Han L K, Kimura Y, Okuda H
Second Department of Medical Biochemistry, School of Medicine, Ehime University, Japan.
Int J Obes Relat Metab Disord. 1999 Feb;23(2):174-9. doi: 10.1038/sj.ijo.0800806.
Chitin and chitosan are polymers containing more than 5000 acetylglucosamine and glucosamine units, respectively, and their molecular weights are over one million Daltons. The present study assessed the effects of chitin-chitosan on the activity of pancreatic lipase in vitro and on the degree of fat storage induced in mice by the oral administration of a high-fat diet for nine weeks.
Mice were fed a high-fat diet and treated with chitin-chitosan for nine weeks. Experiments were also carried out to clarify whether or not chitin-chitosan inhibited pancreatic lipase activity in assay systems using triolein emulsified with lecithin, gum arabic or Triton X-100.
Chitin-chitosan prevented the increase of body weight, hyperlipidaemia and fatty liver induced by a high-fat diet. Chitin-chitosan inhibited hydrolysis of triolein, emulsified with phosphatidylcholine, but not that of triolein emulsified with gum arabic and Triton X-100. These results suggest that the site of inhibitory action of chitin-chitosan may not be the enzyme but its substrate.
The anti-obesity effects of chitin-chitosan in high-fat diet-treated mice might be partly due to the inhibition of intestinal absorption of dietary fat. Consequently, chitin-chitosan might cause improvement of the fatty liver and hyperlipidaemia in mice fed a high fat diet through inhibiting intestinal absorption of dietary fat.
几丁质和壳聚糖分别是含有超过5000个乙酰葡糖胺和葡糖胺单元的聚合物，其分子量超过100万道尔顿。本研究评估了几丁质 - 壳聚糖对体外胰腺脂肪酶活性以及对高脂饮食连续喂养9周诱导的小鼠脂肪储存程度的影响。
给小鼠喂食高脂饮食并使用几丁质 - 壳聚糖处理9周。还进行了实验以阐明几丁质 - 壳聚糖在使用用卵磷脂、阿拉伯胶或吐温X - 100乳化的三油酸甘油酯的测定系统中是否抑制胰腺脂肪酶活性。
几丁质 - 壳聚糖可预防高脂饮食诱导的体重增加、高脂血症和脂肪肝。几丁质 - 壳聚糖抑制用磷脂酰胆碱乳化的三油酸甘油酯的水解，但不抑制用阿拉伯胶和吐温X - 100乳化的三油酸甘油酯的水解。这些结果表明几丁质 - 壳聚糖的抑制作用位点可能不是酶而是其底物。
几丁质 - 壳聚糖在高脂饮食处理的小鼠中的抗肥胖作用可能部分归因于对膳食脂肪肠道吸收的抑制。因此，几丁质 - 壳聚糖可能通过抑制膳食脂肪的肠道吸收而改善高脂饮食喂养小鼠的脂肪肝和高脂血症。
