Search Results (122)

Similarly to conventional field crops, weeds often pose significant problems in the cultivation of medicinal plants. To date, no comprehensive documentation exists regarding weed infestation levels in these crops in Serbia. The objective of this study was to provide a valuable foundation for developing effective, site-specific weed management strategies in medicinal crop production. Weeds in five medicinal crops (lemon balm, fennel, peppermint, ribwort plantain, German chamomile), were surveyed based on the agro-phytosociological method between 2019 and 2024, and across 59 plots. A total of 109 weed species were recorded, belonging to 29 families and 88 genera. Among them, 75 were annuals and 34 perennials, including 93 broadleaved species, 10 grasses, and one parasitic species. All surveyed plots were heavily infested with perennial weeds such as Elymus repens, Cirsium arvense, Convolvulus arvensis, Lepidium draba, Rumex crispus, Sorghum halepense, Taraxacum officinale, etc. Also, several annual species were found in high abundance and frequency, including Amaranthus retroflexus, Chenopodium album, Galium aparine, Lactuca serriola, Lamium amplexicaule, L. purpureum, Papaver rhoeas, Stellaria media, Veronica hederifolia, V. persica, etc. The most important ecological factors influencing the composition of weed vegetation in investigated medicinal crops were temperature and light for fennel and peppermint plots, soil reaction for lemon balm and ribwort plantain plots, and nutrient content for German chamomile plots. A perspective for exploitation of these results is the development of effective weed control programs tailored to this specific cropping system. Weed control strategies should consider such information, targeting the control of the most frequent, abundant, and dominant species existing in a crops or locality. Full article

Knowledge about the composition (volatile and non-volatile) and functionality of natural extracts from Mediterranean plants serves as a basis for their further application. In this study, five selected plants were used for the extraction of plant metabolites. Leaves and flowers of Critmum maritimum, Rosmarinus officinalis, Olea europea, Phylliera latifolia and Mellisa officinalis were collected, and a total of 12 extracts were prepared. Extractions were performed under microwave-assisted conditions, with two solvent types: water (W) and a hydroalcoholic (ethanolic) solution (HA). Detailed extract analysis was conducted. Phenolics were analyzed by detecting individual bioactive compounds using high-performance liquid chromatography and by calculating total phenolic and total flavonoid content through spectrophotometric analysis. Higher concentrations of total phenolics and total flavonoids were obtained in the hydroalcoholic extracts, with the significantly highest total phenolic and flavonoid values in the rosemary hydroalcoholic extract (3321.21 mg_GAE/L) and sea fennel flower extract (1794.63 mg_QE/L), respectively; and the lowest phenolics in the water extract of olive leaves (204.55 mg_GAE/L) and flavonoids in the water extracts of sea fennel leaves, rosemary, olive and mock privet (around 100 mg_QE/L). Volatile organic compounds (VOC) were detected using HS-SPME/GC–MS (Headspace Solid-Phase Microextraction coupled with Gas Chromatography-Mass Spectrometry), and antioxidant capacity was estimated using DPPH (2,2-diphenyl-1-picrylhydrazyl assay) and FRAP (Ferric Reducing Antioxidant Power) methods. HS-SPME/GC–MS analysis of samples revealed that sea fennel had more versatile profile, with the presence of 66 and 36 VOCs in W and HA sea fennel leaf extracts, 52 and 25 in W and HA sea fennel flower extracts, 57 in rosemary W and 40 in HA, 20 in olive leaf W and 9 in HA, 27 in W mock privet and 11 in HA, and 35 in lemon balm W and 10 in HA extract. The lowest values of chlorophyll a were observed in sea fennel leaves (2.52 mg/L) and rosemary (2.21 mg/L), and chlorophyll b was lowest in sea fennel leaf and flower (2.47 and 2.25 mg/L, respectively), while the highest was determined in olive (6.62 mg/L). Highest values for antioxidant activity, determined via the FRAP method, were obtained in the HA plant extracts (up to 11,216 mg_AAE/L for lemon balm), excluding the sea fennel leaf (2758 mg_AAE/L) and rosemary (2616 mg_AAE/L). Considering the application of these plants for fresh fish preservation, antimicrobial activity of water extracts was assessed against Vibrio fischeri JCM 18803, Vibrio alginolyticus 3050, Aeromonas hydrophila JCM 1027, Moraxella lacunata JCM 20914 and Yersinia ruckeri JCM 15110. No activity was observed against Y. ruckeri and P. aeruginosa, while the sea fennel leaf showed inhibition against V. fisheri (inhibition zone of 24 mm); sea fennel flower was active against M. lacunata (inhibition zone of 14.5 mm) and A. hydrophila (inhibition zone of 20 mm); and rosemary and lemon balm showed inhibition only against V. fisheri (inhibition zone from 18 to 30 mm). This study supports the preparation of natural extracts from Mediterranean plants using green technology, resulting in extracts rich in polyphenolics with strong antioxidant potential, but with no clear significant antimicrobial efficiency at the tested concentrations. Full article

