Laurus nobilis L. leaves Suppress Alcohol-Related Liver Disease by Exhibiting Antioxidant and Anti-Inflammatory Effects in Alcohol-Treated Hepatocytes and Mice.

Excessive and prolonged alcohol consumption can lead to a serious health condition known as alcohol-related liver disease (ARLD). This ailment represents a significant worldwide health challenge, affecting populations across various demographics. ARLD has a multifactorial pathogenesis involving oxidative stress, inflammation, dysregulated lipid metabolism, and apoptosis. In this study, we investigated the hepatoprotective effects of Laurus nobilis L. leaf water extract (LLE) against ARLD in alcohol-treated hepatocytes and mice. LLE exhibited antioxidant and anti-inflammatory properties by enhancing antioxidant enzyme activities and suppressing proinflammatory cytokines and CYP2E1 expression in ethanol-treated hepatocytes. Moreover, LLE mitigated lipogenesis by modulating the expression of lipogenic factors in ethanol-treated hepatocytes. In vivo, LLE administration attenuated liver injury, oxidative stress, inflammation, and lipid accumulation induced by alcohol consumption in mice. Additionally, LLE suppressed apoptosis signaling pathways implicated in alcohol-induced hepatocyte apoptosis. These findings suggest that LLE functions as a multifaceted therapeutic agent for ARLD by modulating multiple cellular mechanisms, including the reduction of oxidative damage, mitigation of inflammatory responses, alleviation of lipid-mediated toxicity, and regulation of programmed cell death pathways.

Essential Oils of Laurus nobilis L.: From Chemical Analysis to In Silico Investigation of Anti-Inflammatory Activity by Soluble Epoxide Hydrolase (sEH) Inhibition.

Laurus nobilis L. is commonly used in folk medicine in the form of infusion or decoction to treat gastrointestinal diseases and flatulence as a carminative, antiseptic, and anti-inflammatory agent. In this study, the essential oil (EO) composition of wild-grown L. nobilis L. leaves collected from seven different altitudinal locations in the Molise region and adjacent regions (Abruzzo and Campania) was investigated. EOs from the leaves were obtained by hydrodistillation and analyzed by GC-FID and GC/MS, and 78 compounds were identified. The major oil components were 1,8-cineol (43.52-31.31%), methyl-eugenol (14.96-4.07%), α-terpinyl acetate (13.00-8.51%), linalool (11.72-1.08%), sabinene (10.57-4.85%), α-pinene (7.41-3.61%), eugenol (4.12-1.97%), and terpinen-4-ol (2.33-1.25%). Chemometric techniques have been applied to compare the chemical composition. To shed light on the nutraceutical properties of the main hydrophobic secondary metabolites (≥1.0%) of laurel EOs, we assessed the in vitro antioxidant activities based on 2,2-diphenyl-1-picrylhydrazyl (DPPH•) radical scavenging activity and the reducing antioxidant power by using a ferric reducing power (FRAP) assay. Furthermore, we highlighted the anti-inflammatory effects of seven EOs able to interfere with the enzyme soluble epoxide hydrolase (sEH), a key enzyme in the arachidonic acid cascade, in concentrations ranging from 16.5 ± 4.3 to 8062.3 ± 580.9 mg/mL. Thanks to in silico studies, we investigated and rationalized the observed anti-inflammatory properties, ascribing the inhibitory activity toward the disclosed target to the most abundant volatile phytochemicals (≥1.0%) of seven EOs.

Efficacy of Laurus nobilis L. for Tight Junction Protein Imbalance in Leaky Gut Syndrome.

