Faculté des Sciences de Gabès, Université de Gabès, Tunisia.
Food Chem Toxicol. 2011 Jun;49(6):1224-8. doi: 10.1016/j.fct.2011.02.024. Epub 2011 Mar 3.
Punica granatum peel aqueous extract (PGE) is widely used to treat disorders such as inflammation, ulcers and infections, but its pharmacological target is not known. In this study we investigated the effect of PGE on human neutrophil reactive oxygen species (ROS) production in vitro and on LPS-induced lung inflammation in vivo in mice. Neutrophils were isolated and ROS generation was measured by luminol-amplified chemiluminescence. Superoxide anion generation was detected by the cytochrome c reduction assay. H(2)O(2) was detected by DCFH fluorescence assay. Myeloperoxidase (MPO) activity was measured by the tetramethyl benzidine oxidation method. Lung inflammation was induced in mice by LPS instillation. PGE inhibited luminol-amplified chemiluminescence of resting neutrophils and N-formyl-methionyl-leucyl-phenylalanine (fMLF)- or phorbol myristate acetate (PMA)-stimulated neutrophils, in a concentration-dependent manner. PGE had no effect on superoxide anion generation, suggesting that it does not directly inhibit NADPH oxidase activity or activation pathways, or scavenge superoxide anions. PGE did not scavenge H(2)O(2) but directly inhibited myeloperoxidase activity in vitro. In vivo studies showed that PGE also attenuated LPS-induced lung inflammation in mice. So this study reveals that PGE inhibits neutrophil MPO activity and attenuates LPS-induced lung inflammation in mice. Inhibition of MPO activity by PGE could explain its anti-inflammatory action.
石榴皮水提物（PGE）被广泛用于治疗炎症、溃疡和感染等疾病，但它的药理靶点尚不清楚。本研究旨在探讨 PGE 对人中性粒细胞活性氧（ROS）产生的体外影响，以及对 LPS 诱导的小鼠肺部炎症的体内作用。分离中性粒细胞，通过发光氨增强化学发光法测量 ROS 的产生。通过细胞色素 c 还原试验检测超氧阴离子的生成。通过 DCFH 荧光法检测 H₂O₂。通过四甲基联苯胺氧化法测量髓过氧化物酶（MPO）活性。通过 LPS 滴注诱导小鼠肺部炎症。PGE 以浓度依赖的方式抑制静息和 N-甲酰基-甲硫氨酰-亮氨酰-苯丙氨酸（fMLF）或佛波醇 12,13-二丁酸酯（PMA）刺激的中性粒细胞的发光氨增强化学发光。PGE 对超氧阴离子的生成没有影响，提示其不直接抑制 NADPH 氧化酶活性或激活途径，也不清除超氧阴离子。PGE 不清除 H₂O₂，但可直接抑制体外 MPO 活性。体内研究表明，PGE 还可减轻 LPS 诱导的小鼠肺部炎症。因此，本研究揭示了 PGE 抑制中性粒细胞 MPO 活性并减轻 LPS 诱导的小鼠肺部炎症。PGE 通过抑制 MPO 活性来发挥抗炎作用。
