Search Results (242)

Aeromonas species are among the most important Gram-negative pathogens in aquaculture and represent a One Health concern, as antibiotic-resistant strains circulate at the interface between ornamental fish, the aquatic environment and humans. This study evaluated the in vitro antibacterial activity of four commercial essential oils from tea tree (Melaleuca alternifolia), peppermint (Mentha piperita), rosemary (Rosmarinus officinalis) and lavandin (Lavandula hybrida) against sixteen oxytetracycline-resistant Aeromonas hydrophila and A. veronii isolated from moribund ornamental fish. All tested bacteria were resistant to oxytetracycline (MIC 8–16 µg/mL). Minimum inhibitory (MIC) and minimum bactericidal (MBC) concentrations were determined by broth microdilution. All EOs inhibited every isolate, but their bactericidal capacity differed markedly. Rosemary oil showed the lowest MIC and MBC ranks and the most consistent values, followed by tea tree and lavandin; all three were bactericidal. Peppermint oil, despite a low MIC, showed a high MBC and was bacteriostatic. These findings indicate that the EOs of rosemary, tea tree and lavandin are promising in vitro candidates for use against oxytetracycline-resistant Aeromonas in aquaculture, in line with the One Health approach, and warrant further evaluation. Full article

Essential oils are complex plant-derived volatile blends composed of a myriad of aromatic secondary metabolites. The volatile architecture of plant essential oils suggests a consistent trend under the experimental conditions evaluated, regardless of the distillation scale and methodology. This study presents a comparative chemometric evaluation of two integrated processing systems: laboratory-scale hydrodistillation (HD) of dried biomass versus semi-industrial-scale dry steam distillation (SD) of fresh biomass. Seven economically important botanical species spanning three families were analyzed: Lavandula angustifolia, Salvia officinalis, Hyssopus officinalis, Mentha piperita, Mentha spicata, Achillea millefolium, and Picea abies. Gas chromatography–mass spectrometry (GC-MS) profiling revealed that HD consistently yielded a more chemically diverse volatile profile than SD. Unsupervised Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (HCA) achieved absolute binary segregation between the HD and SD fractions for every species. Supervised Partial Least Squares Discriminant Analysis (PLS-DA) established robust predictive models (Q² cum > 0.98), isolating specific chemical markers responsible for the variance. The results prove a universal physical trend: HD significantly enriched low-boiling oxygenated derivatives (such as oxygenated monoterpene alcohols and oxides), while SD selectively preserved heavier, thermally sensitive hydrocarbon fractions across all taxonomic groups. Ultimately, combining GC-MS with multivariate chemometrics provides an objective, automated framework for quality control, authentication, and industrial process optimization in the essential oil sector. Full article

The sweet potato weevil, Cylas formicarius (Fabricius) (Coleoptera: Brentidae), is one of the most destructive pests of sweet potato [Ipomoea batatas (L.) Lam.] crops worldwide. Current management of the sweet potato weevil relies heavily on conventional pesticides, raising concerns about pesticide residues, environmental impacts, and the development of pesticide resistance. This study evaluated the effects of seven essential oils (EOs): eucalyptus (Eucalyptus globulus), garlic (Allium sativum), marigold (Calendula officinalis), mustard seed (Sinapis alba), peppermint (Mentha piperita), rosemary (Rosmarinus officinalis), and thyme (Thymus gobicus) against different life stages of C. formicarius under laboratory conditions. Feeding activity, oviposition, larval mortality, pupal mortality, and adult survival were evaluated using EO concentrations of 1%, 5%, and 10%, with acetone and distilled water as control treatments. Each treatment consisted of six replicates, with 10 insects per replicate. Statistical analyses were performed using logistic regression models with a binomial distribution. Significant effects of oil type and concentration were observed as lethal to weevil larval and pupal stages. Similarly, the feeding and oviposition were significantly impacted (p < 0.0001). Peppermint oil exhibited the highest efficacy, causing complete or near-complete mortality of second- and third-instar larvae and pupae at 10%. This also substantially reduced adult survival, feeding activity, and oviposition. Rosemary, thyme, and eucalyptus, at higher concentrations. Most oils almost completely suppressed oviposition. These findings demonstrate that plant-derived essential oils (EOs) exhibit significant insecticidal activity against Cylas formicarius, indicating their promise as sustainable tools for integrated pest management programs in sweet potato production systems. Full article

