Search Results (1,549)

Mounting acaricide resistance in Tetranychus mexicanus (McGregor) (Acari: Tetranychidae), among the most damaging phytophagous mites in tropical and subtropical crops, has intensified the search for botanical alternatives. An oil-in-water nanoemulsion of Thymus vulgaris essential oil (TVEO-NE) was developed and evaluated for lethal and sublethal effects on adult females of T. mexicanus. TVEO, composed mainly of thymol (45%) and p-cymene (37%), was formulated by low-energy emulsification yielding stable dispersions (~200 nm; PDI < 0.25; zeta potential of −22.2 mV). At 30.0 mg a.i./mL, TVEO-NE caused 68.3% corrected mortality at 72 h and suppressed fecundity by ~44–52%; vehicle controls exerted only moderate effects, identifying the essential oil as the primary bioactive driver. Morphological examination revealed collapse of female idiosomata and disruption of excretory pellet architecture, corroborating the bioassay data. Molecular docking against a cathepsin L homology model revealed that thymol and p-cymene interact exclusively via hydrophobic contacts and display substantially lower ChemPLP fitness scores than the reference cysteine protease inhibitor E64, indicating weak predicted binding affinity and arguing against enzyme inhibition as the primary mechanism. Taken together, bioassay, morphological, and docking are consistent with supporting membrane partitioning as a plausible primary mode of action, positioning TVEO-based nanoemulsions as promising botanical tools for T. mexicanus management. Full article

Background: Essential oils (EOs) are promising natural antimicrobials against food-borne pathogens, yet their efficacy depends on complex chemical profiles that vary by species and origin. The evaluation of underexplored aromatic plants from the Peruvian Amazon may reveal novel bioactive agents. Methods: We chemically characterized six EOs from Aloysia citrodora, Arracacia xanthorrhiza (two cultivars), Baccharis genistelloides, Piper acutifolium, and Piper lanceifolium using GC-MS and assessed their antibacterial activity against Escherichia coli (ATCC 25922), Salmonella enterica (ATCC 14028), Enterococcus faecalis (ATCC 29212), and Staphylococcus aureus (ATCC 49476). Results: EOs of Aloysia citrodora and Arracacia xanthorrhiza cv. Yellow exhibited the strongest inhibition, effective against both Gram-positive and Gram-negative bacteria, potentially associated with higher relative abundances of oxygenated monoterpenes and aliphatic aldehydes. Dose–response analysis supported their superior antibacterial potency, with the lowest LD₅₀ values observed for these oils. Oils rich in sesquiterpenes showed lower activity. Conclusions: These findings underscore the importance of EO chemical composition for antibacterial potency and suggest that select Amazonian EOs have potential as natural preservatives for food safety applications. Full article

Rosa damascena Mill. is a medicinal and aromatic species of major pharmacological and economic importance, widely valued for its complex profile of bioactive secondary metabolites. While extensive research has focused on field-grown plants and essential oils, comparatively little attention has been devoted to the behavior of R. damascena under in vitro conditions. Plant tissue culture systems provide controlled platforms for investigating secondary metabolism independently of environmental variability; however, their application to R. damascena has produced heterogeneous and often inconsistent results. This review examines the main in vitro culture systems developed for R. damascena, including callus, suspension, and organ-derived cultures, with emphasis on their capacity to accumulate secondary metabolites. Available evidence indicates that undifferentiated cultures generally fail to reproduce the full metabolic complexity observed in planta, particularly for volatile monoterpenes associated with tissue specialization. Nevertheless, several studies demonstrate that in vitro systems can accumulate phenolic compounds with relevant biological activities, supporting their use as experimental models for investigating metabolic regulation. By integrating early studies with recent advances in plant biotechnology, this review highlights current limitations, unresolved questions, and future perspectives for the use of R. damascena in vitro cultures in medicinal plant research. Full article

