Immunomodulative Effects of Chamaecyparis obtusa Essential Oil in Mouse Model of Allergic Rhinitis

Preparation and immunogenicity evaluation of C-HapS-P6 fusion protein vaccine against nontypeable Haemophilus influenzae in mice

Nontypeable Haemophilus influenzae (NTHi) is the dominant pathogen in several infectious diseases. Currently the use of antibiotics is the main intervention to prevent NTHi infections, however with the emergence of drug resistant strains, it has compromised the treatment of respiratory infections with antibiotics. Therefore there is an urgent need to develop a safe and effective vaccine to prevent NTHi infections. We investigate the potential of C-HapS-P6 fusion protein as a vaccine for treating NTHi in murine models. PGEX-6P2/C-HapS-P6 fusion gene was constructed using overlap extension polymerase chain reaction. The recombined plasmid was transformed into Escherichia coli for protein expression. The mice were subjected to intraperitoneal immunization using purified antigens. Immunoglobulin (Ig) G in serum samples and IgA in nasal and lung lavage fluids were analyzed using enzyme-linked immunosorbent assay. Cytokine release and proliferation capacity of splenic lymphocytes in response to antigens were measured in vitro. The protective effect of the C-HapS-P6 protein against NTHi infection was evaluated by NTHi count and histological examination. The data showed that the C-HapS-P6 fusion protein increased significantly the levels of serum IgG and nasal and lung IgA, and promoted the release of interleukin (IL)-2, interferon-ϒ, IL-4, IL-5, and IL-17 and the proliferation of splenic lymphocytes compared with C-HapS or P6 protein treatment alone. Moreover, C-HapS-P6 effectively reduced the NTHi colonization in the nasopharynx and lungs of mice. In conclusion, our results demonstrated that the C-HapS-P6 fusion protein vaccine can significantly enhance humoral and cell immune responses and effectively prevent against NTHi infection in the respiratory tract in murine models.

The Precious Potential of the Sacred Tree Chamaecyparis obtusa (Siebold & Zucc.) Endl. as a Source of Secondary Metabolites with Broad Biological Applications

Chamaecyparis obtusa (Siebold & Zucc.) Endl., which belongs to the Cupressaceae family, occurs naturally in North America and Asia, especially in Korea, Taiwan and Japan, where it is an evergreen, coniferous, sacred, ethnic tree. It has many useful varieties that are widespread throughout the world and grown for decorative purposes. It is most commonly used as an ornamental plant in homes, gardens or parks. It is also widely used in many areas of the economy; for example, its wood is used in architecture as well as furniture production. In addition, oil extracted from Chamaecyparis obtusa is increasingly used in cosmetology for skin care. Due to its wide economic demand, mainly in Japan, it represents the largest area of plantation forest. Despite this, it is on the red list of endangered species. Its use in ethnopharmacology has led to more and more research in recent years in an attempt to elucidate the potential mechanisms of its various biological activities, such as antimicrobial, antioxidant, anticancer, antidiabetic, antiasthmatic, anti-inflammatory, antiallergic, analgesic and central nervous system effects. It has also been shown that Chamaecyparis obtusa can be used as an insect repellent and an ingredient in plant disease treatment. This thesis provides a comprehensive review of the biological studies to date, looking at different areas of the economic fields of potential use of Chamaecyparis obtusa.

Abies holophylla Leaf Essential Oil Alleviates Allergic Rhinitis Based on Network Pharmacology

Abies holophylla is an evergreen coniferous species that has been widely used for treating pulmonary diseases and colds. Previous research has demonstrated the anti-inflammatory effect of Abies species and the anti-asthmatic activities of Abies holophylla leaf essential oil (AEO). As asthma and allergic rhinitis (AR) share pathophysiology and pharmacotherapeutic interventions, AEO inhalation can also ameliorate upper respiratory allergic diseases. This study explored the protective effects of AEO on AR with network pharmacological pathway prediction. The potential target pathways of AEO were analyzed by a network pharmacological approach. The BALB/c mice were sensitized by ovalbumin (OVA) and 10 μm particular matter (PM₁₀) to induce allergic rhinitis. Aerosolized AEO 0.0003% and 0.03% were delivered by nebulizer for 5 min a day, 3 times a week for 7 weeks. Nasal symptoms (sneezing and rubbing), histopathological changes in nasal tissues, serum IgE, and zonula occludens-1 (ZO-1) expressions on nasal tissues were analyzed. After AR induction with OVA+PM₁₀ and inhalation of AEO 0.0003% and 0.03% treatment, AEO significantly decreased allergic symptoms (sneezing and rubbing), hyperplasia of nasal epithelial thickness, goblet cell counts, and serum IgE level. The network analysis demonstrated that the possible molecular mechanism of AEO is highly associated with the IL-17 signaling pathway and tight junction. The target pathway of AEO was investigated in RPMI 2650 nasal epithelial cells. Treatment of AEO on PM₁₀-treated nasal epithelial cells significantly reduced the production of inflammatory mediators related to the IL-17 signaling pathway, NF-κB, and the MAPK signaling pathway and prevented the reduction in TJ-related factors. When taken together, AEO inhalation may be considered as a potential treatment for AR by alleviating nasal inflammation and recovering the tight junction.

