Redox State Modulatory Activity and Cytotoxicity of Olea europaea L. (Oleaceae) Leaves Extract Enriched in Polyphenols Using Macroporous Resin.

The food products derived from Olea europaea are a fundamental part of the Mediterranean diet, and their health-promoting effects are well known. In this study, we analyzed the phytochemical characteristics, the redox state modulatory activity, and the cytotoxic effect of an olive leaf aqueous extract enriched by macroporous resin on different tumor and normal cell lines (LNCaP, PC3, HFF-1). HPLC-DAD analysis, the Folin-Ciocalteu and aluminum chloride methods confirmed the qualitatively and quantitatively high content of phenolic compounds (130.02 ± 2.3 mg GAE/g extract), and a DPPH assay (IC50 = 100.00 ± 1.8 µg/mL), the related antioxidant activity. The biological investigation showed a significant cytotoxic effect, highlighted by an MTT test and the evident cellular morphological changes, on two prostate cancer cell lines. Remarkably, the extract was practically non-toxic on HFF-1 at the concentrations (100, 150, 300 µg/mL) and exposure times tested. Hence, the results are selective for tumor cells. The underlying cytotoxicity was associated with the decrease in ROS production (55% PC3, 42% LNCaP) and the increase in RSH levels (>50% PC3) and an LDH release assay (50% PC3, 40% LNCaP, established necrosis as the main cell death mechanism.

Phytochemical analysis, antibacterial and antifungal effect of Lavandula dentata L. essential oil and methanol extract.

The aim of this study was to analyse the essential oil of Lavandula dentata from Algeria and to test the antioxidant and antimicrobial properties of this plant. The essential oil (EO) (57 constituents) included mainly α-pinene, ß-pinene, nopinone, linalool, cryptone, and limonene. The plant polyphenolic contents and the antioxidant activity were determined. The antimicrobial effect of the EO and the methanolic extract (ME) was assessed against referenced and clinical bacterial strains, and also foodborne fungal isolates. The EO minimal inhibitory concentration (MIC) values varied from 0.25 to 4 mg/mL and minimal bactericidal concentrations (MBCs) were less than 8 mg/mL except for S. aureus, clinical Klebsiella, S. epidermidis, and B. subtilis. The mould strains were significantly inhibited by the EO (87.50% to 88.33%). The MIC values were 3.60-15.62 mg/mL and 0.5-4 mg/mL for ME and EO, respectively. The minimal fungicidal concentration (MFC) values ranged from 31 to 125 mg/mL and from 2 to 8 mg/mL for ME and EO, respectively.

Study of the Chemical Profile and Anti-Fungal Activity against Candida auris of Cinnamomum cassia Essential Oil and of Its Nano-Formulations Based on Polycaprolactone.

BACKGROUND: Candida auris represents an emerging pathogen that results in nosocomial infections and is considered a serious global health problem. The aim of this work was to evaluate the in vitro antifungal efficacy of Cinnamomum cassia essential oil (CC-EO) pure or formulated in polycaprolactone (PCL) nanoparticles against ten clinical strains of C. auris. METHODS: nanoparticles of PCL were produced using CC-EO (nano-CC-EO) and cinnamaldehyde (CIN) through the nanoprecipitation method. The chemical profile of both CC-EO and nano-CC-EO was evaluated using SPME sampling followed by GC-MS analysis. Micro-broth dilution tests were performed to evaluate both fungistatic and fungicidal effectiveness of CC-EO and CIN, pure and nano-formulated. Furthermore, checkerboard tests to evaluate the synergistic action of CC-EO or nano-CC-EO with micafungin or fluconazole were conducted. Finally, the biofilm disrupting activity of both formulations was evaluated. RESULTS: GC-MS analysis shows a different composition between CC-EO and nano-CC-EO. Moreover, the microbiological analyses do not show any variation in antifungal effectiveness either towards the planktonic form (MICCC-EO = 0.01 ± 0.01 and MICnano-CC-EO = 0.02 ± 0.01) or the biofilm form. No synergistic activity with the antifungal drugs tested was found. CONCLUSIONS: both CC-EO and nano-CC-EO show the same antimicrobial effectiveness and are potential assets in the fight against C. auris.

