Di Ilio Vincenzo, Pasquariello Nicoletta, van der Esch Andrew S, Cristofaro Massimo, Scarsella Gianfranco, Risuleo Gianfranco
Biotechnology Biological Control Agency, V. del Bosco, 10--00060 Sacrofano, Roma, Italy.
Mol Cell Biochem. 2006 Jul;287(1-2):69-77. doi: 10.1007/s11010-005-9062-x. Epub 2006 May 2.
Neem oil is a natural product obtained from the seeds of the tree Azadirachta indica. Its composition is very complex and the oil exhibits a number of biological activities. The most studied component is the terpenoid azadirachtin which is used for its insecticidal and putative antimicrobial properties. In this report we investigate the biological activity of partially purified components of the oil obtained from A. indica. We show that the semi-purified fractions have moderate to strong cytotoxicity. However, this is not attributable to azadirachtin but to other active compounds present in the mixture. Each fraction was further purified by appropriate extraction procedures and we observed a differential cytotoxicity in the various sub-fractions. This led us to investigate the mode of cell death. After treatment with the oil fractions we observed positivity to TUNEL staining and extensive internucleosomal DNA degradation both indicating apoptotic death. The anti-proliferative properties of the neem oil-derived compounds were also assayed by evaluation of the nuclear PCNA levels (Proliferating Cell Nuclear Antigen). PCNA is significantly reduced in cells treated with a specific fraction of neem oil. Finally, our results strongly suggest a possible involvement of the mitochondrial pathway in the apoptotic death.
印楝油是一种从印楝树种子中提取的天然产物。其成分非常复杂，该油具有多种生物活性。研究最多的成分是萜类化合物印楝素，它因其杀虫和假定的抗菌特性而被使用。在本报告中，我们研究了从印楝中提取的油的部分纯化成分的生物活性。我们发现半纯化级分具有中度至强细胞毒性。然而，这并非归因于印楝素，而是混合物中存在的其他活性化合物。通过适当的提取程序对每个级分进一步纯化，我们在各个亚级分中观察到了不同的细胞毒性。这促使我们研究细胞死亡的模式。用该油级分处理后，我们观察到TUNEL染色呈阳性以及广泛的核小体间DNA降解，两者均表明细胞凋亡死亡。还通过评估核增殖细胞核抗原（PCNA）水平来测定印楝油衍生化合物的抗增殖特性。在用特定级分的印楝油处理的细胞中，PCNA显著降低。最后，我们的结果强烈表明线粒体途径可能参与了细胞凋亡死亡。
