Phytochemical Profile and In Vitro Cytotoxic, Genotoxic, and Antigenotoxic Evaluation of Cistus monspeliensis L. Leaf Extract

Cistus monspeliensis L. (C. monspeliensis) is used in Italian folk medicine. This study was performed to determine genotoxic and antigenotoxic effects of C. monspeliensis leaf extract against mitomycin C (MMC) using an in vitro cytokinesis-block micronucleus assay (CBMN) in the Chinese Hamster Ovarian K1 (CHO-K1) cell line. The phytochemical composition of C. monspeliensis extract was evaluated using an untargeted metabolomic approach by employing UPLC-PDA-ESI/MS. The automated in vitro CBMN assay was carried out using image analysis systems with a widefield fluorescence microscope and the ImageStreamX imaging flow cytometer. The phytochemical profile of C. monspeliensis extract showed, as the most abundant metabolites, punicalagin, myricetin, gal- locathechin, and a labdane-type diterpene. C. monspeliensis, at the tested concentrations of 50, 100, and 200 μg/mL, did not induce significant micronuclei frequency, thus indicating the absence of a genotoxic potential. When testing the C. monspeliensis extract for antigenotoxicity in the presence of MMC, we observed a hormetic concentration-dependent effect, where low concentrations resulted in a significant protective effect against MMC-induced micronuclei frequency, and higher concentrations resulted in no effect. In conclusion, our findings demonstrate that C. monspeliensis extract is not genotoxic and, at low concentration, exhibits an antigenotoxic effect. In relation to this final point, C. monspeliensis may act as a potential chemo-preventive against genotoxic agents.