本研究探討柚子皮80%乙醇萃取物及沸水萃取物，對糖尿病關鍵酵素（α-葡萄糖苷酶）及高血壓關鍵酵素（血管收縮素轉化酶）之抑制活性。同時亦分析各萃取物的多酚類含量，DPPH自由基清除能力及三價鐵的還原力。試驗結果顯示柚子皮乙醇萃取物及水萃物對α-葡萄糖苷酶的半抑制濃度分別為2.59 mg/mL及49.37 mg/mL；對血管收縮素轉化酶的半抑制濃度分別為11.05 mg/mL及17.65 mg/mL。分析結果也顯示萃取物多酚類含量及抗氧化活性與萃取物對酵素抑制能力之間有正相關。研究結果顯示柚子皮萃取物應可藉由抑制α-葡萄糖苷酶及血管收縮素轉化酶活性，有效應用於糖尿病患餐後血糖值及高血壓的控制，有發展為相關營養保健品的潛力。
The study aims to investigate the inhibitory effects of 80% ethanolic extract and hot water extract of pomelo peels on the key enzymes relevant to diabetes (α-glucosidase) and hypertension (angiotensin converting enzyme). The polyphenol contents, DPPH free radical scavenge activities and ferric reducing power of the extracts were determined as well. The results showed that the half maximal inhibitory concentration (IC_(50)) of ethanolic and hot water extracts on α-glucosidase were 2.59 mg/mL and 49.37 mg/mL respectively; on angiotensin converting enzyme were 11.05 mg/mL and 17.65 mg/mL respectively. A positive correlation of the α-glucosidase and angiotensin converting enzyme inhibitory activity with polyphenol content and antioxidant activity was observed in this study. It is concluded that the extracts from pomelo peels with key enzymes inhibitory activity, could be used as a nutraceutical for the management of type-2 diabetes and hypertension.