Melissa officinalis L. (Lamiaceae) is a perennial plant species widely used in the pharmaceutical and food industries, particularly valued for its sedative properties. This study investigates the impact of synthetic mulch film and planting density as two experimental factors on agronomic performance, raw material quality, and economic efficiency in lemon balm production. The experiment was conducted at three locations in Serbia (L1: Bačko Novo Selo, L2: Bavanište, L3: Vilandrica) from 2022 to 2024, using two planting densities on synthetic mulch film (F1: 8.3 plants m⁻²; F2: 11.4 plants m⁻²) and a control treatment without mulch (C). The synthetic mulch film used was a synthetic black polypropylene film (Agritela Black, 90 g/m²), uniformly applied in strips across the cultivation area, covering approximately 78% of the soil surface. The results showed consistent increases in morphological parameters and yield across the years. Plant height in F1 and F2 treatments ranged from 65 to 75 cm, while in the control it reached up to 50 cm (2022–2024). Fresh biomass yield varied from 13.4 g per plant (C) to 378.08 g per plant (F2), and dry biomass yield from 60.3 g (C) to 125.4 g (F2). The highest essential oil content was observed in F2 (1.2% in 2022), while the control remained at 0.8%. The F2 treatment achieved complete weed suppression throughout the experiment without the use of herbicides, demonstrating both agronomic and ecological advantages. Economic evaluation revealed that F2 generated the highest cumulative profit (€142,164.5) compared to the control (€65,555.3). Despite higher initial investment, F2 had the most favorable cost–benefit ratio in the long term. This study highlights the crucial influence of mulching and planting density on optimizing lemon balm production across diverse climatic and soil conditions, while also underscoring the importance of sustainable, non-chemical weed management strategies in lemon balm cultivation. Full article

Lemon catnip (Nepeta cataria var. citriodora) is an underutilized aromatic and medicinal plant known for its high essential oil yield and distinctive lemon-like scent, and is widely used in the pharmaceutical, cosmetic, food, and biopesticide industries. Unlike typical catnip, it lacks nepetalactones and is rich in terpene alcohols, such as nerol and geraniol, making it a promising substitute for lemon balm. Despite its diverse applications, little attention has been paid to the valorization of byproducts from essential oil distillation, such as hydrolates and their secondary recovery oils. This study aimed to thoroughly analyze the volatile compound profiles of the essential oil from Lemon catnip and the recovery oil derived from its hydrolate over three consecutive growing seasons, with particular emphasis on how temperature and precipitation influence the major volatile constituents. The essential oil was obtained via semi-industrial steam distillation, producing hydrolate as a byproduct, which was then further processed using a Likens–Nickerson apparatus to extract the recovery oil, also known as secondary oil. Both essential and recovery oils were predominantly composed of terpene alcohols, with nerol (47.5–52.3% in essential oils; 43.5–54.3% in recovery oils) and geraniol (25.2–27.9% in essential oils; 29.4–32.6% in recovery oils) as the primary components. While sesquiterpene hydrocarbons were mostly confined to the essential oil, the recovery oil was distinguished by a higher presence of monooxygenated and more hydrophilic terpenes. Over the three-year period, elevated temperatures led to increased levels of geraniol, geranial, neral, and citronellal in both oils, whereas cooler conditions favored the accumulation of nerol and linalool, especially in the recovery oils. Higher precipitation was associated with elevated concentrations of nerol and linalool but decreased levels of geraniol, geranial, and neral, possibly due to dilution or degradation processes. Full article