Laurus nobilis L. (LNL) belongs to the evergreen Lauraceae family. It is native to the Mediterranean and widely distributed in the southern United States, Europe, and the Middle East. LNL is rich in active ingredients of the sesquiterpene lactone series and has been reported to have antioxidant, anti-inflammatory, and anticancer effects. And parthenolide, known as a sesquiterpene lactone-based compound, inhibits the activation of lipopolysaccharide-binding protein (LBP), which is a major trigger for leaky gut syndrome. However, the effectiveness of LNL in improving the state of increased intestinal permeability has not yet been reported. Therefore, we demonstrated the efficacy of LNL, which is known to be rich in parthenolide, in improving intestinal permeability induced by IL-13. We investigated the improvement in permeability and analyzed major tight junction proteins (TJs), permeability-related mechanisms, weight and disease activity indices, and corresponding cytokine mechanisms. LNL maintained TJs homeostasis and clinical improvement by reducing increased claudin-2 through the inhibition of IL-13/STAT6 activation in TJ-damaged conditions. These results are expected to be effective in preventing leaky gut syndrome through the TJ balance and to further improve intestinal-related diseases, such as inflammatory bowel disease.

The quality evaluation of the laurel leaf samples sold in the market under the name of "Defne Yapragi".

Laurus nobilis L. is an aromatic shrub or tree, Mediterranean element. The leaves are employed as a spice and for medicinal purposes. It is known by various names in Turkey, such as "defne, har and tehnel." In this study, 15 different laurel leaf samples were purchased from 6 different cities in Turkey, diagnosed, and evaluated in terms of quality. The conditions of use and sale of these samples were evaluated. The essential oils obtained from the leaf samples were analyzed, and their physical properties such as density, refractive index, and optical rotation were determined. In the chemical composition of the oils, 1,8-cineole (41.2-64.4%), sabinene (1.5-15.9%), and α-terpinyl acetate (1.5-15%) have been found to be the major components. However, in one station, the presence of 1,8-cineole was not be determined. Laurel leaf drugs offered for sale in some provinces of Turkey were purchased from the market and their morphological characteristics and essential oil profiles were examined and evaluated in terms of public health. It was determined that these samples should be standardized and quality-controlled before being released to the market.

GABase and glutaminase inhibitory activities of herbal extracts and acylated flavonol monoglycosides isolated from the leaves of Laurus nobilis L.

This study was to compare GABase [a mixture of γ-aminobutyric acid (GABA) aminotransferase and succinic semialdehyde dehydrogenase] and glutaminase inhibitory activities of 20 herbal extracts and investigate the isolation, structural elucidation and those inhibitory activities of three acylated flavonol monoglycosides from the selected extract of Laurus nobilis L. (laurel). On the basis of the NMR spectroscopic data and the ESI MS spectra together with the comparison with the literature values, three compounds were identified as kaempferol-3-O-(4″-E-p-coumaroyl)-α-l-rhamnopyranoside (1), kaempferol-3-O-(3″,4″-di-E-p-coumaroyl)-α-l-rhamnopyranoside (2) and kaempferol-3-O-(2″,4″-di-E-p-coumaroyl)-α-l-rhamnopyranoside (3), respectively. The IC50 values of GABase inhibitory activity of 1-3 and p-hydroxybenzaldehyde (HBA) as control were 0.24 mM, 0.14 mM, 0.12 mM and 0.43 mM, respectively. Additionally, the IC50 values of glutaminase inhibitory activity of 1-3 and 6-diazo-5-oxo-l-norleucine (DON) as control were 0.34 mM, 0.13 mM, 0.14 mM and 0.33 mM, respectively. The results suggest that the extract from laurel shows the strongest biological activities among 20 herbal extracts and three acylated flavonol monoglycosides may serve as potential lead compounds for the prevention and treatment of neurodegenerative and lifestyle-related diseases by targeting GABase and glutaminase. This is the first report on GABase and glutaminase inhibitory activities of 1-3.

Anti-Helicobacter pylori, Antioxidant, Antidiabetic, and Anti-Alzheimer's Activities of Laurel Leaf Extract Treated by Moist Heat and Molecular Docking of Its Flavonoid Constituent, Naringenin, against Acetylcholinesterase and Butyrylcholinesterase.

