and MBC values, the spearmint EO proved to be the most effective in inhibiting the growth of S. mutans, as well as in annihilating it, followed by the Eucalyptus EO, Tea tree EO and Lemongrass EO. The less effective were determined to be Cinnamon, Clove, Rosemary and Cedarwood EOs. Conclusions: The eight selected EOs demonstrated antimicrobial activity against S. mutans, with Spearmint and Eucalyptus showing the most significant effects, advocating for their potential in dental caries prevention and treatment, and their potential role in oral hygiene applications. Full article

The study presents the potential application of three essential oils (EOs) obtained from various mint species: peppermint (Mentha piperita L.), spearmint (Mentha spicata L.), and pennyroyal (Mentha pulegium L.), as alternative agents against multidrug-resistant Escherichia coli strains isolated from poultry. The aim of research was to determine the effectiveness of EOs from these mint species and their main chemical components (menthol, menthone, carvone, pulegone) against 19 clinical E. coli strains with varying drug susceptibility and the reference strain E. coli ATCC 25922. GC-MS analysis revealed a unique chemical profile for each mint species. In M. piperita, menthol (35.14%), trans-menthone (23.11%), and menthyl acetate (6.96%) were the dominant compounds. In M. spicata, the main components were carvone (58.61%) and 1,8-cineole (18.74%), while in M. pulegium, pulegone was the dominant ingredient (76.54%). Antibacterial activity tests showed that all tested E. coli strains, both susceptible and multidrug-resistant, were sensitive to the EOs. The strongest antibacterial activity was observed for peppermint oil (Minimal Inhibitory Concentration–MIC 0.5–2.0% v/v), which was attributed to its high menthol content. Menthol was also the most effective single component (MIC 0.125–0.5% v/v). The essential oils containing carvone and pulegone showed lower activity (MIC ≥ 2% v/v). Research indicates that mint EOs, particularly those rich in menthol, represent a promising alternative or complement in the treatment of infections caused by multidrug-resistant E. coli strains. Full article

Metal nanoparticles are increasingly used in industry and agriculture to enhance crop yields and combat plant diseases. Their widespread application has led to exposure across all ecosystem components, including humans. However, there is a lack of a comprehensive assessment of the effect of copper nanoparticles on spearmint plants, applied in different ways (root and foliar) in a wide range of concentrations. The effect of copper nanoparticles at the concentration range of 1–100 mg/L on Mentha spicata L. plants under root exposure and foliar spraying conditions was studied during a 28-day experiment. Copper content in soil and spearmint segments was determined using inductively coupled plasma atomic emission spectroscopy, while the morphology of nanoparticles was characterized using transmission electron microscopy. Foliar spraying showed an inverse relationship between the concentration of copper in solution and root uptake. The highest copper uptake in roots of 27.51 mg/kg was attained at a nanoparticle concentration of 1 mg/L. Root exposure inhibited soil microbial activity, with copper mainly accumulating in soil (up to 950.2 mg/kg) and roots (up to 150.5 mg/kg). Both application methods stimulated pigment production and antioxidant activity, with root irrigation showing a more pronounced effect. Copper extraction efficiency varied (3–64%) depending on exposure method and concentration, raising concerns about transfer along the food chain. Health risk assessment associated with consumption of herbal infusions, prepared from copper-contaminated spearmint leaves, did not show adverse effects when copper levels in the infusion remained below 1.53 mg/L. Full article

Kombucha is a functional beverage with growing popularity due to its health-promoting properties. This study aimed to evaluate the impact of herbal infusions on the quality of green tea-based kombucha. Four variants were prepared: a control (K1) and three experimental samples combining 70% green tea with 30% (v/v) Mentha spicata (K2), Hibiscus sabdariffa (K3), or Clitoria ternatea (K4). Fermentation lasted four days at 24 ± 1 °C. Physicochemical parameters, polyphenol profile (HPLC), microbiological safety, and sensory quality were assessed using QDA and electronic tongue analysis. K3 showed the highest polyphenol content (291 mg/L), especially catechins. K4 achieved the highest overall sensory quality due to its fruity aroma, balanced sweet-sour taste, and favorable microbiological profile. K2 had the lowest caffeine content (114 mg/L) and a distinct minty flavor. All samples were microbiologically safe. Herbal additives influenced fermentative microbiota: K3 had fewer acetic acid bacteria, while K4 had the highest lactic acid bacteria count. Electronic tongue analysis confirmed sensory panel results and revealed distinct taste profiles among the variants. Herbal infusions significantly enhance the nutritional and sensory properties of kombucha. Their use offers a promising strategy for developing functional beverages with tailored characteristics. Full article

