Department of Pharmacy, College of Pharmacy, China Medical University, 91 Hsueh-Shih Road, Taichung 40402, Taiwan, ROC.
Department of Bioinformatics and Medical Engineering, Asia University. 500, Lioufeng Rd., Wufeng, Taichung 41354, Taiwan, ROC.
Phytomedicine. 2019 Feb;53:252-262. doi: 10.1016/j.phymed.2018.09.008. Epub 2018 Sep 5.
Multidrug resistance (MDR) in cancer is one of the main obstacles in treatment with chemotherapy. Drug efflux through P-glycoprotein is the major mechanism involved in MDR. A potential strategy to provide the best possible clinical outcomes is to develop P-glycoprotein (P-gp) inhibitors from natural products.
The present study investigated the effects of the natural sesquiterpene lactone tenulin and its derivative isotenulin on human P-gp; the mechanisms of kinetic interactions were also explored.
The human P-gp (ABCB1/Flp-In™-293) stable expression cells were established by using the Flp-In™ system. The effects of tenulin and isotenulin on cell viability were evaluated by SRB assays in established cell lines, sensitive cancer cell line (HeLaS3), and resistant cancer cell line (KB-vin). The transporter inhibition ability was evaluated by calcein-AM uptake assays. The P-gp inhibition kinetics of tenulin and isotenulin were evaluated by rhodamine123 and doxorubicin efflux assays. The ATPase activity was evaluated with the Pgp-Glo™ Assay System.
Tenulin and isotenulin significantly inhibited the P-gp efflux function by stimulating P-gp ATPase activity. Tenulin and isotenulin interacted with the effluxes of rhodamine 123 and doxorubicin through a competitive and noncompetitive mechanism, respectively. The combinations of tenulin and isotenulin with chemotherapeutic drugs significantly resensitized MDR cancer cells.
These results suggested that tenulin and isotenulin are potential candidates to be developed for synergistic treatment of MDR cancers.
癌症的多药耐药性（MDR）是化疗治疗的主要障碍之一。通过 P-糖蛋白外排是 MDR 中涉及的主要机制。从天然产物中开发 P-糖蛋白（P-gp）抑制剂是提供最佳临床效果的潜在策略。
本研究调查了天然倍半萜内酯替宁及其衍生物异替宁对人 P-糖蛋白的影响；还探讨了动力学相互作用的机制。
通过 Flp-In™系统建立了人 P-糖蛋白（ABCB1/Flp-In™-293）稳定表达细胞。采用 SRB 法在建立的细胞系、敏感癌细胞系（HeLaS3）和耐药癌细胞系（KB-vin）中评估替宁和异替宁对细胞活力的影响。通过 calcein-AM 摄取试验评估转运体抑制能力。通过罗丹明 123 和阿霉素外排试验评估替宁和异替宁的 P-gp 抑制动力学。用 Pgp-Glo™Assay System 评估 ATP 酶活性。
替宁和异替宁通过刺激 P-gp ATP 酶活性显著抑制了 P-gp 的外排功能。替宁和异替宁分别通过竞争性和非竞争性机制与 rhodamine 123 和阿霉素的外排相互作用。替宁和异替宁与化疗药物的联合显著增加了 MDR 癌细胞的敏感性。
这些结果表明，替宁和异替宁是开发用于协同治疗 MDR 癌症的潜在候选药物。