It is worth noting that laurel (Laurus nobilis L.) contains several pharmacologically and nutritionally active compounds that may differ according to the pretreatment process. The current study is designed to clarify the effect of moist heat on the phenolic and flavonoid constituents and anti-Helicobacter pylori, antioxidant, antidiabetic, and anti-Alzheimer's activities of laurel leaf extract (LLE). Unmoist-heated (UMH) and moist-heated (MH) LLEs showed the presence of numerous flavonoid and phenolic constituents, although at different levels of concentration. MH significantly induced (p < 0.05) the occurrence of most compounds at high concentrations of 5655.89 µg/mL, 3967.65 µg/mL, 224.80 µg/mL, 887.83 µg/mL, 2979.14 µg/mL, 203.02 µg/mL, 284.65 µg/mL, 1893.66 µg/mL, and 187.88 µg/mL, unlike the detection at low concentrations of 3461.19 µg/mL, 196.96 µg/mL, 664.12 µg/mL, 2835.09 µg/mL, 153.26 µg/mL, 254.43 µg/mL, 1605.00 µg/mL, 4486.02 µg/mL, and 195.60 µg/mL using UMH, for naringenin, methyl gallate, caffeic acid, rutin, ellagic acid, coumaric acid, vanillin, ferulic acid, and hesperetin, respectively. Chlorogenic acid, syringic acid, and daidzein were detected in the UMH LLE but not in the MH LLE, unlike pyrocatechol. The anti-H. pylori activity of the UMH LLE was lower (23.67 ± 0.58 mm of inhibition zone) than that of the MH LLE (26.00 ± 0.0 mm of inhibition zone). Moreover, the values of MIC and MBC associated with the MH LLE were very low compared to those of the UMH LLE. Via MBC/MIC index calculation, the UMH and MH LLEs showed cidal activity. The MH LLE exhibited higher anti-biofilm activity (93.73%) compared to the anti-biofilm activity (87.75%) of the MH LLE against H. pylori. The urease inhibition percentage was more affected in the UMH LLE compared to the MH LLE, with significant (p < 0.05) IC50 values of 34.17 µg/mL and 91.11 µg/mL, respectively. Promising antioxidant activity was documented with a very low value of IC50 (3.45 µg/mL) for the MH LLE compared to the IC50 value of 4.69 µg/mL for the UMH LLE and the IC50 value of 4.43 µg/mL for ascorbic acid. The MH LLE showed significantly higher (p < 0.05) inhibition of α-glucosidase and butyrylcholinesterase activities, with IC50 values of 9.9 µg/mL and 17.3 µg/mL, respectively, compared to those of the UMH LLE at 18.36 µg/mL and 28.92 µg/mL. The molecular docking of naringenin showed good docking scores against acetylcholinesterase 1E66 and butyrylcholinesterase 6EMI, indicating that naringenin is an intriguing candidate for additional research as a possible medication for Alzheimer's disease.

Safety and efficacy of a feed additive consisting of an essential oil from the leaves of Laurus nobilis L. (laurel leaf oil) for all animal species (FEFANA asbl).

Following a request from the European Commission, the EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on the safety and efficacy of an essential oil from the leaves of Laurus nobilis L. (laurel leaf oil), when used as a sensory additive for all animal species. The additive contains up to 4% methyleugenol. The use of the additive at 2 mg/kg complete feed in dogs and cats was considered of low concern. For other long-living and reproductive animals, the use of the additive at 10 mg/kg was considered of concern. For short-living animals, the Panel had no safety concern when the additive is used at 10 mg/kg complete feed for turkeys for fattening, piglets and other growing Suidae, pigs for fattening, veal calves (milk replacer), cattle for fattening and other growing ruminants, horses and rabbits for meat production, salmonids and other fin fish; and at 8.5 mg/kg for chickens for fattening, other growing poultry and other minor species for fattening. The use of laurel leaf oil up to the highest level in feed which was considered of no concern for target animals was also expected to be of no concern for consumers. The additive should be considered as irritant to skin and eyes and the respiratory tract. Due to the high concentration of methyleugenol (≥ 1%), the additive was classified by the applicant as suspected of causing genetic defects and of causing cancer and should be handled accordingly. The use of the additive under the proposed conditions of use was not expected to pose a risk for the environment. Since the leaves of L. nobilis and their preparations were recognised to flavour food and their function in feed would be the same, no further demonstration of efficacy was considered necessary.

