DataSheet1_Alnus hirsuta (Spach) Rupr. Attenuates Airway Inflammation and Mucus Overproduction in a Murine Model of Ovalbumin-Challenged Asthma.docx

Alnus hirsuta (Spach) Rupr. (AH), a member of the Betulaceae family, is widely used in Eastern Asia of as a source of medicinal compounds for the treatment of hemorrhage, diarrhea, and alcoholism. In this study, we investigated the protective effects of a methanolic extract of AH branches against airway inflammation and mucus production in tumor necrosis factor (TNF)-α-stimulated NCI-H292 cells and in an ovalbumin (OVA)-challenged allergic asthma mouse model. Female BALB/c mice were injected with OVA (40 μg) and aluminum hydroxide (2 mg) on days 0 and 14 to induce allergic airway inflammation. The mice were then challenged with 1% OVA from days 21–23. Mice were treated with AH (50 and 100 mg/kg/day; 2% DMSO) or dexamethasone (positive control; 3 mg/kg/day) from days 18–23. AH treatment effectively attenuated airway resistance/hyperresponsiveness and reduced levels of T helper type 2 (Th2) cytokines, eotaxins, and number of inflammatory cells in bronchoalveolar lavage fluid, and immunoglobulin E in serums of OVA-challenged mice. In histological analysis, AH treatment significantly inhibited airway inflammation and mucus production in OVA-challenged mice. AH treatment downregulated the phosphorylation of I kappa B-alpha, p65 nuclear factor-kappa B (p65NF-κB), and mitogen-activated protein kinases with suppression of mucin 5AC (MUC5AC) in lung tissue. Moreover, AH treatment decreased the levels of pro-inflammatory cytokines and Th2 cytokines, as well as MUC5AC expression, and inhibited the phosphorylation of p65NF-κB in TNF-α-stimulated NCI-H292 cells. These results indicate that AH might represent a useful therapeutic agent for the treatment of allergic asthma.

毛桤木（Alnus hirsuta (Spach) Rupr.，简称AH）隶属于桦木科（Betulaceae），在东亚地区被广泛用作药用成分来源，用于治疗出血、腹泻及酒精中毒。本研究探究了AH枝条甲醇提取物在肿瘤坏死因子-α（tumor necrosis factor-α，TNF-α）刺激的NCI-H292细胞，以及卵清蛋白（ovalbumin，OVA）致敏的过敏性哮喘小鼠模型中，对气道炎症与黏液生成的保护作用。
选取雌性BALB/c小鼠，于第0天和第14天分别注射卵清蛋白（OVA，40 μg）与氢氧化铝（aluminum hydroxide，2 mg）以诱导过敏性气道炎症；随后在第21至23天以1% OVA进行造模激发。自第18至23天，分别以AH（50与100 mg/kg/天，溶于2%二甲基亚砜（dimethyl sulfoxide，DMSO））或地塞米松（阳性对照，3 mg/kg/天）对小鼠进行给药处理。
AH给药可有效降低OVA致敏哮喘小鼠的气道阻力/气道高反应性，减少支气管肺泡灌洗液（bronchoalveolar lavage fluid）中辅助性T细胞2型（T helper type 2，Th2）细胞因子、嗜酸性粒细胞趋化因子（eotaxins）的水平与炎症细胞数量，并降低小鼠血清中免疫球蛋白E（immunoglobulin E，IgE）的含量。组织病理学分析显示，AH给药可显著抑制OVA致敏小鼠的气道炎症与黏液生成。AH给药可下调肺组织中IκB-α（I kappa B-alpha）、p65核因子-κB（p65 nuclear factor-kappa B，p65NF-κB）的磷酸化水平，以及丝裂原活化蛋白激酶（mitogen-activated protein kinases，MAPKs）的活性，并抑制黏蛋白5AC（mucin 5AC，MUC5AC）的表达。
此外，在TNF-α刺激的NCI-H292细胞中，AH给药可降低促炎细胞因子与Th2细胞因子的水平，下调MUC5AC的表达，并抑制p65NF-κB的磷酸化。上述结果表明，AH有望成为治疗过敏性哮喘的潜在有效治疗药物。