Suppression of inflammatory and infection responses in lung macrophages by eucalyptus oil and its constituent 1,8-cineole: Role of pattern recognition receptors TREM-1 and NLRP3, the MAP kinase regulator MKP-1, and NFκB

Differential influence of 1,8-Cineol on distinct hypoxia-related immune alterations in human monocytes

1,8-Cineol is a natural plant-based therapeutic agent and is commonly used to treat a broad range of acute and chronic airway inflammatory diseases. 1,8-Cineol has recently been shown to attenuate the checkpoint molecule PDL-1 in circulating monocytes in patients with chronic Otitis media (OM) and was associated with an improved clinical outcome. Hypoxia-inducible factor (HIF) is thought to play an essential role in the middle ear inflammatory process, mainly due to dysfunctions of the eustachian tube. However, the unambiguous impact of 1,8-Cineol on hypoxia-driven immune alterations of human monocytes and the related inflammatory microenvironment have not been investigated thus far. Therefore, we used the human monocytes to investigate the impact of 1,8-Cineol on the cellular hypoxia response with regards to expression levels of different adhesion molecules, chemokine receptors, and different cell stress-related proteins. Furthermore, the secretion patterns of a variety of chemokines and cytokines were evaluated. The study aimed to better understand the influence of the monoterpene 1,8-Cineol on hypoxia and normoxia-associated monocyte characteristics and related inflammatory processes, all of which are crucial for the development of various human diseases.

The comprehensive review of eucalyptol: synthesis, metabolism, and therapeutic applications in disease treatment

BACKGROUND

Eucalyptol (1,8-cineole), a naturally occurring monoterpenoid compound, is ubiquitously distributed across plant, animal, and microbial organisms. This bioactive molecule demonstrates significant therapeutic potential for various neurological and respiratory disorders, including cancer, epilepsy, and tracheitis, attributable to its potent antioxidant, anti-inflammatory, and antimicrobial properties.

SCOPE AND THRUST

The present review systematically examines the biosynthetic pathways and metabolic routes of eucalyptol, while elucidating its molecular mechanisms underlying microbial inhibition. We comprehensively summarize its principal therapeutic pathways in major disease interventions, with particular emphasis on its multi-target pharmacological actions. Furthermore, this analysis addresses potential toxicological concerns associated with eucalyptol application and discusses emerging strategies utilizing biological agents for active enhancement.

CONCLUSION AND SIGNIFICANCE

This comprehensive evaluation not only enhances our understanding of eucalyptol's therapeutic mechanisms but also provides critical insights for its development as a promising phytopharmaceutical agent in clinical practice.

Herbal and Dietary Supplements as Adjunctive Treatment for Mild SARS-CoV-2 Infection in Italy

During the COVID-19 pandemic, several observational studies proved a certain efficacy of nutraceuticals, herbal products, and other dietary supplements as adjuvant therapies used alongside antiviral drugs. Although their use has not been widespread in Italy, according to preliminary evidence, many supplements with demonstrated immunomodulatory effects, such as vitamins C and D, herbal medicines and essential oils, might relieve the respiratory symptoms of COVID-19, since SARS-CoV-2 can activate inflammasome-mediated inflammatory signaling pathways. Other observational studies have shown that herbal treatments, such as Echinacea purpurea and ginseng, help alleviate respiratory symptoms and reduce serum levels of inflammatory cytokines, which are typically overexpressed in both adult and pediatric SARS-CoV-2 patients. Further, vitamins C and D can attenuate the immune response thanks to their cytokine suppression ability and to their known antimicrobial activity and potential to modulate T helper cell response. The strong immune response triggered by SARS-CoV-2 infection is responsible for the severity of the disease. Preliminary data have also shown that L-arginine, an endothelial-derived relaxing factor, is able to modulate endothelial damage, which appears to be one of the main targets of this systemic disease. Finally, some essential oils and their isolated compounds, such as eucalyptol, may be helpful in reducing many of the respiratory symptoms of COVID-19, although others, such as menthol, are not recommended, since it can lead to an undervaluation of the clinical status of a patient. In this narrative review, despite the lack of strong evidence in this field, we aimed to give an overview of the current available literature (mainly observational and cross-sectional studies) regarding herbal products and dietary supplements and their use in the treatment of mild disease from SARS-CoV-2 infection. Obviously, dietary supplements and herbal products do not constitute a standardized treatment for COVID-19 disease, but they could represent an adjunctive and useful treatment when used together with antivirals.

Dietary Nigella sativa nanoparticles enhance broiler growth performance, antioxidant capacity, immunity, gene expression modulation, and cecal microbiota during high ambient temperatures

Environmental heat stress causes significant economic loss in the poultry industry. Therefore, interest has increased in using feed additives to reduce the negative impacts of heat stress on the chickens and improve production performance. This study aimed to assess the effect of supplementing with Nigella sativa nanoparticles (Nano-NS) as an anti-stress and growth promoter in broiler diets under hot climatic conditions. A total of 375 male one-day-old Ross 308 chicks were randomly divided into a control group and four treatment groups (75 chicks/group). The first group fed a basal diet without additives, the second group fed a basal diet supplemented with avilamycin at 50 mg/kg, and the other groups fed a basal diet supplemented with 30, 40, and 50 mg/kg Nano-NS, respectively. Despite that feed intake was not affected, feed conversion ratio, body weight gain, and crude protein digestibility improved in broilers fed Nano-NS (P < 0.05) compared with avilamycin and the control groups. Adding Nano-NS led to an increase in the dressing percentage and the relative weight of the bursa of Fabricius and thymus. Serum high-density lipoprotein levels increased while total cholesterol and low-density lipoprotein concentrations decreased (P < 0.05) in broilers fed Nano-NS compared with control groups. Furthermore, Nano-NS supplementation significantly increased (P < 0.05) serum immunoglobulin (IgG and IgA), and superoxide dismutase (SOD) levels, while decreasing malondialdehyde (MDA), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α) concentration. Moreover, there was a significant increase in the Lactobacillus population and a decrease (P < 0.05) in the E. coli and C. perfringens population in chicks fed Nano-NS. In the intestinal tissues, mucin 2 (MUC2) gene expression increased in chickens fed 50 mg/kg Nano-NS compared to other groups. It is concluded that adding Nano-NS (up to 50 mg/kg) reduced the negative effects of heat stress via enhancing growth performance, immune responses, and antioxidant status, modulating the microbial community structure, and increasing the expression of the MUC2 gene in broilers under high ambient temperature.

Medicinal plants used in traditional medicine to enhance immunity: A survey in the southeastern area of Morocco and a literature review

Objective

The threat of immune escape and the discovery of antibiotic-resistant pathogens, as well as the failure of certain conventional drugs that are already in use for the symptomatic treatment of diseases, have prompted a re-evaluation of ancient therapeutic remedies such as phytotherapy, and aromatherapy. In this context, the present study aims to shed light on some medicinal plants mostly used by the population of the Daraa Tafilalet region to strengthen their immune systems, and to provide an up-to-date literature review on this subject.

Materials and Methods

A survey study was conducted using pre-prepared questionnaires addressed to the population of the Daraa Tafilalet region. MS Windows Excel and SPSS software were used for statistical analysis and results presentation. In addition, for the literature review, searches were conducted across several databases, including Google Scholar, Science Direct, Web of Science, PubMed, and Scopus, using medicinal plants, date products, enhance immunity, and essential oils as keywords.

Results

Among 142 participants interviewed, 108 used medicinal plants to improve their immune systems. However, 34 interviewers prefer conventional medicine. Date palm fruits and oregano were the most commonly used medicinal plants by the Daraa Tafilalet population to enhance the immune system, followed by anise, lavender, rosemary, thyme, and pennyroyal. These results are supported by literature data.

Conclusion

These results reflect the interesting traditional medical knowledge of this population, which merits being documented.

A Patent-Pending Ointment Containing Extracts of Five Different Plants Showed Antinociceptive and Anti-Inflammatory Mechanisms in Preclinical Studies

Background/Objectives: The antinociceptive and anti-inflammatory effects of a patent-pending ointment containing plant extracts from Eucalyptus globulus, Curcuma longa, Hamamelis virginiana, Echinacea purpurea, and Zingiber officinale were evaluated. Methods: Plant extracts were chemically characterized by gas chromatography-mass spectroscopy. The antinociceptive activity of the ointment was assessed using the hot plate, tail flick, and formalin tests, whereas the anti-inflammatory activity was measured using the acute and chronic TPA-induced ear edema tests. Mechanisms of action were evaluated using inhibitors from signaling pathways related to pain response and by using histological analysis and assessing the expression and activity of pro-inflammatory mediators. Results: The ointment showed antinociceptive and anti-inflammatory effects like those observed with diclofenac gel (1.16% v/v) and ketoprofen gel (2.5% v/v). The antinociceptive actions of the ointment are mediated by the possible participation of the opiodergic system and the nitric oxide pathway. The anti-inflammatory response was characterized by a decrease in myeloperoxidase (MPO) activity and by a reduction in ear swelling and monocyte infiltration in the acute inflammation model. In the chronic model, the mechanism of action relied on a decrease in pro-inflammatory mediators such as COX-2, IL-1β, TNF-α, and MPO. An in-silico study with myristic acid, one of the compounds identified in the ointment's plant mixture, corroborated the in vivo results. Conclusions: The ointment showed antinociceptive activities mediated by the decrease in COX-2 and NO levels, and anti-inflammatory activity due to the reduction in IL-1β and TNFα levels, a reduction in MPO activity, and a decrease in NF-κB and COX-2 expression.

