餵飼海藻飼料對糖尿病大白鼠血糖濃度之影響

Abstract

自古以來，海藻就被人類利用，作為食物，也作為藥材。中醫藥典就記載海藻對人體有保健作用及疾病治療效果，為檢驗這些功效，並加以發揚光大，初步篩選3種海藻，紫菜、石花菜及麒麟菜，藉由糖尿病實驗動物模式下，進行降血糖及降血脂之評估實驗，以開發海藻保健食品。 40隻雄性Wistar大鼠10-11週齡，腹腔注射Nicotinamide (230 mg/dL)及Streptozotocin(65 mg/kg BW)，誘發成第二型糖尿病鼠，隨機分成10組，9組海藻處理組，1組控制組，每組3-4隻。將3種海藻乾燥粉末按重量百分比，9%、6%、3%之濃度加入老鼠飼料內，做成海藻飼料餵飼實驗組的老鼠，控制組則餵飼不含海藻的一般飼料。每隔10天為一個餵飼療程，抽血前禁食18-20小時後，以Chloral hydrate麻醉並心臟採血，檢測鼠體血液中Glucose、Total Cholesterol、Triglyceride、Blood Urea Nitrogen (BUN)、Alanine Aminotransferase (ALT)及Aspartate Aminotransferase (AST) 等6項血清生化值的濃度共3次，經由SAS統計分析後以判斷降血糖及降血脂之效果。 結果在降血糖方面，以麒麟菜組效果最明顯，其中以9%濃度組，效果最佳，統計上有顯著性差異。紫菜及石花菜組在降血糖方面上則無明顯作用。降血脂方面，3種海藻在統計上未有顯著性效果，但麒麟菜組比起其他兩組，在三酸甘油脂方面，有明顯下降的趨勢。BUN、ALT及AST生化指數在實驗前及實驗後皆未有明顯的升高，各組肝臟組織切片，在細胞形態上觀察也無明顯變化，顯示以這3種濃度的海藻餵飼老鼠，並不會影響到老鼠的腎臟及肝臟生理功能。

Seaweeds have been utilized as foods and natural medicines by mankind since thousands of years ago. According to the theories of Chinese Traditional Medicine that seaweeds have health promotions and disease curing effects on human bodies. In order to evaluate these effects and promote the functions to the public, three kinds of seaweeds, Porphyra dentata, Gelidium amansii and Eucheuma serra, were selected to investigate the hypoglycemic and hypolipidemic activities on diabetic rats by the experimental animal model. The results may be applied to develop health food products from seaweeds. 40 male wistar rats at 10 or 11 weeks old were induced to type 2 diabetes mellitus by injecting nicotinamide and streptozotocin intraperitoneally. After 7 days, blood samples were drawn and glucose levels were determined to confirm development of diabetes. The diabetic rats were divided randomly into 9 seaweed treatment groups and 1 control group which consisted of 3 or 4 rats each. The rats in seaweed treatment groups were fed on diets in the form of a 9%, 6% or 3% supplement of each seaweed to rodent diet in weight percentile while feeding with unsupplemented rodent diet served as control group. The feeding regimen was designed for 3 periods and each period lasted 10 days. On the last day of each period, rats were fasted for 18-20 hours and blood samples were drawn from heart puncture after anaesthesia by chloral hydrate. The six serum biochemical values from the blood samples: glucose, total cholesterol, triglyceride, blood urea nitrogen (BUN), alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were determined by the automatic blood analyzer. All of above results were tested statistically with the control group by SAS for the effects on the hypoglycemic and hypolipidemic activities. The results showed that Eucheuma serra groups lowered blood glucose levels significantly, especially in the group of a 9% supplement comparing with the values before feeding seaweed diets while the Porphyra dentate groups and Gelidium amansii groups did not show such effects. Three kinds of seaweeds didn’t have effects on lowering blood lipid, but Eucheuma serra groups showed a tendency to reduce triglyceride levels comparing with other groups. The levels of BUN, ALT and AST were not affected obviously during three feeding regimens. The liver sections showed no apparent difference between treatment groups and control group. There were also no side effects observed on the functions of kidney and liver when feeding with various algal supplements in this experiment.