Incarvillateine produces antinociceptive and motor suppressive effects via adenosine receptor activation
作者:Jinwoo Kim、Diane M. Bogdan、Matthew W. Elmes、Monaf Awwa、Su Yan、Joyce Che、Garam Lee、Dale G. Deutsch、Robert C. Rizzo、Martin Kaczocha、Iwao Ojima
DOI:10.1371/journal.pone.0218619
日期:——
(-)-Incarvillateine (INCA) is a natural product that has garnered attention due to its purported analgesic effects and historical use as a pain reliever in China. α-Truxillic acid monoesters (TAMEs) constitute a class of inhibitors targeting fatty acid binding protein 5 (FABP5), whose inhibition produces analgesia in animal models. The structural similarity between INCA and TAMEs motivated us to assess whether INCA exerts its antinociceptive effects via FABP inhibition. We found that, in contrast to TAMEs, INCA did not exhibit meaningful binding affinities toward four human FABP isoforms (FABP3, FABP4, FABP5 and FABP7) in vitro. INCA-TAME, a putative monoester metabolite of INCA that closely resembles TAMEs also lacked affinity for FABPs. Administration of INCA to mice produced potent antinociceptive effects while INCA-TAME was without effect. Surprisingly, INCA also potently suppressed locomotor activity at the same dose that produces antinociception. The motor suppressive effects of INCA were reversed by the adenosine A2 receptor antagonist 3,7-dimethyl-1-propargylxanthine. Collectively, our results indicate that INCA and INCA-TAME do not inhibit FABPs and that INCA exerts potent antinociceptive and motor suppressive effects at equivalent doses. Therefore, the observed antinociceptive effects of INCA should be interpreted with caution.
(-)-醉茄酸单酯(INCA)是一种天然产物,因其所谓的镇痛效果和在中国作为镇痛剂的历史而备受关注。α-曲昔酸单酯(TAMEs)是一类靶向脂肪酸结合蛋白5(FABP5)的抑制剂,抑制该蛋白可在动物模型中产生镇痛效果。INCA 与 TAMEs 在结构上的相似性促使我们评估 INCA 是否通过抑制 FABP 来发挥镇痛作用。我们发现,与 TAMEs 不同,INCA 在体外与四种人类 FABP 异构体(FABP3、FABP4、FABP5 和 FABP7)的结合亲和力并不明显。INCA-TAME是INCA的一种推定单酯代谢物,与TAMEs非常相似,但也缺乏与FABPs的亲和力。给小鼠注射 INCA 会产生强烈的抗痛觉作用,而 INCA-TAME 则没有作用。令人惊讶的是,在产生抗痛觉作用的相同剂量下,INCA 还能有效抑制运动活动。腺苷 A2 受体拮抗剂 3,7-二甲基-1-丙炔黄嘌呤可逆转 INCA 的运动抑制作用。总之,我们的研究结果表明,INCA 和 INCA-TAME 并不抑制 FABPs,INCA 在同等剂量下具有强效的抗痛觉和运动抑制作用。因此,应谨慎解释所观察到的 INCA 的抗痛觉作用。