Chemosensitization of U-87 MG Glioblastoma Cells by Neobavaisoflavone towards Doxorubicin and Etoposide

Glioblastoma (GB) is the most common type of glioma, which is distinguished by high mortality. Due to the rapid progression of the tumor and drug resistance, the treatment is often ineffective. The development of novel therapies in a big part concerns the application of anti-cancer agents already used in clinical practice, unfortunately often with limited effects. This could be overcome through the use of compounds that possess chemosensitizing properties. In our previous work, it has been shown that neobavaisoflavone (NBIF) enhances the in vitro activity of doxorubicin in GB cells. The aim of this study was a further investigation of the possible chemosensitizing effects of this isoflavone. The experimental panel involving image cytometry techniques, such as count assay, examination of mitochondrial membrane potential, Annexin V assay, and cell cycle analysis, was performed in human glioblastoma U-87 MG cells and normal human astrocytes (NHA) treated with NBIF, doxorubicin, etoposide, and their mixes with NBIF. NBIF in co-treatment with etoposide or doxorubicin caused an increase in the population of apoptotic cells and prompted alterations in the cell cycle. NBIF enhances the pro-apoptotic activity of etoposide and doxorubicin in U-87 MG cells, which could be a sign of the chemosensitizing properties of the isoflavone.