Anti-inflammatory effects of α-humulene on the release of pro-inflammatory cytokines in lipopolysaccharide-induced THP-1 cells

While acute inflammation is an essential physical response to harmful external influences, the transition to chronic inflammation is problematic and associated with the development and worsening of many deadly diseases. Until now, established pharmaceutical agents have had many side effects when used for long periods. In this study, a possible anti-inflammatory effect of the sesquiterpene α-humulene on lipopolysaccharide (LPS) induction was tested. Herein, human THP-1-derived macrophages were used and their pro-inflammatory interleukin-6 (IL-6), tumor necrosis factor alpha (TNF-α), and interleukin-1β (IL-1β) cytokine release was measured by means of enzyme-linked immunosorbent assay. A dose-dependent effect of α-humulene on IL-6 release was observed at 0.5 and 100 µM α-humulene, with a maximum IL-6 inhibition of 60% compared to the LPS reference value after the addition of 100 µM α-humulene. TNF-α as well as IL-1β cytokine concentrations were not reduced by the addition of 0.5 and 100 µM α-humulene. This study suggests that α-humulene has potential as a promising natural alternative to established pharmaceuticals for the treatment of elevated IL-6 levels and chronic inflammation in humans.

Cardamom consumption may improve cardiovascular metabolic biomarkers in adults: A systematic review and meta-analysis of randomized controlled trials

The bioactive compounds in cardamom have been found to enhance cardiovascular health by improving blood lipids and inflammation. We hypothesized that cardamom consumption might ameliorate cardiovascular metabolic biomarkers in adults; however, there is still debate regarding its impact on cardiac metabolism. This research was therefore designed to determine if cardamom consumption had a favorable impact on lipid profiles, inflammatory markers, and oxidative stress indices as they related to cardiovascular diseases. A comprehensive search was conducted through PubMed, Scopus, Embase, Web of Science, and the Cochrane Library on July 4, 2023. Using a random-effects model pooled the weighted mean difference (WMD) and 95% confidence interval (CI). The final 12 trials containing 989 participants were included. The results illustrated that cardamom consumption could improve total cholesterol (WMD = -8.56 mg/dL; 95% CI, -14.90 to -2.22), triglycerides (WMD = -14.09 mg/dL; 95% CI, -24.01 to -4.17), high-sensitivity C-reactive protein (WMD = -1.01 ng/mL; 95% CI, -1.81 to -0.22), and interleukin-6 (WMD = -1.81 pg/mL; 95% CI, -3.06 to -0.56). However, it did not have significant influences on high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and some indicators of oxidative stress. In conclusion, cardamom consumption can improve specific cardiovascular metabolic biomarkers and potentially confer protective effects on cardiovascular health. However, more large-scale clinical research with better designs would further validate the findings, which will offer substantial evidence of cardamom as nutritional and functional products.

Identification of CD8 T-cell dysfunction associated with symptoms in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and Long COVID and treatment with a nebulized antioxidant/anti-pathogen agent in a retrospective case series

Background

Patients with post-acute sequelae of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection (PASC, i.e., Long COVID) have a symptom complex highly analogous to many features of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), suggesting they may share some aspects of pathogenesis in these similar disorders. ME/CFS is a complex disease affecting numerous organ systems and biological processes and is often preceded by an infection-like episode. It is postulated that the chronic manifestations of illness may result from an altered host response to infection or inability to resolve inflammation, as is being reported in Long COVID. The immunopathogenesis of both disorders is still poorly understood. Here, we show data that suggest Long COVID and ME/CFS may be due to an aberrant response to an immunological trigger-like infection, resulting in a dysregulated immune system with CD8 T-cell dysfunction reminiscent of some aspects of T-cell clonal exhaustion, a phenomenon associated with oxidative stress. As there is an urgent need for diagnostic tools and treatment strategies for these two related disabling disorders, here, in a retrospective case series, we have also identified a potential nebulized antioxidant/anti-pathogen treatment that has evidence of a good safety profile. This nebulized agent is comprised of five ingredients previously reported individually to relieve oxidative stress, attenuate NF-κB signaling, and/or to act directly to inhibit pathogens, including viruses. Administration of this treatment by nebulizer results in rapid access of small doses of well-studied antioxidants and agents with anti-pathogen potential to the lungs; components of this nebulized agent are also likely to be distributed systemically, with potential to enter the central nervous system.

Methods

and Findings: We conducted an analysis of CD8 T-cell function and severity of symptoms by self-report questionnaires in ME/CFS, Long COVID and healthy controls. We developed a CD8 T-cell functional assay, assessing CD8 T-cell dysfunction by intracellular cytokine staining (ICS) in a group of ME/CFS (n = 12) and Long COVID patients (n = 8), comparing to healthy controls (HC) with similar age and sex (n = 10). Magnet-enriched fresh CD8 T-cells in both patient groups had a significantly diminished capacity to produce both cytokines, IFNγ or TNFα, after PMA stimulation when compared to HC. The symptom severity questionnaire showed similar symptom profiles for the two disorders. Fortuitously, through a retrospective case series, we were able to examine the ICS and questionnaire data of 4 ME/CFS and 4 Long COVID patients in conjunction with their treatment (3-15 months). In parallel with the treatment pursued electively by participants in this retrospective case series, there was an increase in CD8 T-cell IFNγ and TNFα production and a decrease in overall self-reported symptom severity score by 54%. No serious treatment-associated side effects or laboratory anomalies were noted in these patients.

Conclusions

Here, in this small study, we present two observations that appear potentially fundamental to the pathogenesis and treatment of Long COVID and ME/CFS. The first is that both disorders appear to be characterized by dysfunctional CD8 T-cells with severe deficiencies in their abilities to produce IFNγ and TNFα. The second is that in a small retrospective Long COVID and ME/CFS case series, this immune dysfunction and patient health improved in parallel with treatment with an immunomodulatory, antioxidant pharmacological treatment with anticipated anti-pathogen activity. This work provides evidence of the potential utility of a biomarker, CD8 T-cell dysfunction, and suggests the potential for benefit from a new nebulized antioxidant/anti-pathogen treatment. These immune biomarker data may help build capacity for improved diagnosis and tracking of treatment outcomes during clinical trials for both Long COVID and ME/CFS while providing clues to new treatment avenues that suggest potential efficacy for both conditions.

E. globulus leaf EO exhibits anti-inflammatory effects by regulating GSDMD-mediated pyroptosis, thereby alleviating neurological impairment and neuroinflammation in experimental stroke mice

ETHNOPHARMACOLOGICAL RELEVANCE

Aromatic and medicinal plants continue to be a major component of alternative and traditional medicine in the developing countries. Eucalyptus globulus (Labill.) is being employed to cultivation and production in China. However, few studies have reported the chemical composition and anti-inflammatory activity of Eucalyptus globulus (Labill.) leaf essential oil (E. globulus leaf EO) extracted from Eucalyptus globulus.

AIM OF THE STUDY

This study aimed to assess the composition of E. globulus leaf EO and identify its bacteriostatic action as well as anti-inflammatory activity. Importantly, we evaluated the effect of E. globulus leaf EO on neurological impairment and neuroinflammation in experimental stroke mice.

MATERIALS AND METHODS

Gas Chromatography-Mass Spectrometer (GC-MS) analyses was employed to evaluate the chemical components of E. globulus leaf EO, and the relative content of each component was determined by area normalization method. The antimicrobial activity of E. globulus leaf EO was determined by Oxford cup method and microbroth dilution assay. Cytotoxic activity of E. globulus leaf EO on THP-1 cells or BV2 cells in vitro was determined by CCK8 assay. In addition, the lipopolysaccharide (LPS)/ATP-induced inflammation model in THP-1 cells or BV2 cells were established, and the relative expression of TNF-α, IL-1β, MCP-1and IL-6 were confirmed by RT-PCR. Furthermore, the expression of protein GSDMD, IL-lβ, NLRP3 and NFκB signaling pathway were assessed by immunoblotting. In vivo,the experimental stroke model constructed by middle cerebral artery occlusion/reperfusion (MCAO/R) in mice was employed and subsequently treated with E. globulus leaf EO (50,100 mg/kg, subcutaneous injection) for 3 days to assess neurological impairment and neuroinflammation. Behavioral and neuronal damage were assessed using grip strength test, rod trarod test, and Nissl staining. Pro-inflammatory factors in serum or ischemic brain tissue was detected by ELISA kits.

RESULTS

GC-MS analyses revealed that the major compound in E. globulus leaf EO was eudesmol (71.967%). E. globulus leaf EO has antimicrobial activity against Staphylococcus aureus (gram positive bacteria, MIC = 0.0625 mg/mL), Escherichia coli (gram negative bacteria, MIC = 1 mg/mL), and Candida albicans (MIC = 4 mg/mL). E. globulus leaf EO (0.5312, 1.0625, and 2.15 mg/mL) significantly decreased the expression of inflammation-related genes, including IL-1β, TNF-α, MCP-1, and IL-6. Furthermore, reduced levels of TLR4, Myd88, phosphorylated NF-κB P65, and IκBα were found in the E. globulus leaf EO group for BV2 cells (1.025, and 2.125 mg/mL). In addition, the expression levels of GSDMD, NLRP3, IL-1β and AIM2 were significantly decreased in the E. globulus leaf EO group when compared with the LPS -stimulated group, regulating GSDMD-mediated pyroptosis. In vivo, E. globulus leaf EO improved neurological functional deficits, inhibited excessive activation of microglia, and reduced the secretion of pro-inflammatory factors IL-1β, TNF-α in the ischemic tissue and serum after MCAO/R.