Adsorptive removal of hazardous dye (crystal violet) using bay leaves (Laurus nobilis L.): surface characterization, batch adsorption studies, and statistical analysis.

In this study, the surface properties of Laurus nobilis L. were determined by inverse gas chromatography. From this, the surface of Laurus nobilis L. was found to be an acidic ([Formula: see text]). Then, the adsorption of hazardous crystal violet dye on Laurus nobilis L. was examined. For the adsorption process, the optimum conditions were determined as contact time (60 min), adsorbent dosage (1.0 g/L), agitation rate (200 rpm), and initial pH (≅ 7). The efficiencies of initial concentration, contact time, temperature, and their binary combinations on the improvement of adsorption percentage were statistically investigated via three different two-way ANOVA analyses. Adsorption data were applied to different isotherms, and it was determined that the Langmuir isotherm (r2 = 0.9998) was the most suitable isotherm for the adsorption process. The [Formula: see text] value was calculated as 400.0 mg/g at 25 °C from the Langmuir isotherm. According to kinetic models, it was observed that the adsorption occurred in three steps. According to enthalpy (+ 7.52 kJ/mol), activation energy (+ 8.91 kJ/mol), and Gibbs free energy (- 30.0 kJ/mol) values, it was determined that the adsorption occurred endothermically and spontaneously. As a result of reusability studies, it was determined that the adsorbent could be used repeatedly.

Pressurized Liquid Extraction as a Novel Technique for the Isolation of Laurus nobilis L. Leaf Polyphenols.

Laurus nobilis L., known as laurel or bay leaf, is a Mediterranean plant which has been long known for exhibiting various health-beneficial effects that can largely be attributed to the polyphenolic content of the leaves. Pressurized liquid extraction (PLE) is a green extraction technique that enables the efficient isolation of polyphenols from different plant materials. Hence, the aim of this research was to determine optimal conditions for PLE (solvent, temperature, number of extraction cycles and static extraction time) of laurel leaf polyphenols and to assess the polyphenolic profile of the optimal extract by ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) as well as to evaluate the antioxidant activity determined by FRAP, DPPH and ORAC assays. The optimal PLE conditions were 50% ethanol, 150 °C, one extraction cycle and 5 min static time. The polyphenolic extract obtained at optimal PLE conditions comprised 29 identified compounds, among which flavonols (rutin and quercetin-3-glucoside) were the most abundant. The results of antioxidant activity assays demonstrated that PLE is an efficient green technique for obtaining polyphenol-rich laurel leaf extracts with relatively high antioxidant activity.

Development of clinoptilolite zeolite-coated magnetic nanocomposite-based solid phase microextraction method for the determination of Rhodamine B in cosmetic products.

