Kitagawa Rodrigo Rezende, Raddi Maria Stella Gonçalves, Khalil Najeh Maissar, Vilegas Wagner, da Fonseca Luiz Marcos
Instituto de Química de Araraquara, Universidade Estadual Paulista Júlio de Mesquita Filho, Rua Prof. Francisco Degni, s/n, CP 355, 14801-970 Araraquara, SP, Brazil.
Biol Pharm Bull. 2003 Jun;26(6):905-8. doi: 10.1248/bpb.26.905.
Paepalantine (9,10-dihydroxy-5,7-dimethoxy-1H-naphto(2,3c)pyran-1-one), a natural isocoumarin isolated from the capitula of Paepalanthus bromelioides (Eriocaulaceae), was assessed for its effect on the respiratory burst (zymosan-stimulated luminol-enhanced chemiluminescence and PMA-stimulated lucigenin-enhanced chemiluminescence) of polymorphonuclear neutrophils in vitro. Special attention was devoted to establishing the IC(50) for neutrophils. Paepalantine was able to decrease luminol and lucigenin chemiluminescence, reflecting an inhibitory effect on the respiratory burst, with an ED(50) of 0.44+/-0.05 and 0.84+/-0.15 microg/ml, respectively. A cell-free system was performed with paepalantine on myeloperoxidase/H(2)O(2) and myeloperoxidase/H(2)O(2)/Cl(-) systems. Paepalantine inhibited luminol oxidation in both systems. This inhibition was related to the interaction of paepalantine-myeloperoxidase and its scavenger effect on HOCl.
白苞藜芦碱（9,10 - 二羟基 - 5,7 - 二甲氧基 - 1H - 萘并(2,3 - c)吡喃 - 1 - 酮）是从凤梨状白苞藜芦（谷精草科）头状花序中分离得到的一种天然异香豆素，在体外评估了其对多形核中性粒细胞呼吸爆发（酵母聚糖刺激的鲁米诺增强化学发光和佛波酯刺激的光泽精增强化学发光）的影响。特别关注确定中性粒细胞的半数抑制浓度（IC50）。白苞藜芦碱能够降低鲁米诺和光泽精化学发光，反映出对呼吸爆发的抑制作用，其半数有效剂量（ED50）分别为0.44±0.05和0.84±0.15微克/毫升。使用白苞藜芦碱对髓过氧化物酶/H2O2和髓过氧化物酶/H2O2/Cl-系统进行了无细胞体系实验。白苞藜芦碱在两个系统中均抑制鲁米诺氧化。这种抑制作用与白苞藜芦碱 - 髓过氧化物酶的相互作用及其对次氯酸的清除作用有关。
