胶质母细胞瘤（GB）是中枢神经系统内最具侵袭性和最常见的胶质瘤。尽管付出了巨大的努力，GB 的 5 年生存率仍然很低（~6%）。这很大程度上归因于不良的预后和缺乏可行的治疗选择。因此，以植物源化合物为中心的新疗法成为提高患者生存和福祉的引人注目的途径。南非种，Plectranthus hadiensis Schweinf。 （P. hadiensis）是唇形科的一员，在传统医学中具有治疗一系列疾病的历史，包括呼吸系统、消化系统和肝脏疾病。该物种表现出多种生物活性，例如抗炎和抗肿瘤特性，这可能归因于其丰富的天然二萜成分，如松香二萜、7α-乙酰氧基-6β-羟基豆蔻酮 (Roy)。 Roy 在多种癌细胞系中表现出良好的抗肿瘤作用，使其成为进一步研究其抗 GB 机制的有力候选者。本研究旨在研究 Roy（一种天然先导化合物）在 GB 细胞中的抗肿瘤活性和潜在机制。从 P. hadiensis 的丙酮提取物中分离出来，并在一组人 GB 细胞系（U87、A172、H4、U373 和 U118）中评估其抗肿瘤机制，以模拟肿瘤异质性。简而言之，通过Alamar Blue®测定评估Roy处理对细胞代谢活性的影响，同时通过流式细胞术评估细胞死亡、细胞周期调节、线粒体膜电位和活化的caspase-3活性。通过 qPCR 测量靶基因的 mRNA 水平，通过蛋白质印迹评估蛋白质表达。通过共聚焦显微镜评估细胞摄取和对线粒体形态的影响。Roy 通过抑制抗凋亡蛋白的表达和增加活化的 caspase-3 的水平来诱导 G2/M 细胞周期停滞、线粒体断裂和凋亡。达到显着抑制效果所需的 Roy 浓度明显低于标准一线治疗替莫唑胺 (TMZ) 的浓度（6-9 倍），以达到类似的效果。此外，在低浓度（16 μM）下，Roy 影响肿瘤细胞的代谢活性，而对非肿瘤细胞（小胶质细胞和星形胶质细胞）没有显着影响。总体而言，Roy 对 GB 细胞表现出强大的抗肿瘤活性，提供了一种有前景的途径用于开发新型化疗方法。版权所有 © 2024。由 Elsevier B.V. 出版

Glioblastoma (GB) is the most aggressive and prevalent glioma within the central nervous system. Despite considerable efforts, GB continues to exhibit a dismal 5-year survival rate (∼6%). This is largely attributed to unfavorable prognosis and lack of viable treatment options. Therefore, novel therapies centered around plant-derived compounds emerge as a compelling avenue to enhance patient survival and well-being. The South African species, Plectranthus hadiensis Schweinf. (P. hadiensis), a member of the Lamiaceae family, has a history of use in traditional medicine for treating a range of diseases, including respiratory, digestive, and liver disorders. This species exhibits diverse biological activities, such as anti-inflammatory and antitumoral properties, likely attributed to its rich composition of naturally occurring diterpenes, like the abietane diterpene, 7α-acetoxy-6β-hydroxyroyleanone (Roy). Roy has demonstrated promising antitumor effects in various cancer cell lines, making it a compelling candidate for further investigation into its mechanisms against GB.This study aims to investigate the antitumor activity and potential mechanism of Roy, a natural lead compound, in GB cells.Roy was isolated from the acetonic extract of P. hadiensis and its antitumor mechanism was assessed in a panel of human GB cell lines (U87, A172, H4, U373, and U118) to mimic tumor heterogeneity. Briefly, the impact of Roy treatment on the metabolic activity of cells was evaluated by Alamar Blue® assay, while cell death, cell cycle regulation, mitochondrial membrane potential, and activated caspase-3 activity were evaluated by flow cytometry. Measurement of mRNA levels of target genes was performed by qPCR, while protein expression was assessed by Western blotting. Cell uptake and impact on mitochondrial morphology were evaluated by confocal microscopy.Roy induced G2/M cell cycle arrest, mitochondrial fragmentation, and apoptosis by inhibiting the expression of anti-apoptotic proteins and increasing the levels of activated caspase-3. The concentrations of Roy needed to achieve significant inhibitory outcomes were notably lower (6-9 fold) than those of temozolomide (TMZ), the standard first-line treatment, for achieving comparable effects. In addition, at low concentrations (16 μM), Roy affected the metabolic activity of tumor cells while having no significant impact on non-tumoral cells (microglia and astrocytes).Overall, Roy demonstrated a robust antitumor activity against GB cells offering a promising avenue for the development of novel chemotherapeutic approaches.Copyright © 2024. Published by Elsevier B.V.