米麩油的攝取對 STZ 誘導糖尿病大白鼠血糖控制及脂質代謝之影響
Effects of rice bran oil on glycemic control and lipids metabolism in
STZ-induced diabetic rats
中文摘要 本次研究目的在探討米麩油的攝取下，對糖尿病大白鼠體內血糖控制及脂質代謝 之影響。實驗採用 40 隻 10 週齡 Wistar 品系雄鼠，分別為 20 隻經由腹腔注射 nicotinamide (200 mg/kg BW)及 streptozotocin (STZ, 45 ~ 40 mg/kg BW) 誘導糖尿 病大白鼠及 20 隻正常血糖大白鼠，進行四週實驗，以 AIN-76 標準配方調配實 驗飼料。實驗共分成四組為大豆油正常組(SN)、米麩油正常組(RN)、大豆油糖尿 病組(SD)、米麩油糖尿病組(RD)。實驗開始、第二週及第四週採取禁食血液樣本， 實驗結束時犧牲大白鼠取其肝臟及副睪脂肪組織。檢測項目包括：禁食血漿葡萄 糖、胰島素、果糖胺、三酸甘油酯、游離脂肪酸、總膽固醇、低密度脂蛋白膽固 醇、高密度脂蛋白膽固醇濃度及脂肪酸組成；肝臟三酸甘油酯、總膽固醇、脂質 過氧化物 MDA 濃度及脂肪酸組成。結果顯示，此次 STZ 誘導糖尿病模式能引 起糖尿病性高脂血症。四週實驗後，在血糖方面，RD 血漿葡萄糖及果糖胺濃度 顯著低於 SD 組(P=0.0071) (P<0.0001)而胰島素濃度變化不顯著。在脂質方面， RD 組血漿三酸甘油酯、總膽固醇及低密度脂蛋白膽固醇濃度顯著低於 SD 組(三 者皆為 P<0.0001)且 RD 組血漿高密度脂蛋白膽固醇濃度顯著高於 SD 組 (P<0.0001)。RN 組血漿三酸甘油酯、總膽固醇及低密度脂蛋白膽固醇濃度顯著 低於 SN 組(三者皆為 P<0.0001)且 RN 組血漿高密度脂蛋白膽固醇濃度顯著高於 SN 組(P<0.0001)。RD 組肝臟三酸甘油酯濃度顯著低於 SD 組(P=0.0235)。在血漿 脂肪酸方面，RD 組 18:1、總單元不飽和脂肪酸、20:4 及 22:6 顯著高於 SD 組 (P<0.05)；RN 組 16:1 及 18:1 顯著高於 SN 組(P<0.05)。而餵食米麩油飼料組大白 鼠體內 18:2、18:3 及總多元不飽和脂肪酸顯著低於餵食大豆油飼料組大白鼠(分 別為 P<0.0001, P=0.0144 及 0.0002)。RN 組肝臟中 18:1 顯著高於其他各組，而 RD 組肝臟中 22:6 顯著高於其他各組。總結，米麩油的攝取對正常或糖尿病大白 鼠而言，能降低血漿三酸甘油酯、總膽固醇及低密度脂蛋白膽固醇濃度及增加高 密度脂蛋白膽固醇濃度，並降低體內 18:2、18:3 及總多元不飽和脂肪酸含量；對 糖尿病大白鼠而言，能改善血糖控制及降低肝臟三酸甘油酯濃度。 英文摘要
This study was designed to investigate the effects of rice bran oil (RBO) on glycemic control and lipid metabolism in STZ-induced diabetic rats. Diabetes was induced by nictotinamide and streptozotocin injection. The formulas of these experimental diets were modified from the AIN-76 formula. Forty 10-week old male Wistar rats were divided into four groups: a normal rat group fed soybean oil (SBO)-containing diet
(SN) or RBO-containing diet (RN) and a diabetic rat group fed SBO-containing diet (SD) or RBO-containing diet (RD). Fasting blood sampling was conducted at zero time, and at the end of the second and the fourth week in this experiment. At the end of this experiment, all rats were sacrificed, and their livers and epididymal fat pads were collected. In this study, STZ-induced diabetic rats showed hyperlipidemia. Whether normal or diabetic rats fed the RBO-containing diet group, the plasma total cholesterol, triglycerides and low-density lipoprotein cholesterol were significantly lower compared with these fed SBO-containing diet group at week 4 (RD < SD and RN < SN)；(P<0.0001). As to plasma high-density lipoprotein cholesterol, RD and RN were significantly higher compared with SD and SN, respectively (P<0.0001). Liver triglycerides were reduced in RD compared with SD (P=0.0235). Whether normal or diabetic rats fed the RBO-containing diet group, the 18:2, 18:3 and total
polyunsaturated fatty acids (PUFAs) levels as percentages of total plasma fatty acids were significantly lower comparison with fed the SBO-containing diet group (RD < SD and RN < SN)(P<0.05). In conclusion, consumption of RBO could reduce plasma TG, TC, LDL-C, 18:2, 18:3 and total PUFA levels and increase HDL-C concentrations in normal and diabetic rats. In diabetic rats, consumption of RBO could improve glycemic control and decrease liver TG concentrations.