Distillation is widely used for essential oils extraction, and distillation time (DT) influences the quality and quantity of oils. This study presents the effects of 14 DTs (1, 3, 5, 10, 20, 40, 80, 120, 160, 200, 240, 280, 360, and 480 min) on leaf oils from Thuja occidentalis L., aiming to maximise the yield and modulate chemical profiles. Also, a safety assessment of T. occidentalis oils obtained at different DTs was conducted based on thujone levels under International Fragrance Association (IFRA) guidelines. Oil yield varied with DT, reaching a maximum at 40–80 min (0.54 ± 0.04% and 0.59 ± 0.02%, respectively). Monoterpenes (sabinene, fenchone, and thujone) decreased with prolonged DT, whereas higher molecular weight compounds, including sesquiterpenes (caryophyllene) and diterpenes (hibaene and rimuene) increased. Principal component analysis (PCA) grouped samples into three stages, early (1–10 min), mid (20–80 min), and late (120–480 min), with clear compositional separation (PC1: 68.4%, PC2: 11.8%). As DT increased, the fragrance profile progressively shifted from monoterpene-rich characteristics in the early-stage oils to more persistent aromas associated with sesquiterpenes (caryophyllene, α-cadinol, and α-eudesmol) and diterpenes (hibaene and rimuene) in the late-stage oils. Safety assessment revealed that early-stage oils contained high thujone levels (67.19–71.88%), limiting their allowable use. In contrast, prolonged DTs (≥200 min) reduced thujone content, increasing permissible usage across multiple IFRA categories. Overall, DT significantly influences the oil yield, chemical composition, and regulatory applicability of T. occidentalis oils, with extended distillation enhancing formulation flexibility in cosmetic and fragrance applications. 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

Nineteen monoterpene indole alkaloids, including twelve new ones, were successfully isolated and identified from the stems and leaves of Uncaria hirsuta (Havil.). The planar structures were elucidated by nuclear magnetic resonance (NMR), high-resolution mass (HRMS), and ultraviolet (UV) analyses. The absolute configurations of new compounds were determined using electron circular dichroism calculations in conjunction with NMR calculations. The acetylcholinesterase inhibitory activity of the isolated compounds was evaluated in vitro. In further biological evaluation, the isolated compounds were evaluated for their neuroprotective effects on HT22 neuronal cells. Six compounds demonstrated significant protective activity. Their intracellular reactive oxygen species (ROS) levels were measured using the DCFH-DA fluorescent probe, which markedly attenuated glutamate-induced ROS accumulation. The results not only enrich the knowledge on the structural diversity of monoterpene indole alkaloids but also offer substantial evidence for further pharmacological exploration. Full article

Plant U-box E3 ubiquitin ligases (PUBs) are involved in various biological processes in response to abiotic stress. Recent studies have shown that E3 ubiquitin ligases can regulate the production of important compounds in medicinal plants by targeted degradation of transcription factors. Abscisic acid (ABA), a plant stress response hormone, can cause changes in the content of the medically important monoterpene indole alkaloids (MIAs) in U. rhynchophylla. In this study, we explored the relationship between UrPUB gene expression and MIA content. ABA was applied to tissue-cultured seedlings of U. rhynchophylla, resulting in consistent changes in the content of four MIAs. Seventy-three UrPUB genes were identified and bioinformatically characterized from the genome sequence of U. rhynchophylla. The expression levels of transcription factors involved in regulating the biosynthesis pathway of MIAs and UrPUB genes with higher RNA transcript levels in the roots were determined. Co-expression association analysis revealed that UrPUB17, UrPUB40, UrPUB41, UrPUB44 and UrPUB55 negatively correlate with UrGATA8 and UrWRKY37 under ABA stimulation. Based solely on these correlation data, we hypothesize that these UrPUBs might regulate MIA biosynthesis via ubiquitination of UrGATA8 and UrWRKY37, but direct evidence (protein interaction, ubiquitination, degradation, or genetic manipulation) is lacking. This study identified the UrPUB gene family in the U. rhynchophylla genome and proposes this ubiquitination model as a testable hypothesis, not a demonstrated mechanism. These findings provide new insights into the biological function of the PUB family in response to ABA. Full article