Epilepsy manifests as recurrent spontaneous seizures associated with irregular brain activity. Recognizing the limitations of conventional antiepileptic treatments, we explored the therapeutic potential of essential oils (EOs) derived from Greek aromatic plants (Mentha pulegium, Mentha spicata wild, Mentha piperita, Lavandula angustifolia and Origanum Dictamnus). Specifically, we explored their radical scavenging capacity (DPPH), as well as their antioxidant (AOP and MDA levels) and neuroprotective effect in a PTZ-induced epilepsy Balb/c mice model (animals were pretreated with EOs prior to PTZ treatment). Our results indicated that Mentha piperita emerges as the most promising EO, demonstrating strong antioxidant activity and the highest radical scavenging ability (IC₅₀ = 1.9 mg/mL). Mentha pulegium also exhibited considerable antioxidant potential, demonstrating the strongest effect in the AOP assay when administered prior to PTZ treatment. Furthermore, Origanum dictamnus exhibited the strongest potential to attenuate MDA formation in the presence of PTZ. Finally, immunohistochemistry indicated a trend of neuronal preservation in animals pretreated with EOs prior to PTZ, with Mentha piperita demonstrating the most significant effect. Based on these findings, we suggest that certain EOs possess significant antioxidant and neuroprotective properties. Further research is warranted to validate these results and elucidate the active ingredients responsible for the observed properties. Full article

This study aimed to evaluate the inhibitory potential of phenolic-rich extracts from selected medicinal plants belonging to the Lamiaceae and Asteraceae families against the furin protease enzyme, a key target in viral and oncogenic pathways. Extracts of Origanum vulgare, Thymus vulgaris, Mentha piperita, Mentha spicata, Salvia officinalis, and Silybum marianum were prepared using hexane, chloroform, and ethyl acetate. Phenolic compounds were quantified using High-Performance Liquid Chromatography (HPLC). Furin inhibition was assessed spectrophotometrically and analyzed statistically with multivariate approaches. The chloroform extract of Origanum vulgare exhibited 97.44 ± 0.12% inhibition, while the ethyl acetate extract of Mentha spicata showed 97.44 ± 0.08% inhibition. Epicatechin and rutin displayed significant synergistic effects, while naringenin negatively affected inhibition (p < 0.05). Solvent polarity significantly influenced phenolic diversity and biological activity, with ternary combinations showing 33% higher inhibition than single compounds. These findings highlight phenolic blends as promising natural furin inhibitors, with chloroform being optimal for broad-spectrum extraction. Full article

The experiment was conducted in a greenhouse and a growth chamber, in a randomized block design, with three replicates. The use of light-emitting diodes (LEDs) with varying wavelengths, combined with adequate nutrition, positively influence yield and the content of essential macronutrients and micronutrients in mint plants, which play a key role in the processes of growth and development. The average total yield of mint ranged from 23.1 g plant⁻¹ to 48.1 g plant⁻¹, while marketable yield ranged from 22.5 g plant⁻¹ to 47.6 g plant⁻¹. Exposure to violet LED light led to the highest increase in yield. The content of all analyzed macronutrients increased in plants of the evaluated mint species exposed to LED light. On average, the content of N, P, K in the aerial parts of mint plants increased significantly by around 25%, 56%, and 42%, respectively, under exposure to violet LED light, and by around 19%, 44%, and 37%, respectively, under exposure to yellow LED light. The values of K:Ca, K:Mg, and K:(Ca + Mg) ratios were higher in plants grown under LED light than in plants exposed to sodium light, whereas the opposite was noted for the Ca:P ratio. Exposure to violet or yellow LED light did not induce significant changes in Mn, Zn, Cu, and Fe uptake by mint plants. The micronutrient content of plants was largely determined by mint species. Mentha piperita plants had the highest Zn content, and Mentha suaveolens plants had the highest concentrations of Mn, Cu, and Fe. Full article

