## 4 Discussion  
The present work shows the potential cytotoxic activity of _S. spinosum_ extracts against the tested cell lines. The anti-proliferative properties of _S. spinosum_ extracts were previously tested on several cancer cell lines (renal, prostate, melanoma), showing potential cytotoxic effect, which was partially attributed to the action of tormemic acid [20]. Among the four fractions studied in this work, AF was shown to be the one with the strongest anti  
\begin{table}
\begin{tabular}{c c c c c c c} \hline
**Compound** & \begin{tabular}{c} **Concentration** \\ **(\upmu M)** \\ \end{tabular}  & **Jurkat** & **HeLa** & **MCF-7** & **MDA** & **3T3** \\ \hline Stackydrine & 100 & 100 & 28.1 \(\pm\) 2.2 & 64.2 \(\pm\) 3.1 & nt & 89.0 \(\pm\) 3.8 \\  & 10 & 100 & 81.2 \(\pm\) 3.0 & 79.0 \(\pm\) 4.2 & nt & 100 \\  & 1 & 100 & 89.0 \(\pm\) 4.2 & 80.4 \(\pm\) 4.3 & nt & 100 \\  & 0.1 & 100 & 91.2 \(\pm\) 5.1 & 88.2 \(\pm\) 4.1 & nt & 100 \\  & 0.01 & 100 & 95.1 \(\pm\) 4.5 & 86.3 \(\pm\) 4.3 & nt & 100 \\ Benzalkonium chloride & 100 & nt & nt & nt & nt \\  & 10 & nt & 12.1 \(\pm\) 2.0 & 35.0 \(\pm\) 2.0 & nt & 10.0 \(\pm\) 1.8 \\  & 1 & 69.1 \(\pm\) 3.2 & 43.0 \(\pm\) 3.0 & 64.2 \(\pm\) 3.1 & nt & 42.2 \(\pm\) 2.9 \\  & 0.1 & 84.1 \(\pm\) 4.0 & 81.1 \(\pm\) 4.0 & 84.1 \(\pm\) 4.2 & nt & 71.0 \(\pm\) 3.4 \\  & 0.01 & 92.2 \(\pm\) 5.1 & 79.3 \(\pm\) 4.2 & 92.5 \(\pm\) 5.0 & nt & 81.1 \(\pm\) 3.9 \\  & 0.001 & 93.2 \(\pm\) 5.0 & 79.1 \(\pm\) 4.3 & 95.2 \(\pm\) 4.5 & nt & 100 \\ Rutin & 100 & 78.6 \(\pm\) 3.1 & 100 & 100 & 94.0 \(\pm\) 4.2 & 96.0 \(\pm\) 4.0 \\  & 10 & 85.9 \(\pm\) 3.7 & 100 & 100 & 99.3 \(\pm\) 5.1 & 100 \\  & 1 & 91.3 \(\pm\) 4.2 & 100 & 100 & 98.0 \(\pm\) 4.6 & 100 \\  & 0.1 & 100 & 100 & 100 & 98.6 \(\pm\) 4.4 & 100 \\  & 0.01 & 100 & 100 & 100 & 99.3 \(\pm\) 5.1 & 100 \\ Mixture of stachydrine, & & & & & & \\ benzalkonium chloride and & & & & & & \\  & & & & &  
proliferative activity, but overall presenting a relatively weak cytotoxic activity, with better results being obtained against human breast adenocarcinoma and lung cell lines. The results point that, after purification, the different fractions show to be more active leading to better results, than those obtained before purification. The isolated M8R sub-fraction contained three major compounds, two of which ammonium compounds, benzalkonium chloride and stachydrine, and also a flavonoid glycoside, rutin. While all three compounds have been reported in the literature, this is the first study to identify them in _S. spinosum_. Stachydrine is a major constituent of different herbs, plants and fruits, and it is known to possess 0.6 medicinal effects. [PERSON] et al. [PERSON] et al. (2018) reported an in vitro anti-cancer activity of stachydrine against prostate tumor cell lines (PC3 and LNCaPP). Nowadays, stachydrine is used as an osmo-protectant in clinics to promote blood circulation and to ameliorate HUVECs in jury induced by anoxia-reoxygenation [PERSON] et al. (2018), and it is also able to suppress tubular epithelial cell apoptosis and to postpone renal intestinal fibrosis development in an animal model [PERSON] et al. (2018). Stachydrine is also known to inhibit the angiotensin II-induced heart hypertrophy via blockade of the NF-\(\kappa\) B signal pathway [PERSON] et al. (2018) and to improve high-glucose induced endothelial cell senescence [PERSON] et al. (2018) and it is used as a marker of citrus consumption [PERSON] et al. (2018). In addition to its anti-cancer action, regulation of the uterus, neuroprotective effects, etc. the pharmacokinetic properties of stachydrine are also discussed [PERSON] et al. (2018). Benzalkonium chloride is a quaternary ammonium compound used as a biocide, a cationic surfactant and a phase transfer agent to preserve cosmetics, mouthwashes, and skin cleansers [PERSON] et al. (2018) and can also be used for cold sterilization of medical and dental instruments [PERSON] et al. (2018). The results of the present work are in accordance with the conclusions of [PERSON] et al. (2018) and [PERSON] et al.