CONCLUSION

E. globulus leaf EO has strong antibacterial and anti-inflammatory activity, which has been implicated in blocking GSDMD-mediated pyroptosis. Moreover, E. globulus leaf EO could exert neuroprotective effect on cerebral ischemia-reperfusion injury.

1,8-cineole (eucalyptol): A versatile phytochemical with therapeutic applications across multiple diseases

1,8-cineole (Eucalyptol), a naturally occurring compound derived from botanical sources such as eucalyptus, rosemary, and camphor laurel, has a long history of use in traditional medicine and exhibits an array of biological properties, including anti-inflammatory, antioxidant, antimicrobial, bronchodilatory, analgesic, and pro-apoptotic effects. Recent evidence has also indicated its potential role in managing conditions such as Alzheimer's disease, neuropathic pain, and cancer. This review spotlights the health advantages of 1,8-cineole, as demonstrated in clinical trials involving patients with respiratory disorders, including chronic obstructive pulmonary disease, asthma, bronchitis, and rhinosinusitis. In addition, we shed light on potential therapeutic applications of 1,8-cineole in various conditions, such as depression, epilepsy, peptic ulcer disease, diarrhea, cardiac-related heart diseases, and diabetes mellitus. A comprehensive understanding of 1,8-cineole's pharmacodynamics and safety aspects as well as developing effective formulations, might help to leverage its therapeutic value. This thorough review sets the stage for future research on diverse health benefits and potential uses of 1,8-cineole in tackling complex medical conditions.

1,8-cineole ameliorates colon injury by downregulating macrophage M1 polarization via inhibiting the HSP90-NLRP3-SGT1 complex

Ulcerative colitis (UC) is characterized by chronic relapsing intestinal inflammation. Currently, there is no effective treatment for the disease. According to our preliminary data, 1,8-cineole, which is the main active compound of Amomum compactum Sol. ex Maton volatile oil and an effective drug for the treatment of pneumonia, showed remarkable anti-inflammatory effects on colitis pathogenesis. However, its mechanism of action and direct targets remain unclear. This study investigated the direct targets and mechanism through which 1,8-cineole exerts its anti-inflammatory effects using a dextran sulfate sodium salt-induced colitis mouse model. The effects of 1,8-cineole on macrophage polarization were investigated using activated bone marrow-derived macrophages and RAW264.7 cells. In addition, 1,8-cineole targets were revealed by drug affinity responsive target stability, thermal shift assay, cellular thermal shift assay, and heat shock protein 90 (HSP90) adenosine triphosphatases (ATPase) activity assays. The results showed that 1,8-cineole exhibited powerful anti-inflammatory properties in vitro and in vivo by inhibiting the macrophage M1 polarization and protecting intestinal barrier function. Mechanistically, 1,8-cineole directly interacted with HSP90 and decreased its ATPase activity, also inhibited nucleotide-binding and oligomerization domain-, leucine rich repeat-, and pyrin domain-containing 3 (NLRP3) binding to HSP90 and suppressor of G-two allele of SKP1 (SGT1) and suppressed NLRP3 inflammasome activation in macrophages. These results demonstrated that 1,8-cineole is a potential drug candidate for UC treatment.

How to Naturally Support the Immune System in Inflammation-Essential Oils as Immune Boosters

Efficient functionality of the immune system is needed to fight against the development of infectious diseases, including, among others, serious recurrent chronic infections. Research has shown that many modern common diseases, such as inflammatory bowel diseases and cardiovascular diseases, e.g., thromboembolism, cancer, obesity, or depression, are connected with inflammatory processes. Therefore, new, good stimulators of the immune system's response are sought. They include synthetic compounds as well as biological preparations such as lipopolysaccharides, enzymes, bacterial metabolites, and secondary metabolites of plants, demonstrating a multidirectional effect. Essential oils are characterized by many invaluable activities, including antimicrobial, antioxidant, anti-inflammatory, and immunostimulating. Essential oils may stimulate the immune system via the utilization of their constituents, such as antibodies, cytokines, and dendritic cells. Some essential oils may stimulate the proliferation of immune-competent cells, including polymorphonuclear leukocytes, macrophages, dendritic cells, natural killer cells, and B and T lymphocytes. This review is focused on the ability of essential oils to affect the immune system. It is also possible that essential oil components positively interact with recommended anti-inflammatory and antimicrobial drugs. Thus, there is a need to explore possible synergies between essential oils and their active ingredients for medical use.

1,8-Cineole ameliorates diabetic retinopathy by inhibiting retinal pigment epithelium ferroptosis via PPAR-γ/TXNIP pathways

1,8-Cineole, the main component of volatile oil in aromatic plants, has diverse pharmacological properties, including antioxidant, anti-inflammatory, and anti-cancer properties. Diabetic retinopathy (DR) is a common microvascular complication of diabetes mellitus (DM). Here, we investigated the protective effect of 1,8-cineole on DR and found that 1,8-cineole treatment could alter the expression of several genes in both high glucose (HG)-induced ARPE-19 cells and retinal tissues of DM mice, as well as inhibit ferroptosis. Subsequent investigations into the molecular mechanisms underlying this inhibition revealed that expression of thioredoxin-interacting protein (TXNIP) was significantly upregulated while that of peroxisome proliferator-activated receptor γ (PPAR-γ) was significantly downregulated in HG-induced ARPE-19 cells, and treatment with 1,8-cineole could effectively reverse these changes. Treatment with a PPAR-γ pharmacological agonist (rosiglitazone), alone or combined with 1,8-cineole, significantly inhibited the transcription of TXNIP and ferroptosis in HG-induced ARPE-19 cells. Conversely, pretreatment with GW9662, a PPAR-γ inhibitor, upregulated the transcription and expression of TXNIP in HG-induced ARPE-19 cells; 1,8-cineole failed to reverse this upregulated expression. To explore these relationships, we constructed a PPAR-γ adenovirus shRNA to elucidate the effect of 1,8-cineole on the negative regulation of TXNIP by PPAR-γ. Taken together, the present findings indicate that HG-induced ferroptosis in retinal tissue plays an essential role in the pathogenesis of DR, which can be ameliorated by 1,8-cineole.

Potential Application of the Plant-Derived Essential Oils for Atherosclerosis Treatment: Molecular Mechanisms and Therapeutic Potential

Essential oils (EOs) are complex secondary metabolites identified in many plant species. Plant-derived EOs have been widely used in traditional medicine for centuries for their health-beneficial effects. Some EOs and their active ingredients have been reported to improve the cardiovascular system, in particular to provide an anti-atherosclerotic effect. The objective of this review is to highlight the recent research investigating the anti-inflammatory, anti-oxidative and lipid-lowering properties of plant-derived EOs and discuss their mechanisms of action. Also, recent clinical trials exploring anti-inflammatory and anti-oxidative activities of EOs are discussed. Future research on EOs has the potential to identify new bioactive compounds and invent new effective agents for treatment of atherosclerosis and related diseases such as diabetes, metabolic syndrome and obesity.

Immunomodulatory effects and mechanisms of the extracts and secondary compounds of Zingiber and Alpinia species: a review

Zingiber and Alpinia species (family: Zingiberaceae) are popularly used in food as spices and flavoring agents and in ethnomedicine to heal numerous diseases, including immune-related disorders. However, their ethnomedicinal uses have not been sufficiently supported by scientific investigations. Numerous studies on the modulating effects of plants and their bioactive compounds on the different steps of the immune system have been documented. This review aimed to highlight up-to-date research findings and critically analyze the modulatory effects and mechanisms of the extracts and secondary compounds of several Zingiber and Alpinia species, namely, Zingiber officinale Roscoe, Z. cassumunar Roxb., Z. zerumbet (L.) Roscoe ex Sm., Alpinia galanga Linn., A. conchigera Griff, A. katsumadai Hayata, A. oxyphylla Miq., A. officinarum Hance, A. zerumbet (Pers.) Burtt. et Smith, and A. purpurata (Viell.) K. Schum. on the immune system, particularly via the inflammation-related signaling pathways. The immunomodulating activities of the crude extracts of the plants have been reported, but the constituents contributing to the activities have mostly not been identified. Among the extracts, Z. officinale extracts were the most investigated for their in vitro, in vivo, and clinical effects on the immune system. Among the bioactive metabolites, 6-, 8-, and 10-gingerols, 6-shogaol, and zerumbone from Zingiber species and cardamomin, 1'-acetoxychavicol acetate, yakuchinone, rutin, 1,8-cineole, and lectin from Alpinia species have demonstrated strong immunomodulating effects. More experimental studies using cell and animal models of immune-related disorders are necessary to further understand the underlying mechanisms, together with elaborate preclinical pharmacokinetics, pharmacodynamics, bioavailability, and toxicity studies. Many of these extracts and secondary metabolites are potential candidates for clinical development in immunomodulating agents or functional foods to prevent and treat chronic inflammatory disorders.

Modes of Action of 1,8-Cineol in Infections and Inflammation

The monoterpene 1,8-Cineol is a natural plant-based therapeutic agent that is commonly applied to treat different inflammatory diseases due to its mucolytic, anti-microbial and anti-inflammatory properties. It has become increasingly clear in the recent years that 1,8-Cineol spreads almost everywhere in the human body after its oral administration, from the gut to the blood to the brain. Its anti-microbial potential and even its anti-viral effects have been observed to include numerous bacteria and fungi species. Many recent studies help to better understand the cellular and molecular immunological consequences of 1,8-Cineol treatment in inflammatory diseases and further provide information concerning the mechanistic modes of action in the regulation of distinct inflammatory biosynthetic pathways. This review aims to present a holistic and understandable overview of the different aspects of 1,8-Cineol in infections and inflammation.

