Search Results (103)

The objective of this study was to isolate and characterize actinobacteria from the rhizosphere of medicinal and aromatic plants, specifically lavender (Lavandula angustifolia Mill.), lemon balm (Melissa officinalis L.), and oregano (Origanum vulgare L.). Rhizospheric soil samples revealed a high abundance of culturable actinobacteria (6.97–7.23 log₁₀ CFU/g). Six isolates were selected for their promising enzymatic activities (lignin peroxidase, carboxymethyl cellulase) and antimicrobial properties. Isolates M345 and M162 exhibited the highest cellulase activity indices (3.19 ± 0.71 and 2.54 ± 0.22, respectively), with five isolates producing lignin peroxidase. These actinobacteria also demonstrated plant growth-promoting traits such as phosphate solubilization and nitrogen fixation, along with strong antimicrobial activity against Gram-negative bacteria and phytopathogenic fungi. Additionally, they significantly enhanced maize seed germination, increasing the vigor index from 4283.33 ± 1264.37 to 6248.28 ± 1661.94 compared to that of the control. These results indicate that the isolated actinobacteria strains hold potential as microbial inoculants for sustainable agriculture, contributing to soil health, plant growth, and pathogen management. Full article

Eco-friendly functional alginate films with plant extracts (chokeberry pomace (ChP) or lemon balm (LB) herb) were obtained. Moreover, deep eutectic solvents (DESs) based on choline chloride, glucose, and betaine were used to acquire the active substances from plant materials. The films were tested regarding the antioxidant, mechanical, and color properties. The results revealed that the films’ antioxidant capacities (AC) depended on the extract type and DES used, namely AC values for alginate films with LB were higher than those with ChP. Moreover, the results of the films’ mechanical properties depended only on the DES, which acted as a plasticizer in most cases. Furthermore, the color analysis of the studied films showed a dependence on the type of extract and DES. The lightness (L*) was influenced only by the DES type, while the solvent and extract type affected the a* and b* values. Our results show that the films can be applied as active packaging for food products. Full article

The aim of this study was to investigate the impact of different bedding materials on both production performance and foot quality, assessed through the incidence, severity, and microbiological quality of foot pad dermatitis (FPD). A total of 2400 Ross 308 chickens were raised over 42 days, distributed across eight bedding material types (eight groups × four treatments × 75 chickens each). These pellets either lacked medicinal plant components or included 30% of plant parts, such as oregano (Origanum vulgare), summer savory (Satureja hortensis), lemon balm (Melissa officinalis), salvia (Salvia officinalis), and thyme (Thymus vulgaris). Production performance controls included body weight (BW) at 42 days of age, feed conversion ratio (FCR), and mortality. The severity of FPD was evaluated at 28, 35, and 42 days using a scale ranging from S0 to S3. A microbiological analysis of the feet was based on the FPD score. Broilers raised on straw chaff (bedding: 24% oregano and 6% summer savory, 18% oregano and 12% summer savory, and 24% oregano and 6% thyme) exhibited the highest BW. Straw chaff-reared broilers demonstrated the lowest FCR. The highest mortality occurred on 18% oregano and 12% summer savory bedding, which may have been caused by the high share of summer savory, which could be toxic. At 35 and 42 days, broilers in the 24% oregano and 6% summer savory group exhibited the best foot quality, while those on straw chaff and 18% oregano and 12% summer savory had the worst one. The influence of medicinal plants in the pellets was particularly notable in reducing Listeria sp. This reduction was likely due to the presence of carvacrol from summer savory, quercetin from lemon balm, and thymol from thyme. Based on our research, the best bedding materials for foot quality are 24% oregano with 6% summer savory and 18% summer savory with 12% salvia, while 18% summer savory with 12% lemon balm and 18% summer savory with 12% thymus were the most effective in limiting Listeria sp. Full article

