新育种苦瓜调控3T3-L1前脂肪细胞之细胞周期停滞之影响 Effects of New Variety Selection of Bitter Melon on Modulation of Cell Cycle in 3T3-L1 Preadipocytes

近年来由于饮食与生活型态改变，使得肥胖盛行率在过去数十年间以倍数方式急遽增加。苦瓜(Momordica charantia)已知含有三萜类、酚类物质与共轭亚麻油酸，过去已被长期使用作为治疗第二型糖尿病与发炎反应上，然而利用新育种苦瓜探讨3T3-L1前脂肪细胞对细胞周期调控之影响，目前仍缺乏相关文献资料。因此，本研究利用三种新育种苦瓜 (苹果苦瓜、苦瓜明道选72与苦瓜冲绳选33) 之果肉与种子，分别以水、甲醇、乙醇、丙酮与乙酸乙酯所制备之萃取物，探讨三种新育种苦瓜对3T3-L1前脂肪细胞之细胞周期调控之影响。结果显示，在30种苦瓜萃取物中，以苹果苦瓜种子水萃取物具有最佳抑制3T3-L1前脂肪细胞生长之作用，在细胞周期分析结果显示，其亦可发现3T3-L1前脂肪细胞之细胞周期停滞于G1期。在分子机制结果显示，苹果苦瓜种子水萃取物可藉由增加p-p53、p27与p18之蛋白表现，进而抑制CDK2、CDK6、cyclin D1与p-Rb之蛋白表现。综合上述结果显示，苹果苦瓜种子水萃取物可藉由抑制3T3-L1前脂肪细胞之增生，并使细胞周期停滞于G1期。 The obesity prevalence has been increasing significantly over the past few decades, which is due to change lifestyle and dietary pattern. Bitter melon contains many active ingredients, including triterpenoids, phenolics compounds, and conjugated linolenic acids. It was widely used as herbal medicine for anti-diabetes and anti-inflammatory activities. However, the effects of new variety selection of bitter melon on modulation of cell cycle in 3T3-L1 preadipocytes remain unclear. Therefore, the aim of this study was investigate the effects of different solvents (water, methanol, ethanol, acetone, and ethyl acetate) extracts from the fruit and seed of bitter melon (Momordica charantia, Momordica charantia MDS72, and Momordica charantia ONS33) on cell cycle arrest in 3T3-L1 preadipocytes. Of the 30 bitter melon extracts tested, water extract from the seed of Momordica charantia (WESMC) exhibited the strongest inhibited cell growth in 3T3-L1 preadipocytes. In cell cycle analysis, WESMC caused cell cycle arrest at the G1 phase in 3T3-L1 preadipocytes. In the molecular mechanisms, WESMC significantly increased the protein expressions of p-p53, p27, and p18, and decreased the protein expressions of CDK2, CDK6, cyclin D1, and p-Rb. These results demonstrate that WESMC could inhibit cell growth and cell cycle arrest at G1 phase in 3T3-L1 preadipocytes.