Green synthesis of clinoptilolite zeolite/Fe3O4 nanocomposite (MZNC) was carried out using Laurus Nobilis L. leaf extract. Characterization of this MZNC was performed using Scanning Electron Microscopy, Fourier Transform Infrared Spectroscopy, X-Ray Diffraction and Vibrating Sample Magnetometer. According to the VSM analysis results, the saturation magnetization of 23 emu/g and coercivity of 23.5 Oe indicate that the synthesized magnetic nanocomposite is superparamagnetic. A new ultrasonic assisted clinoptilolite zeolite-coated magnetic nanocomposite-based solid phase microextraction (MZNC-SPME) method combined with high performance liquid chromatography was developed for the extraction and determination of Rhodamine B. The preconcentration factor for the MZNC-SPME method was found to be 40 under optimal conditions. Under optimal conditions, the linear range, correlation coefficient (R2), limit of detection (LOD), and intra- and interday relative standard deviation (RSD) were found to be 1.00-100.00 ng mL-1, 0.9995, 0.16 ng mL-1, 1.89% and 2.49%, respectively. The developed method was successfully performed to determine Rhodamine B in 6 different cosmetic samples. 6 ions and 5 different dyes were added to the sample solution to show the selectivity of the method. The obtained results show that the determination of Rhodamine B is possible in the presence of these ions and dyes. In order to determine the accuracy of the MZNC-SPME method, two different concentrations of Rhodamine B concentration in cosmetic samples were added as 10 and 50 ng mL-1. Extraction recoveries were found in the range of 92.03-101.52% and these results are quite satisfactory. It is seen that the developed method for the extraction and determination of Rhodamine B from cosmetic samples is applicable due to the easy synthesis of the sorbent and the short, simple, environmentally friendly and low cost of the method.

Non-Volatile and Volatile Bioactives of Salvia officinalis L., Thymus serpyllum L. and Laurus nobilis L. Extracts with Potential Use in the Development of Functional Beverages.

Functional beverages based on herbal extracts are highly demanded products due to the presence of bioactives with promising health benefits and interesting and characteristic sensory properties. Mediterranean medicinal and aromatic herbs contain a wide range of bioactives (non-volatile polyphenols, volatile terpenes) that are important constituents of herbal extracts and essential oils. The antioxidant capacity and potential health benefits of these bioactives could be associated with their synergistic effects. Therefore, this study aimed to characterize the non-volatile and volatile bioactives of sage (Salvia officinalis L.), wild thyme (Thymus serpyllum L.) and laurel (Laurus nobilis L.) aqueous extracts and their two- and three-component mixtures as well as their antioxidant capacity. The content of total phenols, flavonoids, hydroxycinnamic acids and flavonols was determined spectrophotometrically. Individual polyphenols were analyzed by LC-MS/MS, the volatiles were analyzed by HS-SPME/GC-MS, and the antioxidant capacity was analyzed by ORAC and DPPH assays. The results showed that aqueous extracts of all examined herbs and their mixtures contained a high content of phenolic compounds ranging from 0.97 to 2.79 g L-1 of the sample, among which the most common were flavonols. At the same time, mono- and sesquiterpenes were the main volatiles. All extracts showed high antioxidant capacity, especially L. nobilis (781.62 ± 5.19 µmol TE mL-1 of the sample in the DPPH assay; 1896.10 ± 8.77 µmol TE mL-1 of the sample in the ORAC assay) and the two-component mixture of L. nobilis and T. serpyllum (679.12 ± 5.19 µmol TE mL-1 in the DPPH assay; 1913.38 ± 8.77 µmol TE mL-1 in the ORAC assay). Mixtures of herbal extracts have been shown to possess additive or synergistic effects, consequently contributing to higher antioxidant capacity. Therefore, two-component mixtures of herbal extracts showed promising potential for the production of functional beverages.

Bay Laurel (Laurus nobilis L.) Essential Oil as a Food Preservative Source: Chemistry, Quality Control, Activity Assessment, and Applications to Olive Industry Products.

Essential oils (EOs) find application as flavoring agents in the food industry and are also desirable ingredients as they possess preservative properties. The Mediterranean diet involves the use of a lot of herbs and spices and their products (infusions, EOs) as condiments and for the preservation of foods. Application of EOs has the advantage of homogeneous dispersion in comparison with dry leaf use in small pieces or powder. Among them, Laurus nobilis (bay laurel) L. EO is an interesting source of volatiles, such as 1,8-cineole and eugenol, which are known for their preservative properties. Its flavor suits cooked red meat, poultry, and fish, as well as vegetarian dishes, according to Mediterranean recipes. The review is focused on its chemistry, quality control aspects, and recent trends in methods of analysis and activity assessment with a focus on potential antioxidant activity and applications to olive industry products. Findings indicate that this EO is not extensively studied in comparison with those from other Mediterranean plants, such as oregano EO. More work is needed to establish authenticity and activity methods, whereas the interest for using it for the preparation of flavored olive oil or for the aromatization and preservation of table oils must be further encouraged.

