Delphi Ladan, Sepehri Houri, Khorramizadeh Mohammad Reza, Mansoori Fatemeh
Department of Animal Biology, School of Biology, College of Science, University of Tehran, Tehran, Iran E-mail :
Asian Pac J Cancer Prev. 2015;16(13):5265-71. doi: 10.7314/apjcp.2015.16.13.5265.
The effects of plant products on cancer cells has become a field of major importance. Many substancesmay induce apoptosis in anti-cancer treatment. Pectins, a family of complex polysaccharides, and their degradation products may for exasmple exert apoptotic effects in cancer cells. Apples and citrus fruits are the main sources of pectin which can be applied for anti-cancer research. The present study concerned an intact form of pectic-oligoshaccharide named pectic acid (poly galactronic acid).
Inhibition of cell proliferation assays (MTT), light microscopy, fluorescence microscopy (acridin orange/ethidium bromide), DNA fragmentation tests, cell cycle analysis, annexin PI and Western blotting methods were applied to evaluate apoptosis.
The results indicated that pectic acid inhibited cell growth and reduced cell attachment after 24h incubation. This did not appear to be due to necrosis, since morphological features of apoptosis were detected with AO/EB staining and cell cycling was blocked in the sub-G1 phase. Annexin/PI and DNA fragmentation findings indicated that apoptosis frequency increased after 24h incubation with pectic acid. In addition, the data showed pectic acid induced caspase-dependent apoptosis.
These data indicate that apple pectic acid without any modification could trigger apoptosis in MDA-MB-231 human breast cancer cells and has potential to improve cancer treatment as a natural product.
植物产品对癌细胞的影响已成为一个极其重要的领域。在抗癌治疗中，许多物质可能会诱导细胞凋亡。例如，果胶（一类复杂的多糖）及其降解产物可能对癌细胞产生凋亡作用。苹果和柑橘类水果是可用于抗癌研究的果胶的主要来源。本研究涉及一种名为果胶酸（聚半乳糖醛酸）的完整形式的果胶低聚糖。
采用细胞增殖抑制试验（MTT）、光学显微镜、荧光显微镜（吖啶橙/溴化乙锭）、DNA片段化检测、细胞周期分析、膜联蛋白PI和蛋白质免疫印迹法来评估细胞凋亡。
结果表明，果胶酸在孵育24小时后抑制细胞生长并减少细胞附着。这似乎不是由于坏死，因为通过AO/EB染色检测到了凋亡的形态学特征，并且细胞周期在亚G1期被阻断。膜联蛋白/PI和DNA片段化结果表明，与果胶酸孵育24小时后凋亡频率增加。此外，数据显示果胶酸诱导了半胱天冬酶依赖性凋亡。
这些数据表明，未经任何修饰的苹果果胶酸可触发MDA-MB-231人乳腺癌细胞的凋亡，作为一种天然产物有改善癌症治疗的潜力。
