In vitro genotoxic and antigenotoxic effects of cynarin.

Cynarin is an artichoke phytochemical that possesses a variety of pharmacological features including free-radical scavenging and antioxidant activity. The origin of artichoke species appears to be Mediterranean region. Two of these species, globe artichoke (Cynara cardunculus var. scolymus L.) and cardoon (Cynara cardunculus var. altilis DC), are widely cultivated and consumed. This vegetable, as the basis of the mediterranean diet, has been used as herbal medicine for its therapeutic effects since ancient times. Therefore, this study was performed to determine genotoxic and antigenotoxic effects of cynarin against MMC (mitomycin C) and H₂O₂ (hydrogen peroxide) induced genomic instability using chromosome aberrations (CAs), sister chromatid exchanges (SCEs), micronucleus (MN), and comet assays in human lymphocytes.

Lymphocytes obtained from two healthy volunteers (1 male and 1 female) were exposed to different concentrations of cynarin (12-194 μM) alone and the combination of cynarin and MMC (0.60 μM) or cynarin and H₂O₂ (100 μM, only for comet assay).

Cynarin alone did not induce significant genotoxic effect in the CA, SCE (except 194 μM), MN, and comet assays. The combination of some concentrations of cynarin and MMC decreased the frequency of CAs, SCEs and MN induced by MMC. Furthermore, the combination of cynarin and H₂O₂ reduced all comet parameters at all the concentrations compared to H₂O₂ alone. While the highest concentrations of cynarin significantly decreased mitotic index (MI), the combination of cynarin and MMC increased the reduction of MI induced by MMC alone.

All the results obtained in this study demonstrated that cynarin exhibited antigenotoxic effects rather than genotoxic effects. It is believed that cynarin can act as a potential chemo-preventive against genotoxic agents.