MOXIFLOXACIN - Search Livertox Database
Fluoroquinolone antibiotics provide broad-spectrum coverage for a number of infectious diseases, including respiratory as well as urinary tract infections. One of the important adverse effects of these drugs is phototoxicity which introduces a serious limitation to their use. To gain insight the molecular mechanisms underlying the fluoroquinolones-induced phototoxic side effects, the impact of two fluoroquinolone derivatives with different phototoxic potential, norfloxacin and moxifloxacin, on melanogenesis and antioxidant enzymes activity in normal human melanocytes HEMa-LP was determined. Both drugs induced concentration-dependent loss in melanocytes viability. The value of EC50 for these drugs was found to be 0.5 mM. Norfloxacin and moxifloxacin suppressed melanin biosynthesis; antibiotics were shown to inhibit cellular tyrosinase activity and to reduce melanin content in melanocytes. When comparing the both analyzed fluoroquinolones, it was observed that norfloxacin possesses greater inhibitory effect on tyrosinase activity in melanocytes than moxifloxacin. The extent of oxidative stress in cells was assessed by measuring the activity of antioxidant enzymes: SOD, CAT, and GPx. It was observed that norfloxacin caused higher depletion of antioxidant status in melanocytes when compared with moxifloxacin. The obtained results give a new insight into the mechanisms of fluoroquinolones toxicity directed to pigmented tissues. Moreover, the presented differences in modulation of biochemical processes in melanocytes may be an explanation for various phototoxic activities of the analyzed fluoroquinolone derivatives in vivo.
A new method of enantioselective synthesis of (S,S) ..
Melanin is a biopolymer synthesized by melanocytes in discrete organelles— melanosomes [, ]. Therefore, in this study, we have used the culture of normal human epidermal melanocytes as an in vitro experimental model system. The study was conducted to elucidate the possible involvement of melanin and melanocytes in the mechanisms of fluoroquinolones-induced toxic effects. The melanin content and tyrosinase activity were chosen as the biomarkers for modulatory effect of norfloxacin and moxifloxacin on melanogenesis, whereas the SOD, CAT, and GPx activities as the markers for oxidative stress in normal human melanocytes HEMa-LP.
Moxifloxacin is a fourth-generation synthetic fluoroquinolone antibacterial agent developed by Bayer. Fluoroquinolones are broad-spectrum antibiotics, effective for both gram-negative and gram-positive bacteri, that play an important role in treatment of serious bacterial infections, especially hospital-acquired infections and others in which resistance to older antibacterial classes is suspected. It functions by inhibiting DNA gyrase, a type II topoisomerase, and topoisomerase IV, thereby inhibiting cell replication. Moxifloxacin is used to treat certain infections such as pneumonia, bronchitis, and sinus, skin, and abdominal (stomach area) infections caused by bacteria. It is marketed worldwide (as the hydrochloride) under the brand names Avelox, Avalox, and Avelon for oral treatment.