摘要
神秘果 (Synsepalum dulcificum)，又名miracle fruit，因含有特殊醣蛋白miraculin，故常做甜味劑使用。研究指出神秘果具有改變酸味成為甜味之功能、減少醣類攝取、抗糖尿病、調控血糖、降膽固醇、抗高尿酸血症與抗氧化等功能，其中調控血糖之機制及人體相關研究仍有限。本研究以C2C12肌纖維母細胞探討神秘果對於血糖之調控以及可能有效成分與作用機制。以神秘果之乙醇粗萃取物與結合性酚類化合物萃取物 (bound phenol) 針對C2C12進行2-NBDG攝入試驗、胰島素接收器 (IR)、磷酸肌醇3-激酶 (PI3K) 及葡萄糖轉運子4 (GLUT4) 之測定。結果顯示，結合性酚類化合物萃取物能有效刺激2-NBDG攝入量，在胰島素訊號傳遞中則顯示能有效活化IR、PI3K和GLUT4之表現，顯示結合性酚類化合物萃取物為神秘果調節血糖之主要貢獻物。人體試驗中，我們將34名糖尿病前期受試者隨機分為實驗組與對照組，分別給予受試者神秘果果肉冷凍乾燥粉或麥芽糊精(每日3g)，介入期為12週，於停止服用後進行四週追蹤期。結果發現介入12週後，受試者的空腹血糖值、糖化血色素有顯著下降。本研究顯示神秘果能有效調控血糖。所含之結合性酚類化合物，能有效活化肌纖維母細胞胰島素傳訊因子，進而達到調控血糖之功效。
並列摘要
The Miracle fruit (Synsepalum dulcificum) is often used as a natural sweetener because of its a special glycoprotein named miraculin. Previous studies have indicated that miracle fruit shows the functions of turning sour taste into sweet taste, reducing sugar intake, anti-diabetic, regulating blood sugar, lowering cholesterol, anti-hyperuricemia and antioxidation. However, the role of miracle fruit on the regulatory mechanism and human clinical trial about blood glucose are still limited. In this study, C2C12 myofibroblast cells were used to investigate the potential contributor, regulatory and mechanism on blood sugar. Miracle fruit EtOH crude extract and bound phenol extract were used to evaluate glucose uptake by C2C12 cell. Insulin receptor (IR), phosphoinositide 3-kinase (PI3K) and glucose transporter 4 (GLUT4) were also determined. Results showed that the bound phenol extract can effectively stimulate the uptake of 2-NBDG, and it also effectively activated IR, PI3K and GLUT4 in insulin signaling. This showed that the bound phenol extract would be the main contributor on the regulation of blood glucose in miracle fruit. 34 subjects were assigned into the experimental group and the control group. Each subject was given 3g of freeze-dried powder of miracle fruit pulp or dextrin per day. The total intervention period was 12 weeks. Additional four-week was follow-up period. After 12 weeks of intervention, the subjects' fasting blood glucose, glycosylated hemoglobin decreased significantly. Therefore, this study clearly showed that miracle fruit could effectively regulate blood glucosee. The bound phenols could be the major contributor on blood glucose regulation.