In-vivo anti-inflammatory effects of Roman Chamomile (Chamaemelum nobile) aqueous extracts collected from the National Park of El-Kala (North-East, Algeria).

The aim of our study is to evaluate anti-inflammatory effect of Chamaemelum nobile. Aqueous extracts were administrated to Wistar rats in bronchial-inflammation experimentally induced by an allergen and ovalbumin, administered intraperitoneally / intranasally (20mg/kg/day). Experimentation showed disturbances in bronchoalveolar fluid with increased leukocyte and lymphocyte levels as well as IL-4 concentration in the lungs and erythrocytes associated with high lipid peroxidation. There were disturbances in enzymatic and non-enzymatic antioxidant defense system. Lungs histopathological showed an inflammatory lymphoplasmacytic infiltrate, moderate edema of alveoli, vascular congestion and suffusion hemorrhage. Administration of aqueous extract to OVA-sensitized rats caused a significant and very highly significant improvement of MDA levels in lungs, erythrocytes, GSH, GPx, GST, catalase and SOD. We notice a decrease in IL-4 in LBA and lungs alongside reduced inflammatory cell infiltration, mild bronchiolar dilation, mild alveolar edema and normal cell morphology allowing us to conclude on the effectiveness of anti-inflammatory activity of Roman chamomile.

Analysis of terpenoid biosynthesis pathways in German chamomile (Matricaria recutita) and Roman chamomile (Chamaemelum nobile) based on co-expression networks.

German chamomile and Roman chamomile are the two most widely known chamomile species due to the medicinal properties of volatile compounds from their flowers. We determined the volatile compound content of different organs of these two chamomiles, and found that main volatile compounds in German chamomile were terpenoids and those in Roman chamomile were esters. Furthermore, 24 tissues from two chamomiles were sequenced and analyzed by gene co-expression network. The results showed higher terpene synthase expression levels and more modules correlated with sesquiterpenoids in German chamomile, which may explain its high sesquiterpenoid content. In both chamomiles, unigenes in volatile compound-correlated modules were significantly enriched in pathways related to plant-pathogen interactions and circadian rhythm, demonstrating that volatile compounds of chamomiles are influenced by these factors. There were ten times more unigenes related to plant-pathogen interactions in German chamomile than in Roman chamomile, which indicates German chamomile has higher resistance to pathogens.

Phytochemical and comparative transcriptome analyses reveal different regulatory mechanisms in the terpenoid biosynthesis pathways between Matricaria recutita L. and Chamaemelum nobile L.

BACKGROUND: Matricaria recutita (German chamomile) and Chamaemelum nobile (Roman chamomile) belong to the botanical family Asteraceae. These two herbs are not only morphologically distinguishable, but their secondary metabolites - especially the essential oils present in flowers are also different, especially the terpenoids. The aim of this project was to preliminarily identify regulatory mechanisms in the terpenoid biosynthetic pathways that differ between German and Roman chamomile by performing comparative transcriptomic and metabolomic analyses. RESULTS: We determined the content of essential oils in disk florets and ray florets in these two chamomile species, and found that the terpenoid content in flowers of German chamomile is greater than that of Roman chamomile. In addition, a comparative RNA-seq analysis of German and Roman chamomile showed that 54% of genes shared > 75% sequence identity between the two species. In particular, more highly expressed DEGs (differentially expressed genes) and TF (transcription factor) genes, different regulation of CYPs (cytochrome P450 enzymes), and rapid evolution of downstream genes in the terpenoid biosynthetic pathway of German chamomile could be the main reasons to explain the differences in the types and levels of terpenoid compounds in these two species. In addition, a phylogenetic tree constructed from single copy genes showed that German chamomile and Roman chamomile are closely related to Chrysanthemum nankingense. CONCLUSION: This work provides the first insights into terpenoid biosynthesis in two species of chamomile. The candidate unigenes related to terpenoid biosynthesis will be important in molecular breeding approaches to modulate the essential oil composition of Matricaria recutita and Chamaemelum nobile.

De novo assembly and comparative transcriptome analysis: novel insights into terpenoid biosynthesis in Chamaemelum nobile L.

