The Effects of Several Food Extracts on Glucose Uptake in 3T3-L1 Adipocytes and C2C12 Myotubes

• Main Authors: Tien-Jui Lee, 李天瑞
• Other Authors: Ching-Jang Huang
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/91416622928230853259

碩士 === 國立臺灣大學 === 微生物與生化學研究所 === 97 === Metabolic syndrome and insulin resistance have become worldwide epidemiological issues. Dietary supplement and traditional medicines may be a natural source of for the development of the treatment to counteract insulin resistance in stead of those widely used agents with many side effects. Yam and bitter gourd are common vegetable and tonic foods in Asian and have been shown to exert hypoglycemic effects in animal models and humans, but the mechanism and active constituents are not totally understood. Here we measured 3H-labeled 2-deoxyglucose uptake by normal and pamitate-induced insulin resistance 3T3-L1 adipocytes and C2C12 myotubes, and evaluated whether various extracts from yam and bitter gourd could improve. It is found that yam EA extract showed an insulin-like pattern in myotubes but not in adipocytes. Bitter gourd water extract is the most active fraction that showed a promotion of glucose uptake in both normal or insulin resistant 3T3-L1 adipocytes in a dose-dependent manner. This activity is diminished by heating the extract at 100℃ for 10 min. The activity was not inhibited by compound c but was partially inhibited by wortmannin. Neither AMPK phosphorylation nor Akt activation was changed. Interestingly, the water extract of bitter gourd could not improve the insulin resistance that induced by chronic insulin treatment. It has also been found that constituents with a MW less than 3 kDa were also active. The precise structure in bitter gourd water extract and mechanism of action of those active molecules are worth to be further examined. Bitter gourd thus has the potential for ameliorating insulin resistance.