Study on mechanisms underlying the preventive effects of theChinese olive ethanol extract on modulation of hyperglycemia and hypercholesterolemia in animal model

• Main Authors: Yu-Han Kao, 高郁涵
• Other Authors: Hsu-Chen Hsieh
• Format: Others
• Language: zh-TW
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/44527350654298031236

碩士 === 國立臺灣大學 === 食品科技研究所 === 104 === Chinese olive (Canarium album L.), a plant in the Burseraceae family is widely cultivated in Hsinchu (Taiwan), the southeast area of China and other Asian regions. It has several pharmacological effects including hepatoprotective, antimicrobial, detoxic and antivirus. Phytochemical studies have shown that Chinese olive fruit is rich in polyphenols. These phytochemcals appear to be responsible for the pharmacological activity of Chinese olive fruit and have properties that may reduce the risk of metabolic diseases. Diabetes can be controlled through the reduction of hyperglycaemia. However, the exact mechanism of protection is not real understood. Thus, the objective of this study was to investigate the effects of an ethanol extract of Canarium album L. (COE) on the regulation of glucose and lipid metabolism in type 2 diabetic rats and L6 muscle cell line. Type 2 diabetes was induced in rats by feeding a 60% high-fat diet (HFD) and a low dose (35 mg/kg.BW) of streptozotocin injection. COE significantly reduced the elevated blood glucose levels, epididymal fat, serum FFA, total cholesterol and bile acid level elevated by HFD. Moreover, treatment of COE elevated deoxyglucose uptake in differentiated L6 muscle cells. Our findings demonstrate that COE improves glucose metabolism and in type 2 diabetes by decreased hepatic gluconeogenesis via its regulation on GK and PEPCK expressions. COE could attenuate the hepatic expression of SREBP-2 with a subsequent decrease in hepatic HMGCR mRNA expression and an increase in hepatic LDL receptor to decreased serum cholesterol concention. Also, COE represses hepatic BA synthesis via a FXR/SHP/CYP7A1 signaling pathway. Thus, COE could act as adjuvant therapeutics for metabolic disorders via attenuating obesity, epididymal fat, and improving serum parameters with cholesterol clearance and bile acid regulation of liver.