Potential antioxidant mechanism of action for metronidazole: implications for rosacea management.

Chronic inflammation is believed to account for some symptoms of rosacea. The efficacy of topical metronidazole in the treatment of rosacea may be due to its antimicrobial as well as anti-inflammatory activity. Neutrophils release potent inflammatory mediators, including reactive oxygen species (ROS), and intrafollicular neutrophils have been observed in stage II disease. ROS and other free radicals may contribute to intrinsic and extrinsic aging, both of which accentuate clinical manifestations of rosacea. If, as in vitro data suggest, metronidazole has antioxidant activity, it may help subdue the oxidative tissue damage of intrinsic and extrinsic aging as well as prevent and treat rosacea symptoms.