Molecular mechanism of the anti-inflammatory effects of plant essential oils: A systematic review

ETHNOPHARMACOLOGICAL RELEVANCE

Plant essential oils (PEOs) extracted from aromatic compounds of the plant contain complex mixtures of volatile and lipophilic bioactive compounds. In ancient Egypt, Arabia, Greece, and China, PEOs were traditional used in aromatherapy for various health disorders, including pain and inflammation.

AIM OF THE STUDY

In this review, we provide an overview of the anti-inflammatory effects of PEOs and the underlying mechanisms associated with anti-inflammatory effects using in vitro and in vivo models. Further, clinical trials associated with PEOs were explored.

MATERIALS AND METHODS

The literature search was performed using various web-based tools and databases like Google Scholar, Web of Science, PubMed, CNKI and SCOPUS. The keywords used for conducting the literature review were general terms like "essential oils" followed by (AND) the subject of interest like "in vitro and/or in vivo anti-inflammatory models," "inflammatory response," "inflammatory indicators," "pro-inflammatory cytokines," "signaling pathway," "anti-inflammatory mechanism," "toxicology and side effects" and "clinical trials." The articles selected were published between 2017 and 2022. The articles prior to 2017 were only considered if they were associated with molecular mechanisms or signaling pathways involved in the inflammatory responses.

RESULTS

In vitro and in vivo inflammation models have been used to study the anti-inflammatory effects of 48 PEOs. Studies have reported that PEOs targets and inhibit multiple dysregulated signaling pathways associated with inflammation, including Toll-like receptors, nuclear transcription factor-κ B, mitogen-activated protein kinases, Nod-like receptor family pyrin domain containing 3, and auxiliary pathways like the nuclear factor erythroid 2-related factor 2/antioxidant response element and Janus kinase/signal transducers and activators of transcription) signaling pathways.

CONCLUSION

PEOs extracted from different plant materials had varied qualitative and quantitative compositions of biologically active compounds. Different anti-inflammatory potentials and different molecular signal transduction have been attributed to PEOs-derived bioactive compounds with different chemical structures. The data on therapeutic efficacy and the long-term side effects of PEOs as an anti-inflammatory drug are still unknown due to the lack of clinical trials on PEOs. There is still insufficient evidence to draw conclusions on anti-inflammatory properties of PEOs without promising outcomes from clinical trials.

XBP1 Regulates the Transcription of HIF-1a in BALB/c Mice with Chronic Rhinosinusitis without Polyps

X-box binding protein 1 (XBP1) is a transcription factor that recognizes the CRE-like element in enhancers of human T-cell leukemia virus and MHC class II gene and induces their transcription. This study was performed to characterize the function of XBP1, which was identified to be a differentially expressed gene via GEO database, in chronic rhinosinusitis (CRS) without nasal polyps (CRSsNP). XBP1 expression was significantly elevated in both CRSsNP patients and mice who were accompanied with mucosal thickening, goblet cell hyperplasia and chemosis, glandular hyperplasia, and dense infiltration of inflammatory cells. Silencing of XBP1 suppressed the development of CRSsNP in mice. Mechanistically, knockdown of XBP1 downregulated the expression of hypoxia-inducible factor 1-alpha (HIF-1a), and overexpression of XBP1 led to the opposite result. Silencing of HIF-1a inhibited β-catenin expression and impaired the Wnt/β-catenin pathway. Further overexpression of HIF-1a in XBP1-silenced CRSsNP mice exacerbated pathological changes in mouse nasal mucosal tissues, promoted inflammation, and activated the Wnt/β-catenin pathway. Taken together, overexpression of XBP1 may be associated with increased expression of HIF-1a and possibly contribute to the Wnt/β-catenin pathway activation and the development of CRSsNP.

Chamaecyparis obtusa (Siebold & Zucc.) Endl. leaf extracts prevent inflammatory responses via inhibition of the JAK/STAT axis in RAW264.7 cells

ETHNOPHARMACOLOGICAL RELEVANCE

Chamaecyparis obtusa (Siebold & Zucc.) Endl. (C. obtusa) has been used as folk medicine in East Asia and has been reported to alleviate inflammatory diseases. However, the detailed mechanisms for the anti-inflammatory effects of C. obtusa remain unclear.

AIM OF THE STUDY

Although the anti-inflammatory mechanisms of natural products have been studied for decades, it is still important to identify the potential anti-inflammatory effects of natural sources. In this study, we investigated the anti-inflammatory effects and underlying mechanism of C. obtusa leaf extracts.

MATERIAL &METHODS

The cell viability was determined by MTT and crystal violet staining. NO production in the supernatant was measured using Griess reagent. The cell lysates were analyzed by immunoblotting and RT-qPCR. Secreted cytokines were analyzed using ELISA kit and cytokine array kit. mRNA expression from the GSE9632 database set. Z-scores were calculated for each gene and visualized by heat map.

