School of Food Science and Technology, Jiangnan University, Wuxi, 214122, China.
School of Food Science and Technology, Jiangnan University, Wuxi, 214122, China.
J Ethnopharmacol. 2020 Jul 15;257:112851. doi: 10.1016/j.jep.2020.112851. Epub 2020 Apr 10.
Poria cocos Wolf (P. cocos), a well-known traditional East-Asian medicinal and edible fungus, is one of the most important components in Chinese medicine formulas like "Guizhi fuling wan" to treat hyperplasia of mammary glands and breast cancer.
In this study, we attempted to verify the anticancer efficacy of the ethanol extract of P. cocos (PC) on the breast cancer as well as to investigate its most active compound and its underlying molecular mechanism in vivo and in vitro.
The key anti-cancer components were separated and purified through chromatography and identified by spectral analyses. The in vivo anti-breast cancer efficacy and side effects of PC were evaluated in BALB/c nude mice that have been subcutaneously injected with breast cancer cells MDA-MB-231. Cytotoxicity, apoptosis and cell cycle arrest of PC were evaluated in vitro by cell viability assays and flow cytometry. The protein levels were examined via western blotting.
Pachymic acid (PA), separated and identified as the most active compound, induced the significant cytotoxicity on breast cancer cells MDA-MB-231(IC value, 2.13 ± 0.24 μg/mL) and was not active against the normal breast epithelium cells MCF-10A. The in vivo experiment revealed that PC could significantly inhibit the tumor development and the final mean tumor weight of the mice in the PC group (0.51 ± 0.12g) was significantly lower than that in the model group (1.22 ± 0.45g). Notably, compared to the first-line anticancer drug cisplatin, PC showed less side effects on the function of the vital organs and the muscle strength of the mice. Among in vitro study, PC significantly inhibited the cell growth of MDA-MB-231 by inducing cell apoptosis and cell cycle arrested at G/G phase in a dose-dependent manner. The expression of cell cycle-associated cyclin D1, cyclin E, CDK2, and CDK4 were downregulated, while p53 and p21 expression were upregulated following the PA treatment. In addition, PA downregulated the apoptotic regulator Bcl-2, increased the expression of pro-apoptotic protein Bax, and promoted the release of cytochrome c and the activation of cleaved caspase-3, -9 and caspase -8 via mitochondria-mediated and death receptor-mediated signaling pathways.
This study verified the anticancer efficacy of PC on breast cancer in vivo and in vitro through induction of cell apoptosis and G/G cell cycle arrest. The data also suggested that PA could be developed as an efficacious agent for breast cancer treatment with less side effects.
茯苓（Poria cocos Wolf），一种著名的传统东亚药用和食用真菌，是中药方剂如“桂枝茯苓丸”治疗乳腺增生和乳腺癌的重要组成部分之一。
本研究试图验证茯苓乙醇提取物（PC）对乳腺癌的抗癌功效，并在体内和体外研究其最有效的化合物及其潜在的分子机制。
通过色谱法分离和纯化关键抗癌成分，并通过光谱分析鉴定。将 PC 的体内抗乳腺癌功效和副作用在已皮下注射乳腺癌细胞 MDA-MB-231 的 BALB/c 裸鼠中进行评估。通过细胞活力测定和流式细胞术评估 PC 在体外对细胞的细胞毒性、细胞凋亡和细胞周期停滞的影响。通过 Western blot 检测蛋白水平。
分离并鉴定出的最有效化合物为齿孔酸（PA），对乳腺癌细胞 MDA-MB-231 表现出显著的细胞毒性（IC 值为 2.13 ± 0.24μg/mL），而对正常乳腺上皮细胞 MCF-10A 则无活性。体内实验表明，PC 能显著抑制肿瘤的发展，PC 组小鼠的平均肿瘤重量（0.51 ± 0.12g）明显低于模型组（1.22 ± 0.45g）。值得注意的是，与一线抗癌药物顺铂相比，PC 对小鼠重要器官的功能和肌肉力量的副作用较小。在体外研究中，PC 以剂量依赖的方式通过诱导细胞凋亡和细胞周期停滞在 G1/G0 期，显著抑制 MDA-MB-231 细胞的生长。细胞周期相关蛋白 cyclin D1、cyclin E、CDK2 和 CDK4 的表达下调，而 p53 和 p21 的表达上调。此外，PA 通过线粒体和死亡受体介导的信号通路下调凋亡调节蛋白 Bcl-2，增加促凋亡蛋白 Bax 的表达，并促进细胞色素 c 的释放和 cleaved caspase-3、-9 和 caspase-8 的激活。
本研究通过诱导细胞凋亡和 G1/G0 细胞周期停滞，在体内和体外验证了 PC 对乳腺癌的抗癌功效。数据还表明，PA 可以作为一种有效的乳腺癌治疗药物，副作用较小。
