In-vivo and in-vitro assessment of the free-radical-scavenger activity of Ginkgo flavone glycosides at high concentration
In-vivo and in-vitro assessment of the free-radical-scavenger activity of Ginkgo flavone glycosides at high concentration
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DOI：
10.1211/0022357991777083
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发表时间：
1999-12-01
影响因子：
3.3
通讯作者：
Poelman, MC
中科院分区：
文献类型：
--
作者：
Hibatallah, J;Carduner, C;Poelman, MC
自由基与许多皮肤病有关，尤其是炎症反应和光衰老。为了确定含有 33% 银杏黄酮苷（主要是槲皮素和山奈酚衍生物）的原始无萜银杏叶提取物可能具有的自由基清除作用，我们通过体外和体内实验研究了其活性，并使用超氧化物歧化酶 (SOD) 作为阳性对照。通过体外电子自旋共振 (ESR) 测定我们比较了银杏提取物与其两种苷元槲皮素和山奈酚的活性。槲皮素和银杏提取物具有显着的抗氧化特性，但没有促氧化作用。相反，超过最佳抗氧化剂浓度的山奈酚则充当促氧化剂。体内实验是在抗炎模型上进行的。通过激光多普勒灌注成像仪记录反映皮肤炎症水平的皮肤血流量。数据证实了银杏提取物和 SOD 的自由基清除特性。银杏提取物显着抑制 (37%) 皮肤血流量，其程度与 SOD 相同。这些数据证实了银杏提取物的抗氧化特性。互补的自旋捕获技术将能够识别所涉及的自由基。这种银杏提取物应该有助于保护皮肤免受自由基的侵害。
Free radicals are involved in numerous skin diseases, especially inflammatory reactions and photosenescence. To identify possible free-radical scavenging by an original terpene-free Ginkgo biloba extract containing 33% Ginkgo flavone glycosides, mostly quercetin and kaempferol derivatives, we studied its activity by means of in-vitro and in-vivo experiments, using superoxide dismutase (SOD) as a positive control.By means of an in-vitro electron-spin resonance (ESR) assay we compared the activity of the Ginkgo extract with that of its two aglycones, quercetin and kaempferol. Quercetin and Ginkgo extract had significant antioxidant properties without pro-oxidant effect. In contrast, kaempferol, above an optimum antioxidant concentration, behaved as a prooxidant. The in-vivo experiments were conducted on an anti-inflammatory model. The cutaneous blood flux which reflects the skin inflammatory level was recorded by means of a laser Doppler perfusion imager. The data confirmed the free-radical-scavenging property of both Ginkgo extract and SOD. The Ginkgo extract significantly inhibited (37%) cutaneous blood flux to the same extent as SOD.These data confirmed the antioxidant property of Ginkgo extract. A complementary spin-trapping technique would enable identification of the free radicals involved. This Ginkgo extract should be useful for protection of the skin against free radicals.