Shi Chun, Yao Zhibing, Xu Jie, Yew David T
Department of Anatomy, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong SAR, China.
J Bioenerg Biomembr. 2009 Feb;41(1):61-9. doi: 10.1007/s10863-009-9197-7. Epub 2009 Feb 11.
Standardized Ginkgo biloba extract EGb761 is known to have multivalent properties such as anti-oxidation and anti-apoptosis. In this study, we determined in rat pheochromocytoma (PC12) cells effects of EGb761 treatment on oxidative damage under three different conditions of serum supply: normal growth medium (NGM), serum deprivation (SE) and serum deprivation followed by re-supply (SERS). It was found that, under the condition of serum deprivation, oxidative damage induced less cell death than the condition of serum supply. This appears to be related to inhibition of mitochondrial metabolism. Moreover, after serum deprivation, serum re-supply exacerbated cell necrosis, possibly through enhancement of oxidative damage. EGb761 could attenuate oxidative damage under the condition of serum supply whereas no protective effect on serum-depleted cells was observed. These results suggest that, there is a synergistic effect between trophic factors and EGb761. EGb761 treatment may protect cells from possible oxidative damage induced by the trophic factors. On the other hand, trophic factors appear to strengthen the protective effect of EGb761. To fully understand the synergistic interaction between antioxidants and trophic factors will help to sort out rational use of drugs in clinic practice.
标准化银杏叶提取物EGb761具有抗氧化和抗凋亡等多种特性。在本研究中，我们在大鼠嗜铬细胞瘤（PC12）细胞中，测定了EGb761处理在三种不同血清供应条件下对氧化损伤的影响：正常生长培养基（NGM）、血清剥夺（SE）和血清剥夺后再供应（SERS）。结果发现，在血清剥夺条件下，氧化损伤诱导的细胞死亡比血清供应条件下少。这似乎与线粒体代谢的抑制有关。此外，血清剥夺后，血清再供应加剧了细胞坏死，可能是通过增强氧化损伤。EGb761在血清供应条件下可减轻氧化损伤，而对血清缺乏的细胞未观察到保护作用。这些结果表明，营养因子与EGb761之间存在协同作用。EGb761处理可能保护细胞免受营养因子诱导的可能的氧化损伤。另一方面，营养因子似乎增强了EGb761的保护作用。充分了解抗氧化剂与营养因子之间的协同相互作用将有助于在临床实践中合理用药。