KEY MESSAGE: Analysis of terpenoids content, transcriptome from Chamaemelum nobile showed that the content of the terpenoids in the roots was the highest and key genes involved in the terpenoids synthesis pathway were identified. Chamaemelum nobile is a widely used herbaceous medicinal plant rich in volatile oils, mainly composed of terpenoids. It is widely used in food, cosmetics, medicine, and other fields. In this study, we analyzed the transcriptome and the content and chemical composition of the terpenoids in different organs of C. nobile. Gas chromatography-mass spectrometry analysis showed that the total content of the terpenoids among C. nobile organs was highest in the roots, followed by the flowers. Illumina HiSeq 2500 high-throughput sequencing technology was used to sequence the transcripts of roots, stems, leaves, and flowers of C. nobile. We obtained 139,757 unigenes using the Trinity software assembly. A total of 887 unigenes were annotated to secondary metabolism. In total, 55,711 differentially expressed genes were screened among different organs of C. nobile. We identified 16 candidate genes that may be involved in the terpenoid biosynthesis from C. nobile and analyzed their expression patterns using real-time PCR. Results showed that the expression pattern of these genes was tissue-specific and had significant differential expression levels in different organs of C. nobile. Among these genes, 13 were expressed in roots with the highest levels. Furthermore, the transcript levels of these 13 genes were positively correlated with the content of α-pinene, ß-phellandrene, 1,8-cineole, camphor, α-terpineol, carvacrol, (E,E)-farnesol and chamazulene, suggesting that these 13 genes may be involved in the regulation of the synthesis of the volatile terpenoids. These results laid the foundation for the subsequent improvement of C. nobile quality through genetic engineering.

Antiprotozoal Activity-Based Profiling of a Dichloromethane Extract from Anthemis nobilis Flowers.

A dichlomethane extract of Anthemis nobilis flower cones showed promising in vitro antiprotozoal activity against Trypanosoma brucei rhodesiense and Leishmania donovani, with IC50 values of 1.43 ± 0.50 and 1.40 ± 0.07 µg/mL, respectively. A comprehensive profiling of the most active fractions afforded 19 sesquiterpene lactones, including 15 germacranolides, two seco-sesquiterpenes, one guaianolide sesquiterpene lactone, and one cadinane acid. Of these, 13 compounds were found to be new natural products. The compounds were characterized by extensive spectroscopic data analysis (1D and 2D NMR, HRMS, circular dichroism) and computational methods, and their in vitro antiprotozoal activity was evaluated. The furanoheliangolide derivative 15 showed high potency and selectivity in vitro against T. b. rhodesiense bloodstream forms (IC50 0.08 ± 0.01 µM; SI 63). In silico calculations were consistent with the drug-like properties of 15.

Safety Assessment of Anthemis nobilis-Derived Ingredients as Used in Cosmetics.

Anthemis nobilis (Roman chamomile) flower extract, anthemis nobilis flower oil, anthemis nobilis flower powder, and anthemis nobilis flower water are ingredients that function as fragrance ingredients and skin-conditioning agents in cosmetic products. These ingredients are being used at concentrations up to 10% (anthemis nobilis flower water) in cosmetic products. The available data indicate that these 4 ingredients are not irritating or sensitizing. Chemical composition data and the low use concentrations suggest that systemic toxicity would not be likely if percutaneous absorption of constituents were to occur. Formulations may contain more than 1 botanical ingredient; each may contribute to the final concentration of a single component. Manufacturers were cautioned to avoid reaching levels of plant constituents that may cause sensitization or other adverse effects. Industry should continue to use good manufacturing practices to limit impurities in the ingredient before blending into cosmetic formulations. The Expert Panel concluded that these ingredients are safe in the present practices of use and concentration in cosmetics, when formulated to be nonsensitizing.

Acid-Induced Rearrangement of Epoxygermacranolides: Synthesis of Furanoheliangolides and Cadinanes from Nobilin.

