The effects of gamma irradiation on the total phenolic content, scavenging capacity, mineral and vitamin content of Laurus nobilis L․

Olive oil is a natural, unrefined product obtained mechanically from olives and consumed without refining. Ranging from green to yellow, it is valued for its distinctive sensory properties. It retains bioactive compounds that enhance stability and health benefits, including anti-inflammatory, antimicrobial, antioxidant, circulation-improving, and wound-healing effects (Viola & Viola, 2009; Nasiri et al., 2015). In this study in November 2025, memecik-type olive oils were produced in six formulations: Early Harvest Cold-Pressed (EHCP), Cold-Pressed (B1), bay laurel (Laurus nobilis) leaf-flavored (D1), Origanum-flavored (K1), bitter orange (Citrus aurantium)-flavored (T1), and sage (Salvia fruticosa)-flavored (A1). Flavoring involved adding 10 kg bay laurel, 10 kg thyme, 50 kg bitter orange, or 10 kg sage to 1 ton of olives during processing. Samples were analyzed for free acidity, peroxide value, UV absorbance, aroma, and fatty acids. Biocompatibility (MTT, L929), anti-inflammatory activity (NO in LPS-stimulated RAW264.7 cells), and wound-healing activity (against L929 cell lines) were also evaluated in vitro. Aroma analysis revealed that B1 contained the highest trans-2-hexenal (42.30%). D1, K1, and A1 were rich in 1,8-cineole (22.11%, 20.97%, 17.00%), whereas T1 was dominated by D-limonene (78.36%). After 24 h, NO levels increased by 48% in the LPS control; EHCP and A1 showed no change, while B1 and D1 reduced NO by 33% and 21%, and K1 and T1 showed stronger inhibition (43% and 47%), restoring near-baseline levels. After 72 h, wound closure reached 85% in the control, with the highest healing in D1 (95%), followed by EHCP (82%), B1 (67%), T1 (62%), and K1 (42%). These findings confirm that flavoring plants enhance olive oil’s anti-inflammatory and wound-healing effects by transferring bioactive metabolites.

Introduction. Immunomodulatory medicinal plants have been extensively investigated in vitro, in animal models, and in human studies. Aromatic and essential oil–containing species, including Laurus nobilis, Nigella sativa, Withania somnifera, Echinacea purpurea, and Andrographis paniculata, comprise bioactive phytochemicals such as terpenoids, flavonoids, and phenolic compounds that influence both innate and adaptive immune responses. Aim of the study. This review aimed to provide a translational analysis of mechanistic, preclinical, and clinical evidence supporting their immunomodulatory potential. Methodology. A comprehensive literature search was conducted using PubMed, Scopus, and Web of Science, focusing on experimental and human studies reporting immunological outcomes. Discussion. Preclinical investigations demonstrate that plant-derived compounds modulate macrophage activation, cytokine expression, lymphocyte proliferation, and natural killer (NK) cell activity. For example, andrographolide influences T-cell signalling and cytokine production, while thymoquinone enhances NK cell cytotoxicity and regulates Th1/Th2 balance. Translational human studies report increased lymphocyte counts and cytokine levels following supplementation with standardised extracts. Randomised controlled trials further indicate that Withania somnifera enhances immunoglobulins, T helper cells, and NK cell activity. Echinacea purpurea increases NK cytotoxicity and cytokine production, and Allium-based formulations reduce the incidence and severity of respiratory infections in older adults. From a pharmacological perspective, these plants act as multi-target agents modulating signalling cascades and gene expression. However, variability in extract standardisation, dosage regimens, and bioavailability contributes to heterogeneity in clinical outcomes. Conclusion. Overall, medicinal plants demonstrate regulatory rather than purely stimulatory immune effects, supporting their potential role in integrative immunotherapy. Further large-scale, well-controlled trials using standardised preparations are required to strengthen clinical translation.

