Publication: Olea europaea leaf phenolics oleuropein, hydroxytyrosol, tyrosol, and rutin Induce apoptosis and additionally affect temozolomide against glioblastoma: In particular, oleuropein inhibits spheroid growth by attenuating stem-like cell phenotype
Date
2023-02-01
Authors
Erçelik, Melis
Tekin, Çağla
Aksoy, Seçil Ak
Eser, Pınar
Authors
Erçelik, Melis
Tekin, Çağla
Tezcan, Gülçin
Aksoy, Seçil Ak
Bekar, Ahmet
Kocaeli, Hasan
Taşkapılıoğlu, Mevlüt Özgür
Eser, Pınar
Tunca, Berrin
Journal Title
Journal ISSN
Volume Title
Publisher
Mdpi
Abstract
The effects of Olea europaea leaf extract (OLE) phenolics, including oleuropein (OL), hydroxytyrosol (HT), tyrosol (TYR), and rutin against glioblastoma (GB), independently and in combination with temozolomide (TMZ), were investigated in T98G and A172 cells. Cell growth was assessed by WST-1, real-time cell analysis, colony formation, and cell cycle distribution assays. A dual acridine orange propidium iodide (AO/PI) staining and annexin V assay determined cell viability. A sphere-forming assay, an intracellular oxidative stress assay, and the RNA expression of CD133 and OCT4 investigated the GB stem-like cell (GSC) phenotype. A scratch wound-healing assay evaluated migration capacity. OL was as effective as OLE in terms of apoptosis promotion (p < 0.001) and GSC inhibition (p < 0.001). HT inhibited cell viability, GSC phenotype, and migration rate (p < 0.001), but its anti-GB effect was less than the total effect of OLE alone. Rutin decreased reactive oxygen species production and inhibited colony formation and cell migration (p < 0.001). TYR demonstrated the least effect. The additive effects of OL, HT, TYR and rutin with TMZ were significant (p < 0.001). Our data suggest that OL may represent a novel therapeutic approach against GB cells, while HT and rutin show promise in increasing the efficacy of TMZ therapy.
Description
Keywords
Olive oil, Extract improves, Tumor-necrosis, Expression, Cancer, Phosphorylation, Combination, Efficacy, Therapy, Glioma, Olea europaea leaf extract, Oleuropein, Hydroxytyrosol, Tyrosol, Rutin, Temozolomide, Glioblastoma, Life sciences & biomedicine - other topics, Microbiology