Figure 4.

Cyclic peptide C25 could inhibit CT26 tumor growth not directly killing tumor cells. (A) MTT analysis of the effect of cyclic peptide C25 on the proliferation of CT26 tumor cells in vitro. CT26 xenograft mice model was established, cyclic peptide C25 (2 mg/kg/day) was treated for 14 days when the tumor grew to 40–80 mm³. The (B) tumor volumes, (C) tumor sizes and (D) body weight of cyclic peptide C25 and control group. Data are expressed as the mean ± SD (n = 5) and statistical significance between groups was determined by Student's t test: ^**P < 0.01.