Officinal plants are a source of metabolites whose chemical composition depends on pedoclimatic conditions. In this study, the NMR-based approach was applied to investigate the impacts of different altitudes and agronomical practices (Land, Mountain Spontaneous, and Organically Grown Ecotypes, namely LSE, MSE, and OE, respectively) on the metabolite profiles of Burdock root, Dandelion root and aerial part, and Lemon balm aerial part. Sugars, amino acids, organic acids, polyphenols, fatty acids, and other metabolites were identified and quantified in all samples. Some metabolites turned out to be tissue-specific markers. Arginine was found in roots, whereas myo-inositol, galactose, glyceroyldigalactose moiety, pheophytin, and chlorophyll were identified in aerial parts. Caftaric and chicoric acids, 3,5 di-caffeoylquinic acid, and chlorogenic and rosmarinic acids were detected in Dandelion, Burdock and Lemon balm, respectively. The metabolite amount changed significantly according to crop, tissue type, and ecotype. All ecotypes of Burdock had the highest contents of amino acids and the lowest contents of organic acids, whereas an opposite trend was observed in Lemon balm. Dandelion parts contained high levels of carbohydrates, except for the MSE aerial part, which showed the highest content of organic acids. The results provided insights into the chemistry of officinal plants, thus supporting nutraceutical–phytopharmaceutical research. Full article

Herbs and agro-food wastes are rich sources of bioactive compounds vital for organisms and valuable for many fields of industry. Therefore, in this study, green deep eutectic solvents (DESs) such as choline chloride/citric acid (ChCl:CitA), glucose/citric acid (Gu:CitA), glucose/urea (Gu:U), betaine/citric acid (B:CitA), and betaine/urea (B:U) at a molar ratio of 1:1 for ultrasound-assisted extraction (UAE) of antioxidants from four herbs (chamomile—Cha, lemon balm—LB, mint—M, and nettle—N) and two agro-food wastes (buckwheat husk—BH and chokeberry pomace—ChoP) were proposed. The antioxidant capacity (AC) of the obtained extracts was evaluated utilizing three antioxidant assays: cupric reducing antioxidant capacity (CUPRAC = 0.0–429.9 μmol of Trolox (TE)/g); 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS = 0.0–146.5 μmol TE/g); and 2,2-diphenyl-1-picrylhydrazyl (DPPH = 11.9–170.3 μmol TE/g). The LB extracts revealed the highest CUPRAC (59.3–429.9 μmol TE/g), ABTS (30.7–144.3 μmol TE/g), and DPPH (32.6–170.3 μmol TE/g) values. Due to the lowest antioxidant potential of LB extracts prepared using ChCl:CitA (AC = 30.7–59.3 μmol TE/g) and the highest AC demonstrated by extracts based on B:U (AC = 144.3–429.9 μmol TE/g), the UAE conditions using a new DES consisting of ChCl and U were optimized by the Box–Behnken design (BBD). Effects of three independent variables, molar ratios of the ChCl and U (mol/mol), water content (%), and sonication time (t) on the AC of LB extracts were studied by response surface methodology (RSM). The results of principal component analysis (PCA) and hierarchical cluster analysis (HCA) demonstrated that different DESs had great differences in the extraction of antioxidant compounds from herbs and agro-food residues. Full article

Plants are constantly subjected to environmental changes that deeply affect their metabolism, leading to the inhibition or synthesis of “specialized” compounds, small organic molecules that play a fundamental role in adaptative responses. In this work, Melissa officinalis L. (an aromatic plant broadly cultivated due to the large amounts of secondary metabolites) plants were exposed to realistic ozone (O₃) dosages (80 ppb, 5 h day⁻¹) for 35 consecutive days with the aim to evaluate its potential use as elicitor of specialized metabolite production. Ozone induced stomatal dysfunction throughout the whole experiment, associated with a low photosynthetic performance, a decrease in the potential energy conversion activity of PSII, and an alteration in the total chlorophyll content (−35, −36, −10, and −17% as average compared to the controls, respectively). The production of hydrogen peroxide at 7 days from the beginning of exposure (+47%) resulted in lipid peroxidation and visible injuries. This result suggests metabolic disturbance within the cell and a concomitant alteration in cell homeostasis, probably due to a limited activation of antioxidative mechanisms. Moderate accumulated doses of O₃ triggered the accumulation of hydroxycinnamic acids and the up-regulation of the genes encoding enzymes involved in rosmarinic acid, phenylpropanoid, and flavonoid biosynthesis. While high accumulated doses of O₃ significantly enhanced the content of hydroxybenzoic acid and flavanone glycosides. Our study shows that the application of O₃ at the investigated concentration for a limited period (such as two/three weeks) may become a useful tool to stimulate bioactive compounds production in M. officinalis. Full article

