Chen C, Wei T, Gao Z, Zhao B, Hou J, Xu H, Xin W, Packer L
Institute of Biophysics, Academia Sinica, Beijing, P. R. China.
Biochem Mol Biol Int. 1999 Mar;47(3):397-405. doi: 10.1080/15216549900201423.
The present study was conducted to evaluate the different effects of the constituents of EGb761 (Ginkgo biloba Extract) on apoptosis in cerebellar granule cells induced by hydroxyl radicals. The total flavonoid component of EGb761, two pure EGb761 components (rutin and quercetin), and a mixture of flavonoids and terpenes protected cerebellar granule cells from oxidative damage and apoptosis induced by hydroxyl radicals. ESR(electron spin resonance) results showed that the IC50 of the flavonoids for scavenging hydroxyl radicals was almost the same as that of EGb761, even though flavonoids make up only 24% of EGb761, implying that other constituents of EGb761 besides flavonoids can scavenge hydroxyl radicals. Total terpenes of EGb761 did not protect against apoptosis. Flavonoids and terpenes did not show a synergistic effect in this regard. Terpenes did not scavenge hydroxyl radicals directly, which might be related to their "cage-like" structures.
本研究旨在评估银杏叶提取物761（EGb761）的成分对羟自由基诱导的小脑颗粒细胞凋亡的不同影响。EGb761的总黄酮成分、两种纯EGb761成分（芦丁和槲皮素）以及黄酮类和萜类的混合物可保护小脑颗粒细胞免受羟自由基诱导的氧化损伤和凋亡。电子自旋共振（ESR）结果表明，尽管黄酮类仅占EGb761的24%，但其清除羟自由基的半数抑制浓度（IC50）与EGb761几乎相同，这意味着EGb761中除黄酮类之外的其他成分也能清除羟自由基。EGb761的总萜类不能预防凋亡。在这方面，黄酮类和萜类未显示出协同作用。萜类不能直接清除羟自由基，这可能与其“笼状”结构有关。