Harmful algal blooms pose a persistent threat to the integrity of freshwater ecosystems and public health. However, there are no selective chemical control agents available to suppress cyanobacterial growth without damaging beneficial phytoplankton. In this study, ten structurally diverse monoterpenes were assessed in vitro for their differential activity against the potent toxin-producing cyanobacterium Microcystis aeruginosa and the ecologically valuable microalga Chlorella sorokiniana using disc diffusion (DDM) and minimum inhibitory concentration (MIC) assays. Inhibition zones against M. aeruginosa ranged from 6.9 to 43.6 mm, with thymol recording the largest zone (43.6 mm). MIC values ranged from 0.25 to >1 mg/mL for both organisms, and selectivity indices identified camphor and carvone as the most cyanobacterium-preferential compounds, while carene and α-pinene showed the inverse selectivity pattern. Molecular docking against six AlphaFold2-predicted target proteins, photosynthetic complexes, Adenosine Triphosphate (ATP) synthase subunits, and superoxide dismutase (SOD) from both organisms, revealed binding affinities between −3.9 and −6.2 kcal/mol. Phenolic monoterpenes consistently engaged active-site glutamate and aspartate residues via hydrogen bonds and Pi–Anion interactions, most strikingly in the M. aeruginosa ATP synthase, whereas the M. aeruginosa SOD represented the least amenable target for all compounds. Computational ADMET profiling confirmed favorable pharmacokinetic properties and low predicted toxicity for the full panel. Full article

This study aimed to identify the volatile organic compounds (VOCs) present in the essential oil (EO) of Schinus lentiscifolia and to evaluate the effect of chitosan coatings (1%) enriched with EO of S. lentiscifolia (1000, 2000, and 4000 mg L⁻¹) on the control of Penicillium sp. and on the quality of ‘Fuji’ apples. The EO was extracted from S. lentiscifolia collected in the municipality of Lages, Santa Catarina State, Brazil, in March, May, and November 2022. The antifungal activity of S. lentiscifolia EO against Penicillium sp. was evaluated in vitro. Apples were stored under refrigerated conditions (0 ± 0.5 °C; 90 ± 5% RH) for 30 days and subsequently under ambient conditions (23 ± 3 °C; 70 ± 5% RH) for 5 days. A total of 14 VOCs were identified in the EO of S. lentiscifolia, with the monoterpenes β-pinene (34.68%) and α-pinene (30.61%) as the major compounds, followed by γ-terpinene (10.13%), camphene (9.66%), and o-cymene (7.14%). The application of chitosan coating with S. lentiscifolia EO (2000 mg L⁻¹) reduced the severity of blue mold in ‘Fuji’ apples by 88.1% during refrigerated storage and by 69.2% under ambient conditions. Ethylene production by the apples was also reduced when treated with chitosan and EO. No influence of the treatments was observed on fruit quality attributes. The postharvest application of chitosan coatings combined with S. lentiscifolia EO reduces disease caused by Penicillium sp. in ‘Fuji’ apples without affecting fruit quality. Full article

Essential oils (EOs) are widely investigated as multifunctional agents for cosmetic applications due to antimicrobial and antioxidant properties; however, their efficacy and safety depend on chemical composition and microbiological selectivity. This study characterized ten commercially available EOs (basil, lavender, melissa, mint, oregano, rosemary, sage, thyme, clove, tea tree) and evaluated their antistaphylococcal and antioxidant activities. Chemical composition was analyzed using GC-MS and ATR-FTIR spectroscopy, while antistaphylococcal activity was assessed against Staphylococcus spp. isolated from skin microbiota using the microbroth dilution method. Antioxidant capacity was determined by the DPPH assay. Multivariate statistical analyses were applied to explore chemical composition–activity relationships. The EOs showed distinct chemical profiles dominated by phenolic compounds (eugenol, carvacrol, thymol), oxygenated monoterpenes (linalool, menthol, 1,8-cineole), and terpenoids. Clove, oregano, and thyme EOs exhibited the strongest antistaphylococcal activity (MIC 0.5–2 mg/mL) and highest antioxidant capacity (>80%), whereas lavender, mint, and sage EOs showed weak effects. All EOs demonstrated bactericidal activity with consistent susceptibility patterns among Staphylococcus spp. PCA and FTIR confirmed an association between phenolic content and bioactivity. In conclusion, antimicrobial efficacy is primarily driven by phenolic composition, supporting targeted cosmetic use while acknowledging possible effects on skin Staphylococcus spp. populations. Full article

