School of Pharmacy, China Medical University, Taichung 404, Taiwan.
J Ethnopharmacol. 2011 Jan 27;133(2):426-33. doi: 10.1016/j.jep.2010.10.020. Epub 2010 Oct 21.
The aim of this study is to determine and identify the possible molecular mechanisms of anti-cancer effect of rhubarb under the physiologically achievable concentrations by using an ex vivo approach.
Rats were orally administered rhubarb decoction and then serum metabolites were extracted, prepared and characterized to assay for the following in vitro study. The MTT assay, zymography analysis, wound healing assay, RT-PCR, and Western blot analysis were used to reveal molecular events of rhubarb metabolites in this study. Experimental metastasis model was used to investigate the in vivo anti-metastatic efficacy of rhubarb.
Our results demonstrated that cell line mobility was strongly inhibited and the enzymatic activity of MMP-2 decreased following culture with the rhubarb serum metabolite in human lung adenocarcinoma A549 cells. Further experiments demonstrated that the downregulation of MMP-2 enzymatic activity act through both transcriptional and post-translational mechanisms. NF-κB/c-Jun and uPA were observed involving in the inhibition of MMP-2 transcription and post-translational modification, respectively, in A549 cells treated with rhubarb serum metabolite. Further animal experiments demonstrated a significant reduction in lung metastatic colonies in rhubarb-treated mice, suggesting that rhubarb contain enriched active components that block cancer metastasis.
Our studies, both in vitro and in vivo, clearly demonstrated the anti-tumor effect of rhubarb in an experimental setting of achievable physiological concentrations and also provide possible molecular mechanisms of anti-metastatic mechanisms by rhubarb treatment.
本研究旨在通过离体方法确定和鉴定大黄在生理可达到浓度下的抗癌作用的可能分子机制。
大鼠口服大黄煎剂，然后提取、制备和鉴定血清代谢物，以进行以下体外研究。MTT 测定、酶谱分析、划痕愈合试验、RT-PCR 和 Western blot 分析用于揭示大黄代谢物在本研究中的分子事件。实验性转移模型用于研究大黄在体内的抗转移功效。
我们的结果表明，在人肺腺癌细胞 A549 中培养大黄血清代谢物后，细胞系迁移能力受到强烈抑制，MMP-2 的酶活性降低。进一步的实验表明，MMP-2 酶活性的下调是通过转录和翻译后机制实现的。在大黄血清代谢物处理的 A549 细胞中，观察到 NF-κB/c-Jun 和 uPA 分别参与 MMP-2 转录和翻译后修饰的抑制。进一步的动物实验表明，大黄治疗组小鼠肺转移菌落明显减少，提示大黄含有丰富的活性成分，可阻断癌症转移。
我们的体内外研究清楚地表明，大黄在可达到的生理浓度的实验环境中具有抗肿瘤作用，并且还提供了大黄治疗的抗转移机制的可能分子机制。
