Fig. 2

Effects of ciprofloxacin and levofloxacin in microglia cell viability. Microglia were cultured for 24 h in 10% serum-containing medium, which was replaced with serum-free medium before pre-treatment with (a, c, e) ciprofloxacin (CPFX) and (b, d, f) levofloxacin (LVFX) (50–200 μg/ml) for 1 h followed by stimulation with 100 ng/ml LPS for 6 h. At the end of incubation, cell viability was determined by (a, b) MTT, (c, d) SRB, and (e, f) Trypan blue exclusion assays. Results are expressed as percentage of cell viability relative to LPS-stimulated microglia. Data are means ± SEM (n = at least three independent experiments). Data were analyzed by Kruskal-Wallis test (p = 0.0020 and p = 0.8929 in a, b; p = 0.0048 and p = 0.3920 in c, d; p = 0.0376 and p = 0.9245 in e, f), followed by Dunn’s multiple comparison test. *p < 0.05 and ***p < 0.001 versus LPS-stimulated cells (dashed lines)