Ethanolic Extract of Polish Propolis: Chemical Composition and TRAIL-R2 Death Receptor Targeting Apoptotic Activity against Prostate Cancer Cells
Figure 6
EEP-P sensitizes LNCaP prostate cancer cells to TRAIL-induced cytotoxicity and apoptosis. Cells were incubated with 25–50 μg/mL EEP-P and/or 100 ng/mL TRAIL for 24–48 h. The values represent mean ± SD of three independent experiments performed in quadruplicate (). (a) Cytotoxic activity of EEP-P in combination with TRAIL against LNCaP cells. The percentage of cell death was measured using the MTT cytotoxicity assay ( compared to EEP-P alone, compared to TRAIL alone). (b) Apoptotic activity of EEP-P in combination with TRAIL against LNCaP cells. Apoptotic cell death was detected by flow cytometry using annexin V-FITC staining ( compared to EEP-P alone, compared to TRAIL alone). (c) Apoptotic activity of EEP-P in combination with TRAIL against LNCaP cells: (A) control cells, (B) cells incubated with 25 μg/mL EEP, (C) cells incubated with 50 μg/mL EEP, (D) cells incubated with 100 ng/mL TRAIL, (E) cells incubated with 25 μg/mL EEP and 100 ng/mL TRAIL, (F) cells incubated with 50 μg/mL EEP and 100 ng/mL TRAIL for 24 h, (G) control cells, (H) cells incubated with 25 μg/mL EEP, (I) cells incubated with 50 μg/mL EEP, (J) cells incubated with 100 ng/mL TRAIL, (K) cells incubated with 25 μg/mL EEP and 100 ng/mL TRAIL, and (L) cells incubated with 50 μg/mL EEP and 100 ng/mL TRAIL for 48 h. Apoptotic cell death was detected and visualized by fluorescence microscopy using annexin V-FITC staining. Healthy cells (stained with Hoechst 33342) emitted blue fluorescence and apoptotic cells (stained with Hoechst 33342 and annexin V-FITC) emitted green and blue fluorescence (indicated by arrows).