Phenolic Profiles, Antioxidant and Anti-Inflammatory Activities of Hydrodistillation Wastewaters from Five Lamiaceae Species.

Distillation is the most widely used method to obtain an essential oil from plant material. The biomass used in the process is returned as a solid residue together with variable amounts of water rich in water-soluble compounds, which currently are not addressed to any further application. The scope of this work was to evaluate the phytochemical composition of wastewaters coming from hydrodistillation (DWWs) of five aromatic plants belonging to the Lamiaceae family, and to assess their in vitro antioxidant and anti-inflammatory activities. The phenolic profiles of the DWWs were determined by HPLC-DAD and HPLC-ESI/MS. Free radical scavenging ability, oxygen radical antioxidant capacity and superoxide dismutase mimetic activity of the samples under study were measured. Moreover, to investigate the anti-inflammatory activity of the DWWs, an in vitro experimental model of intestinal inflammation was used. The DWW samples' phytochemical analysis allowed the identification of 37 phenolic compounds, all exhibiting good antioxidant and anti-inflammatory activity. Our study contributes to the knowledge on the polyphenolic composition of the DWWs of five aromatic plants of the Lamiaceae family. The results highlight the presence of compounds with proven biological activity, and therefore of great interest in the pharmaceutical and nutraceutical fields.

Effect of Petal Color, Water Status, and Extraction Method on Qualitative Characteristics of Rosa rugosa Liqueur.

Flowers of Rosa rugosa Thunb. are a rich source of bioactive compounds with high antioxidant properties and are used for the production of jams, teas, juices, and wines. In the present paper, the petals of R. rugosa cv. Alba (white flowers) and Rubra (purple flowers) were evaluated for their morphological and phytochemical characteristics, and for the preparation of an alcoholic liqueur. In particular, the effect of two extraction procedures (conventional and maceration) of fresh and dry petals on the quality of a rose liqueur was determined. As expected, the concentration of the flower's bioactive compounds was affected by petal water content and by tested cultivars: dry petals showed higher total carotenoids and anthocyanins contents with respect to the fresh ones; cv. Rubra evidenced higher values compared to cv. Alba. As regards the quality of rose liqueur, the two petal extraction procedures did not affect the polyphenol content and higher values were recorded only on dry petals with respect to the fresh ones and, in particular, on those from cv. Rubra. The liqueur's flavonoid content was influenced by the petal extraction method, water content, and color as higher values were recorded on rose liqueur prepared after the maceration of cv. Rubra dry petals whereas lower values were observed on alcoholic drinks prepared after the conventional extraction of cv. Alba fresh petals. Our study shows that R. rugosa petals have a fair amount of secondary metabolites with antioxidant activity, making them suitable for use in the beverage industry.

Polymeric Nanocapsules Containing Fennel Essential Oil: Their Preparation, Physicochemical Characterization, Stability over Time and in Simulated Gastrointestinal Conditions.

Plant essential oils, a source of biologically active compounds, represent a promising segment in the pharmaceutical market. However, their volatility, hydrophobicity, poor stability, and low toxicity limit direct use in pharmaceutical-related applications. Nanoencapsulation is a technique that allows overcoming these obstacles by improving bioaccessibility and bioavailability. Nanocapsules (NCs) based on biodegradable and biocompatible poly(ɛ-caprolactone) containing Foeniculum vulgare Mill. essential oil (FEO), known for its biological activities, were successfully prepared by interfacial deposition of the preformed polymer method. The composition of FEO (trans-anethole chemotype) was determined by gas chromatography analyses. The FEO presence inside the NCs was confirmed by nuclear magnetic resonance experiments. The FEO-NCs showed nanometer size (210 nm), low polydispersity index (0.10), negative zeta potential (-15 mV), non-Newtonian rheological behavior, and high efficiency of encapsulation (93%). Moreover, parameters such as FEO-NC particle size, bioactive compound retention, and FEO composition were monitored for 30 days at storage temperatures of 4 and 40 °C, confirming the robustness of the nanosystem. Finally, FEO-NCs were resistant to the simulated gastric digestion and showed an effective bioaccessibility of 29% in simulated intestinal digestion. Based on the results obtained, this FEO-NC nanosystem could find interesting applications in the nutraceutical and pharmaceutical sectors.

