■花生过敏是免疫球蛋白E(IgE)介导的食物过敏。茜草(R.科迪叶),一种中草药,通过抑制体内IgE的产生来防止花生诱导的过敏反应。本研究旨在鉴定R.cordifolia水提取物中的IgE抑制化合物,并使用体外和体内模型研究潜在的机制。
从紫花苜蓿水提取物中分离化合物,并使用人骨髓瘤U266细胞系评估它们对IgE产生的生物活性。纯化的活性化合物,黄嘌呤(XPP),通过LC-MS和NMR鉴定。花生过敏C3H/HeJ小鼠口服给药,每天每只小鼠200µg或400µg,有或没有XPP,持续4周。血清花生特异性IgE水平,症状评分,体温,并在攻击时测量血浆组胺水平。通过ELISA测定脾细胞培养物中的细胞因子,流式细胞术分析IgE+B细胞。评估了急性和亚慢性毒性。IL-4启动子DNA甲基化,RNA-Seq,并进行qPCR分析以确定XPP的调节机制。
■XPP显著且剂量依赖性地抑制U266细胞中的IgE产生。XPP显着降低花生特异性IgE(>80%,p<0.01),和血浆组胺水平,并在早期和晚期治疗实验中保护小鼠免受花生过敏反应(p<0.05,n=9)。甚至在停止治疗后5周,XPP显示出强烈的保护作用。XPP显著降低IL-4水平而不影响IgG或IgA和IFN-γ产生。流式细胞术数据显示,与未处理组相比,XPP减少外周和骨髓IgE+B细胞。XPP增加IL-4启动子甲基化。RNA-Seq和RT-PCR实验显示XPP调控CCND1、DUSP4、SDC1、ETS1、PTPRC、和IL6R,与浆细胞IgE的产生有关。所有安全性测试结果均在正常范围内。
■XPP通过抑制IgE的产生,成功地保护了花生过敏小鼠免受花生过敏反应。XPP抑制小鼠产生IgE的B细胞数量,并抑制人浆细胞中IgE的产生和相关基因。XPP可能是IgE介导的食物过敏的潜在疗法。
Peanut allergy is an immunoglobulin E (IgE) mediated food allergy. Rubia cordifolia L. (R. cordifolia), a Chinese herbal medicine, protects against peanut-induced anaphylaxis by suppressing IgE production in vivo. This study aims to identify IgE-inhibitory compounds from the water extract of R. cordifolia and investigate the underlying mechanisms using in vitro and in vivo models.
Compounds were isolated from R. cordifolia water extract and their bioactivity on IgE production was assessed using a human myeloma U266 cell line. The purified active compound, xanthopurpurin (XPP), was identified by LC-MS and NMR. Peanut-allergic C3H/HeJ mice were orally administered with or without XPP at 200µg or 400µg per mouse per day for 4 weeks. Serum peanut-specific IgE levels, symptom scores, body temperatures, and plasma histamine levels were measured at challenge. Cytokines in splenocyte cultures were determined by ELISA, and IgE + B cells were analyzed by flow cytometry. Acute and sub-chronic toxicity were evaluated. IL-4 promoter DNA methylation, RNA-Seq, and qPCR analysis were performed to determine the regulatory mechanisms of XPP.
XPP significantly and dose-dependently suppressed the IgE production in U266 cells. XPP significantly reduced peanut-specific IgE (>80%, p <0.01), and plasma histamine levels and protected the mice against peanut-allergic reactions in both early and late treatment experiments (p < 0.05, n=9). XPP showed a strong protective effect even 5 weeks after discontinuing the treatment. XPP significantly reduced the IL-4 level without affecting IgG or IgA and IFN-γ production. Flow cytometry data showed that XPP reduced peripheral and bone marrow IgE + B cells compared to the untreated group. XPP increased IL-4 promoter methylation. RNA-Seq and RT-PCR experiments revealed that XPP regulated the gene expression of CCND1, DUSP4, SDC1, ETS1, PTPRC, and IL6R, which are related to plasma cell IgE production. All safety testing results were in the normal range.
XPP successfully protected peanut-allergic mice against peanut anaphylaxis by suppressing IgE production. XPP suppresses murine IgE-producing B cell numbers and inhibits IgE production and associated genes in human plasma cells. XPP may be a potential therapy for IgE-mediated food allergy.