The acid-induced rearrangement of three epoxyderivatives of nobilin 1, the most abundant sesquiterpene lactone in Anthemisnobilis flowers, was investigated. From the 1,10-epoxyderivative 2, furanoheliangolide 5 was obtained, while the 4,5-epoxy group of 3 did not react. Conversely, when the 3-hydroxy function of nobilin was acetylated (12), the 4,5-epoxy derivative did cyclize into cadinanes (15 and 16) under Lewis acid catalysis. The reactivity of the 4,5- and 1,10-epoxy derivatives of nobilin (2 and 3) was compared with that of parthenolide, and rationalized on the basis of quantum chemical calculations. All isolated reaction products were fully characterized by spectroscopic and computational methods, and their in vitro anti-protozoal activity was evaluated. The paper could provide new insights into the biosynthesis of this class of natural products.

Cloning, Expression Profiling and Functional Analysis of CnHMGS, a Gene Encoding 3-hydroxy-3-Methylglutaryl Coenzyme A Synthase from Chamaemelum nobile.

Roman chamomile (Chamaemelum nobile L.) is renowned for its production of essential oils, which major components are sesquiterpenoids. As the important enzyme in the sesquiterpenoid biosynthesis pathway, 3-hydroxy-3-methylglutaryl coenzyme A synthase (HMGS) catalyze the crucial step in the mevalonate pathway in plants. To isolate and identify the functional genes involved in the sesquiterpene biosynthesis of C. nobile L., a HMGS gene designated as CnHMGS (GenBank Accession No. KU529969) was cloned from C. nobile. The cDNA sequence of CnHMGS contained a 1377 bp open reading frame encoding a 458-amino-acid protein. The sequence of the CnHMGS protein was highly homologous to those of HMGS proteins from other plant species. Phylogenetic tree analysis revealed that CnHMGS clustered with the HMGS of Asteraceae in the dicotyledon clade. Further functional complementation of CnHMGS in the mutant yeast strain YSC6274 lacking HMGS activity demonstrated that the cloned CnHMGS cDNA encodes a functional HMGS. Transcript profile analysis indicated that CnHMGS was preferentially expressed in flowers and roots of C. nobile. The expression of CnHMGS could be upregulated by exogenous elicitors, including methyl jasmonate and salicylic acid, suggesting that CnHMGS was elicitor-responsive. The characterization and expression analysis of CnHMGS is helpful to understand the biosynthesis of sesquiterpenoid in C. nobile at the molecular level and also provides molecular wealth for the biotechnological improvement of this important medicinal plant.

Anti-trypanosomal cadinanes synthesized by transannular cyclization of the natural sesquiterpene lactone nobilin.

Acid-catalyzed transannular cyclization of the germacrene-type sesquiterpene lactone nobilin 1 was investigated with the aim of obtaining new anti-trypanosomal cadinane derivatives. The reaction was regiospecific in all tested reaction conditions. Compounds were fully characterized by spectroscopic and computational methods, and the anti-trypanosomal activity was evaluated and compared to nobilin (IC50 3.19±1.69µM). The tricyclic derivative 11 showed most potent in vitro activity against Trypanosoma brucei rhodesiense bloodstream forms (IC50 0.46±0.01µM). Acid-catalyzed transannular cyclization of natural cyclodecadienes is an efficient strategy to generate new natural product derivatives with anti-protozoal activity.

Body composition assessment of English Premier League soccer players: a comparative DXA analysis of first team, U21 and U18 squads.

Professional soccer players from the first team (1st team, n = 27), under twenty-one (U21, n = 21) and under eighteen (U18, n = 35) squads of an English Premier League soccer team were assessed for whole body and regional estimates of body composition using dual-energy X-ray absorptiometry (DXA). Per cent body fat was lower in 1st team (10.0 ± 1.6) compared with both U21 (11.6 ± 2.5, P = 0.02) and U18 (11.4 ± 2.6, P = 0.01) players. However, this difference was not due to variations (P = 0.23) in fat mass between squads (7.8 ± 1.6 v. 8.8 ± 2.1 v. 8.2 ± 2.4 kg, respectively) but rather the presence of more lean mass in 1st team (66.9 ± 7.1 kg, P < 0.01) and U21 (64.6 ± 6.5 kg, P = 0.02) compared with U18 (60.6 ± 6.3 kg) players. Accordingly, fat mass index was not different (P = 0.138) between squads, whereas lean mass index was greater (P < 0.01) in 1st team players (20.0 ± 1.1 kg · m(-2)) compared with U18 players (18.8 ± 1.4 kg · m(-2)). Differences in lean mass were also reflective of higher lean tissue mass in all regions, for example, upper limbs/lower limbs and trunk. Data suggest that training and nutritional interventions for younger players should therefore be targeted to lean mass growth as opposed to body fat loss.

