Alleviating effect of lavender (Lavandula angustifolia) and its major components on postherpetic pain: a randomized blinded controlled trial.

BACKGROUND: Postherpetic neuralgia (PHN) causes severe pain which can lead to decreased quality-of-life. This study aimed to evaluate the effects of inhalation of lavender (Lavandula angustifolia) oil and its major components (linalool and linalyl acetate) on the pain in patients with PHN. METHODS: This study was performed at an outpatient clinic. Sixty-four patients with postherpetic neuralgia were randomly allocated to a control group (almond oil) or one of three experimental groups (lavender oil, linalool, or linalyl acetate diluted in almond oil at concentration of 1% v/v), and the participants inhaled the aroma by natural breathing. Quality, severity, and intensity of pain were measured before and after the intervention. RESULTS: Six patients discontinued the intervention for personal reasons; hence, data from 58 patients were analyzed (control group, n = 14; 1% lavender oil group, n = 15; 1% linalool, n = 15; 1% linalyl acetate, n = 14). Reduction in sensory pain was greater in the 1% lavender oil group, 1% linalool group, and 1% linalyl acetate group than in the control group (all P < 0.001). Reduction in affective pain was greater in the 1% lavender group (P < 0.001) and the 1% linalool group (P = 0.007) than in the control group. Decreases in pain severity and intensity were significantly greater in all three intervention groups than in the control group. CONCLUSIONS: Inhalation of lavender oil and its major volatile components effectively reduced the quality, severity, and intensity of postherpetic pain, suggesting that lavender oil, linalool, and linalyl acetate may each be an effective intervention for reducing pain in patients with postherpetic neuralgia. TRIAL REGISTRATION: This study was retrospectively registered on the Clinical Research Information Service. REGISTRATION NUMBER: KCT0007772, first registration 06/10/2022.

Critical assessment of the endocrine potential of Linalool and Linalyl acetate: proactive testing strategy assessing estrogenic and androgenic activity of Lavender oil main components.

The acyclic linear monoterpenes Linalool (Lin) and Linalyl acetate (LinAc) occur in nature as major constituents of various essential oils such as lavender oils. A potential endocrine activity of these compounds was discussed in literature including premature thelarche and prepubertal gynecomastia due to lavender product use. This study aims to follow-up on these critical findings reported by testing Lin and LinAc in several studies in line with current guidance and regulatory framework. No relevant anti-/ER and AR-mediated activity was observed in recombinant yeast cell-based screening tests and guideline reporter gene in vitro assays in mammalian cells. Findings in the screening test suggested an anti-androgenic activity, which could not be confirmed in the respective mammalian cell guideline assay. Mechanistic guideline in vivo studies (Uterotrophic and Hershberger assays) with Lin did not show significant dose related changes in estrogen or androgen sensitive organ weights and a guideline reproductive toxicity screening study did not reveal evident effects on sex steroid hormone sensitive organ weights, associated histopathological findings and altered sperm parameters. Estrous cycling and mating/fertility indices were not affected and no evident Lin-related steroid hormone dependent effects were found in the offspring. Overall, the initial concerns from literature were not confirmed. Findings in the yeast screening test were aberrant from follow-up guideline in vitro and in vivo studies, which underlines the need to apply careful interpretation of single in vitro test results to support a respective line of evidence and to establish a biologically plausible link to an adverse outcome.

Partnering essential oils with antibiotics: proven therapies against bovine Staphylococcus aureus mastitis.