Abstract Laurus nobilis leaves have phenolic and flavonoid compounds with strong antioxidant properties. However, the studies on their extraction mechanisms are limited. This work comprehensively evaluated the extraction process through kinetics, thermodynamics, mass transfer, and statistical optimization. Kinetic modelling revealed that the pseudo‐first‐order (PFO) model best fitted the data, indicating a diffusion‐controlled extraction with a very low activation energy ( E a = 1.27 kJ mol −1 ). Thermodynamic study showed an endothermic (Δ H = 4.60 kJ mol −1 ), spontaneous (Δ G = −5.20 to −6.52 kJ mol −1 ), and entropy‐driven process (Δ S = 0.0329 kJ mol −1 K −1 ). Effective diffusivity ( D e ) values and Biot numbers (Bi) > 40 showed that internal resistance governed mass transfer. 2‐level Plackett–Burman factorial design screened the effective factors as solid mass, solvent volume, and solvent concentration. The determined parameters were optimized with Box–Behnken design of response surface method (RSM) to get the highest yields of 9.9 mg‐GAE/g‐DM of total phenolic content (TPC), 20.3 mg‐CE/g‐DM of total flavonoid content (TFC), and antioxidant activity (2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) and 2,2′‐azino‐bis(3‐ethylbenzothiazoline‐6‐sulfonic acid) (ABTS) 22.3 mg‐TEAC/g‐DM; cupric ion reducing antioxidant capacity (CUPRAC)) 101.7 mg‐TEAC/g‐DM). Consequently, the integrated kinetic, thermodynamic, mass transfer and RSM optimization approach demonstrates the feasibility of an energy‐efficient and diffusion‐controlled extraction process, showing the industrial potential of L. nobilis leaves as a natural antioxidant source.

Comparative evaluation of biocoagulant and bioflocculant properties of agricultural and green waste biomasses for water treatment

Cocoa-based agroforestry systems (AFS) are a key strategy for strengthening agronomic and economic sustainability in tropical regions; therefore, comprehensive knowledge of their structure and performance is essential. This study characterized 12 cocoa-based agroforestry plots in the Utcubamba province, Amazonas (Peru), through an integrated field assessment that included tree inventory and structural measurements, soil laboratory analysis, pest and disease surveys, and economic evaluation. Tree diversity and structure revealed functionally differentiated communities, reflected in Shannon index values of H′ = 2.24, canopy cover exceeding 60%, and importance value indices (IVI) highlighting dominant species such as Calycophyllum spruceanum (16.79%) and Laurus nobilis (15.64%), which contribute to microclimatic regulation and system resilience. Soil analyses showed strong correlations among soil organic carbon (SOC), soil organic matter (SOM), and total nitrogen (N) (r > 0.95), emphasizing the role of organic matter management in improving soil quality and crop productivity, with SOC ranging from 1.91% to 3.89%, SOM from 3.30% to 6.71%, and total N from 1.65% to 3.35%. Pest incidence exhibited low or insignificant correlations with soil parameters (r ≤ 0.32) and generally moderate levels, suggesting a stronger influence of management practices and shade structure. Economically, the systems showed an average annual net benefit of USD 2,616.91 per hectare per year and a benefit–cost ratio of 2.30, indicating positive economic performance. Overall, cocoa-based AFS function as productive systems capable of maintaining agronomic performance while generating economic profitability under the evaluated conditions.

Seasonal variation is recognized as a key factor affecting the essential oil (EO) yield, chemical composition, and antioxidant activity of Laurus nobilis L. from the Montenegro coast, which constituted the focus of this research. The bay essential oil (BEO) yield was higher in summer (2.12%) and autumn (2.03%) than in winter (1.26%) and spring (1.28%). The total number of BEO components, depending on seasonal variability, ranges from 31 (summer) to 34 (winter and spring). 1,8-cineole (eucalyptol) was the major aromatic compound in all seasons, with the highest content recorded in summer (52.4%). Linalool, as the second most abundant component, is present in the autumn harvest (14.1%), while α-terpinyl acetate, as the third most abundant component, is most prevalent in the winter-spring period (9.6-9.7%). Two groups of monoterpenes, namely the oxygen-containing monoterpene derivatives (80.1%), constitute the most abundant components in BEO leaves, as well as monoterpene hydrocarbons (14.3-15.5%). The phenylpropanoids were the least abundant (4.9-6.3%). Stronger antioxidant activity (DPPH) during an incubation time of 20 min was shown by the BEOs isolated from autumn (EC50 value of 1.15 mg/mL). Early autumn (September) represents the optimal harvest time for L. nobilis in Montenegro, as they ensure a high essential oil yield and better quality, reflected in a high 1,8-cineole content and stronger antioxidant activity of the oil. These results demonstrate that seasonal variations are key factors regulating the quantity and quality of BEO, providing important information for optimizing harvest strategies for medicinal and industrial purposes.