Origanum vulgare ssp. hirtum (Lamiaceae) Essential Oil Prevents Behavioral and Oxidative Stress Changes in the Scopolamine Zebrafish Model.

Origanum vulgare ssp. hirtum has been used as medicinal herbs promoting antioxidant, anti-inflammatory, antimicrobial, and neuroprotective activities. We investigated the protective effects and the mechanism of O. vulgare ssp. hirtum essential oil (OEO) on cognitive impairment and brain oxidative stress in a scopolamine (Sco)-induced zebrafish (Danio rerio) model of cognitive impairment. Our results show that exposure to Sco (100 µM) leads to anxiety, spatial memory, and response to novelty dysfunctions, whereas the administration of OEO (25, 150, and 300 µL/L, once daily for 13 days) reduced anxiety-like behavior and improved cognitive ability, which was confirmed by behavioral tests, such as the novel tank-diving test (NTT), Y-maze test, and novel object recognition test (NOR) in zebrafish. Additionally, Sco-induced brain oxidative stress and increasing of acetylcholinesterase (AChE) activity were attenuated by the administration of OEO. The gas chromatography-mass spectrometry (GC-MS) analyses were used to elucidate the OEO composition, comprising thymol (38.82%), p-cymene (20.28%), and γ-terpinene (19.58%) as the main identified components. These findings suggest the ability of OEO to revert the Sco-induced cognitive deficits by restoring the cholinergic system activity and brain antioxidant status. Thus, OEO could be used as perspective sources of bioactive compounds, displaying valuable biological activities, with potential pharmaceutical applications.

Bioactivity of Different Chemotypes of Oregano Essential Oil against the Blowfly Calliphora vomitoria Vector of Foodborne Pathogens.

Blowflies play a substantial role as vectors of microorganisms, including human pathogens. The control of these insect pests is an important aspect of the prevention of foodborne diseases, which represent a significant public health threat worldwide. Among aromatic plants, spices essential oils (EOs) are the most suitable to protect food from insect pests. In this study, we determined the chemical composition of three oregano EOs and assessed their toxicity and deterrence to oviposition against the blowfly Calliphora vomitoria L. The chemical analyses showed that the EOs belonged to three chemotypes: one with a prevalence of carvacrol, the carvacrol chemotype (CC; carvacrol, 81.5%), and two with a prevalence of thymol, the thymol/p-cymene and thymol/γ-terpinene chemotypes (TCC and TTC; thymol, 43.8, and 36.7%, respectively). The bioassays showed that although all the three EOs chemotypes are able to exert a toxic activity against C. vomitoria adults (LD50 from 0.14 to 0.31 µL insect-1) and eggs (LC50 from 0.008 to 0.038 µL cm-2) as well as deter the oviposition (Oviposition Activity Index, OAI, from 0.40 ± 0.04 to 0.87 ± 0.02), the bioactivity of oregano EOs significantly varies among the chemotypes, with the thymol-rich EOs (TCC and TTC) overall demonstrating more effectiveness than the carvacrol-rich (CC) EO.

Thymus vulgaris Essential Oil Protects Zebrafish against Cognitive Dysfunction by Regulating Cholinergic and Antioxidants Systems.

