Oh G S, Pae H O, Choi B M, Seo E A, Kim D H, Shin M K, Kim J D, Kim J B, Chung H T
Medicinal Resources Research Center of Wonkwang University, Iksan, Chonbuk 570-749, South Korea.
Cancer Lett. 2004 Mar 8;205(1):23-9. doi: 10.1016/j.canlet.2003.09.037.
Ginsenosides from Panax ginseng are metabolized by human intestinal bacteria after oral administration of ginseng extract. 20(S)-Protopanaxatriol (PPT) is one of the major metabolites of ginsenosides. Inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) are important enzymes that mediate inflammatory processes. Improper up-regulation of iNOS and/or COX-2 has been associated with the pathogenesis of inflammatory diseases and certain types of human cancers. Here, we investigated whether PPT could modulate iNOS and COX-2 expressions in RAW 264.7 macrophages stimulated with the endotoxin lipopolysaccharide (LPS). We found that PPT blocked the increase in LPS-induced iNOS and COX-2 expressions through inactivation of nuclear factor-kappaB by preventing I-kappaBalpha phosphorylation and degradation. Thus, it may be possible to develop PPT as a useful agent for chemoprevention of cancer or inflammatory diseases.
口服人参提取物后，人参中的人参皂苷会被人体肠道细菌代谢。20(S)-原人参三醇（PPT）是人参皂苷的主要代谢产物之一。诱导型一氧化氮合酶（iNOS）和环氧化酶-2（COX-2）是介导炎症过程的重要酶。iNOS和/或COX-2的不当上调与炎症性疾病和某些类型的人类癌症的发病机制有关。在此，我们研究了PPT是否能调节经内毒素脂多糖（LPS）刺激的RAW 264.7巨噬细胞中iNOS和COX-2的表达。我们发现，PPT通过阻止I-κBα磷酸化和降解使核因子-κB失活，从而阻断LPS诱导的iNOS和COX-2表达的增加。因此，有可能将PPT开发成为一种用于癌症或炎症性疾病化学预防的有用药物。
