Piper nigrum extract ameliorated allergic inflammation through inhibiting Th2/Th17 responses and mast cells activation.

Piper nigrum (Piperaceae) is commonly used as a spice and traditional medicine in many countries. P. nigrum has been reported to have anti-oxidant, anti-bacterial, anti-tumor, anti-mutagenic, anti-diabetic, and anti-inflammatory properties. However, the effect of P. nigrum on allergic asthma has not been known. This study investigated the effect of P. nigrum ethanol extracts (PNE) on airway inflammation in asthmatic mice model. In the ovalbumin (OVA)-induced allergic asthma model, we analysed the number of inflammatory cells and cytokines production in bronchoalveolar lavage fluid (BALF) and lung tissue; histological structure; as well as the total immunoglobulin (Ig)E, anti-OVA IgE, anti-OVA IgG1 and histamine levels in serum. The oral administration (200 mg/kg) of PNE reduced the accumulation of inflammatory cells (eosinophils, neutrophils in BALF and mast cells in lung tissue); regulated the balance of the cytokines production of Th1, Th2, Th17 and Treg cells, specifically, inhibited the expressions of GATA3, IL-4, IL-6, IL-1β, RORγt, IL-17A, TNF-α and increased the secretions of IL-10, INF-γ in BALF and lung homogenate. Moreover, PNE suppressed the levels of total IgE, anti-OVA IgE, anti-OVA IgG1 and histamine release in serum. The histological analysis showed that the fibrosis and infiltration of inflammatory cells were also ameliorated in PNE treated mice. On the other hand, PNE inhibited the allergic responses via inactivation of rat peritoneal mast cells degranulation. These results suggest that PNE has therapeutic potential for treating allergic asthma through inhibiting Th2/Th17 responses and mast cells activation.

Bui TT ，Piao CH ，Song CH ，Shin HS ，Shon DH ，Chai OH ... -  《-》

Bupleurum chinense extract ameliorates an OVA-induced murine allergic asthma through the reduction of the Th2 and Th17 cytokines production by inactivation of NFκB pathway.

Bupleurum chinense belongs to the Bupleurum spp. family that has been used in traditional herbal medicine for over thousand years. It has been reported to have anti-inflammatory, anti-oxidant, hepato-protective, antipyretic, analgesic, anti-fibrotic and immunomodulatory effect. However, the effect of B. Chinense on allergic asthma remains unclear. This study investigated the immunomodulatory effects of B. Chinense extracts (BCE) on airway inflammation in asthmatic mice model. In the ovalbumin (OVA)-induced allergic asthma model, we evaluated the number of total cells, differential inflammatory cells and the production of proinflammatory cytokines in bronchoalveolar lavage fluid (BALF) and lung homogenate as well as histological structure. The levels of NFκB p65, IκBα, p-NFκB p65, p-IκBα and the total immunoglobulin (Ig) E, anti-OVA IgE, anti-OVA IgG were also examined. The oral administration of 200mg/kg BCE inhibited the accumulation of inflammatory cells especially eosinophils in BALF. Also, BCE regulated the imbalance of Th1, Th2 and Th17-related production, with attenuated the expression of GATA3, IL-1β, IL-4, IL-5, IL-6, TNF-α and RORγt, IL-17A in BALF and lung homogenate, meanwhile, up-regulated the secretion of INF-γ in lung homogenate. The levels of IgE, anti-OVA IgE, anti-OVA IgG1 and anti-OVA IgG2a were also suppressed by BCE treatment in serum. Futhermore, BCE inhibited the proinflammatory cytokines via inactivation of NFκB p65 phosphorylation and IκBα degradation in cytoplasm. The histological analysis showed that the infiltration of inflammatory cells, mucus hypersecretion and collagen fiber deposits were ameliorated in BCE treated mice. In addition, BCE induced the functional differentiation of naive CD4+ T cells forward to Th1 and Tr1 through producing INF-γ and IL-10. These results suggest that BCE may have therapeutic potential for treating allergic asthma through inhibiting Th2/Th17 cytokines production by inactivation of NFκB pathway.

Bui TT ，Piao CH ，Song CH ，Shin HS ，Chai OH ... -  《-》

Piper nigrum extract attenuates food allergy by decreasing Th2 cell response and regulating the Th17/Treg balance.