Thymus vulgaris L. is an aromatic herb used for medicinal purposes such as antimicrobial, spasmolytic, antioxidant, anti-inflammatory, antinociceptive, antitumor, and may have beneficial effects in the treatment of Alzheimer's disease. The present study aimed to investigate whether Thymus vulgaris L. essential oil enhances cognitive function via the action on cholinergic neurons using scopolamine (Sco)-induced zebrafish (Danio rerio) model of memory impairments. Thymus vulgaris L. essential oil (TEO, 25, 150, and 300 µL/L) was administered by immersion to zebrafish once daily for 13 days, whereas memory impairment was induced by Sco (100 µM), a muscarinic receptor antagonist, delivered 30 min before behavioral tests. Spatial memory was assessed using the Y-maze test and novel object recognition test (NOR). Anxiety and depression were measured in the novel tank diving test (NTT). Gas Chromatograph-Mass Spectrometry (GC-MS) analysis was used to study the phytochemical composition of TEO. Acetylcholinesterase (AChE) activity and oxidative stress response in the brain of zebrafish were determined. TEO ameliorated Sco-induced increasing of AChE activity, amnesia, anxiety, and reduced the brain antioxidant capacity. These results suggest that TEO may have preventive and/or therapeutic potentials in the management of memory deficits and brain oxidative stress in zebrafish with amnesia.

Variations of Essential Oil Constituents in Oregano (Origanum vulgare subsp. viridulum (= O. heracleoticum) over Cultivation Cycles.

Oregano is-probably-the most appreciated and widespread aromatic plant in Sicily. With the aim of evaluating the modifications of oregano's essential oil composition over time, between 2013 and 2015 six weekly samplings of three different oregano plantations were carried out, from the beginning of flowering (early May) until the traditional harvest moment (end of June). Samples were hydrodistilled and the obtained essential oils (EOs) were evaluated by means of a combination of GC-FID and GC-MS. The Origanum plants under study were demonstrated to belong to the high-yielding, thymol-type biotypes, with thymol, γ-terpinene and p-cymene as three main components, among the total of about 50 of the evaluated EOs. In each location, EO yields were found to increase throughout survey dates. Significant variations were found in many EO components, both across years and throughout harvest dates within locations. The choice of the harvest moment was confirmed to be crucial in assessing quality aspects of oregano.

Oregano (Origanum vulgare L.) essential oil provides anti-inflammatory activity and facilitates wound healing in a human keratinocytes cell model.

Skin acts as a protective barrier between the body and the external environment. Skin wounds are a common inflammatory disorder for the solution of which plants and essential oils have been applied as a medical option for centuries. Origanum vulgare essential oil (OEO) is largely used in folk medicine, but its molecular mechanisms of action are not fully known. In this study, we evaluated the anti-inflammatory/antioxidant activity as well as wound healing capacity of a well-characterized OEO on human keratinocytes NCTC 2544 treated with interferon-gamma (IFN-γ) and histamine (H) or subjected to a scratch test. The expression of pro-inflammatory mediators such as reactive oxygen species (ROS), inter-cellular adhesion molecule (ICAM)-1, inducible nitric oxide synthase (iNOS), and cyclooxygenase (COX)-2 were verified. The DNA damage was shown by the formation of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-OHdG) and activation of proliferating cell nuclear antigen (PCNA). Moreover, the abnormal modification of extracellular matrix components (ECM) was examined by determining matrix metalloproteinase (MMP)-1, and -12. Compared to untreated control, OEO showed efficacy in supporting and enhancing the cell motility. In IFN-γ and H treated cells, OEO displayed a significant reduction of ROS, ICAM-1, iNOS, COX-2, 8-OHdG, MMP-1, and MMP-12. OEO proved useful to treat inflammation and support cell motility during wound healing.

Antiproliferative Effect and Cell Cycle Alterations Induced by Salvia officinalis Essential Oil and Its Three Main Components in Human Colon Cancer Cell Lines.

