Abstract

Multi-target inhibitors are currently trending in the pharmaceutical research, as they possess increased efficacy and reduced toxicity. In this study multi-target inhibitors for breast cancer are explored from a curated list of natural products, i.e. 4,670 phytochemicals belonging to 360 medicinal plants. In-silico screening of phytochemicals using SeeSAR and AutoDock Vina resulted in identification of Stearyl Palmitate as a potential drug molecule that inhibits three drug targets, i.e. HER-2, MEK-1 and PARP-1 proteins. Molecular Dynamics Simulation for 100 ns each for these three protein-ligand complexes using Desmond, Maestro platform also confirmed the prediction of multi-target inhibition by Stearyl Palmitate. Further in-vitro MTT assay demonstrated that Stearyl Palmitate has a significant IC₅₀ value of 40 µM against MCF-7 cells and >1000 µM against L929 cells. This confirmed that Stearyl Palmitate is having selective cytotoxicity towards breast cancer cells in comparison to non-cancerous cells. Fluorescence staining and flow cytometry analysis confirmed that, Stearyl Palmitate is inducing apoptosis in MCF-7 cells at IC₅₀ concentration. Finally, in-vivo efficacy and toxicity studies were performed using zebrafishes (Danio rerio). It was observed that the fishes treated with IC₅₀ concentration of Stearyl Palmitate demonstrated 2x folds reduction in tumour size, while double dose resulted in 4x folds reduction in tumour size. Stearyl Palmitate did not demonstrate any toxicity or side effects in the zebrafishes. It is concluded that, Stearyl Palmitate, a phytochemical reported to be present in Althea officinalis is a potential anti-breast cancer agent, with ability to inhibit multiple targets such as HER-2, MEK-1 and PARP-2 proteins.

Communicated by Ramaswamy H. Sarma

 抽象

多靶点抑制剂目前是药物研究的趋势，因为它们具有更高的疗效和更低的毒性。在这项研究中，从精选的天然产物清单中探索了乳腺癌的多靶点抑制剂，即属于 360 种药用植物的 4,670 种植物化学物质。使用 SeeSAR 和 AutoDock Vina 对植物化学物质进行计算机筛选，结果发现棕榈酸硬脂酯是一种潜在的药物分子，可抑制三个药物靶点，即 HER-2、MEK-1 和 PARP-1 蛋白。使用 Maestro 平台 Desmond 对这三种蛋白质-配体复合物各 100 ns 进行分子动力学模拟，也证实了棕榈酸硬脂酯对多靶点抑制的预测。进一步的体外 MTT 测定表明，棕榈酸硬脂酯对 MCF-7 细胞具有 40 μM 的显着 IC 50 值，对 L929 细胞具有 >1000 μM 的显着 IC₅₀ 值。这证实了与非癌细胞相比，棕榈酸硬脂酯对乳腺癌细胞具有选择性细胞毒性。荧光染色和流式细胞术分析证实，棕榈酸硬脂酯在 IC₅₀ 浓度下诱导 MCF-7 细胞凋亡。最后，使用斑马鱼 （Danio rerio） 进行体内疗效和毒性研究。据观察，用 IC₅₀ 浓度的棕榈酸硬脂酯处理的鱼显示肿瘤大小减少了 2 倍，而双剂量导致肿瘤大小减少了 4 倍。棕榈酸硬脂酯在斑马鱼中没有表现出任何毒性或副作用。 得出的结论是，据报道存在于木槿花中的植物化学物质棕榈酸硬脂酯是一种潜在的抗乳腺癌药物，能够抑制 HER-2、MEK-1 和 PARP-2 蛋白等多个靶点。

通讯人：Ramaswamy H. Sarma