Objective: The present study investigates the effect of 1,8-cineole on improving lipid metabolism disorder by regulating oxidative stress and inflammation via the TLR4/MyD88/NF-κB pathway. 1,8-Cineole is a monoterpene compound widely found in the essential oils of many plants and has been reported to possess anti-inflammatory and antioxidant activities. However, its role in regulating lipid metabolism disorders remains unclear. This study aimed to investigate the effects of 1,8-cineole on lipid metabolism and explore the potential mechanisms related to oxidative stress and inflammation. Methods: Cell viability was assessed by MTT assay to determine the optimal PA concentration for inducing lipid accumulation and the non-cytotoxic range of 1,8-cineole in HepG2 and AML-12 cells. Lipid droplets were visualized by Oil Red O staining, while triglyceride (TG) and total cholesterol (TC) levels were quantified using enzymatic kits. Oxidative stress markers (ROS by DCFH-DA fluorescence; MDA by TBA method; CAT activity by ammonium molybdate method) and inflammatory cytokines (TNF-α, IL-6, IL-1β, IL-18 by ELISA) were measured. Western blotting analyzed key proteins in the TLR4/MyD88/NF-κB pathway (TLR4, MyD88, p-P65, p-IκBα). Pathway-specific inhibitors were employed for mechanistic validation. Results: 1,8-Cineole (up to 1000 μg/mL) showed no cytotoxicity. It significantly attenuated PA-induced lipid droplet accumulation, reduced TG and TC levels (p < 0.05), and ameliorated oxidative stress by decreasing ROS and MDA while enhancing CAT activity in AML-12 cells (p < 0.01). Furthermore, 1,8-cineole suppressed pro-inflammatory cytokine release (TNF-α, IL-6, and IL-1β; p < 0.01), whereas no significant effect was observed on IL-18 levels. Downregulated TLR4/MyD88/NF-κB pathway activation. Inhibition of TLR4 or NF-κB mirrored these protective effects. Conclusions: 1,8-Cineole alleviates PA-induced lipid metabolism disorders, oxidative stress, and inflammation in hepatocytes, likely through suppression of the TLR4/MyD88/NF-κB signaling pathway. Full article

Delta-3-carene (CAR), a monoterpene derived from plant essential oils, exhibits promising biological properties, including anti-inflammatory, antioxidative, anxiolytic, and antimicrobial activities. Therefore, this study aimed to investigate the anti-inflammatory effects of CAR by analyzing the activity of this terpene on leukocyte activation through the evaluation of cell migration in in vitro and in vivo models. Cell viability analysis demonstrated that CAR (3, 10, 30, and 90 μg/mL) exerted no cytotoxic effects and significantly reduced in vitro neutrophil chemotaxis toward N-formylmethionyl-leucyl-phenylalanine (fMLP). Furthermore, CAR decreased phagocytosis in zymosan-stimulated neutrophils in vitro. In Swiss mice, oral CAR treatment, at doses of 25, 50, and 100 mg/kg, reduced inflammatory and antinociceptive parameters in zymosan-induced peritonitis, carrageenan-induced paw edema and mechanical hyperalgesia, and nociception induced by acetic acid and formalin models. In the persistent inflammation model (for 21 days) induced by complete Freund’s adjuvant (CFA), daily CAR treatment (50 mg/kg) reduced paw edema and mechanical hyperalgesia in all evaluated times at 6, 11, 16, and 21 days after CFA-induced inflammation. In conclusion, our data demonstrated that CAR modifies acute and chronic inflammatory responses, highlighting its potential therapeutic application in managing inflammation and pain. Full article

The fall armyworm (Spodoptera frugiperda), a highly destructive invasive Lepidopteran pest, poses a serious threat to global agriculture, particularly maize production. Plant essential oils (EOs) represent a promising class of botanical pesticides owing to their diverse bioactivities and low environmental persistence. In this study, we evaluated the insecticidal and antifeedant activities of 40 commercially available EOs against third-instar S. frugiperda larvae. After an initial screening at 4 μL/mL, 10 EOs that caused ≥70% mortality at 72 h were selected for bioassays to estimate LC₅₀ value and chemical analysis by GC-MS. Contact toxicity assays showed that geranium EO had the highest activity (LC₅₀ = 2.105 μL/mL at 72 h), followed by cypress (2.123 μL/mL) and niaouli (2.391 μL/mL), whereas tea tree EO exhibited the lowest activity (3.592 μL/mL). Antifeedant tests revealed that clove EO caused the strongest feeding deterrence at both 24 h (antifeedant indices AFI = 72.8%) and 48 h (AFI = 63.4%), while most other EOs lost their deterrent effect within 48 h. GC-MS analysis of the 10 active EOs identified a complex mixture of monoterpenes, sesquiterpenes, and oxygenated derivatives; major constituents included D-limonene, 4-terpineol, carvacrol, caryophyllene, and longifolene. These results provide laboratory evidence that several plant EOs, particularly geranium, cypress, niaouli, and clove, possess strong insecticidal and antifeedant activities against S. frugiperda larvae, supporting their potential as eco-friendly botanical insecticides. Full article