Introduction: There is an urgent need to develop therapeutic options for biofilm-producing Staphylococcus aureus (S. aureus). Therefore, the renewed interest in essential oils (EOs), especially carvacrol, linalool and eugenol, has attracted the attention of our research group. Methods: Multidrug resistance and multivirulence profiles in addition to biofilm production of S. aureus strains isolated from cows with mastitis were evaluated using both phenotypic and genotypic methods. The antimicrobial and antibiofilm activities of EOs were tested using both in vitro and molecular docking studies. Moreover, the interactions between commonly used antibiotics and the tested EOs were detected using the checkerboard method. Results: We found that all our isolates (n= 37) were biofilm methicillin resistant S. aureus (MRSA) producers and 40.5% were vancomycin resistant S. aureus (VRSA). Unfortunately, 73 and 43.2% of the recovered MRSA isolates showed multidrug resistant (MDR) and multivirulence patterns, respectively. The antimicrobial activities of the tested EOs matched with the phenotypic evaluation of the antibiofilm activities and molecular docking studies. Linalool showed the highest antimicrobial and antibiofilm activities, followed by carvacrol and eugenol EOs. Fortunately, synergistic interactions between the investigated EOs and methicillin or vancomycin were detected with fractional inhibitory concentration index (FICI) values ≤ 0.5. Moreover, the antimicrobial resistance patterns of 13 isolates changed to sensitive phenotypes after treatment with any of the investigated EOs. Treatment failure of bovine mastitis with resistant S. aureus can be avoided by combining the investigated EOs with available antimicrobial drugs. Conclusion: We hope that our findings can be translated into a formulation of new pharmaceutical dosage forms against biofilm-producing S. aureus pathogens.

Differential Effects of the Processed and Unprocessed Garlic (Allium sativum L.) Ethanol Extracts on Neuritogenesis and Synaptogenesis in Rat Primary Hippocampal Neurons.

Garlic (Allium sativum L.) is an aromatic herb known for its culinary and medicinal uses for centuries. Both unprocessed (white) and processed (black) garlic are known to protect against the pathobiology of neurological disorders such as Alzheimer's disease (AD) and Parkinson's disease (PD), which has been attributed to their anti-inflammatory and antioxidant properties. The information on the effects of processed and unprocessed garlic on neuronal process outgrowth, maturation, and synaptic development is limited. This study aimed at investigating and comparing the effects of the ethanol extracts of unprocessed (white garlic extract, WGE) and processed (black garlic extract, BGE) garlic on the maturation of primary hippocampal neurons. Neurite outgrowth was stimulated in a dose-dependent manner by both WGE and BGE and the most effective doses were 15 µg/mL and 60 µg/mL, respectively, without showing cytotoxicity. At this optimal concentration, both extracts promoted axonal and dendritic growth and maturation. Furthermore, both extracts substantially increased the formation of functional synapses. However, the effect of WGE was more robust at every developmental stage of neurons. In addition, the gas chromatography and mass spectrometry (GC-MS) analysis revealed a chemical profile of various bioactives in both BGE and WGE. Linalool, a compound that was found in both extracts, has shown neurite outgrowth-promoting activity in neuronal cultures, suggesting that the neurotrophic activity of garlic extracts is attributed, at least in part, to this compound. By using network pharmacology, linalool's role in neuronal development can also be observed through its modulatory effect on the signaling molecules of neurotrophic signaling pathways such as glycogen synthase kinase 3 (GSK3ß), extracellular signal-regulated protein kinase (Erk1/2), which was further verified by immunocytochemistry. Overall, these findings provide information on the molecular mechanism of processed and unprocessed garlic for neuronal growth, survival, and memory function which may have the potential for the prevention of several neurological disorders.

Development of a Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS) Method for Characterizing Linalool Oral Pharmacokinetics in Humans.

Lavender (Lavandula angustifolia Miller or Lavandula officinalis Chaix) is an ethnopharmacological plant commonly known as English lavender. Linalool and linalyl acetate are putative phytoactives in lavender essential oil (LEO) derived from the flower heads. LEO has been used in aroma or massage therapy to reduce sleep disturbance and to mitigate anxiety. Recently, an oral LEO formulation was administered in human clinical trials designed to ascertain its anxiolytic effect. However, human pharmacokinetics and an LC-MS/MS method for the measurement of linalool are lacking. To address this deficiency, a rapid and sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed for the analysis of linalool in human serum. Prior to the analysis, a simple sample preparation protocol including protein precipitation and liquid-liquid extraction of serum samples was created. The prepared samples were analyzed using a C18 reversed-phase column and gradient elution (acetonitrile and water, both containing 0.1% formic acid). A Waters Xevo TQ-S tandem mass spectrometer (positive mode) was used to quantitatively determine linalool and IS according to transitions of m/z 137.1→95.1 (tR 0.79 min) and 205.2→149.1 (tR 1.56 min), respectively. The method was validated for precision, accuracy, selectivity, linearity, sensitivity, matrix effects, and stability, and it was successfully applied to characterize the oral pharmacokinetics of linalool in humans. The newly developed LC-MS/MS-based method and its application in clinical trial serum samples are essential for the characterization of potential pharmacokinetic and pharmacodynamic interactions.

