Dou Fang, Xi Miaomiao, Wang Junxian, Tian Xiangrong, Hong Liangjian, Tang Haifeng, Wen Aidong
Department of Pharmacy, Xijing Hospital, Fourth Military Medical University, Yangling, PR China.
Pharmazie. 2013 Apr;68(4):300-4.
Extracts of eleven traditional Chinese medicines (TCM) with a reputation of usefulness in treating diabetes mellitus were examined for alpha-glucosidase and alpha-amylase inhibitory activities in vitro. The extract with the highest activity was selected for further characterization. The extract of the root bark of Aralia taibaiensis (EAT) outperformed other extracts in the assays with IC50 values of 0.48 +/- 0.01 mg/mL (BSG), 0.41 +/- 0.02mg/mL (SCG), 0.61 +/- .03mg/mL (BLA) and 0.77 +/- 0.03mg/mL (PPA), respectively. To identify which constituents were responsible for the activities, thirteen triterpenoid saponins were isolated from EAT and examined for their inhibitory effects against alpha-glucosidase and alpha-amylase. The results revealed that saponins 2, 3, 4 (IC50: 0.83 +/- 0.05 microM for BSG and IC50: 0.72 +/- 0.03 microM for SCG), 5, 6, 7, 9, 10, 11 and 12 (IC50: 1.07 +/- 0.04 micro.M for BSG and IC50: 0.93 +/- 0.05 micro.M for SCG) showed alpha-glucosidase inhibitory activities, while 2, 3, 4 (IC50: 0.93 +/- 0.04 micro.M for PPA), 5, 6, 7, 9, 10, 11 and 12 (IC50: 1.02 +/- 0.03 micro.M for PPA) possessed significant alpha-amylase inhibitory activities. In addition, the structure-activity relationship of the thirteen saponins was discussed based on their structure features and diabetes mellitus related activities. It is suggested that the glucuronic acid unit at C-3 of the aglycone is the imperative functional group of the antidiabetic activities, and two characteristic structural features are responsible for the remarkable alpha-glucosidase and alpha-amylase inhibitory activities.
对十一种素有治疗糖尿病功效的传统中药提取物进行了体外α-葡萄糖苷酶和α-淀粉酶抑制活性检测。选取活性最高的提取物进行进一步特性分析。太白楤木根皮提取物（EAT）在检测中表现优于其他提取物，其对BSG、SCG、BLA和PPA的IC50值分别为0.48±0.01mg/mL、0.41±0.02mg/mL、0.61±0.03mg/mL和0.77±0.03mg/mL。为确定哪些成分具有这些活性，从EAT中分离出13种三萜皂苷，并检测它们对α-葡萄糖苷酶和α-淀粉酶的抑制作用。结果显示，皂苷2、3、4（对BSG的IC50为0.83±0.05μM，对SCG的IC50为0.72±0.03μM）、5、6、7、9、10、11和12（对BSG的IC50为1.07±0.04μM，对SCG的IC50为0.93±0.05μM）具有α-葡萄糖苷酶抑制活性，而2、3、4（对PPA的IC50为0.93±0.04μM）、5、6、7、9、10、11和12（对PPA的IC50为1.02±0.03μM）具有显著的α-淀粉酶抑制活性。此外，根据这13种皂苷的结构特征和与糖尿病相关的活性，讨论了它们的构效关系。研究表明，苷元C-3位的葡萄糖醛酸单元是抗糖尿病活性的关键官能团，两个特征结构对显著的α-葡萄糖苷酶和α-淀粉酶抑制活性起作用。
