Over the past few decades, complementary and alternative treatments have become increasingly popular worldwide. The purported therapeutic characteristics of natural products have come under increased scrutiny both in vitro and in vivo as part of efforts to legitimize their usage. One such product is tea tree oil (TTO), a volatile essential oil primarily obtained from the native Australian plant, Melaleuca alternifolia, which has diverse traditional and industrial applications such as topical preparations for the treatment of skin infections. Its anti-inflammatory-linked immunomodulatory actions have also been reported. This systematic review focuses on the anti-inflammatory effects of TTO and its main components that have shown strong immunomodulatory potential. An extensive literature search was performed electronically for data curation on worldwide accepted scientific databases, such as Web of Science, Google Scholar, PubMed, ScienceDirect, Scopus, and esteemed publishers such as Elsevier, Springer, Frontiers, and Taylor & Francis. Considering that the majority of pharmacological studies were conducted on crude oils only, the extracted data were critically analyzed to gain further insight into the prospects of TTO being used as a neuroprotective agent by drug formulation or dietary supplement. In addition, the active constituents contributing to the activity of TTO have not been well justified, and the core mechanisms need to be unveiled especially for anti-inflammatory and immunomodulatory effects leading to neuroprotection. Therefore, this review attempts to correlate the anti-inflammatory and immunomodulatory activity of TTO with its neuroprotective mechanisms.
Tea Tree Oil/therapeutic use* ; Melaleuca ; Neuroprotection ; Drug Repositioning ; Neuroinflammatory Diseases ; Australia ; Oils, Volatile ; Anti-Inflammatory Agents/pharmacology*

This paper aimed to explore the antidepressant effect of the essential oil from Schizonepeta tenuifolia Briq.(EOST) on the treatment of depression and its mechanism by using a combination of network pharmacology and the mouse model of lipopolysaccharide(LPS)-induced depression. The chemical components in EOST were identified using gas chromatography-mass spectrometer(GC-MS), and 12 active components were selected as the study objects. The targets related to EOST were obtained by Traditional Chinese Medicines Systems Pharmacology(TCMSP) and SwissTargetPrediction database. The targets related to depression were screened out through GeneCards, Therapeutic Target Database(TTD), and Online Mendelian Inheritance in Man(OMIM) database. The Venny 2.1 was applied to screen out the common targets of EOST and depression. The targets were imported into Cytoscape 3.7.2 to generate "drug-active component-diease-target" network diagram. The protein-protein interaction(PPI) network was constructed using STRING 11.5 database and Cytoscape 3.7.2, and the core targets were screened out. DAVID 6.8 database was used for Gene Ontology(GO) func-tional enrichment analysis and Kyoto Encyclopedia of Genes and Genomes(KEGG) pathway enrichment analysis, and subsequently the enrichment results were visualized through the bioinformatics platform. The mouse model of depression was induced by intraperitoneally injecting with LPS in mice. Before modeling, mice were administrated orally with EOST. The antidepressant effect of EOST was evalua-ted by tail suspension test(TST), forced swimming test(FST), and novelty suppressed feeding test(NSFT) after modeling. The content of interleukin(IL)-1β was determined by enzyme-linked immunosorbent assay(ELISA), and the protein expression levels of IL-1β and pro IL-1β in the hippocampus were determined by Western blot. There were 12 main components and 179 targets in EOAT, of which, 116 targets were related to depression, mainly involved in neuroactive ligand-receptor interaction, calcium signaling pathway, and cyclic adenosine monophosphate(cAMP) signaling pathway. Biological processes such as synaptic signal transduction, G-protein coupled receptor signaling pathway, and chemical synaptic transmission were involved. Molecular functions such as neurotransmitter receptor activity, RNA polymerase Ⅱ transcription factor activity, and heme binding were involved. In mice experiments, the results showed that EOST at 100 mg·kg~(-1) and 50 mg·kg~(-1) significantly shortened the immobility time in TST and FST as well as the feeding latency in NSFT compared with the model group, decreased the levels of serum IL-1β and NO, and reduced the protein expression levels of IL-1β and pro IL-1β in the hippocampus. In conclusion, EOST shows a good antidepressant effect in a multi-component, multi-target, and multi-pathway manner. The mechanism may be attributed to the fact that EOST can down-regulate the protein expression levels of IL-1β and pro IL-1β, decrease the release of inflammatory factors, and reduce neuroinflammation response.
Animals ; Mice ; Oils, Volatile ; Depression ; Lipopolysaccharides ; Network Pharmacology ; Databases, Genetic ; Calcium Signaling ; Disease Models, Animal

