Natural products are irreplaceable reservoirs for cancer treatments. In this study, 12 phenanthrene compounds were extracted and isolated from Dendrobium officinale. Each chemical structure was identified using comprehensive NMR analysis. All compounds were evaluated for their cytotoxic activities against five tumor cell lines, i.e., HeLa, MCF-7, SK-N-AS, Capan-2 and Hep G2. Compound 5, 1,5,6-trimethoxy-2,7-dihydroxyphenanthrene, displayed the most significant cytotoxic effect against HeLa and Hep G2 cells, with an IC50 of 0.42 and 0.20 μM. For Hela cells, further experiments demonstrated that compound 5 could obviously inhibit cell migration, block cell cycle in the G0/G1 phase and induce apoptosis. Expression measurements for p53 indicated that knock down of p53 by siRNA could mitigate the apoptosis induced by compound 5. Therefore, the compound 5 is a potential candidate drug for HeLa cells in cervical cancer.

中文翻译：

---

铁皮石斛中的 1,5,6-三甲氧基-2,7-二羟基菲对 HeLa 细胞表现出抗肿瘤活性

天然产物是癌症治疗不可替代的储库。本研究从铁皮石斛中提取分离出 12 种菲化合物。每种化学结构均通过综合核磁共振分析进行鉴定。所有化合物均针对五种肿瘤细胞系（即 HeLa、MCF-7、SK-N-AS、Capan-2 和 Hep G2）的细胞毒活性进行了评估。化合物5, 1,5,6-三甲氧基-2,7-二羟基菲对HeLa和Hep G2细胞表现出最显着的细胞毒作用，IC50分别为0.42和0.20 μM。对于Hela细胞，进一步的实验表明，化合物5能够明显抑制细胞迁移，将细胞周期阻滞在G0/G1期并诱导细胞凋亡。p53的表达测量表明，通过siRNA敲低p53可以减轻化合物5诱导的细胞凋亡。因此，化合物5是宫颈癌HeLa细胞的潜在候选药物。