Abstract This study aimed to evaluate the selective cytotoxicity of six natural compounds on four cancerous cells (MCF-7, HeLa, Caco-2 and A549) and two normal intestinal and lung cells (Hs1.Int and Wl-38) cells. We also attempted to analyze basically the structure–activity relationships and to understand the mechanism of action of active compounds using the Caspase-Glo® 3/7 kit. Globimetulin B (2) isolated from Globimetula dinklagei was significantly cytotoxic on cancerous cells with 50% inhibitory concentrations (IC50) ranging from 12.75 to 37.65 μM and the selectivity index (SI) values varying between 1.13 and 3.48 against both normal cells. The compound 3-O-β-d-glucopyranosyl-28-hydroxy-α-amyrin (5) isolated from Phragmanthera capitata exhibited the highest cytotoxic activity on HeLa cells with the IC50 of 6.88 μM and the SI of 5.20 and 8.71 against Hs1.Int and Wl-38 cells, respectively. A hydroxyl group at C-3 of compounds was suggested as playing an important role in the cytotoxic activity. The induction of caspase-3 and -7 activity represents some proof that apoptosis has occurred in treated cells. Globimetulin B (2) selectively killed cancer cells with less toxicity to non-cancerous cells as compared to conventional doxorubicin therapy.

中文翻译：

---

从 Globimetula dinklagei 和 Phragmanthera capitalata（Loranthaceae）中分离的化合物的选择性细胞毒活性

摘要 本研究旨在评估六种天然化合物对四种癌细胞（MCF-7、HeLa、Caco-2 和 A549）和两种正常肠和肺细胞（Hs1.Int 和 WL-38）的选择性细胞毒性。我们还尝试使用 Caspase-Glo® 3/7 试剂盒从根本上分析结构-活性关系并了解活性化合物的作用机制。从 Globimetula dinklagei 中分离的 Globimetulin B (2) 对癌细胞具有显着的细胞毒性，50% 的抑制浓度 (IC50) 范围为 12.75 至 37.65 μM，选择性指数 (SI) 值在 1.13 至 3.48 之间变化，对两种正常细胞均不等。从 Phragmanthera capitalata 中分离的化合物 3-O-β-d-glupyranosyl-28-hydroxy-α-amyrin (5) 对 HeLa 细胞表现出最高的细胞毒活性，IC50 为 6.88 μM，SI 为 5.20 和 8。71 分别针对 Hs1.Int 和 WL-38 细胞。建议化合物的 C-3 处的羟基在细胞毒活性中起重要作用。caspase-3 和 -7 活性的诱导代表了处理细胞中发生细胞凋亡的一些证据。与常规多柔比星疗法相比，Globimetulin B (2) 选择性杀死癌细胞，对非癌细胞的毒性较小。