朝药榛子雄花活性成分的分离及肝保护机制研究

Flowers of Corylus heterophylla Fisch. ex Trautv.(Betulaceae), one of the traditional Korean minority folk medicine, have been traditionally used to prevent and treat liver cirrhosis and other liver diseases with a long and extensive application fundamental research. But so far, there is no report on the study of the active components and the related mechanisms of liver injury. This project intends to isolate bioactive constituents from the flowers of C. heterophylla by chromatographic methods, including normal and reverse phase silica, MPLC, HPLC, etc. And these isolated constituents were identified by NMR and mass spectra. The hepatoprotective mechanisms of the active fractions from flowers of C. heterophylla were detected in liver damage induced by D-galactosamine/ lipopolysaccharide (LPS/D-GalN) or carbon tetrachlroride (CCl4). Oxidative stress plays a critical role in liver cell injury, and then hepatoprotective mechanisms of isolated constituents from flowers of C. heterophylla were evaluated against cytotoxicity of HepG2 induced by t-BHP or tacrine via heme oxygenase (HO)-1 and nuclear factor E2-related factor 2 (Nrf2) signaling pathway. The results of the project will provide theoretical basis and technical support for the therapy of flowers of C. heterophylla on liver disease.

榛子雄花（桦木科）是一种中国朝药，常用于预防和治疗肝硬化等各种肝脏疾病，有广泛、悠久的应用基础，但是到目前为止尚无完整的活性成分和相关抗肝损伤机制的研究报道。本项目拟应用正反相、MPLC，HPLC等色谱学方法，从榛子雄花中分离活性成分并利用核磁和质谱进行结构鉴定。利用D-半乳糖胺/脂多糖（D-GalN/LPS）或四氯化碳（CCl4）诱导小鼠肝毒性，评价榛子雄花活性部位的保护机制。氧化应激在肝细胞损伤中起关键作用，为此，我们拟进行从榛子雄花中分离的化合物在t-BHP或他可林诱导的HepG2细胞毒性中的保护作用和血红素加氧酶（HO）-1的表达及核因子E2相关因子2（Nrf2）的相关信号通路的机制研究。本项目的研究结果将对应用榛子雄花治疗肝疾病提供理论基础和技术支持。

榛子雄花是一种中国朝药，在民间上常用于预防和治疗各种肝脏疾病。本项目通过榛子雄花提取物进行了体内外实验验证了肝保护活性，且从榛子雄花提取物中分离得到了30个化合物，其中化合物hirsutanone和oregonin通过血红素加氧酶（HO-1）的表达对肝细胞具有保护作用。Hirsutanone是通过调控MAPK/Keap1-Nrf2-HO-1信号通路起到抗氧化应激的作用；并通过调节Bcl-2/Bax-Caspase信号通路及iNOS、COX-2蛋白的表达抑制细胞凋亡和炎症介质的产生；oregonin对t-BHP处理的HepG2细胞是通过抗氧化酶活性及调节Bcl-2/Bax-Caspase信号通路来保护肝细胞损伤。不同神曲发酵的榛子雄花的提取物均具有一定的抗氧化、抗炎、降血糖以及酪氨酸酶抑制作用。