Colon cancer is one of the most common human malignancies, and chemotherapy cannot yet prevent recurrence in all patients. Essential oils are phytocomplexes with antiproliferative properties. In this study, we elucidated the antiproliferative properties and the effect on cell cycle progression of Sicilian Salvia officinalis essential oil and its three main compounds, α-thujone, 1,8-cineole (eucalyptol) and camphor, on three human colon cancer cell lines. The essential oil was obtained by hydrodistillation and analyzed by gas chromatography. Cell proliferation was evaluated by MTT assay, and the cell cycle distribution was determined by flow cytometry. Thirty-four compounds were identified in the tested essential oil. Growth inhibition was observed after 72 h, with an impact on cell cycle progression and no effect on the viability of normal colonic epithelial cells. The study shows that S. officinalis essential oil and its three main components have an in vitro antiproliferative effect on colon cancer cells.

Rosmarinus officinalis Essential Oil Improves Scopolamine-Induced Neurobehavioral Changes via Restoration of Cholinergic Function and Brain Antioxidant Status in Zebrafish (Danio rerio).

Rosmarinus officinalis L. is a traditional herb with various therapeutic applications such as antibacterial, antioxidant, anti-inflammatory, antidepressant, and anticholinesterase activities, and can be used for the prevention or treatment of dementia. In the present study, we tested whether Rosmarinus officinalis L. could counteract scopolamine-induced anxiety, dementia, and brain oxidative stress in the zebrafish model and tried to find the underlying mechanism. Rosmarinus officinalis L. essential oil (REO: 25, 150, and 300 µL/L) was administered by immersion to zebrafish (Danio rerio) once daily for eight days while scopolamine (100 µM) treatment was delivered 30 min before behavioral tests. The antidepressant and cognitive-enhancing actions of the essential oil in the scopolamine zebrafish model was measured in the novel tank diving test (NTT) and Y-maze test. The chemical composition was identified by Gas chromatograph-Mass spectrometry (GC-MS) analysis. The brain oxidative status and acetylcholinesterase (AChE) activity was also determined. REO reversed scopolamine-induced anxiety, memory impairment, and brain oxidative stress. In addition, a reduced brain AChE activity following the administration of REO in scopolamine-treated fish was observed. In conclusion, REO exerted antidepressant-like effect and cognitive-enhancing action and was able to abolish AChE alteration and brain oxidative stress induced by scopolamine.

Pistacia vera L. oleoresin and levofloxacin is a synergistic combination against resistant Helicobacter pylori strains.

The increasing multidrug resistance in Helicobacter pylori, also correlated to its biofilm-forming ability, underlines the need to search novel strategies to improve the eradication rate. Natural compounds are proposed as antibiotic-resistant-breakers capable to restore the efficacy of conventional drugs. Aim of this work was to evaluate the capability of Pistacia vera L. oleoresin (ORS) to synergize with levofloxacin (LVX) against resistant H. pylori strains. The antimicrobial activity of P. vera L. ORS and LVX and their combinations was determined by MIC/MBC (in neutral and acidic environments) and checkerboard tests. The anti-biofilm effect was determined by biomass quantification. In vivo Galleria mellonella model was used to confirm in vitro data. Pistacia vera L. ORS and LVX MICs ranged respectively from 780 to 3120 mg/l and from 0.12 to 2.00 mg/l, at pH 7.0 and 5.5. MBCs were similar to MICs. Pistacia vera L. ORS was able to synergize with LVX, restoring its effectiveness in LVX resistant strains. Pistacia vera L. ORS, LVX and their synergistic combinations displayed significant biofilm reduction. Pistacia vera L. ORS and LVX, showed protective effect against H. pylori infection on G. mellonella (62% and 63% of survival, respectively). Pistacia vera L. ORS can be considered a promising potentiator to restore the effectiveness of LVX tackling the H. pylori antibiotic resistance phenomenon.

A Two-Year Bio-Agronomic and Chemotaxonomic Evaluation of Wild Sicilian Myrtle (Myrtus communis L.) Berries and Leaves.