Piper nigrum is extensively utilized because of its antioxidation, antiallergic, antitumor, antiinflammatory, antidiarrhea, and gastrointestinal protection. We attempted to indicate whether the Piper nigrum extract (PNE) could alleviate ovalbumin (OVA)-induced food allergy, and to explore its potential mechanism. An OVA-induced food allergy mouse model was established, and different concentrations of PNE were administrated. Symptoms of food allergy, levels of immunoglobulin E (IgE), mucosal mast cell protease-1 (mMCP-1), and intestine pathological changes were assessed. Additionally, the expressions of T helper (Th) 2, Th17 and regulatory T (Treg)-associated cytokines and the proportion of Th17 and Treg cells in CD4+ T cells were measured. We found PNE attenuated symptoms of food allergy and decreased the levels of IgE and mMCP-1. In PNE group, the infiltration degree of inflammatory cells was ameliorated and the villi of small intestine were more complete. Moreover, the expressions of Th2 and Th17 cell-associated cytokines were down-regulated by PNE pretreatment, while the levels of Treg cell-associated cytokines were up-regulated. PNE decreased the number of Th17 cells, while increased the Tregs cells. PNE treatment dose-dependently improved the Th17/Treg balance. PNE plays a protective role in OVA-induced food allergy through inhibiting Th2 cell response and regulating the Th17/Treg balance.

Wang L ，Jia X ，Yu Q ，Shen S ，Gao Y ，Lin X ，Zhang W ... -  《-》

The protective role of Piper nigrum fruit extract in an ovalbumin-induced allergic rhinitis by targeting of NFκBp65 and STAT3 signalings.

Piper nigrum L. is commonly used as a traditional medicine and food in many countries. It has been reported to have anti-oxidant, anti-bacterial, anti-tumor, anti-mutagenic, anti-diabetic, and anti-inflammatory properties. However, the effect of P. nigrum on allergic rhinitis (AR) has been unclear. In the present study, an OVA-induced AR mice model were established to investigate the anti-allergic, anti-inflammation properties of P. nigrum fruit extract (PNE). Oral administrations of PNE inhibited the allergic nasal symptoms including rubbing and sneezing in the early-phage of AR. In both NALF and nasal tissue, PNE suppressed the inflammatory cells accumulation, specifically with eosinophils in NALF. Additionally, PNE prevented the activation of STAT3 and NFκBp65 signaling in the cytoplasm which led to increasing the synthesis of the anti-inflammatory Th1 cytokines and suppressing the inflammatory Th2, Th17 cytokines. These obtained results suggest that PNE has the promising strategy for immunotherapy in allergic rhinitis disease.

Bui TT ，Piao CH ，Hyeon E ，Fan Y ，Van Nguyen T ，Jung SY ，Choi DW ，Lee SY ，Shin HS ，Song CH ，Chai OH ... -  《-》

Piper Nigrum extract improves OVA-induced nasal epithelial barrier dysfunction via activating Nrf2/HO-1 signaling.

Piper nigrum L. (Piperaceae) is commonly used as a spice and traditional medicine in many countries. It has been reported to have anti-oxidant, anti-bacterial, anti-tumor, anti-mutagenic, anti-diabetic, and anti-inflammatory properties. However, the protective role of P. nigrum on epithelial function of upper respiratory tract injury in an allergic rhinitis (AR) mouse model has been unclear. This study aims to investigate the effects of P. nigrum fruit extract (PNE) on the nasal epithelial barrier function of the upper respiratory tract in an ovalbumin (OVA)-induced AR model. AR mouse model was established by intraperitoneal injection with 200 µL saline containing 50 µg OVA adsorbed to 1 mg aluminum hydroxide, and intranasal challenge with 20 µL per nostril of 1 mg/ml OVA. Besides, mice were orally administrated once daily with PNE and dexamethasone (Dex) in 13 days. The nasal symptoms, inflammatory cells, OVA-specific immunoglobulins, cytokines, nasal histopathology, and immunohistochemistry were evaluated. The PNE oral administrations inhibited allergic responses via reduction of OVA-specific antibodies levels and mast cells histamine release, accordingly, the nasal symptoms in the early-phase reaction were also clearly ameliorated. In both nasal lavage fluid and nasal tissue, PNE suppressed the inflammatory cells accumulation, specifically with eosinophils. The intravenous Evans blue injection illustrated the epithelial permeability reduction of nasal mucosa layer in PNE-treated mice. Also; PNE treatments protected the epithelium integrity by preventing the epithelial shedding from nasal mucosa; as a result of enhancing the strong expression of the E-cadherin tight junction protein in cell-to-cell junctions, as well as inhibiting the degraded levels of zonula occludens-1 (ZO-1) and occludin into the nasal cavity. Additionally, PNE protected against nasal epithelial barrier dysfunction via enhancing the expression of Nrf2 activated form which led to increasing synthesis of the anti-inflammation enzyme HO-1. These obtained results suggest that PNE has a promising strategy for epithelial barrier stabilization in allergic rhinitis treatment.

Bui TT ，Fan Y ，Piao CH ，Nguyen TV ，Shin DU ，Jung SY ，Hyeon E ，Song CH ，Lee SY ，Shin HS ，Chai OH ... -  《-》