Department of Food Science, Graduate School of Nutrition and Biosciences, University of Tokushima, Tokushima, Japan.
Free Radic Biol Med. 2011 Oct 1;51(7):1329-36. doi: 10.1016/j.freeradbiomed.2011.06.017. Epub 2011 Jun 23.
Quercetin is widely distributed in vegetables and herbs and has been suggested to act as a neuroprotective agent. Here, we demonstrate that quercetin can accumulate enough to exert biological activity in rat brain tissues. Homogenates of perfused rat brain without detectable hemoglobin contaminants were treated with β-glucuronidase/sulfatase and the released quercetin and its methylated form were analyzed using high-performance liquid chromatography (HPLC) with three different detection methods. Both quercetin and the methylated form were detected in the brain of quercetin-administered rats using HPLC-UV and HPLC with electrochemical detection and were further identified using HPLC-tandem mass spectrometry. Oral administration of quercetin (50mg/kg body wt) attenuated the increased oxidative stress in the hippocampus and striatum of rats exposed to chronic forced swimming. The possible transport of quercetin derivatives into the brain tissue was reproduced in vitro by using a rat brain capillary endothelial cell line, a model of the blood-brain barrier. These results show that quercetin could be a potent nutrient that can access the brain and protect it from disorders associated with oxidative stress.
槲皮素广泛存在于蔬菜和草药中，被认为具有神经保护作用。在这里，我们证明槲皮素可以在大鼠脑组织中积累到足以发挥生物活性的水平。用β-葡糖苷酸酶/硫酸酯酶处理未检测到血红蛋白污染的灌注大鼠脑匀浆，并用三种不同的检测方法使用高效液相色谱（HPLC）分析释放的槲皮素及其甲基化形式。用 HPLC-UV、HPLC 电化学检测和 HPLC 串联质谱法在给予槲皮素的大鼠脑中检测到槲皮素和甲基化形式。口服给予槲皮素（50mg/kg 体重）可减轻慢性强迫游泳暴露大鼠海马和纹状体氧化应激的增加。通过使用大鼠脑毛细血管内皮细胞系（血脑屏障模型）在体外再现了槲皮素衍生物进入脑组织的可能转运。这些结果表明，槲皮素可能是一种有效的营养物质，可以进入大脑并保护其免受与氧化应激相关的疾病的影响。