Octulosonic acid derivatives from Roman chamomile (Chamaemelum nobile) with activities against inflammation and metabolic disorder.

Six new octulosonic acid derivatives (1-6) were isolated from the flower heads of Roman chamomile (Chamaemelum nobile). Their structures were elucidated by means of spectroscopic interpretation. The biological activity of the isolated compounds was evaluated toward multiple targets related to inflammation and metabolic disorder such as NAG-1, NF-κB, iNOS, ROS, PPARα, PPARγ, and LXR. Similar to the action of NSAIDs, all the six compounds (1-6) increased NAG-1 activity 2-3-fold. They also decreased cellular oxidative stress by inhibiting ROS generation. Compounds 3, 5, and 6 activated PPARγ 1.6-2.1-fold, while PPARα was activated 1.4-fold by compounds 5 and 6 only. None of the compounds showed significant activity against iNOS or NF-κB. This is the first report of biological activity of octulosonic acid derivatives toward multiple pathways related to inflammation and metabolic disorder. The reported anti-inflammatory, hypoglycemic, antiedemic, and antioxidant activities of Roman chamomile could be partly explained as due to the presence of these constituents.

High-Quality Assembly and Analysis of the Complete Mitogenomes of German Chamomile (Matricaria recutita) and Roman Chamomile (Chamaemelum nobile).

German chamomile (Matricaria chamomilla L.) and Roman chamomile (Chamaemelum nobile) are the two well-known chamomile species from the Asteraceae family. Owing to their essential oils and higher medicinal value, these have been cultivated widely across Europe, Northwest Asia, North America, and Africa. Regarding medicinal applications, German chamomile is the most commonly utilized variety and is frequently recognized as the "star among medicinal species". The insufficient availability of genomic resources may negatively impact the progression of chamomile industrialization. Chamomile's mitochondrial genome is lacking in extensive empirical research. In this study, we achieved the successful sequencing and assembly of the complete mitochondrial genome of M. chamomilla and C. nobile for the first time. An analysis was conducted on codon usage, sequence repeats within the mitochondrial genome of M. chamomilla and C. nobile. The phylogenetic analysis revealed a consistent positioning of M. chamomilla and C. nobile branches within both mitochondrial and plastid-sequence-based phylogenetic trees. Furthermore, the phylogenetic analysis also showed a close relationship between M. chamomilla and C. nobile within the clade comprising species from the Asteraceae family. The results of our analyses provide valuable resources for evolutionary research and molecular barcoding in chamomile.

Vascular effects of aqueous extract of Chamaemelum nobile: in vitro pharmacological studies in rats.

This study aims to evaluate the in vitro vasorelaxant effect of C. nobile aqueous extract. We use aortic ring isolated from Wistar rats and aqueous C. nobile extract at doses of 5, 10 and 20 mg/ml. Incubation of aqueous C. nobile extract for 30 minutes produced a significant shift of the dose-response curve to norepinephrine (NE) (10(-8) to 10(-5) M) (p < 0.001). This study demonstrates that aqueous C. nobile extract possesses in vitro vasorelaxant effect.

Mycotoxicogenic fungal inhibition by innovative cheese cover with aromatic plants.