Drosophila suzukii is one of the most destructive pests of soft fruits worldwide due to its high reproductive capacity, wide host range, and great adaptability. In this context, Drimys winteri, a tree native to southern Chile and Argentina, is recognized as a source of bioactive compounds with insecticidal and repellent properties. This study evaluated the repellent and oviposition-deterrent activity of essential oils (EOs) from the bark and leaf of D. winteri on D. suzukii. Chemical analysis by GC/MS showed that both EOs were dominated by monoterpenes, with α-pinene, β-pinene, and D-limonene being the major compounds, while the leaf EO exhibited greater chemical diversity and a higher proportion of sesquiterpenes. In choice bioassays, all treatments generated significant avoidance responses, with a preference for the control. The leaf EO showed the greatest repellent effect, exceeding 85% at 12 h and remaining above 80% at 96 h. In oviposition assays, the leaf EO significantly reduced egg laying at all concentrations, with negative oviposition preference index values indicating a consistent deterrent effect. Overall, the leaf EO of D. winteri showed repellent and oviposition-deterrent effects against D. suzukii under laboratory conditions. Full article

Background: Pembrolizumab, a programmed cell death protein 1 (PD-1) inhibitor, is widely employed in oncological practice; however, its propensity to induce nephrotoxicity through immune-mediated oxidative and inflammatory mechanisms remains an insufficiently characterized clinical concern. The present study comparatively investigated the renoprotective effects of flunarizine, a voltage-dependent calcium channel antagonist, and carvacrol, a monoterpene, against pembrolizumab-induced renal injury in rats. Methods: Twenty-four male Wistar albino rats were assigned to four groups (n = 6): healthy control (HG), pembrolizumab alone (PZB), flunarizine+pembrolizumab (FLPZ), and carvacrol+pembrolizumab (CCPZ). Pembrolizumab was administered intraperitoneally at 5 mg/kg; flunarizine orally at 5 mg/kg and carvacrol intraperitoneally at 50 mg/kg, once daily for seven consecutive days. Renal oxidative status was assessed by measuring malondialdehyde (MDA) and total glutathione (tGSH) levels. Histopathological evaluation was performed using hematoxylin and eosin staining. Two double immunofluorescence panels were employed to assess 3,3′-dityrosine/Hepatitis A virus cellular receptor 1 (HAVCR1) and cyclooxygenase-1 (COX-1)/cyclooxygenase-2 (COX-2) expression, respectively. Results: Pembrolizumab caused pronounced oxidative stress and inflammatory responses in renal tissue, leading to a significant increase in renal MDA levels and a marked decrease in tGSH levels. These biochemical alterations were accompanied by severe tubular degeneration and increased expression of 3,3′-dityrosine, which is associated with oxidative damage, as well as HAVCR1, a marker of cellular injury, and COX-1 and COX-2, which reflect inflammatory activity. These findings indicate that pembrolizumab disrupts the renal redox balance and activates both oxidative and inflammatory pathways in kidney tissue. Flunarizine and carvacrol significantly reduced these pathological changes. Both agents attenuated oxidative stress markers and supported antioxidant defenses, thereby alleviating tissue damage. However, flunarizine demonstrated a more pronounced renoprotective effect across all evaluated parameters, restoring MDA and tGSH levels closer to physiological values and reducing tubular injury to a minimal level. Carvacrol showed a more limited but still statistically significant protective effect. Conclusions: Both agents confer significant renoprotection against pembrolizumab-induced oxidative injury; however, flunarizine exhibits a more robust protective profile, likely attributable to its capacity to attenuate calcium-mediated mitochondrial dysfunction and preserve cellular bioenergetic homeostasis. Full article