Based on GC-MS and network pharmacology, the active constituents, potential targets, and mechanism of essential oil from Gleditsiae Fructus Abnormalis(EOGFA) against cerebral ischemia/reperfusion(I/R) injury were explored, and the effective constituents were verified by experiment. To be specific, GC-MS was used identify the constituents of the volatile oil. Secondly, the targets of the constituents and disease were predicted by network pharmacology, and the drug-constituent-target network was constructed, followed by Gene Ontology(GO) term enrichment and Kyoto Encyclopedia of Genes and Genomes(KEGG) pathway enrichment of the core targets. Molecular docking was performed to investigate the binding affinity between the active constituents and the targets. Finally, SD rats were used for experimental verification. The I/R injury model was established, and the neurological behavior score, infarct volume, and pathological morphology of brain tissue were measured in each group. The content of interleukin-1β(IL-1β), interleukin-6(IL-6), and tumor necrosis factor-alpha(TNF-α) was determined by enzyme-linked immunosorbent assay(ELISA), and the protein expression of vascular endothelial growth factor(VEGF) by Western blot. A total of 22 active constituents and 17 core targets were screened out. The core targets were involved in 56 GO terms and the major KEGG pathways of TNF signaling pathway, VEGF signaling pathway, and sphingolipid signaling pathway. Molecular docking showed that the active constituents had high affinity to the targets. The results of animal experiment suggested that EOGFA can alleviate the neurological impairment, decrease the cerebral infarct volume and the content of IL-1β, IL-6 and TNF-α, and down-regulate the expression of VEGF. The experiment verified the part results of network pharmacology. This study reflects the multi-component, multi-target, and multi-pathway characteristics of EOGFA. The mechanism of its active constituents is related to TNF and VEGF pathways, which provides a new direction for in-depth research on and secondary development of Gleditsiae Fructus Abnormalis.
Animals ; Rats ; Rats, Sprague-Dawley ; Network Pharmacology ; Oils, Volatile ; Gas Chromatography-Mass Spectrometry ; Interleukin-6 ; Molecular Docking Simulation ; Tumor Necrosis Factor-alpha ; Vascular Endothelial Growth Factor A ; Reperfusion Injury ; Cerebral Infarction

Angelicae Sinensis Radix is one of the main Chinese medicinal materials with both medicinal and edible values. It has the functions of tonifying and activating blood, regulating menstruation and relieving pain, and moistening intestines to relieve constipation. It is mainly produced in the southeastern Gansu province, and that produced in Minxian, Gansu is praised for the best quality. The chemical components of Angelicae Sinensis Radix mainly include volatile oils, organic acids, and polysaccharides, which have anti-inflammatory, pain-relieving, anti-tumor, anti-oxidation, immunomodulatory and other pharmacological effects. Therefore, this medicinal material is widely used in clinical practice. By reviewing the relevant literature, this study systematically introduced the research status about the chemical constituents and pharmacological effects of processed Angelicae Sinensis Radix products, aiming to provide a theoretical reference and support for the future research, development, and clinical application of related drugs.
Drugs, Chinese Herbal/pharmacology* ; Angelica sinensis ; Oils, Volatile ; Anti-Inflammatory Agents ; Pain

Perilla frutescens is a widely used medicinal and edible plant with a rich chemical composition throughout its whole plant. The Chinese Pharmacopoeia categorizes P. frutescens leaves(Perillae Folium), seeds(Perillae Fructus), and stems(Perillae Caulis) as three distinct medicinal parts due to the differences in types and content of active components. Over 350 different bioactive compounds have been reported so far, including volatile oils, flavonoids, phenolic acids, triterpenes, sterols, and fatty acids. Due to the complexity of its chemical composition, P. frutescens exhibits diverse pharmacological effects, including antibacterial, anti-inflammatory, anti-allergic, antidepressant, and antitumor activities. While scholars have conducted a substantial amount of research on different parts of P. frutescens, including analysis of their chemical components and pharmacological mechanisms of action, there has yet to be a systematic comparison and summary of chemical components, pharmacological effects, and mechanisms of action. Therefore, this study overviewed the chemical composition and structures of Perillae Folium, Perillae Fructus, and Perillae Caulis, and summarized the pharmacological effects and mechanisms of P. frutescens to provide a reference for better development and utilization of this valuable plant.
Perilla frutescens/chemistry* ; Plant Extracts/pharmacology* ; Seeds/chemistry* ; Fruit/chemistry* ; Oils, Volatile/analysis* ; Plant Leaves/chemistry*