Νatural compounds such as lactic, acetic, formic, and oxalic acid and thymol are currently registered for use against Varroa destructor in apiaries in Europe. Complex botanical extracts are yet to be authorized, despite their beneficial ecofriendly profile and advantages in terms of resistance management. This study examined the fumigant activity of the essential oil (EO) of oregano, clove, lavender, dittany, bay laurel, sweet orange, peppermint, blue gum, and lemon balm against V. destructor in laboratory bioassays (Petri dishes). The most effective EOs were those of Origanum vulgare, Syzygium aromaticum, and Origanum dictamnus. These three EOs yielded 33.75% carvacrol, 58.64% eugenol, and 69.77% carvacrol and exhibited significant activity from 18 h of exposure to 0.0013 μL/cm until 48 h of exposure to 0.0068 μL/cm³. Origanum vulgare’s first calculated LC₅₀ value was 0.003 μL/cm³ after 24 h of mites’ exposure to EO vapors. The LC₅₀ values stabilized for oregano, clove, and dittany at 0.001, 0.002, and 0.002 μL/cm³ of 24 h exposure, respectively. This first indication of fumigant miticidal activity in Petri dishes is a promising first step before scaling up to field experiments. Full article

The pharmacological potential of Lamiaceae plants is primarily linked to their high content of phenolic acids and flavonoids, known for strong antioxidant properties. This study investigated the antioxidant activity of ten widely used Lamiaceae herbs—oregano, lavender, basil, savory, garden thyme, wild thyme, sage, rosemary, lemon balm, and mint—prepared as traditional infusions and microwave-assisted extracts. The antioxidant capacity was evaluated using spectrophotometric assays, and total phenolics and flavonoids were quantified via spectrophotometry and HPLC. Chemometric analysis (PCA) was applied to explore correlations among antioxidant parameters. The results demonstrated excellent antioxidant activity across all samples. The IC50 for DPPH radicals was in the range from 3.73(0.13) to 8.03(0.17) μg/mL and that for ABTS radicals was from 2.89(0.12) to 8.55(0.34). The CUPRAC antioxidant assay delivered values in the range from 351.93(11.85) to 1129.68(44.46) μg TE/mg DE. The FRAP method produced values from 1.27(0.03) to 6.60(0.26) μmol Fe/mg DE. The presence of gallic acid was detected in all examined samples, with lemon balm and lavender exhibiting the highest concentrations across both applied extraction methods. Notably, lavender showed especially high levels of p-hydroxybenzoic acid and chlorogenic acid. Microwave-assisted extraction generally yielded higher levels of bioactive compounds compared to infusion. These findings highlight the potential of Lamiaceae herbal extracts, particularly those obtained through microwave-assisted extraction, as valuable sources of dietary antioxidants for everyday use. Full article

The drying temperature is one of the main factors affecting the storage of medicinal and aromatic plants (MAPs). The present study aimed to investigate the impact of different drying temperatures (20, 35, 42, and 49 °C) on Mentha officinalis quality attributes (moisture content, color, chlorophyll content) and the composition of its essential oil (EO), as well as the environmental impact, to determine the optimum drying temperature for this herb. According to the current findings, higher temperatures resulted in shorter drying times. However, this was accompanied by increased energy consumption and higher carbon footprint per hour of operation. Both room temperature (20 °C) and high oven temperature (49 °C) led to a darker colored product (i.e., higher browning index). Drying at 20 °C resulted in a higher EO yield compared to drying at higher temperatures (42 and 49 °C). Furthermore, lower temperatures (20 and 35 °C) and the highest temperature (49 °C) significantly decreased the levels of the two major EO compounds (geranial and neral), whereas both compounds were found in higher levels when the plants were dried at 42 °C. On the other hand, plants dried at 42 °C appeared to have the lowest amount of citronellal, significantly lower than those dried at the other tested temperatures. The results suggest that the optimum temperature for drying M. officinalis is at 42 °C, as it maintained the quality attributes of the dried product while also resulting in high quality EO. Full article

Plastic pollution and environmental degradation necessitate the development of natural, biodegradable food preservation materials. This study examined chitosan-based film-forming solutions using kombucha derived from black tea, lemon balm, and chamomile as natural solvents rich in bioactive compounds. Lemon balm kombucha solutions were used to create chitosan films and coat red peppers. The study assessed the mechanical properties of the films and the effects of chitosan coating on peppers, including texture, ascorbic acid content, sensory attributes, and antioxidant activity. Microbiological tests showed that a chitosan–lemon balm kombucha solution acted against Escherichia coli, Pseudomonas aeruginosa and Salmonella enterica. Lemon balm kombucha had high total phenolic (381.67 µg GAeq/mL) and flavonoid (21.05 µg Qeq/mL) contents. The chitosan film exhibited a tensile strength of 11.08 MPa and an elongation at break of 53.45%. The water vapor transmission rate of the obtained chitosan film was 131.84 g/m²·24 h. Coated peppers showed a 32% increase in skin strength and retained 11% more ascorbic acid after 15 days. Sensory evaluation revealed no significant differences from controls. These results highlight lemon balm kombucha as a promising natural solvent for chitosan coatings, which have the potential to extend red pepper shelf life and to support food preservation. Full article

