Total and differential cell counts in BALF. Exposure to cigarette smoke (CS) increased the numbers of total cells, macrophages, neutrophils, and lymphocytes in BALF. In addition, ST significantly reduced the numbers of these inflammatory cells in BALF to a similar degree as roflumilast. The numbers of cells in BALF were counted using a hemocytometer, and differential cell counts were performed on slides prepared by cytocentrifugation at 250 rpm for 3 min followed by Diff-Quick staining. a) Count of total cell number, b) Count of macrophages, c) Count of neutrophils, d) Count of lymphocytes. n = 5 in all groups. Data are shown as the mean ± S.E.M. Statistical analyses were conducted by one-way ANOVA followed by Newman-Keuls Multiple Comparison test; ###p < 0.001, ##p < 0.01 vs. AIR, ***p < 0.001, **p < 0.01, *p < 0.05 vs. CS.