Fig. 3

Effects of ciprofloxacin and levofloxacin on cytokine release from LPS-stimulated cortical microglia. Microglia were subcultured for 24 h in 10% FBS-containing medium, which was replaced with serum-free medium before pretreatment with (a, c) ciprofloxacin (CPFX) and (b, d) levofloxacin (LVFX) (50–150 μg/ml) for 1 h followed by stimulation with 100 ng/ml LPS for 6 h. Supernatants were collected and analyzed for (a, b) IL-1β and (c, d) TNF-α release. Results are expressed as percentage of cytokine release relative to LPS-stimulated microglia (dark gray bars). Data are means ± SEM (n = at least four independent experiments). Data were analyzed by Kruskal-Wallis test (p < 0.0001 and p = 0.0191 in a, b; p < 0.0001 in c, d) followed by Dunn’s multiple comparison test. *p < 0.05, **p < 0.01, and ***p < 0.001 versus LPS stimulation