Acne vulgaris is a prevalent inflammatory disorder of the pilosebaceous unit involving follicular hyperkeratinization, altered sebum production, Cutibacterium acnes proliferation, microbiome imbalance, and immune activation. Although antibiotics, retinoids, benzoyl peroxide, and keratolytic agents remain central to clinical management, their long-term use may be limited by irritation, recurrence, adherence issues, and increasing antimicrobial resistance. This narrative review critically evaluates the dermatological relevance of Melaleuca alternifolia tea tree essential oil (TTEO), Mentha piperita peppermint essential oil (PPEO), and polyhydroxy acids (PHAs), as well as their incorporation into biopolymeric delivery systems for acne-oriented topical applications. Following SANRA principles, evidence from clinical, preclinical, ex vivo, and in vitro studies was synthesized, with emphasis on antimicrobial activity, inflammatory modulation, keratolytic and barrier-supportive effects, formulation stability, and release behavior. TTEO shows the strongest clinical support among the reviewed natural bioactives, including reductions in lesion counts and acne severity when applied as conventional or nanoemulsion-based formulations. PPEO is mainly supported by experimental evidence, particularly antimicrobial activity against acne-associated microorganisms, anti-inflammatory potential, and menthol-related neurocutaneous effects, whereas acne-specific clinical validation remains limited. PHAs, particularly gluconolactone, are better supported for barrier improvement, hydration, tolerability, and seboregulation than for direct acne lesion reduction. Hydrogels, electrospun nanofibers, polymeric films, nanoencapsulation systems, and controlled-release platforms may improve local retention, protect volatile or irritation-prone compounds, and modulate active release at the skin surface. However, most biopolymeric platforms still rely on early-stage or indirect dermatological evidence. Overall, biopolymeric delivery systems offer a rational formulation strategy to improve the stability, tolerability, and localized action of selected acne-relevant bioactives, but their clinical translation requires standardized composition, reproducible fabrication, skin-relevant release assays, safety assessment, and controlled human studies. Full article

This study explores the use of microwave-assisted extraction of bioactive compounds from peppermint (Mentha piperita L.) using aqueous ethanolic and β-cyclodextrin solvents. The experiments were performed according to Response Surface Methodology, and the central composite design was employed, with the independent variables being treatment time, microwave power and solvent concentration. During the research, the total polyphenol content (TPC, expressed as gallic acid equivalents, GAE), total flavonoid content (TFC, expressed as quercetin equivalents, QUE), antioxidant capacity (AC) using the FRAP (Ferric Reducing Antioxidant Power, expressed as ascorbic acid equivalents, ASE) and DPPH (2,2-diphenyl-1-picrylhydrazyl) methods, and total menthol content (TMC, expressed as menthol equivalents, MEE) were examined. For the ethanolic extraction, the optimum conditions were 571 W, 7.3 min, and 10% v/v. The following results were obtained for these parameters: TPC, 1025 µg GAE/mL; TFC, 66.69 µg QUE/mL; FRAP, 3786.24 µg ASE/mL; DPPH, 80.24%; and TMC, 62.63 µg MEE/mL. In the case of β-cyclodextrin, the optimum conditions are 800 W, 11.81 min, and 1.70 mM. In this case, the results are as follows: TPC, 949.29 µg GAE/mL; TFC, 90.75 µg QUE/mL; FRAP, 4275.54 µg ASE/mL; DPPH, 89.81%; and TMC, 84.99 µg MEE/mL. β-cyclodextrin increased the flavonoid, antioxidant and menthol content, although there were no significant differences between the concentrations. The use of ethanol had a greater effect on the polyphenol content. β-cyclodextrin proved to be an effective green alternative solvent for peppermint. Full article