Phytochemicals in the treatment of inflammation-associated diseases: the journey from preclinical trials to clinical practice

Advances in biomedical research have demonstrated that inflammation and its related diseases are the greatest threat to public health. Inflammatory action is the pathological response of the body towards the external stimuli such as infections, environmental factors, and autoimmune conditions to reduce tissue damage and improve patient comfort. However, when detrimental signal-transduction pathways are activated and inflammatory mediators are released over an extended period of time, the inflammatory process continues and a mild but persistent pro-inflammatory state may develop. Numerous degenerative disorders and chronic health issues including arthritis, diabetes, obesity, cancer, and cardiovascular diseases, among others, are associated with the emergence of a low-grade inflammatory state. Though, anti-inflammatory steroidal, as well as non-steroidal drugs, are extensively used against different inflammatory conditions, they show undesirable side effects upon long-term exposure, at times, leading to life-threatening consequences. Thus, drugs targeting chronic inflammation need to be developed to achieve better therapeutic management without or with a fewer side effects. Plants have been well known for their medicinal use for thousands of years due to their pharmacologically active phytochemicals belonging to diverse chemical classes with a number of these demonstrating potent anti-inflammatory activity. Some typical examples include colchicine (alkaloid), escin (triterpenoid saponin), capsaicin (methoxy phenol), bicyclol (lignan), borneol (monoterpene), and quercetin (flavonoid). These phytochemicals often act via regulating molecular mechanisms that synergize the anti-inflammatory pathways such as increased production of anti-inflammatory cytokines or interfere with the inflammatory pathways such as to reduce the production of pro-inflammatory cytokines and other modulators to improve the underlying pathological condition. This review describes the anti-inflammatory properties of a number of biologically active compounds derived from medicinal plants, and their mechanisms of pharmacological intervention to alleviate inflammation-associated diseases. The emphasis is given to information on anti-inflammatory phytochemicals that have been evaluated at the preclinical and clinical levels. Recent trends and gaps in the development of phytochemical-based anti-inflammatory drugs have also been included.

Molecular Docking Identifies 1,8-Cineole (Eucalyptol) as A Novel PPARγ Agonist That Alleviates Colon Inflammation

Inflammatory bowel disease, comprising Crohn's disease (CD) and ulcerative colitis (UC), is often debilitating. The disease etiology is multifactorial, involving genetic susceptibility, microbial dysregulation, abnormal immune activation, and environmental factors. Currently, available drug therapies are associated with adverse effects when used long-term. Therefore, the search for new drug candidates to treat IBD is imperative. The peroxisome proliferator-activated receptor-γ (PPARγ) is highly expressed in the colon. PPARγ plays a vital role in regulating colonic inflammation. 1,8-cineole, also known as eucalyptol, is a monoterpene oxide present in various aromatic plants which possess potent anti-inflammatory activity. Molecular docking and dynamics studies revealed that 1,8-cineole binds to PPARγ and if it were an agonist, that would explain the anti-inflammatory effects of 1,8-cineole. Therefore, we investigated the role of 1,8-cineole in colonic inflammation, using both in vivo and in vitro experimental approaches. Dextran sodium sulfate (DSS)-induced colitis was used as the in vivo model, and tumor necrosis factor-α (TNFα)-stimulated HT-29 cells as the in vitro model. 1,8-cineole treatment significantly decreased the inflammatory response in DSS-induced colitis mice. 1,8-cineole treatment also increased nuclear factor erythroid 2-related factor 2 (Nrf2) translocation into the nucleus to induce potent antioxidant effects. 1,8-cineole also increased colonic PPARγ protein expression. Similarly, 1,8-cineole decreased proinflammatory chemokine production and increased PPARγ protein expression in TNFα-stimulated HT-29 cells. 1,8-cineole also increased PPARγ promoter activity time-dependently. Because of its potent anti-inflammatory effects, 1,8-cineole may be valuable in treating IBD.

Advances in the Phytochemical Characterisation and Bioactivities of Salvia aurea L. Essential Oil

The Salvia L. genus (Lamiaceae) is largely used in the pharmaceutical and food industry. Several species of biological relevance are extensively employed in traditional medicine, including Salvia aurea L. (syn. S. africana-lutea L.), which is used as a traditional skin disinfectant and in wounds as a healing remedy; nevertheless, these properties have not been validated yet. The aim of the present study is to characterise S. aurea essential oil (EO), unveiling its chemical composition and validating its biological properties. The EO was obtained by hydrodistillation and subsequently analysed by GC-FID and GC-MS. Different biological activities were assessed: the antifungal effect on dermatophytes and yeasts and the anti-inflammatory potential by evaluating nitric oxide (NO) production and COX-2 and iNOS protein levels. Wound-healing properties were assessed using the scratch-healing test, and the anti-aging capacity was estimated through the senescence-associated beta-galactosidase activity. S. aurea EO is mainly characterised by 1,8-cineole (16.7%), β-pinene (11.9%), cis-thujone (10.5%), camphor (9.5%), and (E)-caryophyllene (9.3%). The results showed an effective inhibition of the growth of dermatophytes. Furthermore, it significantly reduced protein levels of iNOS/COX-2 and simultaneously NO release. Additionally, the EO exhibited anti-senescence potential and enhanced wound healing. Overall, this study highlights the remarkable pharmacological properties of Salvia aurea EO, which should be further explored in order to develop innovative, sustainable, and environmentally friendly skin products.

Chemical Composition and Antimicrobial Potential of a Plant-Based Substance for the Treatment of Seborrheic Dermatitis

Seborrheic dermatitis (SD) is the most prevalent dermatological disease, occurring in up to 50% of newborns, children, and adults around the world. The antibacterial and antifungal resistance contributed to the search for new natural substances and the development of a novel substance based on Melaleuca alternifolia (M. alternifolia) leaf oil (TTO), 1,8-cineole (eucalyptol), and α-(-)-bisabolol. Thus, this work aimed to determine the chemical composition of the novel plant-based substance and to evaluate its antimicrobial activity against standard microorganisms involved in the pathogenesis of SD. Moreover, the chemical composition of the substance was analyzed by gas chromatography coupled with mass spectrometry (GC/MS). Staphylococcus epidermidis (S. epidermidis), Staphylococcus aureus (S. aureus), Micrococcus luteus (M. luteus), and Candida albicans (C. albicans) were used for antimicrobial and antifungal assays by means of the broth microdilution method to determine the minimal inhibitory concentration (MIC). Finally, the substance’s ability to inhibit Malassezia furfur (M. furfur) was evaluated. Eighteen compounds from different chemical groups were identified by GC/MS. The major biologically active compounds of the substance were terpinen-4-ol (20.88%), 1,8-cineole (22.28%), (-)-α-bisabolol (25.73%), and o-cymene (8.16%). The results showed that the substance has a synergistic antimicrobial and antifungal activity, while S. epidermidis and C. albicans strains were the most susceptible. Furthermore, the substance inhibited M. furfur, which is a main pathogen involved in the pathogenesis of SD and clinical manifestations. It can be concluded that the novel plant-based substance has a promising potential against M. furfur and scalp commensal bacteria and may be helpful for the development of new drugs for treatment of dandruff and SD.

Natural Monoterpenes as Potential Therapeutic Agents against Atherosclerosis

Traditional herbal medicines based on natural products play a pivotal role in preventing and managing atherosclerotic diseases, which are among the leading causes of death globally. Monoterpenes are a large class of naturally occurring compounds commonly found in many aromatic and medicinal plants. Emerging evidence has shown that monoterpenes have many biological properties, including cardioprotective effects. Remarkably, an increasing number of studies have demonstrated the therapeutic potential of natural monoterpenes to protect against the pathogenesis of atherosclerosis. These findings shed light on developing novel effective antiatherogenic drugs from these compounds. Herein, we provide an overview of natural monoterpenes' effects on atherogenesis and the underlying mechanisms. Monoterpenes have pleiotropic and multitargeted pharmacological properties by interacting with various cell types and intracellular molecular pathways involved in atherogenesis. These properties confer remarkable advantages in managing atherosclerosis, which has been recognized as a multifaceted vascular disease. We also discuss limitations in the potential clinical application of monoterpenes as therapeutic agents against atherosclerosis. We propose perspectives to give new insights into future preclinical research and clinical practice regarding natural monoterpenes.

Chemical Profile, Anti-Microbial and Anti-Inflammaging Activities of Santolina rosmarinifolia L. Essential Oil from Portugal

Fungal infections and the accompanying inflammatory responses are associated with great morbidity and mortality due to the frequent relapses triggered by an increased resistance to antifungal agents. Furthermore, this inflammatory state can be exacerbated during inflammaging and cellular senescence. Essential oils (EO) are receiving increasing interest in the field of drug discovery due to their lipophilic nature and complex composition, making them suitable candidates in the development of new antifungal drugs and modulators of numerous molecular targets. This work chemically characterized the EO from Santolina rosmarinifolia L., collected in Setúbal (Portugal), and assessed its antifungal potential by determining its minimum inhibitory (MIC) and minimum lethal (MLC) concentration in accordance with the Clinical Laboratory Standard Guidelines (CLSI) guidelines, as well as its effect on several Candida albicans virulence factors. The anti-inflammatory effect was unveiled using lipopolysaccharide (LPS)-stimulated macrophages by assessing several pro-inflammatory mediators. The wound healing and anti-senescence potential of the EO was also disclosed. The EO was mainly characterized by β-pinene (29.6%), borneol (16.9%), myrcene (15.4%) and limonene (5.7%). It showed a strong antifungal effect against yeasts and filamentous fungi (MIC = 0.07-0.29 mg/mL). Furthermore, it inhibited dimorphic transition (MIC/16), decreased biofilm formation with a preeminent effect after 24 h (MIC/2) and disrupted preformed biofilms in C. albicans. Additionally, the EO decreased nitric oxide (NO) release (IC₅₀ = 0.52 mg/mL) and pro-IL-1β and inducible nitric oxide synthase (iNOS) expression in LPS-stimulated macrophages, promoted wound healing (91% vs. 81% closed wound) and reduced cellular senescence (53% vs. 73% β-galactosidase-positive cells). Overall, this study highlights the relevant pharmacological properties of S. rosmarinifolia, opening new avenues for its industrial exploitation.