Lippia alba (Verbenaceae) is popularly known as lemon balm or false melissa and is one of the most widely used plants in traditional medicine in the Amazon region. In this study, we conducted a comprehensive bibliometric analysis, with conventional metrics associated with a critical review based on the neuropharmacological activities, to identify potential medical applications and also gaps in knowledge that require further investigation. Fifty-two articles were included according to the eligibility criteria. In the country analysis, Brazil emerged as the main contributor to research with the highest number of publications and citations. Notably, nine of the ten main research institutions are Brazilian, with the Universidade Federal de Santa Maria standing out with 761 citations. The keywords “anesthesia”, “Lippia alba”, and “essential oil” were the most frequent, highlighting their importance in this field. Essential oils are the most common type of extraction, which linalool, citral, geraniol, carvone, and limonene were the main constituents identified. According to the type of study, preclinical studies presented the highest frequency, primarily through fish experimental models. The main neuropharmacological activities identified were sedative–anesthetic, anxiolytic, anticonvulsant, and analgesic, with mechanisms of action via the GABAergic pathway. This bibliometric review provided new evidence reinforcing the potential of L. alba as a promising alternative for the treatment of neuropsychiatric disorders. It also highlighted existing knowledge gaps, mainly related to the comparison of the actions of the different chemotypes of the species and the investigation of the mechanisms underlying their neuropharmacological properties. Additionally, there is a lack of knowledge in other emerging areas related to the central nervous system, such as mood and cognitive disorders. Full article

Background: Modern societies and policymakers increasingly emphasize the advancement of organic farming practices and the preservation of rural culture. Sheep farming faces several challenges, including environmental impacts, antibiotic usage, and public concerns regarding animal welfare. The purpose of this study was to investigate the effects of Melissa officinalis extract and its principal phenolic acids on the motility of the sheep jejunum and colon, with the goal of assessing their potential as health-promoting feed additives, particularly in animals with dysmotilities. Methods: The trials were performed on isolated jejunum and colon preparations collected from sheep undergoing routine slaughter. The effect of extracts from Melissa Officinalis and three major phenolic acids (rosmarinic, chlorogenic, and lithospermic) was evaluated to identify their ability to modify the spontaneous and pharmacologically-induced contractility of circular and longitudinal smooth muscle. Results: Regarding spontaneous contractions: Melissa officinalis extract, rosmarinic acid, and lithospermic acid caused a significant decrease in spontaneous contractility in the jejunum and colon, while chlorogenic acid exhibited myocontractile effects except for colon circular preparations where the effect was myorelaxant as in the other acids. In the case of ACh-induced contractions, all acids and the Melissa officinalis extract caused mostly a significant decrease in the magnitude of acetylcholine-induced contractions in both longitudinal and circular smooth muscle strips of the colon and jejunum. Conclusions: The findings suggest a predominantly myorelaxant effect of the Melissa officinalis extract and its major phenolic acids on the smooth muscle of the sheep jejunum and colon. These results underscore the potential application of the Melissa officinalis extract as a feed additive to modulate intestinal motility and address challenges in livestock production. Full article

The aim of the conducted research was to evaluate the impact of the pressure agglomeration process of lemon balm (Melissa officinalis L.) on the mechanical properties of the obtained product, its antioxidant capacity, and total polyphenol content. Two fractions of lemon balm were isolated with particle sizes of 0.5–2.5 mm and 2.5–5.0 mm. The isolated fractions were compacted using a Fritz Heckert EU 20 hydraulic press, applying compaction pressures of 100, 150, and 200 MPa. A closed die was used, with 2 g of the plant sample introduced each time. The mechanical properties of the obtained product were determined through an abrasion test and diameter test (Brazilian method) using the MTS Insight 2 testing machine. The total polyphenol content and antioxidant activity were measured using the ABTS method, both directly after product preparation and after a 6-month storage period. The compaction of lemon balm resulted in an increase in total polyphenol content and antioxidant properties compared to the unpressed raw material. The obtained product displayed favorable mechanical properties, as confirmed by the conducted mechanical tests. Regardless of the applied herb fraction, an agglomeration pressure of 200 MPa is particularly recommended. Full article

