糖尿病為台灣地區最重要的慢性病之一，而糖尿病的併發症是造成糖尿病死亡的主要原因。本研究在探討histidine與carnosine對於糖尿病老鼠的保護作用，觀察其對血漿中葡萄糖、胰島素、纖維網狀蛋白、TNF-α、IL-6及組織中三酸甘油酯與膽固醇的影響。Balb/cA雄鼠經尾靜脈注射streptozotocin（STZ；200mg/kg）誘發糖尿病，飲水中分別加入0.5 g/l（low dose）及1 g/l（high dose）的histidine及carnosine，其組別分別為(1)Control組(2)Diabetes(3)LHis(4)HHis (5)LCar(6)HCar，採自由飲水的方式。結果顯示，飲用histidine及carnosine的糖尿病鼠，其血漿、心臟及肝臟中histidine及carnosine的含量均顯著增加。而血漿中的葡萄糖及纖維網狀蛋白顯著減少；僅1 g/l的histidine及carnosine組顯著增加血中胰島素的含量。糖尿病鼠心臟及肝臟中的三酸甘油酯含量呈劑量關係的降低；僅有1 g/l的histidine及carnosine顯著降低心臟及肝臟中的膽固醇含量。Histidine及carnosine的補充顯著增加腎臟及肝臟中過氧化氫的活性並降低脂質氧化作用；只有1 g/l的histidine及carnosine顯著增加麩胱過氧化的活性。Histidine及carnosine顯著抑制糖尿病鼠血中升高的IL-6及TNF-α。上述結果顯示，histidine及carnosine可預防或治療糖尿病併發症的發生。
In vivo effects of histidine amd carnosine against diabetes deterioration in diabetic Balb/cA mice were studied. Histidine and carnosine at 0.5, 1 g/l were added into drinking water. After 4 weeks intake of these agents, the content of histidine and carnosine in plasma, heart and liver significantly elevated (p<0.05). The intake of these agents significantly decreased plasma glucose and fibronectin levels (p<0.05); however, only 1 g/l histidine and carnosine treatments significantly increased insulin level (p<0.05) in diabetic mice. Triglyceride level in heart and liver was dose-dependently reduced by histidine or carnosine treatments (p<0.05); however, only 1 g/l histidine and carnosine treatments significantly reduced cholesterol level in heart and liver (p<0.05). The administration of histidine or carnosine significantly enhanced catalase activity and decreased lipid oxidation levels in kidney and liver (p<0.05); however, only 1 g/l histidine and carnosine treatments significantly increased glutathione peroxidase activity (p<0.05). The increased interleukin (IL)-6 and tumor necrosis factor (TNF)-alpha in diabetic mice were significantly suppressed by the intake of histidine or carnosine (p<0.05). These data suggest that histidine and carnosine are potential multiple-protective agents for diabetic complications prevention or therapy.