Sweet Basil between the Soul and the Table-Transformation of Traditional Knowledge on Ocimum basilicum L. in Bulgaria.

The study tracks the utilization of Ocimum basilicum L. (sweet basil)-a garden plant popular for its ritual and ornamental value in the past, that is currently applied in various forms and ways as medicine, food, insect repellent, etc.-in Bulgaria. Previous data for Bulgarian rural home gardens showed a significant number of preserved local landraces; however, it remained unclear how people perceive the large varietal diversity of this species and how the traditions related to its use are preserved. We combined a literature review on the cultural value of sweet basil and the breeding of local genetic resources with an online questionnaire, directed to adult laypeople, that sought to access different aspects of past (recalled) and present use and related knowledge. The identification skills of the participants were tested using images of local plant landraces and foreign varieties. Responses from 220 participants showed that potted "Genovese"-type individual was most frequently identified as sweet basil (89.9%), followed by two examples of local landraces in flower. Participants who grow sweet basil or used it in more varied ways had significantly better identification skills. Ocimum basilicum was most frequently reported as food, while ritual/symbolic use was preserved while devalued during the Communism regime (1945-1989). Food and religious uses were negatively associated in the past, but presently, the tendency is completely reversed. Preferences for the informal exchange of seeds and seed-saving practices were discussed.

Anti-Inflammatory and Antimicrobial Properties of Thyme Oil and Its Main Constituents.

Thyme oil (TO) is derived from the flowers of various plants belonging to the genus Thymus. It has been used as a therapeutic agent since ancient times. Thymus comprises numerous molecular species exhibiting diverse therapeutic properties that are dependent on their biologically active concentrations in the extracted oil. It is therefore not surprising that oils extracted from different thyme plants present different therapeutic properties. Furthermore, the phenophase of the same plant species has been shown to yield different anti-inflammatory properties. Given the proven efficacy of TO and the diversity of its constituents, a better understanding of the interactions of the various components is warranted. The aim of this review is to gather the latest research findings regarding TO and its components with respect to their immunomodulatory properties. An optimization of the various components has the potential to yield more effective thyme formulations with increased potency.

Anti-inflammatory activity of essential oils from Tunisian aromatic and medicinal plants and their major constituents in THP-1 macrophages.

In this study, the capacity of eight essential oils (EOs), sage (Salvia officinalis), coriander (Coriandrum sativum), rosemary (Rosmarinus officinalis), black cumin (Nigella sativa), prickly juniper (Juniperus oxycedrus), geranium (Pelargonium graveolens), oregano (Origanum vulgare) and wormwood (Artemisia herba-alba), on the inhibition of NF-κB activation was screened at concentrations up to 0.25 µL/mL using THP-1 human macrophages bearing a NF-κB reporter. This screening selected coriander, geranium, and wormwood EOs as the most active, which later evidenced the ability to decrease over 50 % IL-6, IL-1ß, TNF-α and COX-2 mRNA expression in LPS-stimulated THP-1 macrophages. The chemical composition of selected EOs was performed by gas chromatography-mass spectrometry (GC-MS). The two major constituents (>50 % of each EO) were tested at the same concentrations presented in each EO. It was demonstrated that the major compound or the binary mixtures of the two major compounds could explain the anti-inflammatory effects reported for the crude EOs. Additionally, the selected EOs also inhibit>50 % caspase-1 activity. However, this effect could not be attributed to the major components (except for ß-citronellol/geranium oil, 40 %/65 % caspase-1 inhibition), suggesting, in addition to potential synergistic effects, the presence of minor compounds with caspase-1 inhibitory activity. These results demonstrated the potential use of the EOs obtained from Tunisian flora as valuable sources of anti-inflammatory agents providing beneficial health effects by reducing the levels of inflammatory mediators involved in the genesis of several diseases.

Lavandula angustifolia Essential Oils as Effective Enhancers of Fluconazole Antifungal Activity against Candida albicans.

