A potential mechanism for the cytotoxic and antitumor effects of fluoroquinolones has been discovered. Treatment of HCT-116wt cells with norfloxacin, ciprofloxacin, and ofloxacin decreased intracellular NAD+ and cell survival. The IC50 values for the effect of fluoroquinolones were 0.314 mM (for norfloxacin), 0.547 mM (for ciprofloxacin), and 0.612 mM (for ofloxacin). The MTT test for cytotoxicity and mitochondrial functional status assessment revealed similar IC50 values of 0.32 mM (for norfloxacin), 0.35 mM (for ciprofloxacin), and 0.67 mM (for ofloxacin). The suggest unveil a new potential mechanism of fluoroquinolone action on cells beyond their antimicrobial activity.
Kuzminov et al. (Thu,) studied this question.