## 3 Results
### Growth Inhibition Effect (MTT method) of WST Extracts on Human Heptoma HepG2 Cells  
As shown in Figure 2, at different WST extract dosages (0, 10, 20, 40, 70, 100, 130, 160, 190, 220 \(\upmu\)g/mL), the growth inhibition rate towards human hepatoma HepG2 cells was 2.5 \(\pm\) 1.1, 10.2 \(\pm\) 0.6, 24.0 \(\pm\) 0.7, 33.2 \(\pm\) 1.4, 48.6 \(\pm\) 0.7, 66.5 \(\pm\) 1.3, 81.1 \(\pm\) 0.6, 91.0 \(\pm\) 0.5, and 94.9 \(\pm\) 0.2, respectively. The WST extracts had a significant and dose-dependent growth inhibitory effect towards HepG2 cells. When the extract dosage was 190 \(\upmu\)g/mL, the cell inhibition rate exceeded 90%, so the 40, 100, and 160 \(\upmu\)g/mL concentrations were selected for use in the follow-up experiments. Effects of WST Extracts on the Gene Expression of Caspase-3, -7, -8, and -9 in Human Heptoma HepG2 Cells  
Effects on gene expression of Caspase-3, -7, -8, and -9 in human hepatoma HepG2 cells, as assessed by RT-qPCR assays, after 48 h of treatment with 40, 100, or 160 \(\upmu\)g/mL of WST extract. As demonstrated \begin{table}
\begin{tabular}{c c c c} \hline \hline \multirow{2}{*}{**Treatment (level of sample, mg/plate)**} & \multicolumn{2}{c}{Revertants/plate} \\ \cline{3-4}  & & 1.25 & 2.5 \\ \hline \multirow{2}{*}{**TA98**} & Spontaneous & 68 \(\pm\) 5  (65.4)} \\  & WST  (37.6)  & \multirow{2}{*}{24 \(\pm\) 2  (65.4)} \\  & Spontaneous & 127 \(\pm\) 7  (60.5)} \\  & WST  (60.5)} \\  & Spontaneous & 127 \(\pm\) 7  (60.5)} \\  & Spontaneous & 127 \(\pm\) 7  (60.5)} \\  & Spontaneous & 127 \(\pm\) 7  (60.5)} \\  & Spontaneous & 127 \(\pm\) 7  (60.5)} \\  & WST  (60.5)} \\  & Spontaneous & 127 \(\pm\) 7  (60.5)} \\  & Spontaneous & 127 \(\pm\) 7  (60.5)} \\  & Spontaneous & 127 \(\pm\) 7  & \multirow{2}{*}{24 \(\pm\) 13  (60.5)} \\  & Spontaneous & 127 \(\pm\) 16  (77.1) \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Effect of WST extracts on the spontaneous mutagenicity of the _Salmonella typhimurium_ TA98 and TA100 strain. in Figure 3A-D, compared with the low expression level of the control group, the expression of the apoptotic genes Caspase-3 (1.2, 1.7 and 2.1 fold), -7 (1.1, 1.3 and 1.6 fold), -8 (1.3, 2.5 and 3.6 fold), and -9 (1.5, 1.9 and 2.5 fold) was significantly increased in the extract-treated cells at concentrations of 40, 100, and 160 \(\upmu\)g/mL, respectively. Figure 3: Effects of WST extracts on the gene expression of Caspase-3 (**A**), -7 (**B**), -8 (**C**), and -9 (**D**) in human hepatoma HepG2 cells. The fold increase of Capases-3 (**A**), -7 (**B**), -8 (**C**), and -9 (**D**) mRNA expression relative to the control. The calculation formula is as follows: gene expression/GAPDH \(\times\) control numerical value (control fold ratio: 1). \({}^{\text{a-d}}\) Mean values with different letters in the same bar graph are significantly different (\(p<0.05\)) according to [PERSON]’s multiple range test. Figure 2: Growth inhibition of human hepatoma HepG2 cells treated with WST extract as evaluated using MTT assays. \({}^{\text{a-j}}\) Mean values with different letters in the same bar graph are significantly different (\(p<0.05\)) according to [PERSON]’s multiple range test. Effects of WST Extracts on the Gene Expression of the Apoptosis-Related Bax and Bcl-2 Genes in Human Hepatoma HepG2 Cells  
The mRNA expression levels of p21 and p53 in HepG2 cells were significantly increased following WST extract treatment compared with the control group (Figure 4A,B). The highest dose of WST extract (160 \(\mathrm{\SIUnitSymbolMicro g}\)/mL) significantly increased the mRNA levels of p21 (2.9 fold) and p53 (3.8 fold) compared to the untreated control group. The 40 and 100 \(\mathrm{\SIUnitSymbolMicro g}\)/mL concentrations of WST extract also increased the mRNA expression of p21 (1.2 and 1.9 fold, respectively) and p53 (2.2 and 2.8 fold, respectively) in HepG2 cells.