The increasing prevalence of Candida albicans resistance to commercial antifungal agents in recent decades has prompted modern medicine and veterinary medicine to search for combined treatment options. The aim of the study was to determine the activity of essential oils from different cultivars and morphological parts of the medicinal lavender (Lavandula angustifolia) in combination with fluconazole against Candida albicans ATCC 10231 strain. The effect of the combination of lavender essential oil with fluconazole was tested using the checkerboard method, and the obtained results were interpreted on the basis of fractional inhibitory concentration indices (FICIs). A synergistic interaction was found for all combinations of fluconazole with essential oils isolated both from flowers and leafy stalks of two tested lavender cultivars: 'Blue River' and 'Ellagance Purple'. The observed enhancement effect of fluconazole antifungal activity was significantly stronger in the case of essential oils obtained from flowers and leafy stalks of 'Blue River' cultivar. Analogous studies were performed for linalool, one of the main components of lavender essential oils, and a similar synergistic interaction with fluconazole was found.

In Vitro Metabolism and CYP-Modulating Activity of Lavender Oil and Its Major Constituents.

The application of essential oils has historically been limited to topical (massage therapy) and inhalational (aromatherapy) routes of administration. More recently, however, evaluation of the therapeutic effects of essential oils has expanded to include the oral route of administration, which increases the herb-drug interaction potential. The purpose of this study was to evaluate the herb-drug interaction potential of lavender essential oil and two of its primary phytoactive constituents, namely linalool and linalyl acetate. The metabolic stability of linalool and linalyl acetate was determined in human liver microsomes (HLM) and S9 fractions by quantitative analysis using UPLC-MS/MS system. Linalool was metabolically unstable in HLM and S9 fractions with an intrinsic clearance of 31.28 mL·min-1·kg-1, and 7.64 mL·min-1·kg-1, respectively. Interestingly, it was observed that linalyl acetate converted to linalool both in HLM and S9 fractions. Lavender oil showed weak inhibitory effect on the catalytic activity of CYP3A4 and CYP1A2 enzymes (IC50 12.0 and 21.5 µg/mL). Linalyl acetate inhibited CYP3A4 (IC50 4.75 µg/mL) while linalool did not show any inhibitory effect on any of the enzymes. The lavender oil and its constituents did not activate PXR to a considerable extent, and no activation of AhR was observed, suggesting a lack of potential to modify the pharmacokinetic and pharmacodynamic properties of conventional medications if used concurrently.

Immunomodulatory effect of Linalool (Lin) against CCl4 -induced hepatotoxicity and oxidative damage in rats.

The current study explored the hepatoprotective and immunomodulatory effects of Linalool (Lin) against carbon tetrachloride (CCl4 )-induced toxicity in mice. Four study groups (n = 8 each) were used: (1) a negative control group and (2) a toxicity control group (single dose of CCl4 administered on day 14 as 1 mL/kg of CCL4 in 1% olive oil). Intraperitoneally (i.p.)), and two experimental groups where mice were treated with either (3) Lin (25 mg/kg b.w., orally, daily for 15 days) or (4) pretreated with Lin (25 mg/kg b.w., orally, daily for 14 days) and intoxicated with CCl4 (1 mL/kg of CCL4 in 1% olive oil. i.p.) on day 14. The levels of the anti-inflammatory cytokine interleukin 10 (IL-10), the proinflammatory cytokines TNF-α, IL-6, and TGF-1ß, and the histopathology of the liver were assessed. According to our findings, IL-10 concentrations were significantly increased in Lin-treated groups, while other cytokine levels were marked by a considerable decrease in the toxicity model group (CCl4 -treated group). Histopathological examinations of liver tissues showed that the Lin-treated groups had an almost normal structure. The current findings showed that Lin could inhibit CCl4 -induced liver injury in mice, which warrants further investigation of Lin as a potential protective and therapeutic agent against hepatotoxicity.

Ethnomedicinal uses of Indian spices used for cancer treatment: A treatise on structure-activity relationship and signaling pathways.

