波叶大黄多糖对胰腺五种酶的抑制作用

 本文报道波叶大黄多糖(Rheum hotaoense polysaccharide,RHP)对胰腺五种酶的抑制作用。结果表明。(1)RHP对胰蛋白酶、胰脂肪酶、胰淀粉酶、胰弹性蛋白酶和胰激肽释放酶均有很明显的抑制作用。IC_(50)分别为250μg/mL、21μg/mL、18μg/mL,189μg/mL和300μg/mL。(2)动力学研究表明,RHP对胰蛋白酶和胰脂肪酶的抑制均是非竞争性的,Km值分别为1.2×10~(-4)μmol/mL和1.2mg/mL,Ki值分别为355.0μg/mL和63.85μg/mL。(3)牛血清白蛋白(BSA)对RHP抑制胰蛋白晦和胰脂肪酶具有拮抗作用。当BSA浓度达72.0mg/mL时,对胰蛋白酶活性的恢复率为71.54％。当BSA浓度达20.0mg/mL时,对胰脂肪酶活性的恢复率为63.64％。上述结果表明,RHP对胰腺五种酶的抑制作用,可能是大黄治疗急性胰腺炎作用的生化机制之一,预示RHP在临床上将有重要应用前景。

Inhibitory Effects of Rheum Hotaocnse Polysaccharide on Five Pancreatic Enzymes

(1)The Rheum hotaoense polysaccharide (RHP) strongly inhibited the activities of pancreatic trypsin, Lipase, amylase, elastase and kallikrein, with IC50 of 250μm/mL, 21μg/mL, 18μg/mL,189μg/mL and 300μg/mL respectively.(2)The inhibitory effeets of RHP on pancreatic trypsin and lipase were non-competitive, with Km value of 1.2×10-4μmol/mL and 1.2mg/mL respectively, Ki value of 355μg/mL and 63.85μg/mL. (3)Bovine Serum albumin(BSA)had antagonistic actions against inhibitory effects of RHP on pancreatic trypsin and lipase. With the concentration of 72mg/mL (BSA), the recovery of trypsin specific activity was 71.54%. With the concentration of 20mg/mL, the recovery of Lipase was 63.64%. It is suggested that the inhibitory effects of RHP on five pancreatic enzymes is perhaps one of the biochemical mechanism of Rhubarb on treating the acute pancreatitis.