Pefloxacin and ciprofloxacin increase UVA-induced edema and immune suppression.

BACKGROUND

Quinolone antibiotics are popularly prescribed antibiotics because of their wide antibacterial spectrum and lowered bacterial resistance. Quinolone antibiotics are one of the well-known photosensitizers that induce phototoxicity. Their role in photocarcinogenesis has been suggested in some studies.

METHODS

Mice were treated with two quinolone antibiotics (ciprofloxacin, which is less phototoxic, and pefloxacin, which is more phototoxic) to study the effect of the antibiotics on sunburn and immune suppression by ultraviolet A (UVA) irradiation. The effects of a combined treatment with UVA and these quinolone antibiotics were measured on back skin swellings, sunburn cell formations, depletion of epidermal Langerhans cells, and local and systemic suppression of contact hypersensitivity.

RESULTS

Mice treated with both UVA and quinolone showed significantly increased back skin swellings and decreased epidermal Langerhans cells than mice treated with UVA only. Sunburn cells were increased significantly in mice treated with pefloxacin and 50 J/cm2 of UVA. Combination of pefloxacin and UVA suppressed local contact hypersensitivity significantly, but not systemic contact hypersensitivity.

CONCLUSIONS

Phototoxic quinolones augmented the effect of UVA by increasing sunburn and apoptosis, depleting Langerhans cells and suppressing local immune response. By affecting apoptosis and immune suppression, they may facilitate photocarcinogenesis caused by UVA.