Cancer is among the major cause of demise worldwide. Though the array of anticancer chemical medications is available but unfortunately, they are also associated with negative health effects. The invaluable therapeutic potential of spices makes them an integral part of our daily diet. Therefore, the present work focuses on the traditional uses of 46 spices and the phytochemical analysis of 31 spices. Out of them, only 29 spices are explored for their cytotoxicity against different cancer cell lines. The pre-clinical and clinical anticancer studies of spices along with their toxicity, mechanism of actions like Wnt/ß-catenin, phosphatidylinositol-3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR), JAK/STAT, mitogen-activated protein kinase (MAPK), Notch-mediated pathways and Quantitative structure-activity relationship (QSAR) studies were also focused. Curcumin was found as one of the most explored bioactive in every aspect such as in-vitro, in-vivo, clinical as well as SAR anticancer studies while some other bioactive such as 1,8-Cineole, trans-Anethole, Diosgenin, Trigonelline are either unexplored or least explored for their clinical and SAR studies. In fact, traditional medicinal uses of spices also provide solid shreds of evidence for the new leads towards the invention of novel anticancer agents. Therefore, further research can be designed for the anticancer marketed formulation from spices after having their placebo and related toxicological data.

Methyl Jasmonate Induces Genes Involved in Linalool Accumulation and Increases the Content of Phenolics in Two Iranian Coriander (Coriandrum sativum L.) Ecotypes.

The medicinal herb coriander (Coriandrum sativum L.), with a high linalool (LIN) content, is widely recognized for its therapeutic benefits. As a novel report, the goals of this study were to determine how methyl jasmonate (MeJA) affects total phenolic content (TPC), LIN content, flavonoid content (TFC), and changes in gene expression involved in the linalool biosynthesis pathway (CsγTRPS and CsLINS). Our findings showed that, in comparison to the control samples, MeJA treatment substantially enhanced the TPC, LIN, and TFC content in both ecotypes. Additionally, for both Iranian coriander ecotypes, treatment-induced increases in CsγTRPS and CsLINS expression were connected to LIN accumulation in all treatments. A 24 h treatment with 150 µM MeJA substantially increased the LIN content in the Mashhad and Zanjan ecotypes, which was between 1.48 and 1.69 times greater than that in untreated plants, according to gas chromatography-mass spectrometry (GC-MS) analysis. Our findings demonstrated that MeJA significantly affects the accumulation of LIN, TPC, and TFC in Iranian C. sativum treated with MeJA, which is likely the consequence of gene activation from the monoterpene biosynthesis pathway. Our discoveries have improved the understanding of the molecular mechanisms behind LIN synthesis in coriander plants.

Natural Compounds in the Battle against Microorganisms-Linalool.

The purpose of this article is to present recent studies on the antimicrobial properties of linalool, the mechanism of action on cells and detoxification processes. The current trend of employing compounds present in essential oils to support antibiotic therapy is becoming increasingly popular. Naturally occurring monoterpene constituents of essential oils are undergoing detailed studies to understand their detailed effects on the human body, both independently and in doses correlated with currently used pharmaceuticals. One such compound is linalool, which is commonly found in many herbs and is used to flavor black tea. This compound is an excellent fragrance additive for cosmetics, enhancing the preservative effect of the formulations used in them or acting as an anti-inflammatory on mild skin lesions. Previous studies have shown that it is extremely important due to its broad spectrum of biological activities, i.e., antioxidant, anti-inflammatory, anticancer, cardioprotective and antimicrobial. Among opportunistic hospital strains, it is most active against Gram-negative bacteria. The mechanism of action of linalool against microorganisms is still under intensive investigation. One of the key aspects of linalool research is biotransformation, through which its susceptibility to detoxification processes is determined.

Insights into the Cytochrome P450 Monooxygenase Superfamily in Osmanthus fragrans and the Role of OfCYP142 in Linalool Synthesis.

