Effects of SBS on MDSCs and serum TGF-β1. (A) Immunohistochemical double staining of MDSCs in tumor tissues or normal colonic tissues. 200 × for all, scale bar = 100 μm. SBS decreased the expression of MDSCs. Semiquantitive analysis is showed in Table 2. (B) Flow cytometry analysis of MDSCs in spleen and tumor. SBS decreased the number of MDSCs versus model group. (C) Enzyme-linked immunosorbent assay of serum TGF-β1 and semiquantitive analysis of Flow cytometry analysis of MDSCs. Serum contents of TGF-β1 was reduced by SBS. Data are presented as mean ± SD. *P < 0.01 vs. model, #P < 0.05 vs. model; △P < 0.01 vs. control, ▲P < 0.0 5 vs. control.