The increasing prevalence of antibiotic resistance and the limited availability of antiviral therapeutics for pathogens such as human respiratory syncytial virus (hRSV) underscore the need for novel, plant-derived antimicrobial substances. In this study, we evaluated the antiproliferative, antibacterial, and antiviral activities of aqueous leaf extracts from two plants commonly found in North America, Osage orange (M. pomifera) and spearmint (M. spicata). Both extracts exhibited no significant cytotoxic or morphologic impact on HEp-2 human cancer cells up to 25 mg/mL. However, both extracts demonstrated strong dose-dependent antibacterial activity, significantly inhibiting replication of E. coli and S. aureus at concentrations ≥ 1 mg/mL. Antiviral assays revealed that both extracts inhibited hRSV infectivity, with spearmint extract showing higher potency (EC₅₀ = 1.01 mg/mL) compared to Osage orange (EC₅₀ = 3.85 mg/mL). Gas chromatography–mass spectrometry (GC-MS) identified three major extract constituents: 3-hydroxybenzyl alcohol, 4-hydroxybenzyl alcohol (Osage orange), and R-(-)-carvone (spearmint). Among these, only carvone significantly inhibited hRSV in vitro, suggesting its key role in spearmint’s antiviral activity. These findings highlight the therapeutic potential of Osage orange and spearmint leaf extracts, particularly as sources of water-soluble compounds with antimicrobial properties, and support further investigation into their mechanisms of action and broader clinical relevance. Full article

This study, conducted in Southern Italy in 2023, investigated the effects of a dynamic agrivoltaics (AV) system on microclimate, water consumption, plant growth, and essential oil yield in six medicinal species: lavender (Lavandula angustifolia L. ‘Royal purple’), lemmon thyme (Thymus citriodorus (Pers.) Schreb. ar. ‘Aureus’), common thyme (Thymus vulgaris L.), rosemary (Salvia rosmarinus Spenn. ‘Severn seas’), mint (Mentha spicata L. ‘Moroccan’), and sage (Salvia officinalis L. subsp. Officinalis). Due to the rotating solar panels, two distinct ground zones were identified: a consistently shaded area under the panels (UP), and a partially shaded area between the panels (BP). These were compared to an adjacent full-sun control area (T). Microclimate parameters, including solar radiation, air and leaf infrared temperature, and soil temperature, were recorded throughout the cultivation season. Reference evapotranspiration (ET_O) was calculated using Turc’s method, and crop evapotranspiration (ET_C) was estimated with species-specific crop coefficients (K_C). Results showed significantly lower microclimatic values in the UP plot compared to both BP and especially T, resulting in ET_C reductions of 81.1% in UP and 13.1% in BP relative to T, an advantage in water-scarce environments. Growth and yield responses varied among species and treatment plots. Except for mint, all species showed a significant reduction in fresh biomass (40.1% to 48.8%) under the high shading of UP compared to T. However, no biomass reductions were observed in BP. Notably, essential oil yields were higher in both UP and BP plots (0.60–2.63%) compared to the T plot (0.51–1.90%). These findings demonstrate that dynamic AV systems can enhance water use efficiency and essential oil yield, offering promising opportunities for sustainable, high-quality medicinal crop production in arid and semi-arid regions. Full article

Herbs are valued for their antioxidant richness and traditional use in cuisine and medicine. This study analysed wild herbs (e.g., Achillea, Lamium) and cultivated spices (Salvia, Artemisia) for their bioactive compounds. It was found that antioxidant profiles varied notably among species, even within the same family. Helichrysum italicum and Salvia officinalis had the highest polyphenol levels, while Achillea millefolium and Ocimum basilicum had the lowest. Total polyphenols did not always correlate with antioxidant activity. For instance, Petroselinum hortense and Salvia rosmarinus showed high antioxidant activity despite low polyphenol levels, whereas Levisticum officinale and Artemisia dracunculus combined both. Mentha spicata, M. x citrata, Origanum vulgare, and S. officinalis were rich in carotenoids, while H. italicum showed high α-carotene but low levels of other carotenoids. Most Lamiaceae accumulated a high amount of chlorophylls and polyphenols. Cultivated herbs like M. spicata, M. x citrata, and S. officinalis exhibited stronger and more diverse properties than wild species. It can be concluded that taxonomy alone does not predict antioxidant potential. The differences observed may be attributed to species-specific metabolic pathways, ecological adaptations, or environmental factors influencing phytochemical expression. These findings highlight the importance of conducting species-level screenings in the search for plant-derived antioxidants with potential therapeutic applications. Full article

The paper deals with the investigation of the ascorbic acid influence on the analytical results of polyphenol content in the samples of the spearmint, fennel, and thyme homogenates. The homogenates without and with addition of ascorbic acid and water were prepared and stabilized by high-pressure treatment. Their analysis was accomplished by high-performance liquid chromatography (HPLC) with DAD detection and by combination of liquid chromatography with mass spectrometry (LC-MS). Volatile terpenes were analyzed in all homogenates by combination of gas chromatography with mass spectrometry technique (GC-MS). The content of polyphenols of acidic nature, e.g., rosmarinic acid, revealed the highest difference between analytical results of the samples with and without ascorbic acid. Finally, prepared herb homogenates are suitable food supplements, which will find increasing application in various food preparations. Full article