ABSTRACT Given Türkiye's global dominance in Laurus nobilis production, this study aimed to characterise its bioactive volatile compounds by optimising automated solvent extraction (ASE) conditions using a three‐factor Box–Behnken design. The main compound in the volatile substance was determined to be 1,8‐cineole (18.63%–43.99%), followed by limonene dioxide (10.98%–31.39%) and epoxylinalol (2.73%–8.97%). The optimal extraction conditions were determined as 80% solvent concentration, 2.398 g solid mass and 18.972 min immersion time. The extract obtained under optimum conditions was subjected to the DPPH and FRAP assays. The extract demonstrated strong antioxidant activity with a DPPH IC 50 value of 60.61 μg/mL and a FRAP value of 620 μmol Fe 2+ /g extract. Additionally, the antimicrobial test identified inhibition zones against both Staphylococcus aureus (16.2 mm) and Bacillus subtilis (14.1 mm). The extract also showed measurable activity against Candida albicans (12.7 mm) and Aspergillus niger (6.4 mm). MIC (minimum inhibitory concentration) values confirmed the high sensitivity of Aspergillus niger (31.25 μg/mL). The data obtained present that the L. nobilis extract has potential as a natural antioxidant and antimicrobial additive in pharmaceutical and functional food formulations.

The tomato leaf miner, Tuta absoluta, is one of the most destructive tomato pests worldwide. The use of chemical pesticides can improve yield and fruit quality; however, it poses serious risks to human health and the environment. Consequently, research efforts are increasingly focusing on sustainable, eco-friendly pest management strategies, including the use of essential oils as biopesticides. This study evaluates the insecticidal activity of Laurus nobilis and Inula viscosa essential oils against the four larval instars of T. absoluta. Essential oils were assessed using a contact toxicity assay, with each dose tested across all larval instars and compared with an untreated control. Lethal doses (LD50 and LD90) were estimated using Probit regression analysis. The bioassays showed that both essential oils exhibited significant larvicidal activity with dose- and stage-dependent mortality. Early larval instars required lower doses to achieve 50% and 90% mortality (10, 20, and 30 µl for I. viscosa; 3, 5, and 10 µl for L. nobilis), whereas later instars were more tolerant and required higher doses. Complete mortality of all four larval instars was obtained at 100 µl of I. viscosa and 30 µl of L. nobilis. Overall, these findings demonstrate the larvicidal potential of these essential oils and support their use as biopesticides within integrated pest management programs in agriculture. To our knowledge, this is the first report of the larvicidal activity of the essential oils from I. viscosa and L. nobilis against T. absoluta in Algeria.

The demand for functional wound dressings for the effective management of acute and chronic wounds is increasing. The composition of functional components such as polymers and essential oils enables the development of wound dressings. In this study, a core-shell nanofiber wound dressing incorporating Nigella sativa and Laurus nobilis oils was developed using the coaxial electrospinning technique. Nigella sativa oil was incorporated into the polylactic acid outer shell, while Laurus nobilis oil was encapsulated within the polyvinyl alcohol inner core. The chemical composition of the essential oils was analyzed using Gas Chromatography-Mass Spectrometry. The fabricated nanofibers were characterized using spectroscopic and morphological analyses, contact angle measurements, mechanical testing, and biological assays. Scanning electron microscopy results revealed a homogeneous fiber morphology with average diameters of 522.8 ± 71.9 nm. FTIR spectra indicated the presence of characteristic functional groups associated with both essential oils within the polymer matrix. Contact angle measurements (θ = 79.27°) indicated moderate surface wettability, which is favorable for wound dressing applications. Tensile testing revealed an increase in mechanical strength corresponding to increased polymer layering. A high antioxidant capacity was determined using the DPPH method. Furthermore, disk diffusion assays demonstrated notable antimicrobial activity, particularly against Staphylococcus aureus (13.50 ± 0.28 mm). MTT assays verified that the material exhibits a high level of biocompatibility and supports cell viability. In conclusion, the developed wound dressing represents a multifunctional biodegradable nanofibrous system combining antimicrobial, anti­oxidant, and cell- supportive properties for wound healing applications.