Isolation of Laurus nobilis Leaf Polyphenols: A Review on Current Techniques and Future Perspectives.

In recent years, the market demand for products enhanced with ingredients derived from natural products, such as polyphenols, is rapidly increasing. Laurus nobilis L., known as bay, sweet bay, bay laurel, Roman laurel or daphne is an evergreen Mediterranean shrub whose leaves have traditionally been used in cuisines and folk medicine due to their beneficial health effects, which can nowadays be scientifically explained by various biological activities of the leaf extracts. Many of these activities can be attributed to phenolic compounds present in L. nobilis leaves which include flavonoids, phenolic acids, tannins (proanthocyanidins) and lignans. In order to enable efficient industrial utilization of these valuable compounds, it is crucial to establish optimal extraction procedures resulting in the highest yields and quality of the extracts. This paper offers the first systematic review of current literature on the influence of conventional and advanced extraction techniques, including microwave-assisted, ultrasound-assisted, enzyme-assisted, supercritical-CO2 and mechanochemical-assisted extraction on the phenolic content of L. nobilis leaf extracts, allowing more efficient planning of further research and simplifying the steps towards industrial utilization of this plant.

Genetic relationships and diversity analysis in Turkish laurel (Laurus nobilis L.) germplasm using ISSR and SCoT markers.

Laurel (Laurus nobilis L.) has been used in the Mediterranean basin since ancient ages. Nowadays, Turkey, Mexico, Portugal, Italy, Spain, France, Algeria, and Morocco use aromatic leaves for commercial purposes, and Turkey is the largest exporter in the world. In this study, molecular characterization, and genetic relationships of 94 Turkish laurel genotypes were determined by ISSR and SCoT markers. The experiment was conducted with 16 ISSR and 10 SCoT markers. While 348 of 373 bands were polymorphic with a 93.3% polymorphism rate, Nei's genetic distances ranged between 0.17 and 0.70 with 0.39 mean in ISSR. In SCoT, 175 of 227 bands were polymorphic with 77.1% polymorphism rate, and Nei's genetic distances varied between 0.12 and 0.51. Sufficient genetic diversity determined with diversity parameters consisting of the average Shannon's information index (ISSR: 0.46, SCoT:0.35), the overall gene diversity (ISSR:0.19, SCoT:0.18), and the effective number of alleles (ISSR:1.52, SCoT:1.38). AMOVA (Analysis of molecular variance) revealed most of the variation was within genotypes (96%). Neighbor-joining algorithms, principal coordinate analysis (PCoA), and model-based structure resulted in harmony and clustered according to the geographical regions and provinces they collected. Genotypes were divided into two groups in ISSR and SCoT with UPGMA clustering resulting in a similar polymorphism distribution. The correlation coefficient (r) determined by marker systems' Nei's genetic distances was 0.25. The results of the study put forward resources for advanced breeding techniques, contribute to the preservation of genetic diversity, and management of genetic resources for the breeders.

Effect of Enzymatic, Ultrasound, and Reflux Extraction Pretreatments on the Chemical Composition of Essential Oils.

The effect of different hydrodistillation pretreatments, namely, reflux extraction, reflux extraction with the addition of cell wall-degrading enzymes, and ultrasound, on the yield and chemical composition of essential oils of sage, bay laurel, and rosemary was examined. All pretreatments improved essential oil yield compared to no-pretreatment control (40-64% yield increase), while the oil quality remained mostly unchanged (as shown by statistical analysis of GC-MS results). However, enzyme-assisted reflux extraction pretreatment did not significantly outperform reflux extraction (no-enzyme control), suggesting that the observed yield increase was mostly a consequence of reflux extraction and enzymatic activity had only a minute effect. Thus, we show that ultrasound and reflux extraction pretreatments are beneficial in the production of essential oils of selected Mediterranean plants, but the application of enzymes has to be carefully re-evaluated.

