Genotoxic potential of Dianthus superbus var. superbus and Petasites paradoxus (Retz.) Baumg. methanolic extracts in Chinese hamster ovary cells.

Dianthus superbus var. superbus (D. superbus) and Petasites paradoxus (Retz.) Baumg. (P. paradoxus) are traditionally used medicinal plants from the Italian flora. This study presents the first investigation into the cytotoxic and genotoxic potential of methanolic leaf extracts from both species. Genotoxicity was assessed using the automated cytokinesis-block micronucleus (CBMN) assay in Chinese Hamster Ovary (CHO-K1) cells. Both extracts exhibited dose-dependent cytotoxic effects, with IC50 values of 27 µg/mL for D. superbus and 56 µg/mL for P. paradoxus. At the lowest tested concentration (6.3 µg/mL), D. superbus extract did not significantly affect micronucleus frequency in the presence or absence of mitomycin C (MMC). However, at the highest concentration (25 µg/mL), D. superbus extract significantly increased micronucleus frequency under both conditions compared to control cells. For P. paradoxus, the lowest concentration tested (12.5 µg/mL) did not alter micronucleus frequency in the absence of MMC, but notably reduced micronucleus formation when co-administered with MMC, suggesting potential antigenotoxic activity. Conversely, the highest concentration of P. paradoxus extract (50 µg/mL) induced a significant increase in micronucleus frequency compared to MMC treatment alone. These results indicate that both extracts possess cytotoxic and genotoxic properties. Future research should focus on elucidating the mechanisms underlying these genotoxic effects and identifying the specific phytochemicals responsible.