Effects of SBS on oncogenic protein expression. (A) Immunohistochemical staining of β-catenin, COX-2, p53 and PCNA expression in tumor tissues or normal colonic tissues. 200× for all, scale bar = 100 μm. SBS significantly decreased the expression of β-catenin, p53 and PCNA, respectively, but not COX-2. (B) Western blot analysis of β-catenin, COX-2, p53, PCNA expression in colonic tissues. The expression of these proteins was reduced in SBS group compared with model group, except COX-2. Semiquantitive analysis of these proteins is showed in Tables 2 and 3.