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

The present study aims to investigate the immunomodulatory effects of essential oil from Chamaecyparis obtusa (EOCO) in an ovalbumin (OVA)-induced allergic rhinitis (AR) mouse model. BALB/c mice were intraperitoneally sensitized and stimulated with OVA. From day 22 to 35, 0.01% and 0.1% ECOC was intranasally administered 1 h before OVA stimulation. Nasal symptoms, as well as serum total and OVA-specific immunoglobulin (Ig) E levels, were measured. Interleukin (IL)-4, IL-10, interferon (IFN)-γ, and tumor necrosis factor (TNF)-α levels in nasal lavage fluid (NLF) and their production by activated splenocytes were measured. Histological changes in the sinonasal mucosa were evaluated through hematoxylin and eosin and periodic acid-Schiff staining procedure. Th cytokines and their transcription factor mRNA expressions were determined using reverse-transcription polymerase chain reaction. Intranasal EOCO administration significantly suppressed allergic symptoms, OVA-specific IgE level, sinonasal mucosal inflammatory cell infiltration, and mucus-producing periodic acid-Schiff (PAS) positive cell count. EOCO also significantly inhibited IL-4, IL-10, and TNF-α levels in NLF and activated splenocytes. Th2 and Treg related cytokines and their transcription factors in sinonasal mucosa were significantly suppressed through intransal EOCO instillation. In conclusion, repetitive EOCO intranasal instillation showed anti-inflammatory and anti-allergic effects by suppressing nasal symptoms and inhibiting the production and expression of inflammatory mediators in the OVA-induced AR mouse model.

Alternaria-induced barrier dysfunction of nasal epithelial cells: role of serine protease and reactive oxygen species.

BACKGROUND: Upper airway barrier dysfunction has been associated with chronic rhinosinusitis and allergic rhinitis. Alternaria is commonly found in nasal secretion and plays a role in the pathogenesis of airway diseases. The aim of this study was to investigate the effects of Alternaria on the junctional complex of nasal epithelial cells. METHODS: Air-liquid interface nasal epithelial cultures from the inferior turbinate of septal surgery patients were stimulated with Alternaria alternate. Production of intracellular reactive oxygen species (ROS) and transepithelial resistance (TER) was measured. The expression of tight junction (TJ) and adherens junction (AJ) molecules was determined using real-time reverse transcriptase-polymerase chain reaction, Western blot analysis, and confocal microscopy. Protease activity in Alternaria was determined using protease inhibitors and heat inactivation. RESULTS: Alternaria enhanced the production of ROS and reduced the TER. Alternaria decreased the messenger RNA and protein expression of TJs (zonula occludens-1, occludin, and claudin-1), but did not influence the AJ molecule. When Alternaria was pretreated with serine protease inhibitor and heat inactivation, ROS, TER, and TJ molecule expression returned to their nonstimulated levels. CONCLUSION: Serine protease in Alternaria altered nasal epithelial barrier function. Intracellular ROS induced by Alternaria may influence the barrier function of nasal epithelial cells and enhance the inflammatory process of nasal mucosa.

Effect of microencapsulated essential oil form Chamaecyparis obtusa on monocyte-derived dendritic cell activation and CD4+ T cell polarization.

The essential oil of Chamaecyparis obtusa (C. obtusa), which is used in soap, toothpaste, and aromatic agents, has been known to have anti-inflammatory properties. In this study, we investigated the effects of microencapsulated C. obtusa essential oil on airborne fungus-induced dendritic cell (DC) activation and Th immune responses. We stimulated monocyte-derived DCs with Alternaria alternate and lipopolysaccharide (LPS). To determine the anti-inflammatory effects, we pre-treated DCs with various concentrations of microencapsulated C. obtusa essential oil and collected the supernatants to measure interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α), and we determined the expression of cell surface molecules. The effects of the essential oil on CD4+ T cells polarization was determine by culturing stimulated DCs and autologous CD4+ T cells. Alternaria enhanced the production of IL-6 and TNF-α from DCs, and pretreating DCs with 0.001, 0.01, and 0.05% of the essential oil significantly inhibited their production. Increased CD80 and CD86 expression by Alternaria was significantly inhibited with 0.05% of the essential oil. Alternaria-induced IL-5, IL-10, and interferon-gamma from CD4+ T cells were significantly inhibited with C. obtusa essential oil in a dose dependent manner. C. obtusa influenced both Alternaria- and LPS-induced Th1 and Th2 polarization of CD4+ T cells. These results suggest a novel pharmacological use for C. obtusa essential oil to treat inflammatory airway diseases.