This study investigates the volatile composition of twelve medicinal plant species belonging to the Lamiaceae family, which are widely recognized for their diverse biological activities, including antioxidant, antibacterial, and antifungal properties. Despite extensive studies on essential oils, comparative analyses using solvent-free techniques under different microclimatic conditions remain limited. This study investigates the volatile compounds in twelve medicinal plants from the Lamiaceae family using headspace solid-phase microextraction coupled with gas chromatography–mass spectrometry (HS-SPME/GC-MS). Lamiaceae plants are recognized for their diverse medicinal properties, including antioxidative, antibacterial, and antifungal effects. A total of 74 volatile compounds were identified, encompassing terpenes, alcohols, esters, aldehydes, and ketones. Notably, Lavandula spica L. exhibited the highest number of unique volatiles (28), while Melissa officinalis L. had the fewest (16). Key compounds included Citral (65.48%) in Melissa officinalis L., Menthol (33.37%) and Menthyl acetate (30.53%) in Mentha piperita L., Carvone (45.86%) in Mentha spicata L., and Eucalyptol (54.71%) in Origanum syriacum L. Plants from Adana Botanic Park were rich in terpenes and ketones, whereas those from Osmaniye contained higher levels of alcohols, aldehydes, and esters. The findings emphasize the impact of geographic location on volatile profiles and suggest avenues for further research into medicinal efficacy and optimal dosage. This study supports the sustainable use of plant biodiversity (SDG 15) and highlights the importance of bioactive compounds for human health and well-being (SDG 3). Full article

This study examines a low-processed, food-grade extraction concept for peppermint leaves (Mentha × piperita L.) using solvents consistent with the principles of green chemistry and an infusion-like protocol. Primary extraction (2–30 min; 50–100 °C) was carried out using water, plasma-treated nanowater, a glycerol–water mixture (65%), an ethanol–water mixture (50%; at room temperature and at 50 °C), and rapeseed oil. To evaluate the potential use of biomass within a circular economy model, the residue remaining after the first extraction was subjected to secondary extraction under identical time–temperature conditions. Primary and secondary extracts were characterized in terms of total phenolic content (TPC), total flavonoid content (TFC), essential oil (EO) recovery, and antioxidant activity (DPPH and FRAP), and extraction yields were expressed relative to a 70% methanolic reference (TPC/TFC) and to the initial EO content in the plant material. Under the most favorable conditions (10 min; 100 °C; ethanol–water at 50 °C), the highest extraction yields of polar phytochemicals (TPC and TFC) were obtained with water and nanowater, whereas the ethanol–water mixture (50%) and rapeseed oil provided the greatest recovery of essential oil (up to complete depletion after the second extraction). Antioxidant activity showed a similar dependence on solvent type, with water and nanowater extracts exhibiting the highest DPPH/FRAP values. Importantly, secondary extraction contributed a substantial share of the total recovered bioactive compounds (often >30% of combined TPC/TFC), confirming that post-extraction residues remain a valuable raw material. The results support a practical, sequential strategy for designing peppermint extracts: aqueous and glycerol systems for phenolic-rich extracts, and ethanol and oil systems for essential-oil-enriched preparations, with secondary extraction enabling simple, low-energy biomass valorization. Full article

Peppermint tea is one of the most widely consumed herbal beverages worldwide, yet limited data are available on the chemical variability and quality of commercial products. This study assessed the essential oil (EO) yield and composition of 39 commercial peppermint (Mentha × piperita L.) teas and commercial EOs obtained from different countries. EO yield showed pronounced variability, ranging from 0.8 to 26.8 mL/kg. In total, 112 compounds were identified by GC-MS, accounting for 88.4–99.5% of the total EO composition. The major constituents were menthol (0.1–25.2%), menthone (0.1–21.8%), and carvone (0.6–30.0%), revealing marked chemical heterogeneity among marketed products. Several samples exhibited unusually high carvone levels accompanied by reduced menthol and menthone contents, reflecting substantial chemotypic diversity and inconsistency among marketed products. The concentrations of the regulated constituents, pulegone (0.02–2.56%) and menthofuran (0.02–6.58%), remained within the European Pharmacopoeia limits. Based on the observed levels of pulegone and menthofuran, the results do not indicate a safety concern for consumers under normal tea preparation and consumption conditions. Overall, the findings demonstrate substantial variability in the quality of commercial peppermint teas and highlight the relevance of essential oil profiling as a tool for assessing the quality and safety of herbal beverages. Full article

