Menendez R, Fernandez S I, Del Rio A, Gonzalez R M, Fraga V, Amor A M, Mas R M
Centro Nacional de Investigaciones Científicas, La Habana, Cuba.
Biol Res. 1994;27(3-4):199-203.
Policosanol is a mixture of aliphatic primary alcohols isolated and purified from sugar cane wax, that induces cholesterol-lowering effects in experimental models and human beings. When human lung fibroblasts were incubated with policosanol for 48 hours prior to the experiment, a dose dependent inhibition of 14C-acetate incorporation into total cholesterol was observed, whereas labeled mevalonate incorporation was not inhibited. Even when cholesterol synthesis was not strongly inhibited, low density lipoprotein (LDL) processing was markedly enhanced. Thus, LDL binding, internalization and degradation were significantly increased after policosanol treatment. In addition, despite the fact that'cholesterol generation was not inhibited at the lowest dose of policosanol assayed, LDL processing was significantly increased. The current data indicate that policosanol inhibits cholesterol synthesis at the earliest steps of the cholesterol biosynthetic pathway. On the other hand, this study suggests that the increase in LDL processing may be partially explained by the inhibition of cholesterol biosynthesis, even though an sterol-independent mechanism might be responsible for the enhancement of LDL-receptor activity.
聚廿烷醇是从甘蔗蜡中分离提纯得到的脂肪族伯醇混合物，在实验模型和人体中均有降胆固醇作用。实验前将人肺成纤维细胞与聚廿烷醇孵育48小时，可观察到14C - 乙酸掺入总胆固醇有剂量依赖性抑制，而标记的甲羟戊酸掺入未受抑制。即使胆固醇合成未受到强烈抑制，低密度脂蛋白（LDL）的代谢也显著增强。因此，聚廿烷醇处理后，LDL的结合、内化和降解均显著增加。此外，尽管在所检测的最低剂量聚廿烷醇下胆固醇生成未受抑制，但LDL代谢仍显著增加。目前的数据表明，聚廿烷醇在胆固醇生物合成途径的最早步骤抑制胆固醇合成。另一方面，本研究提示，LDL代谢的增加可能部分是由于胆固醇生物合成受到抑制，尽管一种不依赖固醇的机制可能是LDL受体活性增强的原因。