Chemical composition, antioxidant and anti-inflammatory properties of Monarda didyma L. essential oil

In the present study, Monarda didyma L. essential oil (isolated from the flowering aerial parts of the plant) was examined to characterize its chemotype and to evaluate, in addition to the quali-quantitative chemical analysis, the associated antioxidant and anti-inflammatory activities. The plants were grown in central Italy, Urbino (PU), Marche region. Different analyses (TLC, GC-FID, GC-MS and ¹H-NMR) allowed the identification of twenty compounds among which carvacrol, p-cymene and thymol were the most abundant. On this basis, the chemotype examined in the present study was indicated as Monarda didyma ct. carvacrol. The antioxidant effect was assessed by DPPH assay. Moreover, this chemotype was investigated for the anti-inflammatory effect in an in vitro setting (i.e., LPS-stimulated U937 cells). The decreased expression of pro-inflammatory cytokine IL-6 and the increased expression of miR-146a are suggestive of the involvement of the Toll-like receptor-4 signaling pathway. Although further studies are needed to better investigate the action mechanism/s underlying the results observed in the experimental setting, our findings show that M. didyma essential oil is rich in bioactive compounds (mainly aromatic monoterpenes and phenolic monoterpenes) which are most likely responsible for its beneficial effect.

Effects of Dietary 1,8-Cineole Supplementation on Growth Performance, Antioxidant Capacity, Immunity, and Intestine Health of Broilers

This study was conducted to investigate the effects of 1,8-cineole on antioxidant capacity, immunity, and intestinal health of broilers. A total of 540 1-day-old Arbor Acres (AA) male broilers were randomly divided into five treatments with six replicates per treatment, and 18 broilers per replicate for 42 days. Dietary treatments were a corn−soybean meal basal diet supplemented with 0, and 10, 20, 30, and 40 mg/kg 1,8-cineole, respectively. Dietary supplementation with 20~30 mg/kg of 1,8-cineole increased the ADG from d 22 to 42 and d 1 to 42 (p < 0.05), and decreased the FCR (p < 0.05). Dietary supplementation of 10~40 mg/kg of 1,8-cineole increased total antioxidant capacity (TAOC) in serum (p < 0.05), and decreased malondialdehyde (MDA) level in the liver on day 21 (p < 0.05). The supplementation of 20~30 mg/kg of 1,8-cineole increased the activity of total superoxide dismutase (T-SOD) in the serum and liver and TAOC in the serum and the liver (p < 0.05), and decreased the level of MDA in the serum and the liver (p < 0.05) on day 42. Dietary supplementation with 20~30 mg/kg of 1,8-cineole increased serum immunoglobulin A, immunoglobulin G, and immunoglobulin M contents on day 21 (p < 0.05). On day 21, dietary supplementation of 20~30 mg/kg of 1,8-cineole increased the VH and VH/CD (p < 0.05) in the jejunum and ileum. The supplementation of 20~30 mg/kg of 1,8-cineole increased the content of secretory immunoglobulin A in the duodenum and ileum mucosa on d 42 (p < 0.05). In conclusion, dietary supplementation of 1,8-cineole improves the growth performance of broilers by enhancing antioxidant capacity, immunity, and intestinal morphology.

Classification of Japanese Pepper (Zanthoxylum piperitum DC.) from Different Growing Regions Based on Analysis of Volatile Compounds and Sensory Evaluation

The Japanese pepper (Zanthoxylum piperitum DC.) is an attractive plant that is highly palatable and benefits human health. There are several lineages of pepper plants in Japan. However, the classification of each lineage by analyzing its volatile compounds and studies on the effects of differences in volatile compounds on human flavor perception have not been performed in detail. Herein, we conducted gas chromatography (GC) and GC/mass spectrometry (GC/MS) analysis of volatile compounds and sensory evaluation of flavor by an analytical panel using 10 commercially available dry powdered Japanese pepper products from different regions. GC and GC/MS analysis detected limonene, β-phellandrene, citronellal, and geranyl acetate as the major volatile compounds of Japanese peppers. The composition of volatile compounds showed different characteristics depending on the growing regions, and cluster analysis of composition classified the products into five groups. The sensory evaluation classified the products into four groups, and the results of both classifications were in good agreement. Our results provide an important basis for proposing cooking and utilization methods that take advantage of the unique characteristics of each lineage based on scientific evidence.

Cineole alleviates the BPA-inhibited NETs formation by regulating the p38 pathway-mediated programmed cell death

Bisphenol A (BPA) is an endocrine disruptor, that can cause immune dysfunction. Cineole (CIN) has that effect of regulating immune function and resist oxidation. Neutrophil extracellular traps (NETs) are one of the ways to resist pathogen invasion. In order to explore the effects of BPA and CIN on the release of chicken NETs and the antagonistic effect of CIN, take chicken peripheral blood neutrophils as object of study, grouping as NC, CIN, BPA + CIN and BPA. SEM, flow cytometry, RT-PCR, Western-blot and other methods were used to detect related indicators. The results showed that BPA inhibited the activities of GPX, SOD and CAT, increased the contents of MDA and NO, increased the activity of iNOS. BPA exposure inhibited the expression of myeloperoxidase (MPO), neutrophil elastase (NE) and histone, and inhibited the release of NETs. BPA activated downstream apoptosis and necroptosis through the p38 mitogen-activated protein kinase (p38-MAPK) pathway, which increased the expression of cytochrome C (CytC), bcl-2 associated K protein gene (bak), cysteinyl aspartate specific proteinase 3 (caspase-3), cysteinyl aspartate specific proteinase 9 (caspase-9), receptor-interacting protein kinase 1 (RIPK1), receptor-interacting protein kinase 1 (RIPK3) and mixed lineage kinase domain-like protein (MLKL), decreased the expression of B-cell lymphoma-2 (bcl-2). However, the co-exposure of CIN and BPA partially recovered the release of NETs, alleviated BPA-induced oxidative stress, and inhibited the activation of p38-MAPK pathway, necroptosis, and mitochondrial apoptosis pathway. These results indicated that CIN modulated p38 pathway alleviated BPA-induced neutrophil necroptosis and apoptosis, and increased NETs formation.

Essential Oil from Eucalyptus globulus (Labill.) Activates Complement Receptor-Mediated Phagocytosis and Stimulates Podosome Formation in Human Monocyte-Derived Macrophages

Eucalyptus essential oil and its major constituent eucalyptol are extensively employed in the cosmetic, food, and pharmaceutical industries and their clinical use has recently expanded worldwide as an adjuvant in the treatment of infective and inflammatory diseases. We previously demonstrated that essential oil from Eucalyptus globulus (Labill.) (EO) stimulates in vitro the phagocytic activity of human monocyte-derived macrophages and counteracts the myelotoxicity induced by the chemotherapeutic 5-fluorouracil in immunocompetent rats. Here we characterize some mechanistic aspects underlying the immunostimulatory ability exerted by EO on macrophages. The internalization of fluorescent beads, fluorescent zymosan BioParticles, or apoptotic cancer cells was evaluated by confocal microscopy. Pro-inflammatory cytokine and chemokine release was determined by flow cytometry using the BD cytometric bead array. Receptor involvement in EO-stimulated phagocytosis was assessed using complement- or IgG-opsonized zymosan particles. The localization and expression of podosome components was analyzed by confocal microscopy and western blot. The main results demonstrated that: EO-induced activation of a macrophage is ascribable to its major component eucalyptol, as recently demonstrated for other cells of innate immunity; EO implements pathogen internalization and clearance by stimulating the complement receptor-mediated phagocytosis; EO stimulates podosome formation and increases the expression of podosome components. These results confirm that EO extract is a potent activator of innate cell-mediated immunity and thereby increase the scientific evidence supporting an additional property of this plant extract besides the known antiseptic and anti-inflammatory properties.

Unravelling the Immune Modulatory Effect of Indian Spices to Impede the Transmission of COVID-19: A Promising Approach

Months after WHO declared COVID-19 as a Global Public Health Emergency of International Concern, it does not seem to be flattening the curve as we are still devoid of an effective treatment modality and vaccination is in the first phase in many countries. Amid such uncertainty, being immune is the best strategy to defend against corona attacks. As the whole world is referring back to immune-boosting traditional remedies, interest is rekindled in the Indian system of Medicine, which is gifted with an abundance of herbal medicines as well as remedies. Among them, spices (root, rhizome, seed, fruit, leaf, bud, and flower of various plants used to add taste and flavors to food) are bestowed with immense medicinal potential. A plethora of clinical as well as preclinical studies reported the effectiveness of various spices for various ailments. The potential immune-boosting properties together with their excellent safety profiles are making spices the current choice of phytoresearch as well as the immune-boosting home remedies during these sceptical times. The present review critically evaluates the immune impact of various Indian spices and their potential to tackle the novel coronavirus, with comments on the safety and toxicity aspects of spices.

