消渴草減輕小鼠FL83B肝臟細胞株胰島素阻抗及脂肪累積之研究

Alleviative effect of Ruellia tuberosa L. on insulin resistance and lipid accumulation in FL83B mouse hepatocytes

黃郁筑(Huang Yu-Chu)

指導教授 ： 沈賜川

國立臺灣師範大學/教育學院/人類發展與家庭學系/碩士(2016年)

https://doi.org/10.6345/NTNU202203922

摘要

第二型糖尿病( Type 2 diabetes mellitus )為一種代謝性慢性疾病，主要病徵為胰島素分泌不足或細胞發生胰島素阻抗，造成高血糖的現象，流行病學調查亦發現約有70-95 %第二型糖尿病患者會同時合併非酒精性脂肪肝(Non-alcohol fatty liver disease)之發生，顯示兩種疾病之間有高度相關性。消渴草(Ruellia tuberosa Linn.)是台灣傳統中草藥，許多研究證實有降血糖、抗發炎、抗氧化和抗糖尿病等功效，但目前對其活性成分之研究尚未有深入的了解。本研究探討消渴草區分物減輕小鼠FL83B肝臟細胞株胰島素阻抗及脂肪累積之效果。首先以腫瘤壞死因子(TNF-α)刺激小鼠FL83B肝臟細胞株形成胰島素阻抗之細胞模式，並以油酸(oleic acid)誘導成合併非酒精性脂肪肝之細胞模式，再以消渴草區分物處理上述細胞，之後以標記螢光的葡萄糖分子2-NBDG來評估細胞對於葡萄糖攝入之能力，其次利用油紅染劑(Oil red O)觀察細胞脂肪累積含量，並分析細胞脂肪合成相關訊息傳遞路徑蛋白的表現量。實驗結果顯示，消渴草之乙酸乙酯(Ethyl acetate)區分物顯著增加具有胰島素阻抗之小鼠肝臟細胞的葡萄糖攝入能力，並降低小鼠肝臟細胞內的脂肪累積含量。western blot結果顯示消渴草之乙酸乙酯區分物可以透過提升小鼠FL83B肝臟細胞內胰島素訊息傳遞路徑蛋白，如胰島素受器(Insulin receptor)、phosphatidylinositol-3-kinase (PI3K)、protein kinase B (Akt/PKB)和葡萄糖轉運蛋白2 (Glucose transporter 2)的表現來增加細胞對葡糖的攝入；另外，消渴草乙酸乙酯區分物可透過增加PPARα而調控基因表現促進細胞脂肪代謝、減少脂肪肝細胞的脂肪累積含量。以上結果顯示，消渴草乙酸乙酯區分物可有效改善胰島素阻抗小鼠肝臟細胞的葡萄糖攝取並增加PPARα的表現來減少小鼠肝臟細胞脂肪之堆積。

關鍵字

消渴草 ； 胰島素阻抗 ； 第二型糖尿病 ； 非酒精性脂肪肝

並列摘要

Type 2 diabetes mellitus (T2DM) is a metabolic disease commonly associate with obesity. Nonalcoholic fatty liver disease (NAFLD) is a disease being at excessive lipid accumulated in the liver, and is highly prevalent among patients with T2DM. Ruellia tuberosa L. (RTL) has been traditionally used to treat DM as a fork medicine in Asia. The present study investigated the effect of RTL on glucose uptake, insulin resistance and lipid accumulation in vitro to mimic the T2DM accompanied with NAFLD in vivo. Mouse hepatocyte FL83B was treated with tumor necrosis factor α (TNFα) to induce insulin resistance, co-incubated with oleic acid to induce lipid accumulation, and then treated with RTL fractions from column chromatography. The uptake of fluorescent 2-NBDG was used to assess the hypoglycemic potential of RTL. The lipid droplet was observed by Oil Red O stain microscopy to evaluate the accumulation of lipid in cells. Western bolt analysis was used to evaluate the insulin signaling and lipid synthesis pathway in mouse hepatocyte FL83B. The results show that ethyl acetate fraction (EAF) from RTL significantly increased glucose uptake and suppressed lipid droplet accumulation in TNFα plus OA-treated FL83B cells. Western blot analysis shows EAF from RTL ameliorates insulin resistance by up-regulating the expression of the insulin signaling-related proteins such as insulin receptor (IR), phosphatidylinositol-3-kinase (PI3K), protein kinase B (Akt/PKB), glucose transporter-2 (GLUT-2) and peroxisome proliferator-activated receptor alpha (PPARα) in TNFα plus OA-treated cells . The above observations suggest that RTL may improve hepatic glucose uptake and lipid accumulation via ameliorating hepatic insulin signaling and suppressing hepatic lipogenesis pathway in TNF-α plus OA treated mouse hepatocyte.

並列關鍵字

Ruellia tuberosa L ； insulin resistance ； diabetes ； non-alcohol fatty liver disease

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