School of Pharmaceutical Science, South-Central University for Nationalities, Wuhan, 430074, PR China.
School of Pharmaceutical Science, South-Central University for Nationalities, Wuhan, 430074, PR China.
J Ethnopharmacol. 2021 Jul 15;275:114071. doi: 10.1016/j.jep.2021.114071. Epub 2021 Apr 6.
In traditional Chinese medicine (TCM), the leaf of Elaeagnus pungens Thunb. (Family Elaeagnaceae) is a herb documented as an antiasthmatic remedy to treat the severe asthma, bronchitis and other respiratory diseases in the early material medica "Bencao Gangmu" (Ming dynasty, about 442 years ago).
This work is purposed to investigate the pharmacological effects and mechanism of total flavonoids from Elaeagnus pungens leaves (FLA) on asthma in vivo and vitro.
Female BALB/c mice were sensitized by intraperitoneal injection of OVA with aluminum hydroxide and intranasal challenged with OVA. After treatment with FLA (10, 20 mg/kg p.o.), the behaviors of mice were observed by score evaluation. Enumeration of total cells and OVA-specific IgE assay in the blood were measured as well as enumeration of total cells and cytokines assay in the BALF. Furthermore, histopathological analysis was performed by HE staining. The in vitro relaxing action on muscle force of FLA (0.0316-10.0 mg/ml) was evaluated using isometric tension in tracheal rings, and VDLCC currents were recorded to explore the relaxation mechanism in the isolated tracheal rings and mouse ASM cells, respectively. In vitro anti-inflammatory actions were assessed with LPS-stimulated RAW 264.7 macrophages. The production of inflammatory mediators and MAPK signaling pathway was estimated using ELISA and Western blotting analysis, respectively.
The high dose of flavones from E. pungens leaf (20 mg/kg) can significantly improve the symptom of asthma breakout and relieve the lung swelling. FLA treatment decreased eosinophils and leukocytes numbers in blood and BLAF with a dosedependent manner. Furthermore, the inhibiting effect of FLA on the level of Ig E and inflammatory-related cytokines including TNF-α, IL-5 showed dose-independent. FLA relaxed high K + -induced contraction in a dose-dependent manner. The maximal relaxation produced by FLA was 99.7% (IC 50 = 0.46 mg/ml). The whole-cell VDLCC currents were abolished by FLA (3.16 mg/ml) and FLA significantly decreased the maximal amplitude of VDLCCs. No cytotoxic effect of FLA was observed in RAW264.7 cells under the tested concentrations (1-300 μg/mL). The increased IL-6 and NO by the stimulation of LPS in RAW264.7 cells were significantly inhibited by FLA in the dosedependent manner. Treatment with LPS in the presence of FLA, LPS-induced phosphorylation of ERK1/2 and JNK was inhibited in the macrophages.
FLA from Elaeagnus pungens leaf can alleviate the inflammation symptom via reducing the eosinophils and leukocytes numbers as well as the production of pro-inflammatory cytokines. This anti-inflammatory effect is related to the modulation of the MAPK signaling pathway. FLA can relax the precontracted TRs by blocking the VDLCCs, which interrupts extracellular Ca 2+ influx and inhibit the rise of [Ca 2+ ]i. It strongly suggests that these flavonoids components are the substances basis of Elaeagnus pungens leaves for allergic action, bronchospasm and inflammation in asthma.
在中国传统医学（TCM）中，胡颓子叶（胡颓子科）被记录为一种抗哮喘的药物，用于治疗早期本草纲目（明朝，约 442 年前）中严重的哮喘、支气管炎和其他呼吸道疾病。
本研究旨在探讨胡颓子叶总黄酮（FLA）对哮喘的体内和体外药理作用及机制。
雌性 BALB/c 小鼠通过腹腔注射氢氧化铝和鼻内滴注 OVA 进行致敏。用 FLA（10、20mg/kg 灌胃）治疗后，通过评分评估小鼠的行为。测量血液中的总细胞数和 OVA 特异性 IgE 以及 BALF 中的总细胞数和细胞因子的测定。此外，通过 HE 染色进行组织病理学分析。使用气管环的等长张力评估 FLA（0.0316-10.0mg/ml）对肌肉力的体外舒张作用，并记录 VDLCC 电流，分别研究在分离的气管环和小鼠 ASM 细胞中的舒张机制。采用 LPS 刺激 RAW264.7 巨噬细胞评估体外抗炎作用。通过 ELISA 和 Western blotting 分析分别估计炎症介质和 MAPK 信号通路的产生。
高剂量的胡颓子叶黄酮（20mg/kg）能显著改善哮喘发作症状，缓解肺部肿胀。FLA 治疗呈剂量依赖性降低血液和 BLAF 中的嗜酸性粒细胞和白细胞数量。此外，FLA 对 IgE 和炎症相关细胞因子（包括 TNF-α、IL-5）水平的抑制作用呈剂量非依赖性。FLA 以剂量依赖性方式松弛高 K+诱导的收缩。FLA 产生的最大松弛作用为 99.7%（IC50=0.46mg/ml）。FLA（3.16mg/ml）完全消除了全细胞 VDLCC 电流，并显著降低了 VDLCC 的最大幅度。在测试浓度（1-300μg/mL）下，FLA 对 RAW264.7 细胞没有细胞毒性作用。FLA 以剂量依赖性方式显著抑制 LPS 刺激 RAW264.7 细胞中 IL-6 和 NO 的增加。在存在 FLA 的情况下用 LPS 处理，抑制了巨噬细胞中 LPS 诱导的 ERK1/2 和 JNK 的磷酸化。
胡颓子叶 FLA 可通过减少嗜酸性粒细胞和白细胞数量以及减少促炎细胞因子的产生来减轻炎症症状。这种抗炎作用与 MAPK 信号通路的调节有关。FLA 可通过阻断 VDLCC 来松弛预先收缩的 TR，从而中断细胞外 Ca2+内流并抑制 [Ca2+]i 的升高。这强烈表明这些类黄酮成分是胡颓子叶用于过敏反应、支气管痉挛和哮喘炎症的物质基础。