Comparison of Chemical Composition and Biological Properties of Essential Oils Obtained by Hydrodistillation and Steam Distillation of Laurus nobilis L.

The purpose of this study was to compare the yield, chemical composition, antimicrobial and antioxidant properties of essential oils isolated from leaves of Laurus nobilis L. by two different distillation methods. The essential oils isolated by hydrodistillation (HD) and steam distillation (SD) were analyzed by gas chromatography coupled to mass spectrometry (GC-MS) and gas chromatography with flame ionization detector (GC-FID). Hydrodistillation produced a yield of 0.95 ± 0.06% which is slightly higher than yield obtained by steam distillation 0.79 ± 0.07%. Seventy three compounds in the bay leaves oil obtained by steam distillation were identified while in essential oil obtained by hydrodistillation were identified only 54 compounds. The antioxidant activity was evaluated by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical method. Antimicrobial activity of obtained essential oils was evaluated by disc diffusion method in comparison with several chosen antimicrobials. The antimicrobial activity was tested on five microorganisms - Escherichia coli, Staphylococcus aureus, Enterococcus faecalis, Pseudomonas aeruginosa and Candida albicans. In general, oils produced by steam distillation had higher antimicrobial and antioxidant activities than hydrodistillation extracts. It seems that hydrodistillation is better for higher yield while steam distillation is better to use for more quality oils with stronger biological properties.

Diagnostic Potential of FT-IR Fingerprinting in Botanical Origin Evaluation of Laurus nobilis L. Essential Oil is Supported by GC-FID-MS Data.

The last years, non-targeted fingerprinting by Fourier-transform infrared (FT-IR) spectroscopy has gained popularity as an alternative to classical gas chromatography (GC)-based methods because it may allow fast, green, non-destructive and cost-effective assessment of quality of essential oils (EOs) from single plant species. As the relevant studies for Laurus nobilis L. (bay laurel) EO are limited, the present one aimed at exploring the diagnostic potential of FT-IR fingerprinting for the identification of its botanical integrity. A reference spectroscopic dataset of 97 bay laurel EOs containing meaningful information about the intra-species variation was developed via principal component analysis (PCA). This dataset was used to train a one-class model via soft independent modelling class analogy (SIMCA). The model was challenged against commercial bay laurel and non-bay laurel EOs of non-traceable production history. Overall, the diagnostic importance of spectral bands at 3060, 1380-1360, 1150 and 1138 cm-1 was assessed using GC-FID-MS data. The findings support the introduction of FT-IR as a green analytical technique in the quality control of these often mislabeled and/or adulterated precious products. Continuous evaluation of the model performance against newly acquired authentic EOs from all producing regions is needed to ensure validity over time.

Complete essential oils of Laurus nobilisinducing antinociceptiveaction by opioid mechanism in C-Reflex and spinal Wind-Up model in rat / Aceites esenciales totales de Laurus nobilis inducen acción antinociceptivamediante mecanismo opioide en el modelode Reflejo-C y Wind-Up espinal en ratas

The essential oil of Laurus nobilis L. was used to test their antinociceptive efficacy. It was applied intraperitoneally (i.p.) to rats subjected to a nociception test (C reflex and spinal wind-up). The results showed that the essential oil applied at higher doses (0.06 mg/Kg) causes a complete abolition of the spinal wind-up, while the C reflex was unchanged, indicating a clear antinociceptive effect. At lower concentrations (0.012 mg/Kg), there was a lowering in the wind-up by 85% within ten minutes of the essential i.p. oil application. Interestingly, there was an effect of naloxone (0.08 mg/Kg i.p.) When applied, a change occurs that almost entirely reversed the antinociception caused by the essential oil from Laurus nobilis. We conclude that there is a significant antinociceptive effect of the essential oil of Laurus nobilis subjected to electric nociception. In addition, it was observed that naloxone reversed the antinociceptive effect (wind-up) produced by Laurus nobilis.

