霜桑叶提取物对胰脂肪酶活性抑制作用的研究

Research of inhibitory activity of extract from frost mulberry leaves on pancreatic lipase

为发掘霜桑叶中的活性成分,采用分光光度法测定霜桑叶的不同极性提取物对胰脂肪酶的抑制活性;通过酶反应动力学方法确定正己烷提取物对胰脂肪酶的抑制类型,并考察其经人工肠液模拟消化后对胰脂肪酶抑制效果的影响。结果表明,霜桑叶提取物中对胰脂肪酶的抑制活性由强到弱依次是正己烷提取物(半数抑制浓度IC_50=1.14 mg/m L)>二氯甲烷提取物(IC_50=8.51 mg/m L)>乙酸乙酯提取部位(IC_50=13.60 mg/m L)。正己烷提取物对胰脂肪酶的作用类型为非竞争性抑制。体外模拟消化后,正己烷提取物对胰脂肪酶仍有较强的抑制效果,而且抑制率随浓度的升高而增大。由此可见,霜桑叶的正己烷提取物可作为良好的胰脂肪酶抑制剂,具有调节脂质代谢的潜在功效。本研究为进一步以霜桑叶为原料开发降脂、减肥的功能性食品提供了理论依据。

To investigate the active substances of frost mulberry leaves, the pancreatic lipase inhibitory activities of different polar extracts were measured by spectrophotometry.The inhibition type of hexane extracts was confirmed hy enzymatic kinetics assay.After simulated digesting by artificial intestine fluid, the inhibitory effect of hexane extracts on pancreatic lipase was determined.The results showed that the order sequenced by inhibitory ability on pancreatic lipase from strong to weak was hexane extracts（ IC50 = 1.14 mg/mL） 〉 methylene chloride extracts（ IC50 = 8.51 mg/mL） 〉 ethyl acetate extracts（ IC50 = 13.60 mg/mL）. Moreover,the inhibition type of hexane extracts was non-competitive inhibition. In addition, the digested hexane extracts still exhibited strong lipase inhibitory activity and its inhibitory rate was increased with the rising of concentration.Thus,the hexane extracts of frost mulberry leaves can be used as a good pancreatic lipase inhibitor and exert a potential effect on regulating lipid metabolism.This study provided a theoretical basis for the further development of lipid- lowering, weight loss functional foods using the frost mulberry leaves as raw material.