Introduction:
Despite medical advances glioblastoma multiforme (GBM) is still the most common malignant primary brain tumor. Additionally, the gold standard treatment possesses poor (only 12–15 months) survival median. Thus, drug repurposing may be a helpful strategy for discovering more effective GBM chemotherapeutic drugs. Interestingly, phenothiazine derivatives have been considered a promising candidate for drug repurposing for cancer therapy, since they possess several biological activities, such as anticancer, antibacterial, antifungal, and antiviral effects.

Material and methods:
We investigated the impact of perphenazine on the viability of several human glioblastoma (U-87 MG, A172, and T98G) cell lines after 24-, 48-, and 72-hour incubation using WST-1 assay.

Results:
Data showed that the tested phenothiazine derivative decrease glioblastoma viability in a time- and concentration-dependent manner.

Conclusions:
Based on EC₅₀ values, perphenazine is the most efficient against A172 human glioblastoma in all of the tested treatment time periods compared to T98G and U-87 MG cells. Based on previous research, which revealed that perphenazine does not affect normal human astrocytes, this drug is a promising candidate for glioblastoma treatment. Further studies are required to unravel the complete antitumor mechanism of these phenothiazine derivatives in GBM.