Chang Han-Lin, Chang Fang-Rong, Chen Jin-Shan, Wang Hui-Po, Wu Yi-Hsiu, Wang Chien-Chiao, Wu Yang-Chang, Hwang Tsong-Long
Graduate Institute of Natural Products, Chang Gung University, Taoyuan 333, Taiwan.
Eur J Pharmacol. 2008 May 31;586(1-3):332-9. doi: 10.1016/j.ejphar.2008.02.041. Epub 2008 Mar 4.
Reactive oxygen species and granule proteases produced by neutrophils contribute to the pathogenesis of inflammatory diseases. In this study, a cellular model in isolated human neutrophils was established to elucidate the anti-inflammatory functions of 16-hydroxycleroda-3,13(14)E-dien-15-oic acid (PL3S), a clerodane diterpenoid from Formosan Polyalthia longifolia var. pendula. PL3S significantly inhibited the generation of superoxide anion and the release of elastase in formyl-l-methionyl-l-leucyl-l-phenylalanine (FMLP)-activated human neutrophils in a concentration-dependent fashion with IC50 values of 3.06+/-0.20 and 3.30+/-0.48 microM, respectively. PL3S did not affect cAMP-dependent pathway, and the inhibitory effect of PL3S was not reversed by protein kinase A inhibitor. PL3S did not display antioxidant or superoxide anion-scavenging ability, and it failed to alter the subcellular NADPH oxidase activity. PL3S concentration-dependently inhibited calcium mobilization caused by FMLP but not thapsigargin. Furthermore, PL3S attenuated the FMLP-induced protein kinase B (AKT) and p38 mitogen-activated protein kinase phosphorylation. However, PL3S had no effect on FMLP-induced phosphorylation of extracellular regulated kinase and c-Jun N-terminal kinase. In summary, these results indicate that the suppressive effects of PL3S on human neutrophil respiratory burst and degranulation are at least partly mediated by inhibition of calcium, AKT, and p38 signaling pathways.
中性粒细胞产生的活性氧和颗粒蛋白酶会导致炎症性疾病的发病机制。在本研究中，建立了分离的人中性粒细胞的细胞模型，以阐明16 - 羟基克罗烷 - 3,13(14)E - 二烯 - 15 - 酸（PL3S）的抗炎功能，PL3S是一种来自台湾假鹰爪变种的克罗烷二萜。PL3S以浓度依赖性方式显著抑制甲酰 - l - 蛋氨酰 - l - 亮氨酰 - l - 苯丙氨酸（FMLP）激活的人中性粒细胞中超氧阴离子的产生和弹性蛋白酶的释放，IC50值分别为3.06±0.20和3.30±0.48 microM。PL3S不影响cAMP依赖性途径，蛋白激酶A抑制剂也不能逆转PL3S的抑制作用。PL3S不具有抗氧化或超氧阴离子清除能力，也不能改变亚细胞NADPH氧化酶活性。PL3S浓度依赖性地抑制FMLP引起的钙动员，但不抑制毒胡萝卜素引起的钙动员。此外，PL3S减弱了FMLP诱导的蛋白激酶B（AKT）和p38丝裂原活化蛋白激酶的磷酸化。然而，PL3S对FMLP诱导的细胞外调节激酶和c - Jun N末端激酶的磷酸化没有影响。总之，这些结果表明，PL3S对人中性粒细胞呼吸爆发和脱颗粒的抑制作用至少部分是通过抑制钙、AKT和p38信号通路介导的。