Osmanthus fragrans flowers have long been used as raw materials in food, tea, beverage, and perfume industries due to their attractive and strong fragrance. The P450 superfamily proteins have been reported to widely participate in the synthesis of plant floral volatile organic compounds (VOCs). To investigate the potential functions of P450 superfamily proteins in the fragrance synthesis of O. fragrans, we investigated the P450 superfamily genome wide. A total of 276 P450 genes were identified belonging to 40 families. The RNA-seq data suggested that many OfCYP genes were preferentially expressed in the flower or other organs, and some were also induced by multiple abiotic stresses. The expression patterns of seven flower-preferentially expressed OfCYPs during the five different flower aroma content stages were further explored using quantitative real-time PCR, showing that the CYP94C subfamily member OfCYP142 had the highest positive correlation with linalool synthesis gene OfTPS2. The transient expression of OfCYP142 in O. fragrans petals suggested that OfCYP142 can increase the content of linalool, an important VOC of the O. fragrans floral aroma, and a similar result was also obtained in flowers of OfCYP142 transgenic tobacco. Combined with RNA-seq data of the transiently transformed O. fragrans petals, we found that the biosynthesis pathway of secondary metabolites was significantly enriched, and many 2-C-methyl-D-erythritol 4-phosphate (MEP) pathway genes were also upregulated. This evidence indicated that the OfCYP proteins may play critical roles in the flower development and abiotic response of O. fragrans, and that OfCYP142 can participate in linalool synthesis. This study provides valuable information about the functions of P450 genes and a valuable guide for studying further functions of OfCYPs in promoting fragrance biosynthesis of ornamental plants.

Essential Oil Content and Compositional Variability of Lavandula Species Cultivated in the Mid Hill Conditions of the Western Himalaya.

The increase in the utilization of Lavandula essential oil in industries led to an impressive rise in the demand for quality essential oils. However, a post-harvest drying of Lavandula species can be a decisive factor to determine the quantity and quality of essential oil. The study was conducted in western Himalayan conditions to assess the essential oil content and composition of two Lavandula species viz., lavender (Lavandula angustifolia Mill.), and lavandin (Lavandula × intermedia Emeric ex Loisel), at four different drying duration (0 h, 24 h, 48 h and 72 h after the harvest). The higher growth attributes viz., plant height (71.7 cm), ear length (8.8 cm), number of spikes (18.1), and number of flowers per ear (47.5) were higher in lavandin, while the number of branches (17.1) was higher in lavender. Essential oil content (%) and moisture reduction (%) were significantly higher at 72 h than at 0 h. The major components of lavender and lavandin essential oil were linalool (33.6-40.5%), linalyl acetate (10.8-13.6%), lavandulyl acetate (2.8-14.5%), and linalyl propionate (5.3-14.1%) in both the Lavandula species. There was a decreasing trend in linalool and an increasing trend in linalyl acetate content in lavandin, with an increase in drying duration up to 72 h; while in lavender, no regular trend was observed in linalool and linalyl acetate content. It was observed that linalool and linalyl acetate levels were the highest at 24 and 0 h of drying in lavender and lavandin, respectively, and essential oil extraction can be done according to the desire of the constituent at varied drying duration.

Potential anti-Parkinsonian's effect of S-(+)-linalool from Cinnamomum osmophloeum ct. linalool leaves are associated with mitochondrial regulation via gas-1, nuo-1, and mev-1 in Caenorhabditis elegans.

Parkinson's disease (PD) is one of the prevalent neurodegenerative diseases, and developing new treatments from natural products is of particular interest. Essential oils from Cinnamomum osmophloeum ct. linalool leaves contain high levels (~95%) of S-(+)-linalool. The neuroprotective effects of linalool have been previously described, yet the underlying molecular mechanisms remain largely unknown. This study aimed to investigate the potential anti-Parkinsonian's effect of S-(+)-linalool on mitochondrial regulation and decipher the underlying molecular mechanisms in Caenorhabditis elegans PD model. Essential oils at 20 mg/L and 20 mg/L S-(+)-linalool each significantly attenuated the damaging effects of 6-hydroxydopamine (6-OHDA) on dopaminergic (DA) neurons and decreased the mitochondrial unfolded protein response (UPRmt ) to antimycin. RNAi knockdown of mitochondrial complex I (gas-1, nuo-1), and complex II (mev-1) genes prevented the improvement of mitochondrial activity by S-(+)-linalool. The protective effects of S-(+)-linalool on 6-OHDA-induced behavior changes were absent in a DA-specific strain of C. elegans produced by gas-1, nuo-1, and mev-1 RNAi knockdown. These results suggest the potential anti-Parkinsonian's effect of S-(+)-linalool is associated with mitochondrial activity and regulated by gas-1, nuo-1, and mev-1 in C. elegans. Our findings suggest that S-(+)-linalool might be a promising candidate for therapeutic application to inhibit the progression of PD.