BACKGROUND: The use of aromatic plants and their extracts with antimicrobial properties may be compromised in the case of cheese, as some type of fungal starter is needed during its production. Penicillium verrucosum is considered a common cheese spoiler. The aim of this study was to evaluate the innovative use of certain aromatic plants as natural cheese covers in order to prevent mycotoxicogenic fungal growth (P. verrucosum). A collection of 12 essential oils (EOs) was obtained from various aromatic plants by solvent-free microwave extraction technology, and volatile characterisation of the EOs was carried out by gas chromatography/mass spectrometry. RESULTS: The most effective EOs against P. verrucosum were obtained from Anethum graveolens, Hyssopus officinalis and Chamaemelum nobile, yielding 50% inhibition of fungal growth at concentration values lower than 0.02 µL mL⁻¹. All EOs showed high volatile heterogeneity, with α-phellandrene, pinocamphone, isopinocamphone, α-pinene, camphene, 1,8-cineole, carvacrol and trans-anethole being found to be statistically significant in the antifungal model. CONCLUSION: The use of these aromatic plants as natural covers on cheese can satisfactorily inhibit the growth of some mycotoxicogenic fungal spoilers. Among the volatile compounds present, α- and ß-phellandrene were confirmed as the most relevant in the inhibition.

[Comparison of antioxidant activity between two species of chamomiles produced in Xinjiang by TLC-bioautography].

OBJECTIVE: To compare the antioxidant active components from two species of chamomile-matricaria and Roman chamomile produced in Xinjiang. METHOD: The TLC-bioautography was used, with 1,1-Diphenyl-2-picrylhydrazyl (DPPH) radical as the experimental model. The peak areas of various antioxidant components were obtained by TLC-scanning for analyzing antioxidant active components contained in volatile oil extracts and flavone extracts from the two species of chamomiles. The total peak area was taken as the indicator for comparing the antioxidant capacities of the two types of extracts, and comparing them with the total antioxidant activity of flavone extracts of the two species of chamomiles. RESULTS: According to the result of TLC-bioautography in volatile oil extracts from the two species of chamomiles, volatile oil extracts from chamomile showed four white antioxidant spots, including en-yne-dicycloether, and volatile oil extracts from Roman chamomile showed only one white antioxidant spot. The TLC-scanning result showed that the peak area of antioxidant spots of volatile oil extracts from chamomile was significantly larger than that of volatile oil extracts from Roman chamomile. According to the test on the antioxidant activity of the two species of chamomiles with ultraviolet-visible spectrophotometry, the concentration of chamomile after scavenging 50% of DPPH radicals was 0.66 g x L(-1), whereas the figure for Roman chamomile was 0.33 g x L(-1). According to the result of TLC-bioautography in flavone extracts from the two species of chamomiles, flavone extracts from chamomile showed seven yellowish antioxidant spots, including apigenin and apigenin-7-glucoside, and flavone extracts of Roman chamomile showed eight yellowish antioxidant spots, including apigenin and apigenin-7-glucoside. The TLC-scanning results showed that the peak area of antioxidant spots of flavone extracts from Roman chamomile was significantly larger than that of flavone extracts from chamomile. CONCLUSION: Volatile oil extracts from the two species of chamomiles have significant difference in the antioxidant activity in TLC-bioautography. Specifically, the antioxidant activity of volatile oil extracts from chamomile is stronger than volatile oil extracts from Roman chamomile; the known antioxidant active components in volatile oil extracts from chamomile is en-yne-dicycloether, while all of the other three antioxidant active components as well as antioxidant active components in volatile oil extracts from Roman chamomile are unknown components and remain to be further determined. Considering the significant difference in the number of antioxidant active spots in volatile oil extracts from the two species of chamomiles, the result can be applied to distinguish the two species of chamomiles. The antioxidant activity determination result for flavone extracts from two species of chamomiles was consistent with the result of TLC-bioautography, showing that flavone extracts from chamomile and Roman chamomile are more antioxidant active, while that of Roman chamomile is stronger than chamomile. Flavone extracts from both of the two species of chamomiles contain apigenin and pigenin-7-glucoside, which are known, while all of the other five antioxidant active components contained in flavone extracts from chamomile and the other six antioxidant active components contained in flavone extracts from Roman chamomile are unknown and remain to be further identified. The method lays a foundation for further identification of antioxidant active components contained in chamomile.

Eye movement evidence that readers maintain and act on uncertainty about past linguistic input.

