## 3 Results and Discussion
### Cell Viability and Oxidative Stress
\begin{table}
\begin{tabular}{c c c c c} \hline  & **\(\mu\)g/mL** & **Orte 1 F4 P10** & **Orte 2 F7 P2** & **Gato 1** \\ \hline \multirow{6}{*}{Stem} & 6.25 & 49.62 \(\pm\) 1.54 \({}^{\text{a}}\) & 34.42 \(\pm\) 4.07 \({}^{\text{b}}\) & 31.54 \(\pm\) 2.38 \({}^{\text{b}}\) \\  & 3.13 & 43.65 \(\pm\) 0.26 \({}^{\text{a}}\) & 29.23 \(\pm\) 3.23 \({}^{\text{ns}}\) & 33.65 \(\pm\) 4.52 \({}^{\text{b}}\) \\  & 1.56 & 43.46 \(\pm\) 0.53 \({}^{\text{a}}\) & 29.23 \(\pm\) 2.38 \({}^{\text{ns}}\) & 32.31 \(\pm\) 0.87 \({}^{\text{a}}\) \\  & 0.78 & 44.04 \(\pm\) 4.36 \({}^{\text{a}}\) & 26.54 \(\pm\) 3.55 \({}^{\text{ns}}\) & 22.69 \(\pm\) 2.15 \({}^{\text{ns}}\) \\  & 0.39 & 43.08 \(\pm\) 3.36 \({}^{\text{a}}\) & 25.19 \(\pm\) 5.99 \({}^{\text{ns}}\) & 26.73 \(\pm\) 0.59 \({}^{\text{ns}}\) \\ \hline \multirow{6}{*}{SFH} & 200 & 38.08 \(\pm\) 5.36 \({}^{\text{a}}\) & 35.19 \(\pm\) 3.92 \({}^{\text{b}}\) & 46.73 \(\pm\) 0.01 \({}^{\text{a}}\) \\  & 100 & 50.77 \(\pm\) 0.73 \({}^{\text{a}}\) & 45.96 \(\pm\) 6.54 \({}^{\text{a}}\) & 43.65 \(\pm\) 0.26 \({}^{\text{a}}\) \\ \cline{1-1}  & 50 & 33.65 \(\pm\) 1.02 \({}^{\text{b}}\) & 38.08 \(\pm\) 1.49 \({}^{\text{a}}\) & 35.19 \(\pm\) 3.04 \({}^{\text{a}}\) \\ \cline{1-1}  & 25 & 38.08 \(\pm\) 3.87 \({}^{\text{a}}\) & 34.81 \(\pm\) 5.29 \({}^{\text{b}}\) & 29.23 \(\pm\) 2.21 \({}^{\text{ns}}\) \\ \cline{1-1}  & 12.5 & 48.27 \(\pm\) 3.28 \({}^{\text{a}}\) & 30.77 \(\pm\) 1.16 \({}^{\text{ns}}\) & 28.08 \(\pm\) 3.28 \({}^{\text{ns}}\) \\ \hline \end{tabular}
\end{table} 
Table 8: Cell viability (%) obtained by MTT assay on differentiated SH-SYSY cells treated with stem and SFH extracts for 24 h and 1 h with H\({}_{2}\)O\({}_{2}\). The data are expressed as mean \(\pm\) SD. Samples vs. Crtl + (cell viability 29.62% \(\pm\) 1.04): a, for \(p\) \(<\) 0.0001; b, for \(p\) \(<\) 0.001; ns: not significant. As shown in Figure 17, Grato 1 SFH and Orte 2 F7 P2 stem extracts resulted in the highest and most significant reduction in intracellular ROS levels, restoring those of not H\({}_{2}\)O\({}_{2}\) stressed cells (Ctrl). However, overall, all extracts tested showed activity in reducing intracellular ROS levels (Figure 17). Since GSH is the most abundant intracellular antioxidant, playing a key role in controlling the production of free radicals formed by oxidative stress, such as that induced by H\({}_{2}\)O\({}_{2}\), the MCB assay was used to evaluate the effects of stem and SFH extracts on intracellular GSH levels. Differentiated SH-SYSY cells were pre-treated 24 h earlier with 6.25 \(\upmu\)g/mL and 200 \(\upmu\)g/mL of stem and SFH extracts, respectively, and then exposed to H\({}_{2}\)O\({}_{2}\). As shown in Figure 17, the treatment with H\({}_{2}\)O\({}_{2}\) resulted in a significant reduction in GSH levels compared to control cells. The stem and SFH extracts of Orte 1 F4 P10 and Orte 2 F7 P2 significantly increased GSH levels compared to cells exposed to H\({}_{2}\)O\({}_{2}\), with values comparable to those of control cells. However, cells treated with Grato 1 stem and SFH extracts did not show a significant increase in GSH levels compared to H\({}_{2}\)O\({}_{2}\) treated cells. Figure 3: Increased GSH levels following treatment with stem and SFH extracts of Orte 1 F4 P10, Orte 2 F7 P2 and Grato 1 genotypes. * \(p<0.001\). Figure 2: Reduction of H\({}_{2}\)O\({}_{2}\) induced in intracellular free radical ROS following treatment with stem and SFH extracts of Orte 1 F4 P10, Orte 2 F7 P2 and Grato 1 P3 genotypes. * \(p<0.001\). Oxidative stress plays a key role in the progression of numerous neurodegenerative conditions, characterized by a complex and often reciprocal relationship, where oxidative stress fuels the manifestation of key disease features, which, in turn, exacerbate oxidative stress [27 ]. Neuronal functions are commonly modeled in vitro using cell lines such as differentiated SH-SYSY cells, which, upon exposure to H\({}_{2}\)O\({}_{2}\), exhibit metabolic alterations and cell death processes resembling those observed in neurodegenerative diseases [27 ].