Kanipandian Nagarajan, Li Deyu, Kannan Soundarapandian
Proteomics and Molecular Cell Physiology Laboratory, Department of Zoology, Periyar University, Salem, 636 011, TN, India.
Department of Hepato-Biliary Pancreatic Surgery, Henan Provincial People's Hospital, Zhengzhou, Henan Province, People's Republic of China.
Biotechnol Rep (Amst). 2019 Apr 30;23:e00339. doi: 10.1016/j.btre.2019.e00339. eCollection 2019 Sep.
In the past decade, the research communities raised wide concerns on using medicinal plants for synthesis of nanomaterials due to its effective biological activity, lower side effects and also eco-friendly manner. Our previous report concentrated on the biomedical efficacy of fine characterized silver nanoparticles (AgNPs) from (cotton) leaf extract. Further, the current examination is planned to reveal the molecular mechanisms involving for activation of mitochondria-mediated signaling pathway by AgNPs in human lung cancer cells (A549) using various biological endpoints such as apoptotic induction by HOECHST 33342, AO/EtBr and Rhodamine 123 staining, cell cycle analysis using flow cytometry, gene and protein expressions by RT-PCR and immunoblotting respectively. This study was further extended to identify the toxicity of AgNPs using an animal model. Interestingly, we observed that A549 cells treated with AgNPs resulted in G/M arrest and ultimately leads to induction of apoptosis cell death. Moreover, gene analysis demonstrated that diminished expression of anti-apoptotic (Bcl-2) and enhanced expression of pro-apoptotic (Bax) mitochondrial genes. The alterations in the gene pattern may interrupt of mitochondrial membrane potential which facilitates the releasing of cytochrome c (cyt c) into cytosol. The cyt c act as a key molecule for activation of caspases (9 and 3) to initiate intrinsic apoptotic signaling cell death process. The histological analysis proven the application of AgNPs in nanomedicine is quietly harmless and would not cause any discernible stress like swelling and inflammation to the organs of mice. Taken together, this investigation may provide solid evidence for cotton crop mediated AgNPs induced apoptosis cell death pathway and offer a novel approach for cancer therapy.
在过去十年中，研究界对利用药用植物合成纳米材料给予了广泛关注，因为其具有有效的生物活性、较低的副作用且方式环保。我们之前的报告专注于来自棉花叶提取物的精细表征银纳米颗粒（AgNPs）的生物医学功效。此外，当前的研究计划利用各种生物学终点，如通过HOECHST 33342、AO/EtBr和罗丹明123染色诱导凋亡、使用流式细胞术进行细胞周期分析、分别通过RT-PCR和免疫印迹进行基因和蛋白质表达，来揭示AgNPs在人肺癌细胞（A549）中激活线粒体介导的信号通路所涉及的分子机制。本研究进一步扩展到使用动物模型确定AgNPs的毒性。有趣的是，我们观察到用AgNPs处理的A549细胞导致G/M期阻滞，并最终导致凋亡性细胞死亡。此外，基因分析表明抗凋亡（Bcl-2）基因表达减少，促凋亡（Bax）线粒体基因表达增强。基因模式的改变可能会中断线粒体膜电位，从而促进细胞色素c（cyt c）释放到细胞质中。cyt c作为激活半胱天冬酶（9和3）以启动内在凋亡信号细胞死亡过程的关键分子。组织学分析证明AgNPs在纳米医学中的应用相当无害，不会对小鼠器官造成任何明显的肿胀和炎症等应激反应。综上所述，本研究可能为棉花作物介导的AgNPs诱导的凋亡细胞死亡途径提供确凿证据，并为癌症治疗提供一种新方法。
