尿激酶型纤溶酶原激活物抑制剂和粗提植物提取物的细胞抑制活性。

Inhibitors of urokinase type plasminogen activator and cytostatic activity from crude plants extracts.

机构信息

Department of Chemistry, University of Puerto Rico at Cayey, 205 Ave. Antonio R. Barcelo, Cayey, PR 00736.

出版信息

Molecules. 2013 Jul 26;18(8):8945-58. doi: 10.3390/molecules18088945.

DOI:10.3390/molecules18088945

PMID:23896619

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC4034058/

Abstract

In view of the clear evidence that urokinase type plasminogen activator (uPA) plays an important role in the processes of tumor cell metastasis, aortic aneurysm, and multiple sclerosis, it has become a target of choice for pharmacological intervention. The goal of this study was thus to determine the presence of inhibitors of uPA in plants known traditionally for their anti-tumor properties. Crude methanol extracts were prepared from the leaves of plants (14) collected from the subtropical dry forest (Guanica, Puerto Rico), and tested for the presence of inhibitors of uPA using the fibrin plate assay. The extracts that tested positive (6) were then partitioned with petroleum ether, chloroform, ethyl acetate and n-butanol, in a sequential manner. The resulting fractions were then tested again using the fibrin plate assay. Extracts from leaves of Croton lucidus (C. lucidus) showed the presence of a strong uPA inhibitory activity. Serial dilutions of these C. lucidus partitions were performed to determine the uPA inhibition IC₅₀ values. The chloroform extract showed the lowest IC₅₀ value (3.52 µg/mL) and hence contained the most potent uPA inhibitor. Further investigations revealed that the crude methanol extract and its chloroform and n-butanol partitions did not significantly inhibit closely related proteases such as the tissue type plasminogen activator (tPA) and plasmin, indicating their selectivity for uPA, and hence superior potential for medicinal use with fewer side effects. In a further evaluation of their therapeutic potential for prevention of cancer metastasis, the C. lucidus extracts displayed cytostatic activity against human pancreatic carcinoma (PaCa-2) cells, as determined through an MTS assay. The cytostatic activities recorded for each of the partitions correlated with their relative uPA inhibitory activities. There are no existing reports of uPA inhibitors being present in any of the plants reported in this study.

摘要

鉴于尿激酶型纤溶酶原激活物（uPA）在肿瘤细胞转移、主动脉瘤和多发性硬化等过程中发挥着重要作用，它已成为药物干预的首选靶点。因此，本研究的目的是确定在具有抗肿瘤特性的传统植物中是否存在 uPA 抑制剂。从植物叶片（14 种）中提取粗甲醇提取物，这些植物来自亚热带干旱森林（波多黎各关塔那摩），并使用纤维蛋白平板测定法检测 uPA 抑制剂的存在。阳性测试（6 种）的提取物随后用石油醚、氯仿、乙酸乙酯和正丁醇依次进行分配。然后，再次使用纤维蛋白平板测定法测试得到的馏分。从 Croton lucidus（C. lucidus）叶中提取的提取物显示出存在强烈的 uPA 抑制活性。对这些 C. lucidus 馏分进行系列稀释，以确定 uPA 抑制 IC₅₀ 值。氯仿提取物显示出最低的 IC₅₀ 值（3.52 µg/mL），因此含有最有效的 uPA 抑制剂。进一步的研究表明，粗甲醇提取物及其氯仿和正丁醇馏分不会显著抑制密切相关的蛋白酶，如组织型纤溶酶原激活物（tPA）和纤溶酶，表明它们对 uPA 具有选择性，因此在药物用途方面具有潜在的优势，副作用更少。在进一步评估它们预防癌症转移的治疗潜力时，通过 MTS 测定，C. lucidus 提取物对人胰腺癌细胞（PaCa-2）显示出细胞生长抑制活性。每个馏分的细胞生长抑制活性与它们相对的 uPA 抑制活性相关。在本研究报告的植物中，没有关于存在 uPA 抑制剂的现有报道。