In prevailing approaches to human sentence comprehension, the outcome of the word recognition process is assumed to be a categorical representation with no residual uncertainty. Yet perception is inevitably uncertain, and a system making optimal use of available information might retain this uncertainty and interactively recruit grammatical analysis and subsequent perceptual input to help resolve it. To test for the possibility of such an interaction, we tracked readers' eye movements as they read sentences constructed to vary in (i) whether an early word had near neighbors of a different grammatical category, and (ii) how strongly another word further downstream cohered grammatically with these potential near neighbors. Eye movements indicated that readers maintain uncertain beliefs about previously read word identities, revise these beliefs on the basis of relative grammatical consistency with subsequent input, and use these changing beliefs to guide saccadic behavior in ways consistent with principles of rational probabilistic inference.

Exposure to specific herbal products during pregnancy and the risk of low birth weight.

CONTEXT: Despite the fact that herbal products (HP) are used frequently during gestation worldwide, studies indicate that they may not be free of danger for fetuses. Evidence about the safety of HP use during pregnancy and their impact on pregnancy outcomes is currently lacking. OBJECTIVE: To quantify the association between HP use during the last 2 trimesters of pregnancy (≥15 weeks of gestation [WG]) and more specifically, between use of chamomile (Anthemis nobilis), flax (Linum usitatissimum), peppermint (M. balsamea), or green tea (Camellia sinensis) (alone or in combination with other HPs) and the risk of low birth weight (LBW). DESIGN: We evaluated data from the Quebec Pregnancy Registry, which was created by the linkage of 3 administrative databases in Quebec, and a self-administered questionnaire mailed to subjects. Participants 8505 women were randomly selected from the registry. Overall, 38.5% of women (n = 3273) returned their questionnaires, and 3183 were included in the study (8 were excluded because of missing values on birth weight or giving birth to twins or triplets). Outcome measures We performed a case-control analysis. Cases were defined as women who delivered a newborn <2500g and controls as women who delivered a newborn ≥2500g. Multivariate logistic regression models were used to analyze data. RESULTS: Amongst the selected 3183 participants, 424 (13.32%) were cases. After adjusting for potential confounders, no statistically significant associations were found between the use of any HP during the last 2 trimesters of pregnancy and the risk of LBW, or between the use of flax, chamomile, peppermint, or green tea (alone or in combination with other HPs) during the last 2 trimesters of pregnancy and the risk of LBW. CONCLUSION: HP use during the last 2 trimesters of pregnancy and more specifically, use of flax, chamomile, peppermint, or green tea alone or in combination with other HPs did not significantly increase the risk of LBW.

Valorisation of Roman chamomile (Chamaemelum nobile L.) herb by comprehensive evaluation of hydrodistilled aroma and residual non-volatile fractions.

Valorization of botanicals for the development of natural food-grade ingredients is an important task in terms of sustainability and processing waste reduction. In this study, Roman chamomile (Chamaemelum nobile L.) herb was collected at six different vegetation phases in the period 26 May - 23 August 2019 and subjected to biorefining into the several valuable fractions. The yield of hydro-distilled essential oil (EO) was in the range of 0.22% (intensive vegetative growth) to 0.80% (full flowering). Angelic, isobutyric, butyric and methacrylic acid esters and some monoterpene and sesquiterpene derivatives were the major EO constituents: 3-methylpentyl angelate (20.11-27.56%), methallyl angelate (7.28-10.33%), isoamyl angelate (5.57-9.02%), isobutyl angelate (4.84-6.79%), 2-methylbutyl angelate (3.11-6.32%), 3-methylamyl methacrylate (5.04-6.17%), 3-methylpentyl isobutyrate (4.29-6.64%), 3-methylamyl isobutyrate (4.29-6.64%), α-pinene (1.61-6.37%) and pinocarvone (1.46-4.67%). In order to valorize water soluble and solid EO distillation residues their antioxidant potential was evaluated by several in vitro assays: water extracts were considerably stronger antioxidants than acetone extracts isolated from the solid residues. Water extracts of the plants collected at flowering phases were the strongest antioxidants; their TPC, FRAP and ORAC values were up to 143.2 mg gallic acid equivalents/g, 650, and 5601 µmol TE/g dry extract, respectively, while effective concentrations (EC50) of DPPH• and ABTS•+ scavenging, were down to 0.59 and 0.49 mg/mL, respectively. Among 7 tentatively identified by UPLC/Q-TOF/MS phenolic constituents the intensity of molecular ion of 3,5-dicaffeoyl quinic acid was the largest. The results obtained may assist for developing flavorings, antioxidants and health beneficial preparations from C. nobile extracts.