OBJECTIVE: Anxiety is one of the most common symptoms associated with autistic spectrum disorder. The essential oil of Cananga odorata (Lam.) Hook. f. & Thomson, usually known as ylang-ylang oil (YYO), is often used in aromatherapy as a mood-regulating agent, sedative, or hypotensive agent. In the present study, the effects and mechanisms of YYO in alleviating anxiety, social and cognitive behaviors in autism-like rats were investigated. METHODS: The prenatal valproic acid (VPA) model was used to induce autism-like behaviors in offspring rats. The effectiveness of prenatal sodium valproate treatment (600 mg/kg) on offspring was shown by postnatal growth observation, and negative geotaxis, olfactory discrimination and Morris water maze (MWM) tests. Then three treatment groups were formed with varying exposure to atomized YYO to explore the effects of YYO on the anxiety, social and cognitive behaviors of the autistic-like offspring through the elevated plus-maze test, three-chamber social test, and MWM test. Finally, the monoamine neurotransmitters, including serotonin, dopamine and their metabolites, in the hippocampus and prefrontal cortex (PFC) of the rats were measured using a high-performance liquid chromatography. RESULTS: Offspring of VPA exposure rats showed autism-like behaviors. In the VPA offspring, medium-dose YYO exposure significantly elevated the time and entries into the open arms in the elevated plus-maze test, while low-dose YYO exposure significantly enhanced the social interaction time with the stranger rat in session 1 of the three-chamber social test. VPA offspring treated with YYO exposure used less time to reach the platform in the navigation test of the MWM test. YYO exposure significantly elevated the metabolism of serotonin and dopamine in the PFC of VPA offspring. CONCLUSION YYO exposure showed the effects in alleviating anxiety and improving cognitive and social abilities in the offspring of VPA exposure rats. The role of YYO was related to the regulation of the metabolism of serotonin and dopamine. Please cite this article as: Zhang N, Wang ST, Yao L. Inhalation of Cananga odorata essential oil relieves anxiety behaviors in autism-like rats via regulation of serotonin and dopamine metabolism. J Integr Med. 2023; 21(2): 205-214.
Pregnancy ; Female ; Rats ; Animals ; Autistic Disorder/drug therapy* ; Oils, Volatile/therapeutic use* ; Serotonin/metabolism* ; Cananga/metabolism* ; Dopamine ; Anxiety/drug therapy* ; Valproic Acid/pharmacology* ; Plant Oils ; Disease Models, Animal

Essential oils(EOs) from Chinese medicinals, which can be used as adjuvants and exert certain therapeutic effect, are directly used in Chinese medicine formulas. Conventional research strategy for EOs from Chinese medicinals is to compare the efficacy of the prescriptions before and after the addition of EOs, and the penetration-enhancing mechanisms of EOs remain unclear. In modern research on EOs from Chinese medicinals, the method for studying chemical penetration enhancers is often used, which fails to reflect the overall efficacy of EOs. This study clarified the property regularity of EOs from Chinese medicinals as transdermal penetration enhancers, and thereby proposed a research model which integrated the medicinal and adjuvant properties of EOs from Chinese medicinals via "component-delivery-effect" characterization route. The core concept is that constituents of EOs from Chinese medicinals and their delivery process play a key role in their external application. This research model is expected to serve as a reference for further research on EOs from Chinese medicinals for transdermal application.
Adjuvants, Pharmaceutic ; Administration, Cutaneous ; China ; Drugs, Chinese Herbal/pharmacology* ; Oils, Volatile/pharmacology*