Objective: This study explored the anticancer properties of Laurus nobilis seed extracts at different maturity stages on PC3 prostate cancer cells, aiming to understand how developmental stages influence biological activities. Methods: Extracts from early-stage (green) and late-stage (black) L. nobilis seeds were tested on PC3 cells. Cytotoxicity, cell migration, wound healing, and gene expression were analyzed. HUVEC cells were used to assess toxicity on normal cells. Results: Early-stage extracts showed low cytotoxicity and promoted cell migration and wound healing. Late-stage extracts exhibited potent dose-dependent cytotoxicity and significantly inhibited cell migration. Both extracts demonstrated lower toxicity towards HUVEC cells. Gene expression analysis revealed suppression of epithelial-mesenchymal transition and migration in cells treated with late-stage extracts. Conclusion: The study highlights the stage-dependent anticancer potential of L. nobilis seed extracts. Late-stage extracts showed promising anticancer effects, while early-stage extracts promoted cell growth. These findings emphasize the importance of harvest time and maturity stage in determining the biological activity of L. nobilis extracts, providing valuable insights for future anticancer research and applications.

The persistent challenges posed by ovarian cancer, marked by its high mortality rates and resistance to conventional therapies, drive a continuous search for innovative and effective treatment strategies. In the current study, laurus nobilis extract was loaded into chitosan nanoparticles to investigate its potential anti-cancer effects against SKOV3 ovarian cancer cells. The developed nanocarriers were loaded into a collagen hydrogel to better mimic the tumor microenvironment. In vitro studies including scanning electron microscopy, cell viability assay, cell migration assay, hemocompatibility assay, release assay, real-time polymerase chain reaction assay, cell imaging, and anti-inflammatory assays were performed in order to characterize the three-dimensional model. The study showed that our developed system reduced the viability and migratory activity of cancer cells. Real-time polymerase chain reaction assay suggested that anti-cancer effects of our developed system may be attributed to the downregulation of Polo-Like Kinase 1 (PLK1) and Poly (ADP-Ribose) Polymerase 1 (PARP1) genes. Our developed model may be used for studying the effects of different anti-cancer drugs on ovarian cancer cells.

Gamma radiation effects on microbial load, quality, and structure of Laurus nobilis L.

The purpose of this study is to evaluate the antimicrobial effect of bay laurel extract (Laurus nobilis, L. nobilis) on chicken meat during storage for 15 days at a temperature 4 C. Chicken meat was treated either with doxycycline (positive control) or with bay laurel extracts (100ppm,300ppm,900ppm), negative control was chicken meat without any treatment. The Folin measured total phenolic content- ciocalteu colorimetric method. The total plate count (TPC) of bacteria was monitored after the days (1-7-14) of treatment. All extracts showed antimicrobial activity against the tested bacteria, but the 900-ppm concentration was most effective for extending the shelf life of chicken meat.

