香蕉抗性淀粉对营养型肥胖大鼠减肥机理的探究

本研究利用从富含抗性淀粉的青香蕉而来的香蕉抗性淀粉干预营养型肥胖大鼠,观察其减肥功效,探索其减肥作用的机理。结果表明:与肥胖对照组相比,香蕉抗性淀粉中、高剂量组能显著降低(P0.05)大鼠体重,分别降低7.26%和7.99%;三个剂量组都能在一定程度上改善大鼠血糖、血清瘦素、总胆固醇、甘油三酯、低密度脂蛋白和高密度脂蛋白等生化指标,提高大鼠粪脂率,且呈剂量依赖关系,表明其具有较好的减肥功效。低、中、高香蕉抗性淀粉剂量组分别降低大鼠摄食量16.63%、19.61%和23.86%。通过研究3种与控制食欲有关的胃肠激素,探索香蕉抗性淀粉的减肥机理。中、高剂量组能显著升高血清胆囊收缩素CCK水平(P0.05),升高幅度达到24.36%和24.97%;低剂量组虽有升高,但没有显著性差异。低、中、高三个剂量组均能显著升高血清酪酪肽PYY水平(P0.01),升高幅度达到22.35%、28.34%和34.84%;而对血清饥饿素ghrelin无影响。可见香蕉抗性淀粉是通过刺激影响食欲的胃肠激素分泌,控制大鼠摄食量、延长胃排空,达到减肥目的。

Mechanism of Weight Loss with Resistant Starch from Banana in Diet-induced Obese Rats

In this study, the anti-obesity effect of green bananas, rich in resistant starch, on diet-induced obese rats was evaluated and the mechanism of weight loss was studied. The results showed that, compared with rats in the obese control group, the body weight of rats in the medium- and high-dose (of banana resistant starch) groups reduced significantly (P < 0.05) by 7.26% and 7.99%, respectively. Rats in all three groups showed improved biochemical profiles, including blood glucose, serum leptin, total cholesterol, triglycerides, low-density lipoprotein, and high-density lipoprotein levels, and a dose-dependent increase in fecal fat excretion, indicating that resistant starch from banana displayed good anti-obesity effect. Compared with the obese control group, low, medium, and high doses of resistant starch from banana reduced food intake of rats by 16.63%, 19.61%, and 23.86%, respectively. Three kinds of gastrointestinal hormones related to appetite control were investigated to explore the mechanism of weight loss. Medium and high doses of resistant starch from banana significantly increased serum cholecystokinin (CCK) levels (P < 0.05) by 24.36% and 24.97%, respectively. The serum CCK level also increased in the low-dose group, with no statistically significant differences. Serum peptide YY (PYY) level in the low-, medium-, and high-dose groups increased significantly (P < 0.01), by 22.35%, 28.34%, and 34.84%, respectively. However, no effects were observed on ghrelin. Therefore, the mechanism of weight loss by resistant starch from banana involved in stimulating the secretion of gastrointestinal hormones that affected appetite, controlling food intake of rats, and prolonging gastric emptying.