Mild cognitive impairment (MCI) represents an intermediate stage between normal aging and Alzheimer’s disease. This study investigated the neuroprotective effects of a combined extract of Mentha piperita (MP) and Cornus officinalis (CO) (MC) using in vitro and in vivo models. In SK-N-SH cells, pretreatment with MC (50–150 μg/mL) significantly attenuated H₂O₂-induced cellular injury, as evidenced by a reduction in Annexin V-positive cells and an increase in brain-derived neurotrophic factor (BDNF) mRNA expression. Rosmarinic acid and loganin, the marker compounds of MP and CO, alone or combined at a 6:4 ratio, mitigated H₂O₂-induced decreases in cell viability and BDNF mRNA. In the in vivo study, male Sprague–Dawley rats were orally administered MC (50, 100, or 200 mg/kg/day) for 28 days, with phosphatidylserine (50 mg/kg/day) serving as a positive control. MC administration significantly improved cognitive performance in rats with scopolamine-induced memory impairment, as demonstrated by increased step-through latency in the passive avoidance test and reduced escape latency in the Morris water maze. Furthermore, in the probe trial, MC-treated rats spent significantly more time in the target quadrant, indicating enhanced spatial memory retention. Mechanistically, MC restored hippocampal acetylcholine levels and reversed the scopolamine-induced decrease in BDNF and its downstream signaling. Specifically, MC upregulated hippocampal BDNF expression and enhanced the phosphorylation of extracellular signal-regulated kinase (ERK), protein kinase B (AKT), and cAMP response element-binding protein (CREB). In conclusion, these results demonstrate that the MC extract possesses potent neuroprotective and learning- and memory-enhancing effects, highlighting its potential as a therapeutic candidate for managing age-related cognitive decline and MCI. Full article

Gelling agents are widely used to solidify plant tissue culture media, yet differences among commercial products may influence the medium’s physical properties and in vitro development of explants. The aim of this study was to characterize the rheological behavior of six gelling agents (Daishin agar, Gelcarin, Gelrite, Microagar, Phytoagar, and Plant agar) and to examine it in parallel with in vitro performance in Hypericum perforatum, Mentha × piperita, and Stevia rebaudiana. Rheological measurements were performed under steady shear by recording apparent viscosity and shear stress across 5–300 s⁻¹. Daishin agar showed the highest apparent viscosity (49,028.95 ± 128 mPa·s), whereas Gelrite exhibited the lowest viscosity (7826.75 ± 98 mPa·s). Plant responses were evaluated after four weeks on PGR-free Driver and Kuniyuki Walnut (DKW) medium by assessing shoot growth, rooting parameters, and shoot water content. In H. perforatum, the longest shoots were obtained on Gelrite (3.92 ± 0.34 cm), accompanied by the highest rooting percentage (95%). In M. × piperita, Gelcarin produced the longest shoots (8.20 ± 0.55 cm) and the highest number of roots per explant (9.75). In S. rebaudiana, Gelcarin promoted superior root elongation (2.86 ± 0.16 cm) and enhanced shoot growth, while Plant agar also supported favorable shoot development. Shoot water content ranged between 74% and 90%, depending on species and gelling agent. These findings highlight the practical relevance of considering low-shear rheological properties when comparing gelling agents for improving the consistency of in vitro culture media. Full article

Background: Serum-free culture of red blood cells (RBCs) typically leads to rapid loss of viability, limiting experimental and translational applications. Lipid-rich formulations and essential oils may provide biocompatible support for RBC integrity while limiting microbial overgrowth. Methods: RBCs from nine healthy adult donors were cultured in serum-free RPMI under four conditions: control, vehicle (olive oil, 1:100 v/v), genuine adenosine triphosphate (ATP)-oil^® (1:100 v/v), and laboratory oil, “mimicking” ATP-oil^®. Cultures were maintained for 18 days. Viability was assessed by light microscopy and trypan blue exclusion; bacterial contamination was qualitatively observed on day 18. Results: Genuine ATP-oil^® maintained 35–45% RBC viability at day 18, whereas control and vehicle cultures declined rapidly. The mimicking preparation did not reproduce these effects. ATP-oil^® immersion was associated with a qualitative reduction in bacterial contamination versus control, consistent with a dual action on RBC preservation and microbial suppression under serum-free conditions. Conclusions: Supplementation with ATP-oil^® substantially prolongs RBC survival and limits bacterial overgrowth in vitro, outperforming commonly used serum or plasma supplements on a per-volume basis. These findings suggest potential applications for improving ex vivo handling or storage of blood components and for reducing background contamination in diagnostic microbiology. Further studies with larger cohorts are warranted to reveal underlying mechanisms and to define active constituents in order to standardize production. Full article