Moslae Herba is a commonly used aromatic Chinese medicinal with volatile oil as the main effective component and exhibits broad-spectrum antibacterial and antiviral effects. However, the irritation and instability of Moslae Herba volatile oil necessitate the preparation into a specific dosage form. In this study, the steam distillation method was employed to extract the Moslae Herba volatile oil. The content of thymol and carvacrol in Moslae Herba volatile oil was determined by HPLC as(0.111 9±0.001 0) and(0.235 4±0.004 7) mg·mL~(-1), respectively. Pseudo-ternary phase diagrams and surfactants compounding were applied in the selection of the optimal excipients(surfactant and cosurfactant). On this basis, a nanoemulsion was prepared from the Moslae Herba volatile oil and then loaded into pressure vessels to get sprays, whose stability and antibacterial activity were evaluated afterward. With clarity, viscosity, smell and body feeling as comprehensive indexes, the optimal formulation of the Moslae Herba volatile oil nanoemulsion was determined as follows: Moslae Herba volatile oil∶peppermint oil∶cremophor EL∶absolute ethanol∶distilled water 7.78∶1.58∶19.26∶6.15∶65.23. The as-prepared nanoemulsion was a light yellow transparent liquid, with Tyndall effect shown under the irradiation of parallel light. It has the pH of 5.50, conductivity of 125.9 μS·cm~(-1), average particle size of 15.45 nm, polydispersity index(PDI) of 0.156, and Zeta potential of-17.9 mV. Under a transmission electron microscope, the Moslae Herba volatile oil nanoemulsion was presented as regular spheres without adhesion and agglomeration. Stability test revealed that the Moslae Herba volatile oil nanoemulsion was stable at 4-55 ℃, which was free from demulsification and stratification within 30 days. After the centrifugation at 12 000 r·min~(-1) for 30 min, there was no stratification either. The nanoemulsion had good inhibitory effects on Escherichia coli, Staphylococcus aureus and resistant S. aureus strains, with the minimum inhibitory concentrations of 0.39, 3.12 and 1.56 mg·mL~(-1), respectively. The above results demonstrated that the nanoemulsion was prepared feasibly and showed stable physical and chemical properties and good antibacterial effects. This study provides a practicable technical solution for the development of anti-epidemic and anti-infection products from Moslae Herba volatile oil.
Anti-Bacterial Agents/pharmacology* ; Emulsions ; Methicillin-Resistant Staphylococcus aureus ; Microbial Sensitivity Tests ; Oils, Volatile ; Particle Size

This study was designed to predict the Q-markers of Citri Reticulatae Pericarpium volatile oil and conduct quantitative analysis by GC-MS. The common components of Citri Reticulatae Pericarpium volatile oil were detected by GC-MS. The network pharmacology approaches were utilized for constructing the component-target network and protein-protein interaction(PPI) network, followed by the GO and KEGG pathway enrichment analysis to clarify the pharmacological effects of common components. Molecular docking was conducted to observe the biological activities of common components, thus identifying the Q-markers of Citri Reticulatae Pericarpium volatile oil. The obtained Q-markers were subjected to quantitative analysis by GC-MS. The GC-MS analysis of 19 batches of Citri Reticulatae Pericarpium volatile oil revealed three common components, namely, D-limonene, γ-terpinene, and myrcene. The common components were analyzed based on network pharmacology, and the results showed that Citri Reticulatae Pericarpium volatile oil mainly acted on the core targets GABRA1, GABRA6, GABRA5, GABRA3, and GABRA2 through D-limonene and γ-terpinene, with five important pathways such as nicotine addiction and GABAergic synapse involved. The core targets were mainly distributed in olfactory region, cerebral cortex, cerebellum, basal ganglia, hippocampus, and amygdala to exert the pharmacological effects. As revealed by molecular docking, D-limonene and γ-terpinene exhibited good biological activities, so they were identified as the Q-markers of Citri Reticulatae Pericarpium volatile oil. The results of quantitative analysis showed that the volume fraction of D-limonene was within the range of 0.77-1.03 μL·mL~(-1), and that of γ-terpinene within the range of 0.04-0.13 μL·mL~(-1). The prediction of D-limonene and γ-terpinene as the Q-markers of Citri Reticulatae Pericarpium volatile oil has laid an experimental foundation for the establishment of the quality evaluation standard for Citri Reticulatae Pericarpium volatile oil.
Citrus ; Drugs, Chinese Herbal/pharmacology* ; Gas Chromatography-Mass Spectrometry ; Molecular Docking Simulation ; Network Pharmacology ; Oils, Volatile/pharmacology*

Due to worldwide abuse of chemical antibiotics and continuous emergence of "superbugs", the harm of bacterial drug resistance to human beings has become more and more serious. Therefore, it is of great significance to look for green antibiotics with a wide range of sources, broad antibacterial spectrum, non-toxicity or low toxicity, environmentally friendliness, diverse active components and low drug resistance. The volatile oil of traditional Chinese medicine is a kind of volatile oily liquid that exists in plants and can be distilled with steam and immiscible with water. Because of its good potential to resist drug-resistant pathogens, it is widely used in food, medicine and other fields. This paper summarized the antibacterial advantages and characteristics of volatile oil of traditional Chinese medicine, and the antibacterial effect and antibacterial mechanism of combined application of volatile oil of traditional Chinese medicine, in order to provide some theoretical basis and study ideas for solving the problem of bacterial drug resistance and developing natural and green antibiotics.
Anti-Bacterial Agents/pharmacology* ; Anti-Infective Agents ; Drugs, Chinese Herbal/pharmacology* ; Humans ; Medicine, Chinese Traditional ; Oils, Volatile/pharmacology*