Increase in apoptosis by combination of metformin with silibinin in human colorectal cancer cells

Figure 1 Treatment with silibinin and metformin in combination or alone reduces the viability of COLO 205 cells. Reduced cell viability was observed following 24-h incubation with silibinin (0-200 μmol/L) and metformin (0-20 mmol/L) in combination or alone. The gray bars depict the results from COLO 205 cells, and the open bars correspond to the results from human colonic epithelial cells (HCoEpiC) (A). The time course (0-24 h) (B) and combination index (C) are shown in COLO 205 cells treated with silibinin (100 μmol/L) and metformin (10 mmol/L) in combination (M + S) or alone. The data are expressed as mean ± SE (n = 6 for each group). ^aP < 0.01 and ^bP < 0.001 vs Control COLO 205 cells; ^cP < 0.05 and ^dP < 0.01 vs Control HCoEpiC. M + S: Metformin and silibinin.