# Cytoprotective-Antioxidant Effect of _Brunfelsia grandiflora_ Extract on Neuron-like Cells
## 3 Results
### GSH  
Tripeptide GSH is the most abundant nonenzymatic antioxidant defense and the main intracellular reducing power. Assessing GSH concentration offers the most reliable information on the cell redox condition. Since bioactive compound-rich plant extracts administered for long treatments could induce changes in the basal GSH concentration that could alter its future reaction to an impending oxidant insult, a direct treatment (22 h) with _B. grandiflora_ concentrations was carried out on SH-SYSY cells. Table 2A shows that _B. grandiflora_ extract (50-200 \(\mathrm{\SIUnitSymbolMicro g}\)/mL) did not produce changes in the GSH levels of neuron-like cells. Later, we assessed the protective capacity of the extracts on neuron-like cells submitted to the two different conditions of oxidative stress. Thus, t-BOOH (co- and pretreatment) on neuron-like cells evoked around a 20% decrease in the cell GSH concentration (Table 2B). When neuron-like cells were pretreated with the three _B. grandiflora_ concentrations before exposure to t-BOOH, there was a significant dose-dependent recovery of the diminished GSH, whereas only the highest extract concentration of 200 \(\mathrm{\SIUnitSymbolMicro g}\)/mL produced a significant recovery of GSH when cotreated with t-BOOH (Table 2B). These results indicate a partial protection of the depleted GSH induced by oxidative stress via a co- or pretreatment of the cells with the three tested _B. grandiflora_ extracts. These results also point out that co- or \begin{table}
\begin{tabular}{c c c} \hline \hline  & \multicolumn{2}{c}{**MDA Levels (Mean \(\pm\) SD)**} \\ \cline{2-3}  & **Cotreatment** & **Pretreatment** \\ \hline Control & 5.18 \({}^{\mathrm{a}}\)\(\pm\) 0.12 & 5.18 \({}^{\mathrm{a}}\)\(\pm\) 0.12 \\ t-BOOH & 8.64 \({}^{\mathrm{b}}\)\(\pm\) 0.31 & 7.63 \({}^{\mathrm{b}}\)\(\pm\) 0.29 \\
50 \(\mathrm{\SIUnitSymbolMicro g}\)/mL BG + t-BOOH & 0.28 \({}^{\mathrm{c}}\)\(\pm\) 0.11 & 0.50 \({}^{\mathrm{c}}\)\(\pm\) 0.21 \\
100 \(\mathrm{\SIUnitSymbolMicro g}\)/mL BG + t-BOOH & 2.22 \({}^{\mathrm{d}}\)\(\pm\) 0.20 & 0.68 \({}^{\mathrm{d}}\)\(\pm\) 0.17 \\
200 \(\mathrm{\SIUnitSymbolMicro g}\)/mL BG + t-BOOH & 3.16 \({}^{\mathrm{e}}\)\(\pm\) 0.15 & 0.88 \({}^{\mathrm{e}}\)\(\pm\) 0.18 \\ \hline \hline \end{tabular} Data are from 3 replicates. Superscripts (a, b, c, d, e) indicate statistically significant (\(p<0.05\)) differences between groups.  
\end{table} 
Table 1: Effect of different concentrations of _B. grandiflora_ extract (BG) in co- and pretreatment on MDA levels (nmol MDA/mg protein). \begin{table}
\begin{tabular}{c c} \hline \hline  & **(A)** \\ \hline  & **GSH Levels** \\ \hline  & **nmol/mg Prot \(\pm\) SD** \\ \hline Control & 0.47 \(\pm\) 0.01 \\
50 \(\mathrm{\SIUnitSymbolMicro g}\)/mL BG & 0.48 \(\pm\) 0.04 \\
100 \(\mathrm{\SIUnitSymbolMicro g}\)/mL BG & 0.53 \(\pm\) 0.05 \\
200 \(\mathrm{\SIUnitSymbolMicro g}\)/mL BG & 0.51 \(\pm\) 0.01 \\ \hline  & **(B)** \\ \hline  & **GSH Levels** \\ \hline  & **nmol/mg Prot \(\pm\) SD** \\ \hline  & **Cotreatment** & **Pretreatment** \\ \hline Control & 0.46 \({}^{\mathrm{a}}\)\(\pm\) 0.01 & 0.47 \({}^{\mathrm{a}}\)\(\pm\) 0.01 \\ t-BOOH & 0.38 \({}^{\mathrm{b}}\)\(\pm\) 0.02 & 0.40 \({}^{\mathrm{b}}\)\(\pm\) 0.01 \\
50 \(\mathrm{\SIUnitSymbolMicro g}\)/mL BG + t-BOOH & 0.41 \({}^{\mathrm{b}}\)\(\pm\) 0.02 & 0.41 \({}^{\mathrm{b}}\)\(\pm\) 0.01 \\
100 \(\mathrm{\SIUnitSymbolMicro g}\)/mL BG + t-BOOH & 0.41 \({}^{\mathrm{b}}\)\(\pm\) 0.01 & 0.43 \({}^{\mathrm{c}}\)\(\pm\) 0.01 \\
200 \(\mathrm{\SIUnitSymbolMicro g}\)/mL BG + t-BOOH & 0.45 \({}^{\mathrm{ac}}\)\(\pm\) 0.01 & 0.44 \({}^{\mathrm{c}}\)\(\pm\) 0.01 \\ \hline \hline \end{tabular} Data are from 3 replicates. Superscripts (a, b, c) indicate statistically significant (\(p<0.05\)) differences between groups.  
\end{table} 
Table 2: (**A**) Direct effect of different concentrations of _B. grandiflora_ extract (BG) for 22 h on GSH levels in SH-SYSY cells. (**B**) Effects of _B. grandiflora_ extract (co- and pretreatment) on GSH levels in SH-SYSY cells.