Throat Spray With Blended Essential Oils Promotes Healthy Lung Function Among Women: A Randomized, Double Blinded, Placebo Controlled Clinical Trial

INTRODUCTION

There are numerous internal and external environmental threats to lung health. Compromised respiratory health can affect a person's quality of life. This clinical trial evaluated the effects of Teramune Bronchus on lung health among healthy adult women.

METHODS

The participants were women, aged 18 - 60 years old (n = 35). They sprayed either the proprietary essential oil based blended product (Teramune Bronchus) or a placebo into their throats 4-6 times per day during waking hours for 3 days. There was a baseline survey before using the spray and then follow-up data were collected at the end of day 3. The three primary outcomes for this study include a total bronchial symptom score, the chest domain in the Wisconsin Upper Respiratory Symptom Scale (WURSS), and subjective bronchial wellbeing.

RESULTS

On day 3, the bronchial health of the participants who received the throat spray had significantly larger change scores when compared those with the placebo spray. All chest-related symptoms were resolved fully by the end of the trial for the participants who used Teramune. Participants using the intervention were almost twice as likely to say they felt better and believed the product helped them achieve lung health.

CONCLUSION

This study provides evidence that the use of Teramune Bronchus supports respiratory health. Teramune Bronchus boosts respiratory health among healthy women through the use of plant-based essential oils.

Anti-inflammatory effect of lavender (Lavandula angustifolia Mill.) essential oil prepared during different plant phenophases on THP-1 macrophages

BACKGROUND

Pseudomonas aeruginosa is the most common Gram-negative bacterium associated with nosocomial respiratory infections. Lavender essential oil is mainly used in aromatherapy, but it has several pharmacological and therapeutic properties. Furthermore, it possesses antifungal and antibacterial activities. The anti-inflammatory activity of essential oils may depend on the composition and the ratio of the compounds. The constitution of the essential oils extracted from the different stages of flowering period varies, which makes it plausible that the collection time of the flowers influences the anti-inflammatory effects. Different types of essential oils reduce inflammation acting similarly by modulating the activity and action of the NFκB signalling pathway, which is the major regulator of the transcription of pro-inflammatory cytokines.

METHODS

Lavender essential oils were distilled from lavender plant cultivated in Hungary and the flowers were harvested at the beginning and at the end of flowering period. The experiments were carried out on THP-1 human monocyte/macrophage cell line as in vitro cell culture model for monitoring the effects of lavender essential oils and the main compound linalool on P. aeruginosa LPS stimulated inflammation. The mRNA and protein levels of four pro-inflammatory cytokines, IL-6, IL-1β, IL-8 and TNFα were determined by Real Time PCR and ELISA measurements. The effects of essential oils were compared to the response to two NFκB inhibitors, luteolin and ACHP.

RESULTS

Linalool and lavender essential oil extracted from plants at the beginning of flowering period were successful in decreasing pro-inflammatory cytokine production following LPS pretreatment. In case of IL-8 and IL-1β lavender oil showed stronger effect compared to linalool and both of them acted similarly to NFκB inhibitors. Pretreatments with linalool and lavender essential oil/beginning of flowering period prevented pro-inflammatory cytokine production compared to LPS treatment alone. Although lavender essential oil/end of flowering period decreased IL-6, IL-1β and IL-8 mRNA expression in case of LPS pretreatment, it was not capable to reduce cytokine secretion.

CONCLUSION

Based on our results it has been proven that lavender essential oil extracted at the beginning of flowering period is a potent inhibitor of the synthesis of four pro-inflammatory cytokines IL-6, IL-8, IL-β and TNFα of THP-1 cells. This supports the relevance of the collection of the lavender flowers from early blooming period for essential oil production and for the utilization as an anti-inflammatory treatment.

1,8-Cineole: a review of source, biological activities, and application

1,8-Cineole (also known as eucalyptol) is mostly extracted from the essential oils of plants, which showed extensively pharmacological properties including anti-inflammatory and antioxidant mainly via the regulation on NF-κB and Nrf2, and was used for the treatment of respiratory diseases and cardiovascular, etc. Although various administration routes have been used in the application of 1.8-cineole, few formulations have been developed to improve its stability and bioavailability. This review retrospects the researches on the source, biological activities, mechanisms, and application of 1,8-cineole since 2000, which provides a view for the further studies on the application and formulations of 1,8-cineole.

Immunostimulant and Antidepressant Effect of Natural Compounds in the Management of Covid-19 Symptoms

In recent years, the use of natural compounds as adjuvant treatments and alternatives to traditional pharmacological therapies has become increasingly popular. These compounds have a wide range of biological effects, such as: antioxidant, anti-aging, hypocholesterolizing, hypoglycemic, antitumoral, antidepressant, anxiolytic activity, etc. Almost all of these compounds are easily available and are contained in different foods. At the end of 2019 the Coronavirus SARS-CoV-2 appeared in China and quickly spread throughout the world, causing a pandemic. The most common symptoms of this infection are dry cough, fever, dyspnea, and in severe cases bilateral interstitial pneumonia, with consequences that can lead to death. The nations, in trying to prevent the spread of infection, have imposed social distancing and lockdown measures on their citizens. This had a strong psychological-social impact, leading to phobic, anxious and depressive states. Pharmacological therapy could be accompanied by treatment with several natural compounds, such as vitamins, baicalein, zinc and essential oils. These compounds possess marked immunostimulant activity, strengthening the immune response and mitigating interactions between the virus and the host cell. They also have an antidepressant effect, acting on certain neurotransmitters.

Benefits of Cardamom (Elettaria cardamomum (L.) Maton) and Turmeric (Curcuma longa L.) Extracts for Their Applications as Natural Anti-Inflammatory Adjuvants

The genus Zingiberaceae has been widely used for phytotherapeutic purposes in traditional medicine throughout the world for its anti-inflammatory activity. Experimental studies have established that inflammation caused by chronic infections represents a risk factor for different forms of cancer. The objective of this study was focused on determining the anti-inflammatory capacity and cytotoxic activity of aqueous extracts of Elettaria cardamomum (cardamom) and Curcuma Longa (turmeric). The extracts were obtained by maceration and, through GC-MS/MS, a total of 11 different chemical components were determined in the aqueous extract of cardamom and 7 in the extract of turmeric. The main compounds found in cardamom and turmeric were α-terpinyl acetate (54.46%) and β-turmerone (33.45%), respectively. RT-qPCR results showed significantly lower gene expression levels of innate inflammatory cytokines (IL-6 and TNF-α) compared to the control (LPS). Also, it was observed that the extracts do not possess cytotoxic activity against different cell lines, where E. cardamomum showed EC₅₀ (µg/mL) of 473.84 (HeLa cells), 237.36 (J774A.1 cells), 257.51 (Vero E6 cells), and 431.16 (Balb/C peritoneal cells) and C. longa showed EC₅₀ (µg/mL) of 351.17 (HeLa cells), 430.96 (J774A.1 cells), 396.24 (Vero E6 cells), and 362.86 (Balb/C peritoneal cells). The results of this research suggest that natural extracts of E. cardamomum and C. longa possess anti-inflammatory effects and no cytotoxic activity against HeLa, J774A.1, Vero E6, and Balb/C peritoneal cell lines. Finally, it was observed that the extracts also decreased nitric oxide (NO) production in peritoneal macrophages.

Can Eucalyptol Replace Antibiotics?

One of the primary reasons for the search for new antimicrobial agents is the increasing and spreading resistance of microorganisms to previously used drugs. This is particularly important in the case of rapidly progressing infections that require the rapid administration of an appropriately selected antibiotic. However, along with the administration of antibiotics, complications in the disease-weakened body may arise in the form of systemic mycoses, viral infections, and protozoan infections. Therefore, there is an increasing interest among researchers focusing on the use of naturally occurring terpenic compounds in stand-alone or combined therapies with antibiotics. In this publication, the aim of our work is to present the results of a literature review on the antimicrobial activity of eucalyptol.

β-Caryophyllene attenuates lipopolysaccharide-induced acute lung injury via inhibition of the MAPK signalling pathway

OBJECTIVES

Acute lung injury (ALI) is a pulmonary manifestation of an acute systemic inflammatory response, which is associated with high morbidity and mortality. Accordingly, from the perspective of treating ALI, it is important to identify effective agents and elucidate the underlying modulatory mechanisms. β-Caryophyllene (BCP) is a naturally occurring bicyclic sesquiterpene that has anti-cancer and anti-inflammatory activities. However, the effects of BCP on ALI have yet to be ascertained.

METHODS

ALI was induced intratracheally, injected with 5 mg/kg LPS and treated with BCP. The bone marrow-derived macrophages (BMDMs) were obtained and cultured then challenged with 100 ng/ml LPS for 4 h, with or without BCP pre-treatment for 30 min.

KEY FINDINGS

BCP significantly ameliorates LPS-induced mouse ALI, which is related to an alleviation of neutrophil infiltration and reduction in cytokine production. In vitro, BCP was found to reduce the expression of interleukin-6, interleukin-1β and tumour necrosis factor-α, and suppresses the MAPK signalling pathway in BMDMs, which is associated with the inhibition of TAK1 phosphorylation and an enhancement of MKP-1 expression.

CONCLUSIONS

Our data indicate that BCP protects against inflammatory responses and is a potential therapeutic agent for the treatment of LPS-induced acute lung injury.

