Heo Ho Jin, Kim Dae-Ok, Choi Soo Jung, Shin Dong Hoon, Lee Chang Yong
Department of Food Science and Technology, Cornell University, Geneva, New York 14456, USA.
J Agric Food Chem. 2004 Jun 30;52(13):4128-32. doi: 10.1021/jf049953x.
The free radical scavenging activities of two major flavonoids (baicalein and baicalin) in Scutellaria baicalensis were determined. The antioxidant capacities of baicalein and baicalin were determined by the 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid)(*)(-) scavenging assay and showed about 110 and 70% vitamin C equivalent antioxidant capacity, respectively. Because amyloid beta (Abeta) protein is known to increase free radical production and lipid peroxidation in PC12 nerve cells, leading to apoptosis and cell death, treatment with baicalein and baicalin may result in the prevention of cellular damage by the Abeta-induced reactive oxygen species. We found that baicalein and baicalin resulted in a dose-dependent anti-Abeta toxicity by means of three different assays [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide reduction, lactate dehydrogenase release, and trypan blue exclusion assays]. These results suggest that baicalein as well as baicalin can reduce the cytotoxicity of Abeta protein in PC12 cells, possibly by a reduction of oxidative stress, and these flavonoids may be useful in the chemoprevention of Alzheimer's disease.
测定了黄芩中两种主要黄酮类化合物（黄芩素和黄芩苷）的自由基清除活性。通过2,2'-联氮双(3-乙基苯并噻唑啉-6-磺酸)（*）(-)清除试验测定了黄芩素和黄芩苷的抗氧化能力，结果显示它们的维生素C等效抗氧化能力分别约为110%和70%。由于已知β-淀粉样蛋白（Aβ）会增加PC12神经细胞中的自由基产生和脂质过氧化，导致细胞凋亡和死亡，因此用黄芩素和黄芩苷进行处理可能会预防Aβ诱导的活性氧对细胞的损伤。我们通过三种不同的试验[3-(4,5-二甲基噻唑-2-基)-2,5-二苯基四氮唑溴盐还原试验、乳酸脱氢酶释放试验和台盼蓝排斥试验]发现，黄芩素和黄芩苷可产生剂量依赖性的抗Aβ毒性。这些结果表明，黄芩素和黄芩苷可能通过降低氧化应激来降低PC12细胞中Aβ蛋白的细胞毒性，并且这些黄酮类化合物可能对阿尔茨海默病的化学预防有用。