El aceite esencial de Laurus nobilis L. se usó para probar su eficacia antinociceptiva. Se aplicó por vía intraperitoneal (i.p.) a ratas sometidas a una prueba de nocicepción (reflejo-C y wind-up espinal). Los resultados mostraron que el aceite esencial aplicado a dosis más altas (0.06 mg/Kg) abolió completamente el wind-up espinal, mientras que el reflejo-C no cambió, lo que indica un claro efecto antinociceptivo. A concentraciones más bajas (0.012 mg/Kg), hubo una disminución en el wind-up en un 85% dentro de los diez minutos del i.p. la aplicación del aceite esencial. Curiosamente, hubo un efecto de la naloxona (0.08 mg/Kg i.p.) la cual revierte casi por completo la antinocicepción causada por el aceite esencial de Laurus nobilis. Concluimos que existe un efecto antinociceptivo significativo del aceite esencial de Laurus nobilis sometido a nocicepción eléctrica. Además, se observó que la naloxona revirtió el efecto antinociceptivo (wind-up) producido por Laurus nobilis.

Suppression of Propionibacterium acnes-Induced Skin Inflammation by Laurus nobilis Extract and Its Major Constituent Eucalyptol.

Acne is an inflammatory skin disorder in puberty with symptoms including papules, folliculitis, and nodules. Propionibacterium acnes (P. acnes) is the main anaerobic bacteria that cause acne. It is known to proliferate within sebum-blocked skin hair follicles. P. acnes activates monocytic cell immune responses to induce the expression of proinflammatory cytokines. Although the anti-inflammatory function of the Laurus nobilis (L. nobilis) extract (LNE) on several immunological disorders have been reported, the effect of LNE in P. acnes-mediated skin inflammation has not yet been explored. In the present study, we examined the ability of the LNE to modulate the P. acnes-induced inflammatory signaling pathway, and evaluated its mechanism. LNE significantly suppressed the expression of P. acnes-mediated proinflammatory cytokines, such as IL-1ß, IL-6, and NLRP3. We also found that LNE inhibited the inflammatory transcription factor NF-κB in response to P. acnes. In addition, eucalyptol, which is the main constituent of LNE, consistently inhibited P. acnes-induced inflammatory signaling pathways. Moreover, LNE significantly ameliorated P. acnes-induced inflammation in a mouse model of acne. We suggest for the first time that LNE hold therapeutic value for the improvement of P. acnes-induced skin inflammation.

Laurus nobilis leaf extract controls inflammation by suppressing NLRP3 inflammasome activation.

Laurus nobilis Linn. (Lauraceae), commonly known as Bay, has been used as a traditional medicine in the Mediterranean and Europe to treat diverse immunological disorders. Although the effects of L. nobilis on immunosuppression have been reported, the detailed underlying mechanism remains unclear. In this study, to elucidate the anti-inflammatory mechanism of L. nobilis, we examined the effect of L. nobilis leaf extract on inflammasome activation in mouse bone marrow-derived macrophages. L. nobilis leaf extract inhibited NOD-like receptor pyrin domain-containing 3 (NLRP3) inflammasome activation, which was associated with caspase-1 activation, interleukin-1ß secretion, and apoptosis-associated speck-like protein containing a CARD (ASC) pyroptosome complex formation. We also observed that 1,8-cineole, the major component of L. nobilis extract, consistently suppressed NLRP3 inflammasome activation. Furthermore, L. nobilis leaf extract attenuated the in vivo expression of proinflammatory cytokines in an acute lung injury mouse model. Our results provide the first evidence that L. nobilis leaf extract modulates inflammatory signaling by suppressing inflammasome activation.