## 3 Results and Discussion
### Extraction Yields Determination and Phytochemicals Analysis  
The results of the extraction yield calculation of the two aerial parts of the studied plants (_C. monacantha_ Del., and _A. articulata_ (Frossk.) Moq. ), extracted by the UAE method following the optimized protocol validated by the Box-Behnken Desing and their phytochemical data are summarized in Table 5. It shows a significant difference (\(p<0.05\)) between the two plants studied in extraction yield (which were 14.68% and 13.56%), total polyphenol content (which were 37.27 and 58.38 \(\upmu\)g GAE/mg DE), and total flavonoid content (which were 7.21 and 6.44 \(\upmu\)g QE/mg DE) for _C. monacantha_ Del. and _A. articulata_ (Forssk.) Moq., respectively. Based on our results, the TPC recorded in the ethanolic extract of the aerial part of _C. monacantha_ Del. (37.27 \(\pm\) 0.68 \(\upmu\)g GAE/mg DE) is significantly lower than that reported by [PERSON] et al. [91] for the methanolic extract of the aerial part of _C. monacantha_ Del. from the Grand Erg of the Algerian Sahara, which was 64.03 \(\upmu\)g GAE/mg DE. However, this obtained result is significantly higher than that declared by [PERSON] et al. [92] for the aqueous extract of the aerial part of _C. monacantha_ Del. from the El-Oued region (southeastern Algeria), which was 31.33 \(\upmu\)g GAE/mg DE. Nevertheless, the TPC recorded in the ethanolic extract of _C. monacantha_ Del. aerial part (7.21 \(\pm\) 0.31 \(\upmu\)g QE/mg DE, \begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline \multicolumn{2}{c}{**Optimum Extraction Conditions**} & \multicolumn{4}{c}{**Predicted Response Values**} & \multicolumn{4}{c}{**Experimental Response Values**} \\ \hline \begin{tabular}{c} **Solid-to-** \\ **Liquid Ratio** \\ **(g/mL)** \\ \end{tabular} & \begin{tabular}{c} **Temperature** \\ **(\({}^{\circ}\)C)** \\ \end{tabular} & \begin{tabular}{c} **Time** \\ **(min)** \\ \end{tabular} & **Yield (\%)** & \begin{tabular}{c} **TPC (\(\upmu\)g** \\ **GAE/mg** \\ **DE** \\ \end{tabular} & \
\begin{tabular}{c} **TFC (\(\upmu\)g** \\ **QE/mg DE** \\ \end{tabular} &
\begin{tabular}{c} **TFC (\(\upmu\)g** \\ **GE/mg DE** \\ \end{tabular} \\ \hline
0.5:10 & 45 & 30 & 14.590 & 37.210 & 7.368 & 14.68 \(\pm\) 0.16 & 37.27 \(\pm\) 0.68 & 7.21 \(\pm\) 0.31 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Optimum extraction conditions and their predicted and experimental response values. respectively) is higher than that reported by [PERSON] et al. [91] for the methanolic extract of the aerial part of _C. monacantha_ Del., which was 6.82 \(\upmu\)g QE/mg DE. In addition, the TPC recorded in this study for the ethanolic extract of the aerial part of _A. articulata_ (Frossk.) Moq. (58.38 \(\pm\) 0.65 \(\upmu\)g GAE/mg DE) is significantly lower than that reported by [PERSON] et al. [93] for the methanolic extract of _A. articulata_ (Frossk.) Moq., which was 72.10 \(\upmu\)g GAE/mg DE. Furthermore, our TFC obtained value (6.44 \(\pm\) 0.21 \(\upmu\)g QE/mg DE) is significantly lower than that obtained by [PERSON] et al. [94] for the methanolic extract of _A. articulata_ (Frossk.) Moq., which was 9.50 \(\upmu\)g QE/mg DE. Therefore, the difference between the results obtained in this investigation and those obtained by previous research suggests that numerous factors--such as genetic heritage, environment, the extraction method adopted, the matrix effect influencing extraction \begin{table}
\begin{tabular}{c c c} \hline \hline
**Sample** & **Yield (\%)** & **TPC (\(\upmu\)g GAE/mg DE)** & **TFC (\(\upmu\)g QE/mg DE)** \\ \hline _C. monacantha_ Del. & 14.68 \(\pm\) 0.16 \({}^{\text{a}}\) & 37.27 \(\pm\) 0.68 \({}^{\text{b}}\) & 7.21 \(\pm\) 0.31 \({}^{\text{a}}\) \\ _A. articulata_ (Frossk.) Moq. & 13.56 \(\pm\) 0.15 \({}^{\text{b}}\) & 58.38 \(\pm\) 0.65 \({}^{\text{a}}\) & 6.44 \(\pm\) 0.21 \({}^{\text{b}}\) \\ \hline \hline \end{tabular} \({}^{\text{a}}\): Different letters in the same column indicate a significant difference (\(p<0.05\)) between the studied samples.  
\end{table}