Tian Jingwei, Zhang Shumin, Li Guisheng, Liu Zhifeng, Xu Benming
School of Pharmacy, Yantai University, Yantai, PR China.
Phytother Res. 2009 Apr;23(4):486-91. doi: 10.1002/ptr.2653.
Ginseng, the root of Panax ginseng C.A. Meyer (Araliaceae), is a well-known traditional Chinese herbal medicine. Ginsenosides, which are triterpene derivatives that contain sugar moieties, are the main active ingredients of ginseng. 20(S)-Ginsenoside Rg3, a triterpene glycoside which chemically belongs to the protopanaxadiol ginsenoside group, is effective in attenuating brain infarction after cerebral ischemia, but the detailed mechanism is not known. This study examined the effect of 20(S)-ginsenoside Rg3 on mitochondrial permeability transition pore (MPTP) in the rat brain. 20(S)-Ginsenoside Rg3 at 2-16 microm inhibited Ca(2+)- and H(2)O(2)-induced swelling of mitochondria isolated from rat brains. The addition of Ca(2+) generated reactive oxygen species (ROS) in isolated mitochondria. 20(S)-Ginsenoside Rg3 (2-16 microm) inhibited Ca(2+) induced generation of ROS. At the same time, 20(S)-ginsenoside Rg3 significantly improved mitochondrial energy metabolism, enhanced ATP levels and the respiratory control ratio. These results suggest that 20(S)-ginsenoside Rg3 inhibits the opening of MPTP by free radical scavenging action in the brain, and this implies that inhibition of MPTP may contribute to the neuroprotective effect of 20(S)-ginsenoside Rg3.
人参是五加科植物人参（Panax ginseng C.A. Meyer）的根，是一种著名的传统中药。人参皂苷是含有糖基部分的三萜衍生物，是人参的主要活性成分。20(S)-人参皂苷Rg3是一种化学上属于原人参二醇型人参皂苷组的三萜糖苷。它在减轻脑缺血后的脑梗死方面具有显著疗效，但具体机制尚不清楚。本研究探讨了20(S)-人参皂苷Rg3对大鼠脑线粒体通透性转换孔（MPTP）的影响。20(S)-人参皂苷Rg3浓度为2-16微摩尔时，可抑制由钙离子（Ca2+）和过氧化氢（H2O2）诱导的大鼠脑线粒体肿胀。在分离的线粒体中，钙离子的加入会产生活性氧（ROS）。20(S)-人参皂苷Rg3（2-16微摩尔）可抑制钙离子诱导的活性氧生成。同时，20(S)-人参皂苷Rg3显著改善线粒体能量代谢，提高ATP水平和呼吸控制率。这些结果表明，20(S)-人参皂苷Rg3通过清除脑中的自由基来抑制MPTP的开放，这意味着抑制MPTP可能有助于20(S)-人参皂苷Rg3的神经保护作用。