RESULTS

Among the extracts of C. obtusa obtained with different extraction methods, the 99% ethanol leaf extract (CO99EL) strongly inhibited lipopolysaccharide (LPS)-induced inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expression and Janus kinase/signaling transducer and activator of transcription (JAK/STAT) phosphorylation in RAW264.7 cells. In addition, CO99EL strongly inhibited LPS-induced interleukin (IL)-1β, IL-6, IL-27, and C-C motif chemokine ligand (CCL)-1 production and directly inhibited LPS-induced JAK/STAT phosphorylation in RAW264.7 cells.

CONCLUSIONS

These findings demonstrate that CO99EL significantly prevents LPS-induced macrophage activation by inhibiting the JAK/STAT axis. Therefore, we suggest the use of C. obtusa extracts as therapeutic approach for inflammatory diseases.

The Immuno-Modulatory Activities of Pentaherbs Formula on Ovalbumin-Induced Allergic Rhinitis Mice via the Activation of Th1 and Treg Cells and Inhibition of Th2 and Th17 Cells

Allergic rhinitis (AR) is a highly prevalent allergic disease induced by immunoglobulin (Ig) E-mediated hypersensitivity reaction at the nasal epithelium against inhaled allergens. Previous studies have demonstrated that Pentaherbs formula (PHF), a modified herbal formula comprising five herbal medicines (Flos Lonicerae, Herba Menthae, Cortex Phellodendri, Cortex Moutan and Rhizoma Atractylodis), could suppress various immune effector cells to exert anti-inflammatory and anti-allergic effects in allergic asthma and atopic dermatitis. The present study aimed to further determine the anti-inflammatory activities of PHF in an ovalbumin (OVA)-induced AR BALB/c mouse model. Nasal symptoms such as sneezing and nose rubbing were recorded and the serum total IgE and OVA-specific IgG1, as well as interleukin (IL)-4, IL-5, IL-10, IL-13, chemokines CXCL9 CXCL10, and tumor necrosis factor (TNF)-α concentrations in nasal lavage fluid (NALF) were measured during different treatments. Effects of PHF on the expression of inflammatory mediators in the sinonasal mucosa were quantified using real-time QPCR. PHF was found to suppress allergic symptoms, infiltration of inflammatory cells, and hyperplasia of goblet cells in the nasal epithelium of the OVA-induced AR mice. PHF could reduce OVA-specific IgG1 level in serum, and TNF-α and IL-10 in nasal lavage fluid (NALF), significantly up-regulate the splenic regulatory T (Treg) cell level, increase the Type 1 helper T cell (Th1)/Type 2 helper T cell (Th2) ratio, and reduce the Th17 cells (all p < 0.05). PHF could also alleviate in situ inflammation in sinonasal mucosa of OVA-induced AR mice. In conclusion, oral treatment of PHF showed immuno-modulatory activities in the OVA-induced AR mice by regulating the splenic T cell population to suppress the nasal allergy symptoms and modulating inflammatory mediators, implicating that PHF could be a therapeutic strategy for allergic rhinitis.

Anti-Allergic Rhinitis Effects of Medicinal Plants and Their Bioactive Metabolites via Suppression of the Immune System: A Mechanistic Review

Allergic rhinitis (AR) is a common inflammatory condition of the nasal mucosa and it is an immunoglobulin E-mediated disease. The incidence and prevalence of AR globally have been escalating over recent years. Antihistamines, intranasal corticosteroids, decongestants, intranasal anticholinergics, intranasal cromolyn, leukotriene receptor antagonists and immunotherapy have been used in the treatment of AR. However, there is a need to search for more effective and safer remedies as many of the current treatments have reported side effects. Medicinal plants have been used traditionally to relief symptoms of AR but their efficacy and safety have not been scientifically proven. In this review, up-to-date reports of studies on the anti-allergic rhinitis of several medicinal plants and their bioactive metabolites through suppression of the immune system are compiled and critically analyzed. The plant samples were reported to suppress the productions of immunoglobulin E, cytokines and eosinophils and inhibit histamine release. The suppression of cytokines production was found to be the main mechanistic effect of the plants to give symptomatic relief. The prospect of these medicinal plants as sources of lead molecules for development of therapeutic agents to treat AR is highlighted. Several bioactive metabolites of the plants including shikonin, okicamelliaside, warifteine, methylwarifteine, luteolin-7-O-rutinoside, tussilagone, petasin, and mangiferin have been identified as potential candidates for development into anti-allergic rhinitis agents. The data collection was mainly from English language articles published in journals, or studies from EBSCOHOST, Medline and Ovid, Scopus, Springer, and Google Scholar databases from the year 1985-2020. The terms or keywords used to find relevant studies were allergic rhinitis OR pollinosis OR hay fever, AND medicinal plant OR single plant OR single herb OR phytotherapy. This comprehensive review serves as a useful resource for medicinal plants with anti-allergic rhinitis potential, understanding the underlying mechanisms of action and for future exploration to find natural product candidates in the development of novel anti-allergic rhinitis agents.