A collection of nine Myrtus communis samples from different localities of Sicily was evaluated. Morphological traits and production characteristics have been chosen as parameters to arrange the samples into homogeneous groups and to identify the best biotypes for possible future agro-industrial exploitation. The plant material has been subjected to taxonomic characterization from biometric and phytochemical perspectives. Myrtle berries and leaves have been analyzed for their content in metabolites, applying a cascade extraction protocol for M. communis leaves and a single hydroalcoholic extraction for berries, whereas hydrodistillation procedures have been applied to obtain the essential oils from berries and leaves. The analyses of non-volatile components were carried out by LC-UV-DAD-ESI-MS. All the extracts were characterized by the presence of numerous polyphenols, namely highly hydroxylated flavonols such as quercetin and myricetin; and ellagic acid detected in all samples. In addition, myrtle berries contained nine different anthocyanins, namely delphinidin, petunidin, cyanidin and malvidin derivatives. The essential oils (EOs) were analyzed by a combination of GC-FID and GC/MS. A total of 33 and 34 components were fully characterized with the predominance of α-pinene, myrtenyl acetate, linalool, 1,8-cineole and linalyl acetate. All phytochemical profiles were subjected to cluster analyses, which allowed subdividing the myrtle samples in different chemical groups.

Chemical composition of Pistacia vera L. oleoresin and its antibacterial, anti-virulence and anti-biofilm activities against oral streptococci, including Streptococcus mutans.

OBJECTIVE: The aim of this study was to characterize the chemical composition of oleoresin of Pistacia vera L. and to determine its antimicrobial and anti-virulence activity versus selected oral streptococci. DESIGN: A gaschromatografic analysis of the oleoresin was performed. The antimicrobial and anti-virulence activity of the oleoresin and its fractions was evaluated by the Minimum Inhibitory Concentration (MIC) and/or Minimum Bactericidal Concentration (MBC), biofilm production and haemolytic activity inhibition experiments. RESULTS: The oleoresin MBCs were ≥1024 µg/mL for all tested strains; the neutral and acidic fraction MBCs ranged from 128 to 2048 µg/mL. Essential oil's MBCs (from 256 to 2048 µg/mL) were almost identical to MICs, suggesting a bactericidal effect. P. vera oleoresin at sub-lethal concentrations significantly reduced biofilm production by Streptococcus mutans (up to 49.4%) and by Streptococcus sanguinis (up to 71.2%). In addition, the acidic fraction showed a specific anti-biofilm activity against S. mutans (up to 41.3% reduction). A significant dose-dependent reduction in the haemolytic activity of S. mutans (up to 65.9%) and of S. anginosus (up to 78.3%) was observed after growth in the presence of oleoresin at sub-lethal concentrations. The acidic fraction reduced haemolytic activity (up to 54.3% at 64 µg/mL) of S. mutans only. CONCLUSIONS: Given the anti-virulence activity of the P. vera oleoresin and its acidic fraction against S. mutans, our findings suggest their potential use in oral hygiene. These data represent the first step in the exploitation of P. vera L. oleoresin.

Phytochemical profiles, phototoxic and antioxidant properties of eleven Hypericum species - A comparative study.

