Fig. 2

piTRL and laser irradiation promoted apoptosis of CT-26 carcinoma. CT-26 cells were incubated with PBS, TRL, iTRL or piTRL for 1 h, and the cells were treated with or without laser irradiation at 1 W/cm² for 5 min and cultured for 24 h. a Cell viability of CT-26 was measured by MTT assay; ** p < 0.01. b Apoptosis was analyzed by annexin-V and 7AAD staining on flow cytometry. c Mean percentages of apoptotic cells, ** p < 0.01. d The expression levels of procaspase-8, − 9, and − 3 were assayed by western blotting analysis. β-actin was used as a loading control