Anxiolytic effect of Anthemis nobilis L. (roman chamomile) and Citrus reticulata Blanco (tangerine) essential oils using the light-dark test in zebrafish (Danio rerio).

ETHNOPHARMACOLOGICAL RELEVANCE: The anxiety disorders are the most prevalent mental health condition, and anxiety is considered the sixth cause of disability surpassing diabetes mellitus, chronic obstructive pulmonary disease, and osteoarthritis. Besides, the COVID-19 pandemic provided an increase in the number of psychiatric diseases diagnosis in all social layers around the world. About 55%-94% of patients diagnosed with anxiety disorders are treated with benzodiazepines, meanwhile benzodiazepines can promote several adverse effects. In this way, alternative therapies, such as essential oils may offer significant benefits in the treatment of patients with anxiety disorders. However, the anxiolytic effect of these essential oils must be proper evaluated appropriate as well as the suitable dosage and side effect need further research. AIM OF THE STUDY: The aim was to evaluate the anxiolytic effect of Roman chamomile (Anthemis nobilis L.) and tangerine (Citrus reticulata Blanco) essential oils using the light-dark test in adult zebrafish (Danio rerio). MATERIAL AND METHODS: Both essential oils were analyzed by GC-MS and the major compounds were identified. The anxiolytic effect was evaluated by light-dark test in adult zebrafish. RESULTS: The results showed that roman chamomile essential oil has anxiolytic effect in adult zebrafish, whereas tangerine essential oil tends to reduce anxiety The major compounds of tangerine essential oil were limonene and γ-terpinene, and the major compounds of roman chamomile were pentadecyl-3-methyl-2-butenoate, hexadecyl-3-methyl-2-butenoate, 1-piperidinol and trans-1-ethyl-3-methyl-cyclopentane. CONCLUSIONS: The present study demonstrated that this anxiolytic effect may be attributed to the synergistic effect of the compounds present in roman chamomile essential oil, particularly the major compounds. The roman chamomile essential oil at the highest concentration showed anxiolytic effect. The tangerine essential oil showed a tendency to reduce anxiety, but it was not statistically significative. In addition, roman chamomile and tangerine essential oils did not cause cause alteration in locomotion activity and exploratory ability of the fish.

Action mechanism of Roman chamomile in the treatment of anxiety disorder based on network pharmacology.

Anxiety disorder is a common psychiatric disease. Roman chamomile as medicine or tea has long been used as a mild tranquilizer to reduce anxiety, but the mechanism is unclear. This research is based on network pharmacology combined with database mining to find the ingredients, action pathways and key targets of Roman chamomile for the treatment of anxiety. About 126 common targets related to chamomile and anxiety were obtained, and these targets were involved in 56 KEGG pathways. GEO screened LRRK2 as a key protein, and molecular docking showed that the protein could stably bind to drug components. Roman chamomile has the characteristics of multi-target and multi-pathway in the treatment of anxiety disorder. Its possible mechanism is to intervene anxiety disorder in the process of disease development, such as neuroactive ligand-receptor interaction, serotonin synapse, and cAMP signaling pathway. LRRK2 may be an important gene for Roman chamomile in the treatment of anxiety disorder. PRACTICAL APPLICATIONS: Roman chamomile is well known for its use in medicine and tea making. It contains many nutrients, which can relieve people's anxiety, help sleep, antibacterial and anti-inflammatory. In this article, through network pharmacology combined with Gene Expression Omnibus data mining and molecular docking, the target and mechanism of Roman chamomile in the treatment of anxiety were discussed, and its efficacy was verified by model animals, which not only clarified its mechanism at the systematic level, but also proved to be effective at the biological level. It provides a reference for the further development and utilization of Roman chamomile.