Impact of sparfloxacin on melanogenesis and antioxidant defense system in normal human melanocytes HEMa-LP - An in vitro study.

Fluoroquinolones are a group of broad spectrum bactericidal antibiotics used to treat various infections of urinary and respiratory systems, as well as in ophthalmology and dermatology. This class of antibiotics causes toxic effects directed to pigmented tissues, what introduces a serious limitation to their use. The aim of this work was to examine the impact of sparfloxacin on melanogenesis and the antioxidant defense system in normal human epidermal melanocytes, adult, lightly pigmented (HEMa-LP). The effect of sparfloxacin on cell viability was determined by WST-1 assay; melanin content, tyrosinase activity as well as antioxidant enzymes activity were measured spectrophotometrically. Sparfloxacin induced the concentration - dependent loss in melanocytes viability. The value of EC50 was determined to be ∼0.25 mM. Sparfloxacin inhibited tyrosinase activity and reduced the melanin content in human melanocytes. To study the antioxidant defense system in melanocytes, the activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) in cells exposed to sparfloxacin were determined. It was observed that sparfloxacin caused depletion of the antioxidant status of melanocytes. The observed sparfloxacin-dependent inhibition of melanogenesis and changes of antioxidant enzymes activities in human melanocytes give a new insight into the mechanism of fluoroquinolones toxicity directed to pigmented tissues.