Division of Infectious Diseases and Immunology, Council of Scientific and Industrial Research (CSIR)-Indian Institute of Chemical Biology, 4 Raja S. C. Mullick Road, Jadavpur, Kolkata 700032, West Bengal, India.
J Biol Chem. 2012 Jul 13;287(29):24844-61. doi: 10.1074/jbc.M112.341321. Epub 2012 May 29.
Macrophage migration inhibitory factor (MIF) is responsible for proinflammatory reactions in various infectious and non-infectious diseases. We have investigated the mechanism of anti-inflammatory activity of epoxyazadiradione, a limonoid purified from neem (Azadirachta indica) fruits, against MIF. Epoxyazadiradione inhibited the tautomerase activity of MIF of both human (huMIF) and malaria parasites (Plasmodium falciparum (PfMIF) and Plasmodium yoelii (PyMIF)) non-competitively in a reversible fashion (K(i), 2.11-5.23 μm). Epoxyazadiradione also significantly inhibited MIF (huMIF, PyMIF, and PfMIF)-mediated proinflammatory activities in RAW 264.7 cells. It prevented MIF-induced macrophage chemotactic migration, NF-κB translocation to the nucleus, up-regulation of inducible nitric-oxide synthase, and nitric oxide production in RAW 264.7 cells. Epoxyazadiradione not only exhibited anti-inflammatory activity in vitro but also in vivo. We tested the anti-inflammatory activity of epoxyazadiradione in vivo after co-administering LPS and MIF in mice to mimic the disease state of sepsis or bacterial infection. Epoxyazadiradione prevented the release of proinflammatory cytokines such as IL-1α, IL-1β, IL-6, and TNF-α when LPS and PyMIF were co-administered to BALB/c mice. The molecular basis of interaction of epoxyazadiradione with MIFs was explored with the help of computational chemistry tools and a biological knowledgebase. Docking simulation indicated that the binding was highly specific and allosteric in nature. The well known MIF inhibitor (S,R)-3-(4-hydroxyphenyl)-4,5-dihydro-5-isoxazole acetic acid methyl ester (ISO-1) inhibited huMIF but not MIF of parasitic origin. In contrast, epoxyazadiradione inhibited both huMIF and plasmodial MIF, thus bearing an immense therapeutic potential against proinflammatory reactions induced by MIF of both malaria parasites and human.
巨噬细胞移动抑制因子（MIF）负责各种感染性和非感染性疾病的促炎反应。我们研究了从印楝（Azadirachta indica）果实中分离出的一种单萜环氧角鲨烯抑制 MIF 的抗炎活性的机制。环氧角鲨烯以非竞争性和可逆的方式抑制人类（huMIF）和疟原虫（Plasmodium falciparum（PfMIF）和 Plasmodium yoelii（PyMIF））MIF 的互变异构酶活性（K（i），2.11-5.23 μm）。环氧角鲨烯还显著抑制 RAW 264.7 细胞中 MIF（huMIF、PyMIF 和 PfMIF）介导的促炎活性。它阻止 MIF 诱导的巨噬细胞趋化迁移、NF-κB 向核内易位、诱导型一氧化氮合酶的上调和 RAW 264.7 细胞中的一氧化氮产生。环氧角鲨烯不仅在体外表现出抗炎活性，而且在体内也表现出抗炎活性。我们在小鼠中同时给予 LPS 和 MIF 以模拟败血症或细菌感染的疾病状态，测试了环氧角鲨烯的抗炎活性。环氧角鲨烯阻止了促炎细胞因子如 IL-1α、IL-1β、IL-6 和 TNF-α的释放，当 LPS 和 PyMIF 同时给予 BALB/c 小鼠时。借助计算化学工具和生物知识库，探讨了环氧角鲨烯与 MIFs 相互作用的分子基础。对接模拟表明，结合具有高度特异性和变构性质。众所周知的 MIF 抑制剂（S,R）-3-（4-羟基苯基）-4,5-二氢-5-异恶唑乙酸甲酯（ISO-1）抑制 huMIF，但不抑制寄生虫来源的 MIF。相比之下，环氧角鲨烯抑制 huMIF 和疟原虫 MIF，因此对疟原虫和人类的 MIF 引起的促炎反应具有巨大的治疗潜力。