Rosmarinic acid (RA) is a phenolic compound with antiviral properties, often encountered in dietary supplements and herbal drugs. Data on the pharmacokinetics of RA are lacking in cases of the chronic use of supplements containing this compound, and only limited data on the metabolism and distribution of RA are available. The aim of the study was to investigate the plasma levels of RA after 12 weeks of use and determine potential interactions of RA and selected antiretroviral drugs. Patients infected with human immunodeficiency virus took a supplement containing RA for 12 weeks, after which the RA concentrations in the plasma samples were analyzed. A detailed in silico analysis was conducted in order to elucidate the potential interactions between RA and the drugs efavirenz, darunavir and raltegravir. It was found that RA can be detected in patients’ plasma samples, mainly in the form of sulphoglucuronide. The potential interactions are suggested on the level of liver metabolizing enzymes and efflux P-glycoprotein, with RA competing with antiretroviral drugs as a substrate in metabolism and distribution systems. The present study suggests that the simultaneous use of RA and antiretroviral therapy (containing efavirenz, darunavir or raltegravir) may affect the plasma levels of RA after prolonged supplementation. Full article

This study reports the use of front-face fluorescence spectroscopy with principal component analysis (PCA) as a tool for the characterisation of selected Polish herbhoneys (raspberry, lemon balm, rose, mint, black current, instant coffee, pine, hawthorn, and nettle). Fluorimetric spectra registered in the ranges ascribed to fluorescence of amino acids, polyphenols, vitamins, and products of Maillard’s reaction enabled the comparison of herbhoney compositions. Obtained synchronous spectra combined with PCA were used to investigate potential differences between analysed samples and interactions between compounds present in them. The most substantial influence on the total variance had the intensities of polyphenols fluorescence. These intensities were the main factor differentiated by the analysed products. Full article

Deep eutectic solvents (DESs) are now widely recognized as a new class of ionic liquid analogues and have large-scale usage as green solvents. Due to their superior characteristics compared to traditional organic solvents, DESs are increasingly being used. The aim of the work was to examine the effectiveness of DES extractants of phenolic compounds from monocomponent teas from plants of the Lamiaceae family produced at the Institute for the Study of Medicinal Plants, “Dr. Josif Pančić”. Ten samples of herbal drugs (basil, thyme, savory, oregano, sage, thyme, mint, lavender, rosemary, and lemon balm) were tested. Extraction was performed with two types of DESs (a mixture of menthol and methylsalicylate (1:1) and a mixture of menthol and dodecanoic acid (2:1)), as well as microwave and traditional extraction. The content of phenolic acids and flavonoids in the tested preparations was determined using high-performance liquid chromatography (HPLC). Menthol–methylsalicylate and menthol–dodecanoic acid mixtures showed significant efficiency in the isolation of quercetin and naringenin from herbal drugs, while the effectiveness of the menthol–methylsalicylate mixture stands out in the isolation of chlorogenic acid and cinnamic acid from all samples, as well as rosmarinic acid from basil. The concentration of quercetin ranged from 0.2035 to 0.7543 mg/g of the drug for the menthol–methylsalicylate mixture, and from 0.1189 to 0.2025 mg/g of the drug for the menthol–dodecanoic acid mixture. In this study, an environmentally friendly, economical, and efficient extraction based on menthol and methylsalicylate, and also menthol and dodecanoic acid, was applied. Based on the results presented, DESs may be useful in the isolation of target compounds from plants. This research represents an excellent basis for further research and testing of other green solvents as new extractants. Full article

