## 3 Results and Discussion
### Antimutagenic Effect of FFL Extracts  
The antimutagenic effect of the FFL extracts was evaluated using the mutagens (4 NQO, SA, and 2-AA), as shown in Figure 4. Based on the results of the mutagenicity test, the highest concentration of FFL extracts was selected, exhibiting no toxicity or mutagenicity on both strains. The positive controls were 4 NQO (TA98 \(-\)S9 mix), SA (TA100 \(-\)S9 mix), and 2-AA (TA98 and TA100 \(+\)S9 mix), respectively. In the TA98 strain, all the FFL extracts did not induce any inhibitory effect in the condition without the S9 mix; however, they exhibited a dose-response inhibition with the S9 mix (Figure 4a,b). The half maximal inhibitory concentration (IC\({}_{50}\)) values for each FFL extract were 1984 (0%), 1926 (30%),  
Figure 3: The antioxidant activities of the _Fomes fometarius_ L. (FFL) extracts. The activities were assessed through **(a)** DPPH free radical scavenging, **(b)** ABTS total antioxidant capacity, and **(c)** DTT activity. Different letters (a–c, A–C, and _a–c_) in the same concentrations are significantly different at \(p\) \(<\) 0.05 by Duncan’s test. The data are shown as means \(\pm\) SD. AC: ascorbic acid.  
1020 (50%), 473.2 (70%), and 585.3 (100%) \(\mu\)g/plate, respectively. They were ranked in the following order: 70% > 100% > 50% > 30% > 0%. A similar tendency was also observed in the TA100 strain (Figure 4c,d). Only the inhibitory effect was observed with the S9 mix. The IC\({}_{50}\) values were 1603 (0%), 2191 (30%), 1544 (50%), 1163 (70%), and 1579 (100%) \(\mu\)g/plate, respectively. The were ranked in the following order: 70% > 50% \(\geq\) 100% \(\geq\) 0% > 30%.  
Of note, a clear divergence was observed depending on whether metabolic activation occurred. This indicates that the metabolized compounds of the FFL extract significantly contribute to the antimutagenic effect in both strains. In general, the main reason for including the S9 mix in antimutagenic or mutagenic tests is to mimic the metabolic activation that occurs in a living organism, allowing for the assessment of a compound's mutagenic potential after metabolic conversion [36]. Larger antimutagenic effects were observed in other plant extracts under the S9 mix [37; 38; 39]. Notably, this was also observed in mushrooms. [PERSON] et al. tested the antimutagenic effects of eight mushroom species [40]. All extracts exhibited larger antimutagenic effects in the presence of the S9 mix compared to the absence of the S9 mix. This implies that the metabolized substances mainly contribute to the antimutagenic effects by preventing the activation of mutagens in or out of body cells [41]. Meanwhile, the extracts with higher ethanol percentages (over 70%) induced more robust antimutagenic effects compared to the extracts with lower percentages. This difference appears to be closely related to the increased ethanol proportion. An increased proportion of organic solvents enhances the extraction of components such as essential oils, organic acids, polyphenols, and steroids compared to hot water extraction methods [26]. Therefore, the enriched concentration of these components in the extracts likely contributes to their enhanced antimutagenic properties. Through this test, we could confirm the an  
Figure 4: Antimutagenicity effects of two strains by FFL extracts in the presence and absence of S9 mix; (**a**,**b**) TA98 strain; (**c**,**d**) TA100 strain. The inhibitory effect was tested using the mutagens (4-nitroquinoline-1-oxide (4 NQO), sodium azide (SA), and 2-aminoanthracene (2-AA)). For the indirect mutation (+S9 mix), 2-AA was applied at 0.5 \(\mu\)g/plate. For the direct mutation (\(-\)S9 mix), 4 NQO (TA98) and SA (TA100) were applied at 1.0 and 0.5 \(\mu\)g/plate, respectively. The inhibition rate is shown as means \(\pm\) SD.  
timutagenicity of the FFL extracts under the metabolic activation and performed solvent fractionation of the crude extract (70% FFL extract).