Novel compounds of Taiwanese green propolis induce apoptosis of human glioblastoma cells by daylight photodynamic action.

Background: Glioblastoma, an aggressive brain cancer, has limited treatment options and poor prognosis. Taiwanese green propolis, known for its tumor-inhibitory properties, shows promise when combined with photodynamic therapy (PDT), a targeted, low-toxicity treatment. This study investigated a novel Taiwanese green propolis-based compound for inducing apoptosis in glioblastoma cells and its synergistic potential with daylight PDT.

Methods: Ethanol extracts of green propolis, wheatgrass, and mulberry leaves were combined and analyzed using High-Performance Liquid Chromatography (HPLC). Apoptosis induction in U87 glioblastoma cells was assessed via the MTT assay following treatment with the compound alone and in combination with daylight PDT at 570 nm.

Results: We identified Artepillin C as the main active component in the compound by HPLC, which significantly induced apoptosis in glioblastoma cells. Combined with daylight PDT, it demonstrated enhanced efficacy, with cell viability reduced from 95.2% at 0.25 µL to 11.3% at 8 µL of the compound extract. The EC₅₀ decreased, indicating greater apoptotic activity compared to the extract alone.

Conclusion: This study provides the first in vitro evidence of synergistic anti-tumor effects of a Taiwanese green propolis-based compound daylight PDT (GPDT), highlighting a promising novel therapeutic approach that warrants further clinical investigation.