Manganese complexes displaying superoxide dismutase activity: a balance between different factors.

Superoxide radicals are one of the most toxic reactive oxygen species and its damaging effects lead to a variety of detrimental health conditions including cardiovascular diseases, neurodegenerative disorders and other types of age-related diseases. Following Nature example, chemists have designed manganese complexes that mimic the protecting action of the superoxide dismutases (SOD), metalloenzymes that catalyze the conversion of superoxide radical to the less toxic oxygen and hydrogen peroxide. This review provides an overview of the different SOD mimic manganese complexes developed mainly over the last decade, with particular attention to those factors that could be playing a crucial role in determining their activity.