Activated carbons obtained via the thermochemical treatment of lemon balm and mint herbs were applied for ionic polymers adsorption, which directly affects the stability of these types of aqueous suspensions. The examined carbonaceous materials were characterized by well-developed specific surface area (approximately 1000 m²/g) and mesoporous structure. The adsorbed amounts of anionic poly(acrylic acid) and cationic polyethyleneimine from one-component solutions reached significant levels, but the efficiency of adsorption of these compounds from binary solutions slightly decreased. Moreover, the ionic polymers showed stabilizing properties towards the activated carbons suspensions. For both adsorbents, the most stable suspensions were systems containing both types of polymeric macromolecules with different ionic characters. This was due to the occurrence of electrosteric and depletion stabilization mechanisms. Furthermore, the zeta potential and size of particle aggregates were also influenced by the presence of polymers in the aqueous suspensions of activated carbons. Full article

Bioactive compounds are molecules that may have therapeutic potential with influence on oxidative stress, pro-inflammatory state and metabolic disorders. Herbs are recognized as a significant source of natural antioxidants. The aim of this study was to determine the antioxidant properties of peppermint (Mentha piperita L.), lemon balm (Melissa officinalis L.) and lavender (Lavandula angustifolia Mill.). Fresh plant materials were harvested and obtained from the Experimental Station of Agriculture University in Kraków, Poland. Proximate analysis (protein, fat, ash and dry matter) was performed on herbs. Total polyphenol content and polyphenol profile antioxidant activity (ABTS and FRAP methods) were measured in an extract prepared with deionized distilled hot water (infusion), 70% methanol or 70% methanol acidified with formic acid. It was found that the water extract of peppermint had the highest polyphenol content and antioxidant activity measured by the FRAP method. The highest antioxidant activity measured with the ABTS method was in methanolic lemon balm extract. The highest amount of total phenolic compound was determined in the water extract of peppermint. The water and acidified methanol extract of peppermint contained a higher amount of naringin, rutin, hesperidin and rosmarinic acid. Evaluated plants can be used as natural antioxidants instead of synthetic antioxidants in the food and pharmaceutical industries. Full article

Lemon balm (Melissa officinalis) is an aromatic and medicinal plant, rich in bioactive ingredients and with superior antioxidant activity. The essential oil of this plant is an expensive product, so the use of the by-products of the essential oil industry is particularly useful. The aim of this research was to process Melissa officinalis distillation by-products to develop a series of polyphenol-rich formulations. In the present research, lemon balm was distilled in a laboratory-scale distiller, and the recovered by-product was used for further successive extractions with acetone and water, using a fixed-bed semi-batch extractor. Acetone extract exhibited relatively poor results as far as yield, phenolic composition and antiradical activity are concerned. However, the aqueous extract presented high yield in both total phenolic content (i.e., 111 mg gallic acid equivalents (GAE)/g, on a dry herb basis (dw)), and anti-radical capacity (205 mg trolox equivalents (TE)/g dw). On a dried extract basis, the results were also impressive, with total phenols reaching 322 mg GAE/g dry extract and antiradical capacity at 593 mg TE/g dry extract. The phenolic components of the extract were identified and quantified by HPLC-DAD. Rosmarinic acid was the major component and amounted to 73.5 mg/g dry extract, while the total identified compounds were quantified at 165.9 mg/g dry extract. Finally, formulations with two different wall materials (gum arabic–maltodextrin and maltodextrin) and two different drying methods (spray-drying and freeze-drying) were applied and evaluated to assess their performance, yield, efficiency and shelf-life of total phenolic content and rosmarinic acid concentration. From the present investigation, it is concluded that after one year of storage, rosmarinic acid does not decrease significantly, while total phenolic content shows a similar decrease for all powders. According to the yield and efficiency of microencapsulation, maltodextrin alone was chosen as the wall material and freeze-drying as the preferred drying method. Full article

