McAnuff Marie A, Harding Wayne W, Omoruyi Felix O, Jacobs Helen, Morrison Errol Y, Asemota Helen N
Department of Basic Medical Sciences, Biochemistry Section, University of the West Indies, Mona, Kingston 7, Jamaica.
Food Chem Toxicol. 2005 Nov;43(11):1667-72. doi: 10.1016/j.fct.2005.05.008.
In this study, three steroidal sapogenins (Delta3 diosgenin, diosgenin, and pennogenin) and the phytosterols, stigmasterol and beta-sitosterol were isolated from Jamaican bitter yam, Dioscorea polygonoides. Their effects on fasting blood glucose and intestinal amylase and ATPases in streptozotocin-induced diabetic rats were studied. The diabetic rats (fed supplemented and unsupplemented diets) lost weight significantly compared to the normal group. There was a significant increase in the activity of alpha-amylase in the proximal region of the small intestinal mucosa of diabetic rats fed sapogenin extract or commercial diosgenin. However, this did not result in increased fasting blood glucose. Instead, supplementation of the diet with bitter yam sapogenin extract significantly decreased fasting blood glucose compared to the diabetic group. Supplementation of the diet with bitter yam sapogenin extract or commercial diosgenin significantly reduced Na+-K+-ATPase activity in all three regions compared to the diabetic control group. Commercial diosgenin supplementation resulted in a significant increase in Ca2+ ATPase activity in proximal region compared to the diabetic control and bitter yam sapogenin extract groups. The effect of bitter yam sapogenin extract or commercial diosgenin on intestinal Na+-K+-ATPase activity could account for their hypoglycemic properties. However, there was adverse effect on the body weight.
在本研究中，从牙买加薯蓣（Dioscorea polygonoides）中分离出三种甾体皂苷元（Δ3 薯蓣皂苷元、薯蓣皂苷元和原薯蓣皂苷元）以及植物甾醇豆甾醇和β-谷甾醇。研究了它们对链脲佐菌素诱导的糖尿病大鼠空腹血糖、肠道淀粉酶和ATP酶的影响。与正常组相比，糖尿病大鼠（喂食补充和未补充饮食）体重显著减轻。喂食皂苷元提取物或市售薯蓣皂苷元的糖尿病大鼠小肠黏膜近端区域的α-淀粉酶活性显著增加。然而，这并未导致空腹血糖升高。相反，与糖尿病组相比，用牙买加薯蓣皂苷元提取物补充饮食可显著降低空腹血糖。与糖尿病对照组相比，用牙买加薯蓣皂苷元提取物或市售薯蓣皂苷元补充饮食可显著降低所有三个区域的Na+-K+-ATP酶活性。与糖尿病对照组和牙买加薯蓣皂苷元提取物组相比，补充市售薯蓣皂苷元可使近端区域的Ca2+ ATP酶活性显著增加。牙买加薯蓣皂苷元提取物或市售薯蓣皂苷元对肠道Na+-K+-ATP酶活性的影响可能解释了它们的降血糖特性。然而，对体重有不良影响。
