# In Vitro Genotoxicity Assessment from the _Glycyrrhiza_ New Variety Extract
## 4 Discussion
Moreover, because it is widely used, a broad database of CHL cells already exists [42]. When WG extract was treated for 6 h with S9 mix, the frequency of numerical aberrations in the 1400 \(\upmu\)g/mL WG extract treatment group was beyond the range of HCD. However, the result was not statistically significantly increased and not a dose-related response. At that time, we observed no significant increase in the frequency of structural aberrations in any of the WG-dosed groups. Nor did we observe a significant increase the frequency of structural and numerical aberrations in any of the WG-dosed groups after the WG extract was treated for 6 h and 24 h without S9 mix (Table 2). These results suggest that WG extract didn't damage DNA under the in vitro conditions of this study. A micronucle tests is a useful means of assessing the mutagenicity of test articles that affect the equitable distribution of chromosomes under the cell division [43]. This test is typically performed using bone marrow from experimental animals, as the tested substance can conveniently be orally administrated to the animals and then digested, metabolized, and spread to the target organs (including bone marrow). The micronucle test is especially well suited to an evaluation of mutagenicity as it permits consideration of multiple processes and reflects the cytogenetic effects of active forms of test substance [44,45]. Chromosomal damage, such as double strand chromosome breakage (clastogenesis) or impaired spindle (aneugenicity), induces the creation of micronuclelei; the number of micronuclelei, therefore, is an indicator of chromosomal damage [46]. We observed no statistically significant increase in the frequency of MNPCEs after administration of up to 5000 mg/kg/day of WG compared to the negative control group. Moreover, the PCE:RBC ratio, which is an index of cytotoxicity, was not significantly decreased by administration of up to 5000 mg/kg/day of WG compared to the negative control group. These results indicate that WG extracts did not induce the chromosomal damage under the conditions of this study. A number of previous studies have reported on the genotoxicity of licorice extracts and compounds. _G. glabra_ water extract induced mutagenicity at 2500 \(\upmu\)g/mL in the AMES test (TA100), but chloroform and methanol extracts did not [47]. In a study of chromosome aberration and micronucle tests in human lymphocytes, _G. glabra_ methanolic extract did not occur genotoxicity after up to 20 ug/mL was administered per day [48]. Licorice flavonoid oil (LFO) induced structural chromosome aberrations when given at concentrations higher than 600 ug/mL with S9 mix in CHL cells. Pursuant to the AMES test, LFO did not increase the number of revertant colonies up to 5000 ug/plate in any tester strains (TA100, TA1535, TA98, TA1537, and WP2 _uvr_A), and nor did LFO increase the frequency of MNPCEs when up to 5000 mg/kg/day was provided, but cytotoxicity was observed when 5000 mg/kg/day was administered in micronucle tests of F344 rats [49]. Standardized de-glycyrrhizinated _G. glabra_ extract did not induce genotoxicity when up to 501 ug/mL was provided (according to the AMES IITM test using TA98 and TAMix strains), or when between 40 ug/mL with 4 h treatment and 14.6 ug/mL with 18 h treatment (according to the chromosome aberration test using CHO-K1 cells), or when 40 ug/mL was administered (according to the micronucle tests test using the CHO-K1 cells). However, cytotoxicity was observed when 40 ug/mL was administered in the chromosome aberration test as well as the micronucle test [50]. Disodium glycyrrhizinate (up to 5000 ug/plate) didn't increase the number of revertant colonies in the AMES test (TA92, TA1535, TA100, TA1537, TA94, and TA98), but did induce structural chromosome aberrations at 4000 ug/mL in the chromosome aberration test on the CHL cells.