Nerium oleander L. (Apocynaceae; common oleander) is a woody plant native to the Palearctic and planted as an ornamental worldwide. In May 2024, small brown necrotic spots were detected on leaves of a residential oleanders, an area with many California Bay Laurel (Umbellularia californica) infested by P. ramorum, in Mill Valley, Marin County, CA (37.90481ºN, 122.55282ºW). Symptomatic leaves tested positive using a genus-specific lateral flow assay (LFA) for Phytophthora (Agdia Inc, Elkhart, IN, USA). Leaves were surface sterilized using 70% ethanol, plated on selective PARPH media (Jeffers et al. 1986) and incubated at 20ºC. After 6 days, a single culture was isolated (NORS074) from the necrotic spots and produced morphological structures typical of P. ramorum, including coralloid mycelium, chlamydospores and semi-papillate sporangia (Fig. 1) (Werres, S., et al. 2001). The internal transcribed spacer (ITS) and beta tubulin regions were sequenced using the primers ITS1/ITS4 (White et al. 1990; accession no. PX270955) and TUBUF2/TUBUR1 (Kroon et al. 2004; accession no. PX551880), respectively. A BLAST search revealed 99.50% identity for ITS and 99.68% for the beta tubulin with P. ramorum ex-type strain CBS 101553 (accession no. NR_147877.1 and LC595884.1, respectively). Ten unwounded and ten wounded leaves of N. oleander were inoculated with strain NORS074 using two methods: i) mycelial plugs and ii) zoospore solution (1.72 x 105 zoospores/ml). All four treatments induced necrotic leaf spots; and P. ramorum was re-isolated from the leaves. Sporulation of the isolate on inoculated leaves was observed. Pathogenicity tests were also performed on whole plants of N. oleander variety Austin City Limits (N = 10; 40 cm tall and 35 cm wide) using two methods: i) a zoospore solution (1.9 × 105 zoospores/ml) was sprayed on the plants until runoff; ii) leaf tips were immersed in 1.5 ml of the zoospore solution in a 15 ml conical tube attached to the plant during entire experiment. Ten leaves per plant were wounded for each assay. The inoculations were carried out in an open-field environment to simulate natural condition. Plants were misted with water and kept individually in plastic bags for 72 hours to maintain humidity level. Leaves inoculated with all four different treatments developed symptoms 12 dpi consisting of small black necrotic spots and lesions along the midrib vein (Fig. 2). Symptomatic leaves tested positive using the same Phytophthora LFA, and P. ramorum was re-isolated on PARPH media. The identity of the re-isolates was confirmed morphologically and by ITS sequencing. No symptoms were detected on untreated control plants. To our knowledge, this is the first report of P. ramorum occurring on N. oleander in the United States, and the first time ever, that Koch’s postulates have been confirmed for this host-pathogen combination. Previously, P. ramorum was detected on N. oleander in Ireland, but no inoculation studies were reported (O'Hanlon et al. 2016). This study provides the evidence to reclassify N. oleander from an APHIS 'associated host' (APHIS 2022) to a proven host. An ‘associate host’ is a plant from which a pathogen was isolated; a ‘proven host’ is a plant, for which Koch’s Postulates were confirmed. The original infection, occurring during the exceptionally wet 2023/24 winter in a shaded area, was condition-dependent; failure to re-isolate P. ramorum in Spring 2025 suggests the occurrence was transient and driven by extreme environmental pressures.

Laurus nobilis hydrosol (HyLN), a water-soluble byproduct of essential oil extraction, containing beneficial antioxidants and antimicrobial compounds, was used as a sustainable ingredient in the development of a natural antioxidant-rich hydrogel formulation. Hydrogels were formulated using sodium hyaluronate and xanthan gum, natural ingredients with beneficial effects on the skin, while β-cyclodextrin (βCD) was added to enhance the stability of antioxidants in HyLN. Extensive rheological and textural analyses were employed to optimize the hydrogel formulation for dermal administration, while stability studies assessed the chemical and physical stability of developed formulations. A combination of sodium hyaluronate and xanthan gum provided several HyLN hydrogel formulations with tunable rheological and textural properties, presenting adequate physical and microbiological stability over 6 months of storage. The use of βCD failed to stabilize inherently unstable antioxidants in HyLN hydrogels, yet their residual antioxidant activity remained notable. An in vitro scratch test using a human keratinocyte cell line showed that the developed HyLN gel does not interfere with wound healing. HyLN hydrogels showed a pronounced occlusive effect in vitro, reaching up to 80% of that measured for Vaseline, which helps maintain skin hydration and appearance.

