Lee Ming Hong, Kim Jae Yeon, Yoon Jeong Hoon, Lim Hyo Jin, Kim Tae Hee, Jin Changbae, Kwak Wie-Jong, Han Chang-Kyun, Ryu Jae-Ha
College of Pharmacy, Sookmyung Women's University, 52 Hyochangwon-Gil, Yongsan-Gu, Seoul, Korea.
Phytother Res. 2006 Sep;20(9):742-7. doi: 10.1002/ptr.1942.
Activated microglia by neuronal injury or inflammatory stimulation overproduce nitric oxide (NO) by inducible nitric oxide synthase (iNOS) and reactive oxygen species (ROS) such as superoxide anion, resulting in neurodegenerative diseases. The toxic peroxynitrite (ONOO-), the reaction product of NO and superoxide anion further contributes to oxidative neurotoxicity. A butanol fraction obtained from 50% ethanol extracts of Opuntia ficus indica var. saboten (Cactaceae) stem (SK OFB901) and its hydrolysis product (SK OFB901H) inhibited the production of NO in LPS-activated microglia in a dose dependent manner (IC50 15.9, 4.2 microg/mL, respectively). They also suppressed the expression of protein and mRNA of iNOS in LPS-activated microglial cells at higher than 30 microg/mL as observed by western blot analysis and RT-PCR experiment. They also inhibited the degradation of I-kappaB-alpha in activated microglia. Moreover, they showed strong activity of peroxynitrite scavenging in a cell free bioassay system. These results imply that Opuntia ficus indica may have neuroprotective activity through the inhibition of NO production by activated microglial cells and peroxynitrite scavenging activity.
神经元损伤或炎症刺激激活的小胶质细胞会通过诱导型一氧化氮合酶（iNOS）过量产生一氧化氮（NO）以及超氧阴离子等活性氧（ROS），从而导致神经退行性疾病。有毒的过氧亚硝酸盐（ONOO-）是NO与超氧阴离子的反应产物，会进一步加剧氧化神经毒性。从仙人掌科植物米邦塔仙人掌（Opuntia ficus indica var. saboten）茎的50%乙醇提取物中获得的丁醇馏分（SK OFB901）及其水解产物（SK OFB901H）以剂量依赖性方式抑制脂多糖（LPS）激活的小胶质细胞中NO的产生（IC50分别为15.9、4.2微克/毫升）。如蛋白质免疫印迹分析和逆转录-聚合酶链反应（RT-PCR）实验所示，它们在高于30微克/毫升的浓度下还能抑制LPS激活的小胶质细胞中iNOS的蛋白质和mRNA表达。它们还抑制激活的小胶质细胞中I-κB-α的降解。此外，在无细胞生物测定系统中，它们表现出很强的过氧亚硝酸盐清除活性。这些结果表明，米邦塔仙人掌可能通过抑制激活的小胶质细胞产生NO以及过氧亚硝酸盐清除活性而具有神经保护活性。
