The inhibitory effect of ciprofloxacin on proliferation of a murine bladder carcinoma cell line.

Ciprofloxacin was tested for its effect on proliferation of a bladder carcinoma cell line, Jurkat T-cell leukaemia cell line and a normal human foreskin derived from a fibroblast cell line. Cell proliferation was measured by MTT tetrazolium salt colorimetric assay. Proliferation of bladder carcinoma cells was inhibited by ciprofloxacin in a dose and time dependent fashion. Initial inhibition was observed at a concentration of 25 mg/L (approximately 35% inhibition; P greater than 0.01) while 250 mg/L of ciprofloxacin, a concentration achievable in urine following conventional oral treatment, exerted a lytic effect on these cells. A maximum suppressive effect on cell proliferation was reached within the first 24 h of ciprofloxacin addition to cell cultures. The rate of reversal of the inhibition of proliferation was dependent on the initial drug concentration. Exposure of bladder carcinoma cell cultures to 250 mg/L ciprofloxacin resulted in irreversible inhibition of proliferation. Similar results were obtained for the fibroblast cell line and Jurkat T-cell line. The latter being slightly more sensitive towards ciprofloxacin treatment in vitro.