背景:苏木(Lignumsappan),CaesalpiniasappanL.的干心材,是一种用作止痛药和抗炎剂的传统中药。
目的:本研究旨在从Sumu中发现具有抗炎和抗氧化双重活性的天然磷酸二酯酶4(PDE4)抑制剂,用于治疗慢性阻塞性肺疾病(COPD)。
方法:为了准确有效地从苏木中鉴定天然PDE4抑制剂,分子对接和分子动力学(MD)分析方法用于基于结构的虚拟筛选Sumu中一级多酚的自建数据库。根据前人对苏木和多酚的自由基清除机理的研究,从通过对接预测的潜在PDE4抑制剂中选择了Sumu报道的抗氧化成分以及具有邻苯二酚和π-共轭部分的抗氧化药效团的潜在抗氧化剂。SappanoneA,来自Sumu的具有抗氧化活性的潜在PDE4抑制剂,被选中,计算和合成,以评估其在体外和体内研究中的抗炎和抗氧化双重功能。本文测定了苏伯酮A对PDE4酶活性的抑制作用,RAW264.7巨噬细胞中脂多糖(LPS)诱导的肿瘤坏死因子-α(TNF-α)的产生和小鼠肺匀浆中Fe2诱导的丙二醛(MDA)的产生;还测定了sappanoneA的自由基(DPPH)清除能力,在体外减少Fe3+和复合Fe2+。此外,LPS诱导的小鼠急性肺损伤(ALI)用于评估其作为PDE4抑制剂的体内抗炎活性,并测定支气管肺泡灌洗液(BALF)中TNF-α和总蛋白的水平和肺中髓过氧化物酶(MPO)的活性。
结果:本研究预测并验证了苏木是一种有前途的PDE4抑制剂,具有苏木的双重抗炎和抗氧化活性。体外,sappanoneA显着抑制了LPS诱导的RAW264.7巨噬细胞中PDE4酶活性并减少了TNF-α的产生,并降低了Fe2诱导的小鼠肺匀浆中MDA的产生。同时,它表现出出色的清除DPPH自由基的能力,还原Fe3+和络合Fe2+。在体内,沙丁酮A(25mg/kg和50mg/kg,i.p.,每天两次,共7天)通过降低BALF中TNF-α和总蛋白的水平以及肺部MPO活性,明显预防了LPS诱导的小鼠ALI。
结论:苏木是一种天然PDE4抑制剂,具有抗炎和抗氧化双重活性,这可能是一个有前途的治疗药物,以防止COPD炎症和氧化应激的恶性循环。
BACKGROUND: Sumu (Lignum sappan), the dry heartwood of
Caesalpinia sappan L., is a traditional Chinese medicine used as an analgesic and anti-inflammatory agent.
OBJECTIVE: The study aspired to discover natural phosphodiesterase 4 (PDE4) inhibitors with dual anti-inflammatory and antioxidant activities from Sumu for the treatment of chronic obstructive pulmonary disease (COPD).
METHODS: To accurately and efficiently identify natural PDE4 inhibitors from Sumu, molecular docking and molecular dynamics (MD) analysis methods were used for structure-based virtual screening of a self-built database of primary polyphenols in Sumu. According to the previous studies of Sumu and the free radical scavenging mechanism of polyphenols, the reported antioxidant components from Sumu and the potential antioxidants with the antioxidant pharmacophore of catechol and π-conjugated moieties were selected from the potential PDE4 inhibitors predicted by docking. Sappanone A, a potential PDE4 inhibitor with antioxidant activity from Sumu, was selected, calculated and synthesized to evaluate its dual anti-inflammatory and antioxidant functions in vitro and in vivo studies. Herein sappanone A was assayed for its inhibitory effects against PDE4 enzyme activity, tumor necrosis factor-alpha (TNF-α) production induced by lipopolysaccharide (LPS) in RAW264.7 macrophages and malondialdehyde (MDA) production induced by Fe2+ in mouse lung homogenate; sappanone A was also assayed for its abilities of radical (DPPH) scavenging, reducing Fe3+ and complexing Fe2+ in vitro. Additionally, LPS-induced acute lung injury (ALI) in mice was used to evaluate its anti-inflammatory activity as a PDE4 inhibitor in vivo, and the levels of TNF-α and total protein in bronchoalveolar lavage fluid (BALF) and myeloperoxidase (MPO) activity in the lung were assayed.
RESULTS: The present study predicted and validated that sappanone A was a promising PDE4 inhibitor from Sumu with dual anti-inflammation and antioxidant activities from Sumu. In vitro, sappanone A remarkably inhibited PDE4 enzyme activity and reduced TNF-α production induced by LPS in RAW264.7 macrophages and MDA production induced by Fe2+ in mouse lung homogenate. Meanwhile, it showed outstanding abilities of scavenging DPPH radicals, reducing Fe3+ and complexing Fe2+. In vivo, sappanone A (25 mg/kg and 50 mg/kg, i.p., twice daily for 7 days) distinctly prevented LPS-induced ALI in mice by reducing the levels of TNF-α and total protein in BALF and MPO activity in the lung.
CONCLUSIONS: Sappanone A is a natural PDE4 inhibitor with dual anti-inflammatory and antioxidant activities from the traditional Chinese medicine Sumu, which may be a promising therapeutic agent to prevent the vicious cycle of COPD inflammation and oxidative stress.