Acaricidal and anthelmintic efficacy of Ocimum basilicum essential oil and its major constituents estragole and linalool, with insights on acetylcholinesterase inhibition.

The present study evaluated the acaricidal and anthelmintic action of Ocimum basilicum essential oil and its main components against ticks and helminth parasites as well as to relate these activities to acetylcholinesterase inhibition. The in vitro acaricidal activity against Hyalomma scupense was evaluated by Adult Immersion Test (AIT) and Larval Packet Test (LPT), while the in vivo nematocidal potential was assessed in laboratory mice infected with Heligmosomoides polygyrus using fecal egg count reduction (FECR) and total worm count reduction (TWCR). Chemical analyzes were performed by gas chromatography coupled to mass spectrometry (GC-MS). Estragole (80.87%) and linalool (16.12%) were the major compounds detected in O. basilicum essential oil. In the AIT assay for H. scupense tick, LC50 of estragole, O. basilicum oil and linalool were 0.73, 0.81 and 0.97 mg/mL, respectively. In LPT, estragole, linalool and essential oil showed LC50 of 0.22, 1.11 and 1.19 mg/mL, respectively. Against He. polygyrus, the highest activity was observed with estragole administered at 100 mg/kg body weight (bwt), which resulted in a FECR of 90.86% and a TWCR of 82.91%. The O. basilicum essential oil, estragole and linalool inhibited the enzyme acetylcholinesterase (AChE) extracted from both parasites species. Estragole was found the most active AChE inhibitor with IC50 of 0.176 mg/mL for H. scupense and IC50 of 0.138 mg/mL for He. polygyrus larvae. The results of the present study pointed out the importance of the traditional use of O. basilicum as an eco-friendly alternative against endo and ectoparasites. In vivo trials should also be conducted to confirm the above-mentioned activities and to assure the safe use of natural plants.

Comprehensive investigation on non-volatile and volatile metabolites in four types of green teas obtained from the same tea cultivar of Longjing 43 (Camellia sinensis var. sinensis) using the widely targeted metabolomics.

In this study, we produced roasted, baked, steamed, and sun-dried green tea products using the same batch of fresh tea leaves (FTL) of Longjing 43 (Camellia sinensis var. sinensis), and explored processing effects on the metabolic profiles of four types of green teas (FGTs) using the widely targeted metabolomics. Results showed that 146 differential metabolites including flavonoids, amino acids, lipids, and phenolic acids were screened among 1034 non-volatiles. In addition, nineteen differential metabolites were screened among 79 volatiles. Most of non-volatiles and volatiles metabolites changed notably in different manufacturing processes, whereas there were no significant differences (p＞0.05) in the levels of total catechins between FGTs and FTL. The transformation of metabolites was the dominant trend during green tea processing. The results contribute to a better understanding of how the manufacturing process influences green tea quality, and provide useful information for the enrichment of tea biochemistry theory.

Light synergistically promotes the tea green leafhopper infestation-induced accumulation of linalool oxides and their glucosides in tea (Camellia sinensis).

Linalool, which is one of the most representative aroma substances in tea, is transformed into other aroma-related compounds, including linalool 3,6-oxides and linalool 3,7-oxides. The objective of this study was to elucidate the linalool oxide synthesis pathway and its response to stress in tea. By feeding experiment, chemical synthesis, and compound analysis, it was found that linalool can be transformed to linalool oxides via 6,7-epoxylinalool. The conversion rate from 6,7-epoxylinalool to linalool oxides was relatively high under acidic conditions. Four linalool oxide glucosides obtained from tea were structurally characterized. Additionally, tea green leafhopper infestation was observed to activate the whole metabolic flow from linalool into linalool oxides and their glucosides (p < 0.01). Moreover, light treatments further increased the accumulation of linalool oxides and their glucosides (p < 0.05). These results will be useful for elucidating the mechanism mediating linalool oxides content changes in response to stress in tea.