紫薯粉對高脂質餵食大白鼠引起體脂肪生成之抑制作用及機轉

體脂肪分為內臟脂肪與皮下脂肪，當內臟脂肪含量變高，會增 加脂肪組織中的發炎因子 IL-6、TNF-α 表現量。花青素具有抗氧 化、抗發炎特性。本研究採用含花青素的紫薯粉，在大鼠餵食高脂 飲食模式中，檢測是否有效抑制體脂肪形成並探討作用機轉。我們 以 43%高脂食物餵食動物誘導肥胖後，再介入紫薯粉 19 週，測量體 重及體脂變化，並檢測內臟脂肪及皮下脂肪的發炎因子、發炎小體 (inflammasome)、脂肪酸合成相關因子、調節脂肪棕色化的蛋白表現 量，進而觀察紫薯粉調節體脂肪的機轉。研究結果顯示在 19 週的餵 食中，紫薯粉在已經肥胖的個體對體重、總膽固醇、三酸甘油酯、 HDL-C、LDL-C 及血糖，無顯著改善，但可顯著減少內臟脂肪重量 (p <0.05) 及減少脂肪細胞面積。對內臟脂肪及皮下脂肪則顯著減少 發炎因子 IL-6、TNF-α、MCP-1、HIF1-α、CD36、inflammasome 的 NLRP3、IL-1β、Caspase-1 的蛋白表現、脂肪酸合成相關之 PPARγ、ACC1、FAS 的表現量。並顯著增加調節體脂的蛋白 FNDC5、UCP-1、PGC-1α 的表現量。歸納結果，在動物誘導肥胖 後，紫薯粉雖無法改善體重、血脂及血糖，但可透過降低發炎反應 及體脂而減少內臟脂肪累積。

Body fat is divided into visceral fat and subcutaneous fat. When the visceral fat content raised, it will increase the levels of inflammatory factors, IL-6 and TNF-α, in adipose tissue. Anthocyanins have antioxidative and anti-inflammatory properties. In this study, purple sweet potato (Ipomoea batatas L.) powder (PSP) containing anthocyanins was used to evaluate the efficacy in inhibiting body fat and explore the mechanism in rats fed a high-fat diet (HFD). We fed animals 43% high- fat food to induce obesity, thereafter, HFD with PSP fed for 19 weeks to measure body weight, and body fat, and relative molecules In visceral fat and subcutaneous fat, the regulatory proteins in inflammasomes, fatty acid synthesis, and adipocyte browning were examined to elucidate the mechanism of PSP in regulating body fat. The results showed that during 19 weeks of feeding, PSP cannot improv the body weight, total cholesterol, triglycerides, HDL-C, LDL-C and blood sugar in obese individuals , but it can significantly reduce visceral fat weight. (p <0.05) and the size of adipocytes. In visceral fat and subcutaneous fat, PSP significantly reduced the inflammatory factors IL-6, TNF-α, MCP-1, HIF1-α, CD36; the protein expression of inflammasome NLRP3, IL-1β, Caspase-1; fatty acid synthesis-related PPARγ, ACC1, and FAS. Interestingly, PSP significantly increased the proteins of adipocyte browning, including FNDC5, UCP-1, PGC-1α, that regulate the metabolism of body fat. Taken the results together, although PSP cannot improve body weight, blood lipids and blood sugar in obese animals, it can reduce visceral fat accumulation by reducing inflammation, body fat, and inducing the adipocyte browning.