Anti-Pathogenic and Immune-Modulatory Effects of Peroral Treatment with Cardamom Essential Oil in Acute Murine Campylobacteriosis

Human infections with enteropathogenic Campylobacter jejuni (C. jejuni) including multi-drug resistant isolates are emerging worldwide. Antibiotics-independent approaches in the combat of campylobacteriosis are therefore highly desirable. Since the health-beneficial including anti-inflammatory and anti-infectious properties of cardamom have been acknowledged for long, we here addressed potential anti-pathogenic and immune-modulatory effects of this natural compound during acute campylobacteriosis. For this purpose, microbiota-depleted IL-10^-/- mice were orally infected with C. jejuni strain 81-176 and subjected to cardamom essential oil (EO) via the drinking water starting on day 2 post-infection. Cardamom EO treatment resulted in lower intestinal pathogen loads and improved clinical outcome of mice as early as day 3 post-infection. Furthermore, when compared to mock controls, cardamom EO treated mice displayed less distinct macroscopic and microscopic inflammatory sequelae on day 6 post-infection that were paralleled by lower colonic numbers of macrophages, monocytes, and T cells and diminished pro-inflammatory mediator secretion not only in the intestinal tract, but also in extra-intestinal and, remarkably, systemic organs. In conclusion, our preclinical intervention study provides the first evidence that cardamom EO comprises a promising compound for the combat of acute campylobacteriosis and presumably prevention of post-infectious morbidities.

TREM-1 promoted apoptosis and inhibited autophagy in LPS-treated HK-2 cells through the NF-κB pathway

Triggering receptor expressed by myeloid cells (TREM-1) is an amplifier of inflammatory responses triggered by bacterial or fungal infection. Soluble TREM-1 (sTREM-1) expression was found to be upregulated in sepsis-associated acute kidney injury (SA-AKI) and predicted to be a potential biomarker. However, the mechanism remains unclear. The human kidney-2 (HK-2) cell line was treated with lipopolysaccharide (LPS) and used to examine the potential roles of TREM-1 in apoptosis and autophagy. A cell viability assay was employed to assess the number of viable cells and as a measure of the proliferative index. The concentrations of sTREM-1, interleukin (IL)-1β, tumor necrosis factor-α (TNFα) and IL-6 in cell-free culture supernatants were measured by enzyme-linked immunosorbent assay (ELISA). Western blot analysis was performed to analyze apoptosis, autophagy and the relevant signaling pathways. The results suggested that TREM-1 overexpression after LPS treatment decreased proliferation and increased apoptosis. The concentrations of sTREM-1, IL-1β, TNFα and IL-6 in cell-free culture supernatants were increased in the TREM-1 overexpression group after LPS treatment. Expression of the antiapoptotic gene Bcl-2 was downregulated in the TREM-1 overexpression group, while that of the proapoptotic genes Bax, cleaved caspase-3 and cleaved caspase-9 was upregulated. Overexpression of TREM-1 downregulated expression of the autophagy genes Beclin-1, Atg-5 and LC3b and increased the gene expression of p62, which inhibits autophagy. Conversely, treatment with TREM-1-specific shRNA had the opposite effects. The nuclear factor-κB (NF-κB) signaling pathway (P-p65/p65 and P-IκBα/IκBα) in LPS-induced HK-2 cells was regulated by TREM-1. In summary, TREM-1 promoted apoptosis and inhibited autophagy in HK-2 cells in the context of LPS exposure potentially through the NF-κB pathway.

Evidence-based management of acute rhinosinusitis with herbal products

Background

The overuse of antibiotics for unjustified indications such as the management of acute uncomplicated rhinosinusitis has contributed to the emergence of antibiotic-resistant strains of bacteria and prompted the need for alternative treatments. This review assesses the quality of evidence for the management of acute rhinosinusitis with herbal products, with the goal of positioning them among other treatments and identifying future research directions. The MEDLINE database was searched for randomized controlled trials with Sinupret®, Pelargonium sidoides extract, Cyclamen europaeum (CE), cineole, and GeloMyrtol®. Searches with N-acetylcysteine and mometasone furoate nasal spray (MFNS) were performed to compare the strength of evidence of herbal products to these conventional products, which are indicated for acute rhinosinusitis.

Main body

Evidence was strongest for Sinupret, followed by Pelargonium sidoides extract. Their use in acute rhinosinusitis is supported by randomized placebo-controlled trials demonstrating both clinical efficacy and safety. Comparative data with conventional treatments such as topical glucocorticosteroids were found only for Sinupret and suggested comparable efficacy in a small study.

For other herbal products, the overall level of evidence was low. The search retrieved two small-scale placebo-controlled randomized studies with CE nasal spray. The two trials were not powered to draw conclusions about the safety and efficacy of CE nasal spray and reported a lack of efficacy with CE on symptom reduction. Only one randomized placebo-controlled trial was identified for GeloMyrtol and cineole. These suggested an improvement in acute rhinosinusitis symptoms with both products, but the results warrant replication in larger trials.

Studies directly comparing herbal products are scarce; one randomized trial has compared cineole with Sinupret, but the results need confirmation in further studies.

Studies with N-acetylcysteine are limited to small-scale clinical trials, while MFNS is supported by a strength of evidence comparable to Sinupret in this indication.

Conclusion

State-of-the-art studies demonstrating the efficacy and safety of herbal products for the management of acute rhinosinusitis are available. Given that the evidence for Sinupret is the strongest and comparable to that of a widely available topical corticosteroid, MFNS, Sinupret may be considered for the management of acute uncomplicated rhinosinusitis.

The odorant receptor OR2W3 on airway smooth muscle evokes bronchodilation via a cooperative chemosensory tradeoff between TMEM16A and CFTR

The recent discovery of sensory (tastant and odorant) G protein-coupled receptors on the smooth muscle of human bronchi suggests unappreciated therapeutic targets in the management of obstructive lung diseases. Here we have characterized the effects of a wide range of volatile odorants on the contractile state of airway smooth muscle (ASM) and uncovered a complex mechanism of odorant-evoked signaling properties that regulate excitation-contraction (E-C) coupling in human ASM cells. Initial studies established multiple odorous molecules capable of increasing intracellular calcium ([Ca2+]i) in ASM cells, some of which were (paradoxically) associated with ASM relaxation. Subsequent studies showed a terpenoid molecule (nerol)-stimulated OR2W3 caused increases in [Ca2+]i and relaxation of ASM cells. Of note, OR2W3-evoked [Ca2+]i mobilization and ASM relaxation required Ca2+ flux through the store-operated calcium entry (SOCE) pathway and accompanied plasma membrane depolarization. This chemosensory odorant receptor response was not mediated by adenylyl cyclase (AC)/cyclic nucleotide-gated (CNG) channels or by protein kinase A (PKA) activity. Instead, ASM olfactory responses to the monoterpene nerol were predominated by the activity of Ca2+-activated chloride channels (TMEM16A), including the cystic fibrosis transmembrane conductance regulator (CFTR) expressed on endo(sarco)plasmic reticulum. These findings demonstrate compartmentalization of Ca2+ signals dictates the odorant receptor OR2W3-induced ASM relaxation and identify a previously unrecognized E-C coupling mechanism that could be exploited in the development of therapeutics to treat obstructive lung diseases.

Hypericum ascyron L. extract reduces particulate matter-induced airway inflammation in mice

The consequences of increased industrialization increased the risk of asthma and breathing difficulties due to increased particulate matter in the air. We aim to investigate the therapeutic properties of Hypericum ascyron L. extract (HAE) in airway inflammation and unravel its mechanism of action. We conducted nitric oxide and cell viability assay, real-time PCR and western blot analyses along with in vitro studies. in vivo studies include a model of coal fly ash and diesel exhaust particle (CFD)-induced airway inflammation in mice. HAE reduced coal fly ash (CFA)-induced nitric oxide secretion without exhibiting cytotoxicity in MH-S cells. HAE also reduced the mRNA expression of pro-inflammatory cytokines and reduced the expression of proteins in the NFκB and MAPK pathways. In a mice model of CFD-induced airway inflammation, HAE effectively reduced neutrophil infiltration in bronchoalveolar lavage fluid (BALF) and increased the amount of T cells in the BALF, lungs, and blood while reducing all other immune cell subtypes to reduce airway inflammatory response. CXCL-1, IL-17, MIP-2, and TNF-α expression in the BALF were also reduced. HAE effectively reduced MIP-2 and TNF-α mRNA expression in the lung tissue of mice. In a nutshell, HAE is effective in preventing airway inflammation induced by CFA in MH-S cells, as well as inflammation induced by CFD in mice.

In vitro leishmanicidal activity of monoterpenes present in two species of Protium (Burseraceae) on Leishmania amazonensis

ETHNOPHARMACOLOGICAL RELEVANCE

Leishmaniasis is a neglected disease that affects millions of people around the world. Parasite resistance and the toxicity to the current treatments lead to the search for new effective molecules. Plants are widely used in traditional and indigenous medicine to treat different diseases. The oleoresin of the genus Protium, which is rich in volatile compounds active against different microorganisms, is among these plants.

AIM

The aim of this study was to evaluate the leishmanicidal potential of Protium altsonii (PaEO) and P. hebetatum (PhEO) (Burseraceae) oleoresins, as well as of three representative monoterpenes in their constitution: α-pinene, p-cymene and 1,8-cineole.

MATERIALS AND METHODS

Protium altsonii (PaEO) and P. hebetatum (PhEO) oleoresins and three of their constituents were tested in vitro on promastigotes and amastigotes-infected macrophages in different concentrations. Their toxicity for macrophages was analyzed by XTT assay and phagocytic ability. It was evaluated the ability of the compounds to induce NO production on treated-macrophages using Griess reaction and the effect of them in lipid profile on treated-parasite through Thin Layer Chromatography.

