The genotoxic and antigenotoxic potential of the methanolic root extract of Glycyrrhiza glabra L. on human peripheral blood lymphocytes.

Glycyrrhiza glabra L. (licorice) is one of the most important medicinal plants, which is widely used throughout the world both in traditional and contemporary medical industries. This study was undertaken to investigate the potential genotoxic activity of G. glabra methanolic root extract, and its possible antigenotoxic properties against mitomycin C (MMC)-induced DNA damage in in vitro chromosome aberrations (CAs) and cytokinesis-block micronucleus (CBMN) assays in human peripheral blood lymphocytes (PBLs). Lymphocytes were treated with 25, 50, and 100 µg/ml G. glabra methanolic root extract alone as well as in combination with MMC (0.1 µg/ml) for 24 and 48 h treatment periods. It was found that there were no statistically significant differences between the negative control and the groups treated with all concentrations of G. glabra root extract of alone (p > 0.05), demonstrating the absence of genotoxic effects at both 24 and 48 h treatment periods. Besides, the co-treatment of G. glabra methanolic root extract and MMC significantly decreased the percentage of structural CAs and MN formation when compared with the culture treated with MMC alone (p < 0.001). In addition, the negative interaction factor (IF) values obtained for all combinations represent an antagonistic effect of G. glabra versus MMC. We can state that this extract acts as an antagonist and markedly decreased MMC-induced cytogenotoxicity. In conclusion, the present results demonstrate that in the tested experimental conditions, G. glabra methanolic root extract is not genotoxic in cultured human PBLs and has also antigenotoxic activity against MMC, which is widely used in chemotherapy against cancer.