Division of Life Science and Center for Chinese Medicine, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong.
Evid Based Complement Alternat Med. 2012;2012:278273. doi: 10.1155/2012/278273. Epub 2012 Jun 17.
Flavonoids, a group of compounds mainly derived from vegetables and herbal medicines, share a chemical resemblance to estrogen, and indeed some of which have been used as estrogen substitutes. In searching for possible functions of flavonoids, the neuroprotective effect in brain could lead to novel treatment, or prevention, for neurodegenerative diseases. Here, different subclasses of flavonoids were analyzed for its inductive role in neurite outgrowth of cultured PC12 cells. Amongst the tested flavonoids, a flavonol aglycone, isorhamnetin that was isolated mainly from the leaves of Ginkgo biloba L. showed robust induction in the expression of neurofilament, a protein marker for neurite outgrowth, of cultured PC12 cells. Although isorhamnetin by itself did not show significant inductive effect on neurite outgrowth of cultured PC12 cells, the application of isorhamnetin potentiated the nerve growth factor- (NGF-)induced neurite outgrowth. In parallel, the expression of neurofilaments was markedly increased in the cotreatment of NGF and isorhamnetin in the cultures. The identification of these neurite-promoting flavonoids could be very useful in finding potential drugs, or food supplements, for treating various neurodegenerative diseases, including Alzheimer's disease and depression.
类黄酮是一组主要来源于蔬菜和草药的化合物，其化学结构与雌激素相似，其中一些已被用作雌激素替代品。在寻找类黄酮可能的功能时，其在大脑中的神经保护作用可能为神经退行性疾病提供新的治疗或预防方法。在这里，分析了不同类别的类黄酮对培养的 PC12 细胞突起生长的诱导作用。在测试的类黄酮中，一种从银杏叶中分离得到的黄酮醇苷异鼠李素，对培养的 PC12 细胞中神经丝的表达有很强的诱导作用，神经丝是突起生长的蛋白质标志物。虽然异鼠李素本身对培养的 PC12 细胞的突起生长没有显著的诱导作用，但异鼠李素的应用增强了神经生长因子（NGF）诱导的突起生长。同时，在 NGF 和异鼠李素的共同处理下，培养物中的神经丝表达明显增加。这些促进突起生长的类黄酮的鉴定对于寻找治疗各种神经退行性疾病（包括阿尔茨海默病和抑郁症）的潜在药物或食品补充剂非常有用。