Abstract Heavy metal contamination in Mediterranean riparian ecosystems presents serious risks to biodiversity and human health, requiring innovative biomonitoring methods for polluted watersheds. This study developed a comprehensive biomonitoring framework for an industrially impacted Mediterranean river basin, with approximately 100,000 tons of contaminated waste in landfills from decades of metallurgical processing. We investigated heavy metal bioaccumulation patterns in five taxonomically diverse native riparian species ( Equisetum arvense , Laurus nobilis , Rubus ulmifolius , Sambucus nigra , and Salix alba ) across contaminated and reference sites using Total Reflection X-ray Fluorescence (TXRF) spectroscopy. TXRF was validated against Inductively Coupled Plasma Atomic Optical Spectroscopy (ICP-AOS) using standard reference materials, demonstrating superior sensitivity for trace element detection in plant matrices. Heavy metal concentrations varied significantly among species and sites in riparian vegetation, with Fe (23.14 ± 5.21 mg/kg), Mn (2.74 ± 0.89 mg/kg), and Cr (3.33 ± 1.12 mg/kg) showing the highest accumulation. Laurus nobilis appeared as a multi-metal hyperaccumulator with the highest Pollution Load Index (PLI = 2.67) and exceptional accumulation of Cr (14.74 mg/kg) and Fe (63.64 mg/kg). Statistical analysis (Kruskal-Wallis test, p < 0.05) confirmed that Mn and Cr represented primary anthropogenic pollutants, with contaminated sites showing 2.20-fold and 1.92-fold increases, respectively. Principal Component Analysis revealed distinct co-accumulation networks, with Fe-Cr-Ni-Cu forming synchronized uptake mechanisms, while Mn operated independently. Biogeochemical ratio analyses (Fe/Zn, Cu/Mn) provided sensitive contamination indicators, detecting physiological stress beyond simple concentration measurements. Results support species-specific phytoremediation strategies aligned with UN Sustainable Development Goals, with Laurus suitable for multi-metal extraction and Equisetum for Mn-specific remediation, advancing sustainable environmental management in industrially impacted Mediterranean watersheds.

The aim of this study was to investigate the effect of phyto-additive mixture supplementation on semen quality and on some reproductive parameters after artificial insemination in rabbits. The trial run 120 days on 20 adult New Zealand white rabbit bucks that were allocated into two different groups, first was control (CON; n = 10) fed with commercial pelleted-feed and second was considered experimental group (EXP; n = 10) which received in feed a natural feed additive mixture (0.1% of dried Chlorella vulgaris powder and 0.1% of dried Laurus nobilis leaves powder). Consequently, the quality assessment of semen by the Computer Assisted Semen Analyzer (CASA) system, samples were instrumentally inseminated on rabbit does for two consecutive reproductive cycles, and productive and reproductive indexes were evaluated. Results demonstrate that while spermatozoa concentration and ejaculate volume did not differ significantly among experimental groups or between reproduction cycles, spermatozoa motility parameters were significantly enhanced in rabbits receiving the phyto-additive mixture, as evidenced by increased total motility (87.83% vs. 70.63%) and progressive motility (75.68% vs. 50.10%) compared with the control group (p < 0.01). No differences were observed in prolificacy traits during the first reproductive cycle, whereas in the second cycle the phyto-additive treatment increased the number of kits born alive per litter (12.29 vs. 10.19; p < 0.05) and improved kit growth performance at birth (79.17 vs. 66.75 g), at weaning (1085.28 vs. 963.15 g), and in average daily gain (28.75 vs. 25.61 g/day). The study provides evidence of alternative practises based on feeding programme to enhance reproductive traits in rabbit production. The goal is to provide farmers with examples of good farming practise (such as precision farming), focused on sustainability and efficiency, and a certain transfer of knowledge.

Numerous insecticides utilized for pest control contribute to environmental pollution. For this reason, it is important to develop alternative strategies that reduce the adverse impacts associated with toxic insecticides. This study investigated the biological effects of Laurus nobilis ( L. nobilis ) leaf extract on the model pest Galleria mellonella ( G. mellonella ), focusing on survival rates, developmental times, and molecular interactions. This study demonstrated that dietary L. nobilis leaf extract significantly reduced the survival rate and prolonged the developmental stages of G. mellonella larvae. The study also investigated the binding potentials of key compounds in L. nobilis , such as methyl‐eugenol, α ‐terpinyl acetate, sabinene, linalool, 1,8‐cineole, quercetin, α ‐pinene, eugenol, and terpinen‐4‐ol, with the juvenile hormone binding protein through molecular docking analyses. Results showed strong interactions, particularly between quercetin and the juvenile hormone binding protein, suggesting potential for L. nobilis ‐derived compounds in pest management. Molecular docking revealed quercetin binding affinities of −7.3 kcal/mol with Juvenile binding protein. The findings highlight the efficacy of plant‐derived bioinsecticides as environmentally friendly alternatives to conventional chemical insecticides.

Production of natural aroma powder by spray drying Bay Laurel (Laurus nobilis L.) essential oil-loaded emulsion