Hypericum is one out of the nine genera belonging to the botanical family Clusiaceae Lindl (syn. Hypericaceae Juss.; APG III, 2009). The genus contains 484 species spread worldwide, one of which, Hypericum perforatum, is largely used in folk medicine. The aim of this study was to evaluate the chemical composition, along with the antioxidant and phototoxic activity, of 11 Hypericum species grown in Sicily (H. perforatum L., H. aegypticum L., H. androsaemum L., H. calycinum L., H. hircinum L., H. hirsutum L., H. montanum L., H. patulum Thunb., H. perfoliatum L., H. pubescens Boiss., H. tetrapterum Fr.). Samples of flowering tops collected from these Hypericum species were extracted and analysed by high performance liquid chromatography with diode-array detection and mass spectrometry (HPLC-DAD-MS) to determine their content of main polyphenols, acylphloroglucinols, and naphthodianthrones. The extracts were also subjected to a photocytotoxic assay using murine fibroblast (NIH/3T3), and their antioxidant activity evaluated by means of Folin-Ciocalteau, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, and oxygen radical antioxidant capacity assays. Phytochemical analysis allowed us to identify and quantify 20 metabolites, each of them possessing a well-known biological activity. Furthermore, all examined species showed a good cytotoxic and antioxidant/radical scavenging activity. These results indicate that in addition to the well-known H. perforatum, at least other three species (H. tetrapterum, H. pubescens, and H. montanum) represent potential sources of biologically active compounds, and at least other two species (H. perfoliatum and H. tetrapterum), due to their phototoxicity are candidates for application in photodynamic therapy.

Essential oil composition and antinociceptive activity of Thymus capitatus.

CONTEXT: The essential oil (EO) from Thymus capitatus Hoff. et Link. (Lamiaceae) has been traditionally used for its medicinal properties, such as anti-inflammatory, analgesic, antioxidant and antimicrobial properties. OBJECTIVE: Characterize the constituents from T. capitatus EO and further evaluate the antinociceptive activity by in vivo and in vitro procedures. MATERIALS AND METHODS: Gas chromatography-mass spectrometry was used to identify and quantify the constituents of the T. capitatus EO. The antinociceptive activity was evaluated in vivo by the glutamate-induced nociception model in male Swiss mice (25 g), at doses of 3, 6 and 12 mg/kg, 1 h before evaluation of the licking time response (0-15 min). The mechanism of T. capitatus EO (1-500 µg/mL) on the isolated nerve excitability of Wistar rat (300 g) was assessed by the single sucrose technique. RESULTS AND DISCUSSION: The EO of T. capitatus presented 33 components, mainly monoterpenes and sesquiterpenes, carvacrol (ca. 80%) was its major constituent. T. capitatus EO induced antinociception in orally treated mice (3, 6, and 12 mg/kg) reducing the licking time from control (100.3 ± 11.9 s) to 84.8 ± 12.2, 62.7.6 ± 9.9, and 41.5 ± 12.7 s, respectively (n = 8; p < 0.05). Additionally, we have demonstrated that T. capitatus EO (500 µg/mL) decreased the compound action potential amplitude (VCAP) of about 80.0 ± 4.3% from control recordings (n = 4; p < 0.05). Such activity was presumably mediated through a voltage-gated Na+ channels. CONCLUSIONS: The present study demonstrated the antinociceptive activity of Thymus capitatus essential oil, which acts via peripheral nervous excitability blockade.

Phytochemical, Ecological and Antioxidant Evaluation of Wild Sicilian Thyme: Thymbra capitata (L.) Cav.

In a broad survey conducted throughout the Sicily region, 45 different sites were identified where thyme grows wild. All the biotypes collected were classified as Thymbra capitata (L.) Cav. (syn. Thymus capitatus (L.) Hoffmanns. & Link). Cluster analysis based on the main morphological characteristics of the plant led to the division of the biotypes into 3 major groups. All samples were analyzed for their secondary phytochemical metabolites identified in the extracts and the essential oils. LC-UV-DAD/ESI-MS and GC-FID/GC-MS have been applied to characterize the extracts and the essential oils, respectively. In the extracts, 15 flavonoid derivatives with taxifolin-di-O-glucoside and thymusin as main components, and 2 organic acids, with a large predominance of rosmarinic acid, were identified. On the whole 37 compounds were fully characterized in the essential oils, carvacrol was identified as the main component with an average value of 73.93%. The total phenol content and the antioxidant activity of all phytochemical complexes were determined with the Folin-Ciocalteu (FC) assay, the UV radiation-induced peroxidation in liposomal membranes (UV-IP test), and the scavenging activity of superoxide radical (O2∙-).