Figure 6. Inhibition of lipopolysaccharide (LPS)-induced expression of interleukin-1β and interleukin-6 by SPA4 peptide. (A, B) Colon carcinoma SW480 cells were challenged with 1 µg/mL LPS for 4 h and then with the SPA4 peptide (1, 10, 50 µM) for additional 1 h and 5 h. Total proteins were probed with antibodies specific for (A) interleukin (IL)-1β and (B) IL-6. Densitometric readings of immunoreactive bands were normalized to those of β-actin, which served as loading control. Results are from one out of two independent experiments.