In this study, the effectiveness of three choline chloride (ChCl)-based deep eutectic solvents (DESs) formed using malonic acid (MalA), glycerol (Gly), and glucose (Glu) as hydrogen bond donors and two conventional solvents (50% methanol and 50% ethanol) for ultrasonic-assisted extraction (UAE) of antioxidant compounds from four herbs (chamomile, lemon balm, nettle, and spearmint) were estimated. The antioxidant capacity (AC) of the obtained herb extracts was determined by the modified 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), 2,2-diphenyl-1-picrylhydrazyl (DPPH), and cupric reducing antioxidant capacity (CUPRAC) methods. Profiles of phenolic acids, flavonoid aglycones, and flavonoid glycosides in the green and conventional herb extracts were quantitatively analyzed using ultra-performance liquid chromatography (UPLC). Among the prepared DESs, the highest antioxidant potential and total contents of phenolic acids, flavonoid aglycones, and flavonoid glycosides in herb extracts were achieved using ChCl:MalA (1:1). Unexpectedly, the selected green solvents extracted significantly lower amounts of total antioxidants from the investigated herbs than 50% alcohols. Additionally, macroelements (K, Na, Ca, Mg), micronutrients (Mn, Zn, Fe, Cu), and a toxic element (Cd) in four herbs were analyzed using inductively coupled plasma–mass spectrometry (ICP–MS). Determining the compositions of antioxidants and elements in herbs is essential for understanding their nutritive importance when applied in the food, cosmetic, and pharmaceutical industries. Full article

Synthetic agents are regularly used as preservatives in pork meat products such as sausages. However, these compounds can be harmful to human health, due to their carcinogenic potential. As a result, natural antioxidants derived from herbs and medicinal plants are continuously and thoroughly assessed to replace/minimize the application of synthetic agents during meat processing and storage. The current study was consequently implemented to highlight the effects of natural polyphenols and/or an herbal mix on the quality characteristics of pork sausages. Five batches of sausages were manufactured using the same recipe and raw materials; the control, without sodium nitrate and natural preservatives (CON), and four groups supplemented with sodium nitrate at 0.015% (SN), olive polyphenols at 0.2% (POL), an herbal mix containing rosemary, savory, camelia, thyme, lemon balm and turmeric at 0.2% (NM), or the concomitant addition of olive polyphenols (0.1%) and the herbal mix (0.1%) (POL + NM). Assessment of pH, color, cooking loss, tenderness and oxidative stability was implemented immediately after the manufacture of the sausages (day 0) and at 1, 2 and 3 months after refrigerated storage. It was illustrated that the oxidative stability of sausages was ameliorated as a consequence of POL or/and NM addition, since the values of malondialdehyde (MDA) were significantly decreased compared to the control (p < 0.001) at months 1, 2 and 3, and the values were similar to those observed in the SN group that served as a positive control. Values for the lightness (L), shear force and cooking loss were similar among the experimental treatments (p > 0.05). On the other hand, pH values were greater in the SN and NM groups than in the other groups (p < 0.05). Redness (a*) was significantly higher in the SN group and yellowness (b*) in the NM and POL + NM groups compared to the other groups (p < 0.001). It can be concluded that the examined polyphenols and/or herbal mix could be used as an alternative to nitrates for the amelioration of oxidative stability in pork sausages. Full article

Herbal dust, a waste byproduct from filter-tea production, was annealed to form ash that can be incorporated into natural rubber as an eco-friendly filler. Three types of herbal dust ash (HDA), green tea, hibiscus, and lemon balm, were added at two different contents, 2.5 and 5 phr, into the rubber compound, while the content of carbon black, as a filler, was maintained at 50 phr in all samples. The impact of HDA type and content on the rheological and mechanical properties of rubber products was evaluated. Rheological analysis showed that HDA samples exhibited slightly lower maximum torque values (around 11.6 dNm) than ash-free samples (13.53 dNm), yet maintained vulcanization effectiveness with minimal impact on torque or cure rate metrics. Mechanical testing found that samples with 2.5 phr of lemon balm ash achieved comparable properties to samples without added ash, while samples with added hibiscus preserved crosslinking density and hardness. The addition of HDA led to decreases in tensile strength, elongation at break, and hardness values, with slight changes suggesting its applicability in similar industrial contexts. The findings highlight HDAs potential as a cost-effective, sustainable filler for rubber production, contributing to circular economy practices by repurposing significant amounts of tea waste into high-quality rubber materials. Full article