Spodoptera frugiperda is a major pest affecting maize production worldwide, and its control relies heavily on synthetic insecticides, which generate environmental risks and resistance. Essential oils (EOs) represent a promising alternative due to their biodegradability and the biological activity of their terpenoid constituents. This study evaluated the chemical composition, larvicidal activity, and acetylcholinesterase (AChE) inhibitory potential of the EOs from Origanum vulgare, Lavandula dentata, and Mentha piperita against S. frugiperda larvae at the L1, L2, and L4 instars. Chemical characterization by GC–MS revealed distinct chemotypes: a phenolic/terpenoid profile in O. vulgare, a 1,8-cineole-type profile in L. dentata, and a menthol-rich composition in M. piperita. Larvicidal assays showed dose- and stage-dependent responses, and M. piperita EO tended to produce the most robust mortality across instars and times, consistently producing high mortality (75%) at 90 µg·mL⁻¹ air concentration. AChE inhibition assays revealed that carvacrol and menthone were the most active constituents with IC₅₀ values of 312–330 µg·mL⁻¹. Molecular docking supported these results, as carvacrol and menthone showed the most favorable interactions with amino acid residues of the AChE catalytic site. These data support their suitability as candidates for integrated pest management programs targeting S. frugiperda. Future research should focus on formulation strategies, synergistic combinations, detoxification mechanisms, and field validation. Full article

Agricultural production residues are an easily accessible raw material for energy recovery in a circular economy. Therefore, the possibility of biogas production from herb processing waste, namely common thyme (Thymus vulgaris L.), peppermint (Mentha × piperita L.), curled mint (Mentha crispa L.), and currants (woody stems and leaves), was investigated. In this study, the evaluation of the natural biodegradability of plant waste under conditions typical for an agricultural biogas plant was consciously carried out without the application of pre-treatment processes (shredding, steam hydrolysis, chemical treatment) to facilitate the methane fermentation process. The average values of biogas production efficiency ranged from 75 to 320 m³/mg DM for herb species and from 152 to 209 m³/mg DM for currant varieties under normal conditions. As part of laboratory tests, the elemental composition, i.e., C, H, N, S, O, was determined. Moreover, the analysis showed the energy potential of the tested waste in thermochemical processes (combustion). Garden thyme residues have particularly high energy potential, as indicated by the high calorific value, low nitrogen and sulfur content, and low ash content. Full article

The agar diffusion method was used to test the antibacterial activity of 12 plant species against Agrobacterium tumefaciens, the bacterium that is responsible for crown gall disease. Leaf, root, or flower extracts were prepared, but not all parts were used for each of the 12 plants listed. Plant extracts from leaves exhibited higher antibacterial activity than those from flowers and roots. Furthermore, the type of solvent had a significant influence on both the antibacterial activity and the flavonoid and polyphenol content. Acetone and alcohol extracts contained higher contents of these compounds than water extracts. The strongest bacteriostatic effect was of the leaf extracts of eucalyptus (Eucalyptus nicholii L.) and St. John’s wort (Hypericum perforatum L.). Based on HPTLC analysis, eucalyptus extracts contained, among others, chlorogenic acid, hyperoside, and quercetin, while St. John’s wort extracts contained rutin, hyperoside, and quercetin. The tansy leaf extracts (Tanacetum vulgare L.) were also rich in flavonoids and phenolic acids, such as kaempferol-3-glucoside, luteolin, chlorogenic acid, cynarine, and rutin. However, a moderate inhibitory effect against the tested bacterium was found in tansy extracts, as well as hop (Humulus lupulus L.), wormwood (Artemisia absinthium L.), peppermint (Mentha piperita L.), yarrow (Achillea millefolium L.), and nettle (Urtica dioica L.) extracts. The least effective were the root extracts of dandelion (Taraxacum officinale F.H. Wiggers coll.) and valerian (Valeriana officinalis L.), as well as the flower extracts of chamomile (Matricaria chamomilla L.) and marigold (Calendula officinalis L.). Given the lack of effective chemical products and the unavailability of commercially resistant cultivars, the use of plant-based extracts for protecting against crown gall appears to be of particular interest. The preliminary results are promising and suggest that eucalyptus and St. John’s wort extracts are the most promising for controlling A. tumefaciens. Full article