Medicinal and aromatic plants (MAPs) are potential sources of natural polyphenols. Solid residues (SRs) from the essential oil (EO) industry are produced in significant volumes and may be used as natural sources of bioactive compounds. Therefore, this work was designed to examine the antioxidant and antibacterial characteristics of phenolic extracts obtained from SRs that have remained after EO distillation. SR extracts of Greek oregano, rosemary, spearmint, lemon balm, and Greek sage were assessed for their total phenolic content (TPC), antioxidant activity, and antimicrobial activity against Escherichia coli, Salmonella Typhimurium, Listeria monocytogenes, Staphylococcus aureus, Bacillus subtilis, Bacillus licheniformis, and Bacillus cereus in the concentration range of 500-3000 mg/L. The rosemary and Greek sage extracts exhibited the strongest antibacterial activities against all the Gram-positive species, while the spearmint and oregano extracts were less effective and only had an effect at the highest concentration used. The lemon balm extract did not show any inhibitory effect; however, it had the highest TPC, showing moderate antioxidant activity, along with spearmint. The oregano extract exhibited the strongest antioxidant activity, followed by Greek sage and rosemary. The experimental findings pointed to the potential use of extracts from post-distillation residues of MAPs as antimicrobials in the food industry, in addition to being rich sources of bioactive compounds. Full article

The foliar feeding of soil-grown plants with essential elements such as molybdate can restore their Nitrate reductase activity. However, the activity of nitrate reductase under the foliar feeding of plants with molybdate and nitrate in hydroponic conditions has not been investigated. Thus, we wanted to investigate the effect of the foliar feeding of molybdate and nitrate on the nitrate reductase activity in the leaves of lemon balm plants under hydroponic conditions. Nitrate and molybdate solutions were applied by spraying the leaves of lemon balm plants and the nitrate reductase activity was determined by the colorimetric method. The results of our study demonstrated that the application of molybdate and KNO₃ solution enhanced the nitrate reductase activity in the leaves of lemon balm plants. Importantly, our results indicate that foliar fertilization with nitrate and molybdate can improve nitrogen metabolism and carbon fixation in the leaves of lemon balm plants under hydroponic conditions. Full article

The production and consumption of organic products have been increasing in Portugal, as well as in the European Union as a whole. The main objective of this work is to understand the consumption habits of organic medicinal and aromatic plants (OMAPs) among Portuguese adults. An online questionnaire was distributed using social networks, resulting in the collection and statistical analysis of 300 responses. Of the participants who reported consuming OMAPs, 44.3% showed a daily consumption pattern. The most frequently mentioned OMAPs for fresh consumption were parsley (Petrosselinum crispum L., 92%), garlic (Allium sativum L., 84.1%), and coriander (Coriandrum sativum L., 78.1%). The most commonly mentioned OMAP for consumption as dried plants were oregano (Origanum vulgare L., 74.6%), lemon balm (Melissa officinalis L., 49.2%), and lemon verbena (Aloysia citrodora L., 46.8%). The main reasons cited for using OMAPs were their benefits to health (58.7% of participants), benefits to the environment (33.2%), and reduced salt consumption (29.5%). Among these, the main health benefits mentioned included anti-inflammatory properties (45.0%), prevention of cardiovascular diseases (41.6%), and prevention of high cholesterol (39.9%). Furthermore, 82.5% of respondents considered themselves sufficiently, well, or excellently informed about the nutritional properties of OMAPs. This research initiates a discussion about whether profiling OMAP consumption habits can serve as a valuable tool for promoting organic farming in Portugal, increasing OMAP production and consumption, and strengthening the connection between these products and potential positive human health effects. Full article