Antioxidant activity and protective effect on DNA cleavage of extracts from Cistus incanus L. and Cistus monspeliensis L.

The genus Cistus includes many typical species of Mediterranean flora; Cist us species are used as antidiarrheics, as general remedies for treatment of various skin diseases in folk medicine and as anti-inflammatory agents. Th ese species contain flavonoids that are considered to be chain-breaking ant ioxidants. In this work, we have investigated the effects of crude aqueous extracts from Cistus incanus and Cistus monspeliensis on DNA cleavage and t heir free-radical scavenging capacity. In addition, their effect on lipid p eroxidation in rat liver microsomes was evaluated. These extracts showed a protective effect on DNA cleavage and a dose-dependent free-radical scaveng ing capacity; Cistus monspeliensis was more active than Cistus incanus; the se results were confirmed by a significant inhibition of lipid peroxidation in rat liver microsomes. The experimental evidence, therefore, suggests th at because of their antioxidant activity these extracts may offer excellent photoprotection for skin and may be useful in the treatment of human disea ses where oxidative stress plays a key role.