Objective: Interleukin (IL)-33 has been attracting more and more attention as a new member of theIL-1 cytokine family in recent years. However, the underlying mechanisms referred to the regulation of endogenous IL-33 production are not fully illustrated. Paeoniflorin (PF) has been reported to possess multiple pharmacological activities, including anti-inflammation and anti-allergy. In this study, we aimed to investigate the effect of PF on IL-33 production by macrophages and explore the underlying mechanisms.Methods: In vivo, IL-33 production in mice after lipopolysaccharide (LPS) injection together with PF application was detected by enzyme-linked immunosorbent assay (ELISA). In vitro, MTT, Real-time PCR, ELISA, Calcium (Ca2+) imaging and Western blot were used to assess the cytotoxicity of PF, IL-33 expression at mRNA and protein levels, Ca2+ influx, protein kinase C (PKC) activity, nuclear factor-kappa B (NF-κB), and mitogen-activated protein kinase (MAPK) activation in LPS-stimulated RAW264.7 macrophages with PF administration.Results: Our results indicated that PF (5 and 25 mg/kg) significantly reduced the production of TNF-a, IL-1β, and IL-33 in the peritoneal exudate of LPS-treated mice. In vitro assay, upregulation of PF concentration (≥ 20 μM) showed an increased cytotoxicity in RAW264.7 cells during the 24-h cell culture. PF (10 μM) inhibited IL-33 production, Ca2+ influx, PKC activity, NF-κB (p65) activation, and P38MAPK phosphorylation in LPS-treated macrophages. Notably, NF-κB inhibitor (BAY 11-7085), P38MAPK inhibitor (SB203580), and Ca2+ blocker (NiCl2) also curbed LPS-induced IL-33 production, respectively.Conclusions: PF suppresses IL-33 production by macrophages via inhibiting NF-κB and P38MAPK activation associated with the regulation of Ca2+ mobilization.

中文翻译：

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eon药苷抑制巨噬细胞产生IL-33。

目的：白细胞介素（IL）-33作为IL-1细胞因子家族的新成员，近年来受到越来越多的关注。但是，尚未完全阐明涉及调节内源性IL-33产生的潜在机制。据报道药苷（PF）具有多种药理活性，包括抗炎和抗过敏作用。在这项研究中，我们旨在研究PF对巨噬细胞产生IL-33的影响并探讨其潜在机制。方法：体内，通过酶检测脂多糖（LPS）注射和PF施加后小鼠中IL-33的产生联免疫吸附测定（ELISA）。在体外，MTT，实时荧光定量PCR，ELISA，钙（Ca2 +）成像和Western印迹用于评估PF，IL-33在mRNA和蛋白质水平的细胞毒性，Ca2 +流入，蛋白激酶C（PKC）活性，核因子-κB（NF-κB）和丝裂原激活的蛋白激酶（MAPK）在PF刺激下脂多糖刺激的RAW264.7巨噬细胞中的激活。结果：我们的结果表明， PF（5和25 mg / kg）显着降低LPS处理小鼠腹膜分泌物中TNF-a，IL-1β和IL-33的产生。在体外测定中，PF浓度（≥20μM）的上调显示在24小时细胞培养期间RAW264.7细胞的细胞毒性增加。PF（10μM）抑制LPS处理的巨噬细胞中IL-33的产生，Ca2 +流入，PKC活性，NF-κB（p65）活化和P38MAPK磷酸化。值得注意的是，NF-κB抑制剂（BAY 11-7085），P38MAPK抑制剂（SB203580）和Ca2 +阻滞剂（NiCl2）也分别抑制了LPS诱导的IL-33产生。