RESULTS

Our data showed that both essential oils have toxic effect on promastigotes and amastigotes of L. amazonensis in vitro in a dose-dependent manner. PaEO IC₅₀ were 14.8 μg/mL and 7.8 μg/mL and PhEO IC_50s were 0.46 μg/mL and 30.5 μg/m for promastigotes and amastigotes, respectively. Toxicity to macrophages was not observed at 50 μg/mL with both EOs. The compounds 1,8- cineole, α-pinene, and p-cymene inhibited amastigotes survival in a dose-dependent manner with IC_50s of 48.4 μg/mL, 37 μg/mL, 46 μg/mL, respectively. Macrophage viability was around 90% even at 200 μg/mL and the phagocytic capacity was not altered in the treated-macrophages to up 50 μg/mL. The compounds were not able to modulate the nitric oxide production either at rest or LPS-activated macrophages. In addition, treated promastigote revealed an important change in their lipid profile after 48 h at 50 μg/mL in the presence of the compounds.

CONCLUSIONS

The results indicate that oleoresins of Protium genus are potent against Leishmania and α-pinene, p-cymene and 1,8-cineole have anti-Leishmania properties that could be explored in synergistic assays in order to develop new drug candidates.

Effects of Different Doses of Eucalyptus Oil From Eucalyptus globulus Labill on Respiratory Tract Immunity and Immune Function in Healthy Rats

Eucalyptol (1,8-cineole), the major constituent of eucalyptus oil (EO), was used in traditional medicine as a remedy for colds and bronchitis. This study aimed at clarifying the effect of eucalyptol on respiratory immune function of CD8 and CD4 cells, and alveolar macrophages (AM). Thirty male Sprague-Dawley rats were divided into experimental and control groups. The drug was given once a day for 3 weeks and the experimental group was divided according to the eucalyptol dose into: 30, 100, and 300 mg·kg^-1 groups. Flow cytometry was used to detect the phagocytic function of CD4, CD8 cells, and AM in the bronchopulmonary lavage fluid. The 30 and 100 mg·kg^-1 groups had an up-regulation effect on CD8 (p < 0.05), with no significant effect on macrophage phagocytosis. The 300 mg·kg^-1 group had an inhibitory effect on CD8 and macrophage phagocytosis (p < 0.05), with no significant difference in CD4 between groups. Further investigation was conducted to evaluate the effect of EO on immune function in rats by detecting blood T, B, and NK cells using flow cytometry, and blood IgA, IgG, IgM, and IFN-γ levels by ELISA. High dosage of eucalyptol significantly reduced the proportion of blood B and NK cells (p < 0.05). IgA was decreased in the 100 and 300 mg·kg^-1 groups (p < 0.05). There are no significant differences between the number of T cells and the IgG, IgM, and IFN-γ levels between experimental and control groups. Rational use of EO containing eucalyptol can improve the immune function of the respiratory tract and the body immunity, while high dose could have damaging effects, through modifying the phagocytic function of CD8 cells and reducing the proportion of blood B cells, NK cells, and IgA.

Immunomodulatory Activities of Selected Essential Oils

Recently, the application of herbal medicine for the prevention and treatment of diseases has gained increasing attention. Essential oils (EOs) are generally known to exert various pharmacological effects, such as antiallergic, anticancer, anti-inflammatory, and immunomodulatory effects. Current literature involving in vitro and in vivo studies indicates the potential of various herbal essential oils as suitable immunomodulators for the alternative treatment of infectious or immune diseases. This review highlights the cellular effects induced by EOs, as well as the molecular impacts of EOs on cytokines, immunoglobulins, or regulatory pathways. The results reviewed in this article revealed a significant reduction in relevant proinflammatory cytokines, as well as induction of anti-inflammatory markers. Remarkably, very little clinical study data involving the immunomodulatory effects of EOs are available. Furthermore, several studies led to contradictory results, emphasizing the need for a multiapproach system to better characterize EOs. While immunomodulatory effects were reported, the toxic potential of EOs must be clearly considered in order to secure future applications.

Innate Immune Response against Staphylococcus aureus Preincubated with Subinhibitory Concentration of trans-Anethole

The study aimed to analyze morphological and functional changes of Staphylococcus aureus cells due to trans-anethole (a terpenoid and the major constituent of fennel, anise, or star anise essential oils) exposition, and their consequences for human neutrophils phagocytic activity as well as IL-8 production (recognized as the major chemoattractant). The investigation included the evaluation of changes occurring in S. aureus cultures, i.e., staphyloxanthin production, antioxidant activities, cell size distribution, and cells composition as a result of incubation with trans-anethole. It was found that the presence of trans-anethole in the culture medium reduced the level of staphyloxanthin production, as well as decreased antioxidant activities. Furthermore, trans-anethole-treated cells were characterized by larger size and a tendency to diffuse in comparison to the non-treated cells. Several cell components, such as phospholipids and peptidoglycan, were found remarkably elevated in the cultures treated with trans-anethole. As a result of the aforementioned cellular changes, the bacteria were phagocytized by neutrophils more efficiently (ingestion and parameters associated with killing activity were at a higher level as compared to the control system). Additionally, IL-8 production was at a higher level for trans-anethole modified bacteria. Our results suggest that trans-anethole represents a promising measure in combating severe staphylococcal infections, which has an important translational potential for clinical applications.

Magnoliae Flos Essential Oil as an Immunosuppressant in Dendritic Cell Activation and Contact Hypersensitivity Responses

Magnoliae Flos is a commonly used traditional medicinal material in Asia. It is used to treat sinusitis, nasal congestion, and hypersensitive skin. Because Magonlia Flos was described as an aromatic material in ancient Chinese texts, we hypothesized that its essential oil may be used to treat immune disorders. Dendritic cells (DCs), regarded as a major target of immunomodulators to control immune responses, play a critical role in the adaptive immune response. In this study, Magnoliae Flos essential oil (MFEO) decreased the production of the cytokines TNF-[Formula: see text], IL-6, and IL-12p70 in lipopolysaccharide (LPS)-stimulated DCs. It also suppressed the surface markers MHC II, CD80, and CD86 in LPS-stimulated DCs. Animal models demonstrated that the 2,4-Dinitro-1-fluorobenzene (DNFB) inducing a contact hypersensitivity response was inhibited following treatment with MFEO. In addition, MFEO inhibited the infiltration of T cells in the ears of DNFB-induced mice. To explore its bioactive compounds, the components of MFEO were analyzed using gas chromatography (GC) and GC-mass spectrometry. The results revealed that the major compounds in MFEO are camphor and 1,8-cineole. Additional DC bioassays confirmed that these compounds substantially suppressed cytokine production in LPS-induced DCs. Therefore, we demonstrated that MFEO exhibits an immunosuppressive effect both in vivo and in vitro, and camphor and 1,8-cineole may be the major components responsible for its immunosuppressive ability. The findings indicate that MFEO has the potential to be developed as a new immunosuppressant for excessive diseases.

Therapeutic Potential of Volatile Terpenes and Terpenoids from Forests for Inflammatory Diseases

Forest trees are a major source of biogenic volatile organic compounds (BVOCs). Terpenes and terpenoids are known as the main BVOCs of forest aerosols. These compounds have been shown to display a broad range of biological activities in various human disease models, thus implying that forest aerosols containing these compounds may be related to beneficial effects of forest bathing. In this review, we surveyed studies analyzing BVOCs and selected the most abundant 23 terpenes and terpenoids emitted in forested areas of the Northern Hemisphere, which were reported to display anti-inflammatory activities. We categorized anti-inflammatory processes related to the functions of these compounds into six groups and summarized their molecular mechanisms of action. Finally, among the major 23 compounds, we examined the therapeutic potentials of 12 compounds known to be effective against respiratory inflammation, atopic dermatitis, arthritis, and neuroinflammation among various inflammatory diseases. In conclusion, the updated studies support the beneficial effects of forest aerosols and propose their potential use as chemopreventive and therapeutic agents for treating various inflammatory diseases.

Effects of 1,8-cineole on neuropathic pain mediated by P2X2 receptor in the spinal cord dorsal horn

As an intractable health threat, neuropathic pain is now a key problem in clinical therapy, which can be caused by lesions affecting the peripheral nervous systems. 1,8-cineole is a natural monoterpene cyclic ether present in eucalyptus and has been reported to exhibit anti-inflammatory and antioxidant effects. Research has shown that 1,8-cineole inhibits P2X3 receptor-mediated neuropathic pains in dorsal root ganglion. The P2X2 and P2X3 receptors participate in the transmission of algesia and nociception information by primary sensory neurons. In the present study, We thus investigated in the spinal cord dorsal horn whether 1,8-cineole inhibits the expression of P2X2 receptor-mediated neuropathic pain. This study used rats in five random groups: group of chronic constriction injury(CCI) with dimethysulfoxide control (CCI + DMSO); group of CCI; sham group(Sham); group of CCI treated with a low dose 1,8-cineole (CCI + 50 mg/kg); group of CCI with a high dose (CCI + 100 mg/kg). We observed the effects of 1,8-cineole on thermal withdrawal latency (TWL) and mechanical withdrawal threshold (MWT). We examined P2X2 receptors mRNA change in rat spinal cord dorsal horn by In situ nucleic acid hybridization(ISH) and Quantitative realtime polymerase chain reaction (qRT-PCR) methods. Western Blotting and Immunohistochemical staining methods were used to observe P2X2 receptor protein expressions in the rat spinal cord dorsal horn. It demonstrated that oral administration of 1,8-cineole inhibits over-expression of P2X2 receptor protein and mRNA in the spinal cord and dorsal horn in the CCI rats. And the study explored new methods for the prevention and treatment of neuropathic pain.