## 3 Results and Discussion
### NO (Nitric Oxide) Assay  
NO is a modulator with an important role in both its physiological and pathological states. The overproduction of NO induces inflammation and apoptosis, while NO, as an inflammatory factor, causes various chronic inflammatory diseases [33; 34]. LPS from _Escherichia coli_ induces oxidative stress to stimulate immune cells, thereby increasing the production of nitric oxide synthase (iNOS) and prostaglandin G2 (PGE\({}_{2}\)) [35]. In this study, anti-inflammatory activity was measured for each part of the ice plant using LPS-treated macrophages. In the experiment to measure NO production after LPS treatment, the group treated solely with LPS led to NO production of 13.81 \(\pm\) 0.55 uM, a level higher than that of the control (1.99 \(\pm\) 0.28) with uninduced LPS, indicating an adequate level of LPS-induced inflammatory response. As shown in Table 5, it was found that the extracts from different parts of the ice plant could reduce excess NO production in LPS-induced macrophages, indicating an effect as immune response modulators. In a previous study, the LPS-induced NO production could be reduced in a concentration-dependent manner by the extracts of plebeian sage leaves [36]. Another study showed the NO inhibitory activity of the extract fractions of northern bamboo leaves [37]. The trend agreed with a study reporting the change in NO production caused by the extracts of lemon myrtle leaves [38].  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Concentration** (\#g/mL)} & \multicolumn{2}{c}{**Nitric Oxide (NO) Production (\(\mu\)M) (Mean \(\pm\) S.D.)**} & \multirow{2}{*}{**F-Value (\(p\))**} \\ \cline{2-2} \cline{4-4}  & **Cotyledon** & & & **Stems** & **Shoot** \\ \hline Control & 1.99 \(\pm\) 0.28 & 1.99 \(\pm\) 0.28 & 1.99 \(\pm\) 0.28 & \\
0 & 13.81 \(\pm\) 0.55 \({}^{\text{C}}\) & 13.81 \(\pm\) 0.55 \({}^{\text{D}}\) & 13.81 \(\pm\) 0.55 \({}^{\text{D}}\) & 0.000 (1.000) \\
10 & 13.24 \(\pm\) 0.55 \({}^{\text{BC}}\) & 13.41 \(\pm\) 0.56 \({}^{\text{CD}}\) & 13.67 \(\pm\) 0.30 \({}^{\text{CD}}\) & 0.593 (0.582) \\
30 & 13.42 \(\pm\) 0.37 \({}^{\text{BC}}\) & 13.18 \(\pm\) 0.14 \({}^{\text{CD}}\) & 12.97 \(\pm\) 0.76 \({}^{\text{BC}}\) & 0.614 (0.572) \\
50 & 13.10 \(\pm\) 0.59 \({}^{\text{BC}}\) & 12.63 \(\pm\) 0.32 \({}^{\text{C}}\) & 12.24 \(\pm\) 0.21 \({}^{\text{B}}\) & 3.384 (0.104) \\
100 & 12.69 \(\pm\) 0.58 \({}^{\text{BB}}\) & 11.50 \(\pm\) 0.34 \({}^{\text{AB}}\) & 11.37 \(\pm\) 1.77 \({}^{\text{AA}}\) & 9.870 (0.013) \({}^{\ast}\) \\
300 & 11.48 \(\pm\) 0.44 \({}^{\text{BA}}\) & 10.00 \(\pm\) 0.81 \({}^{\text{AA}}\) & 10.75 \(\pm\) 0.24 \({}^{\text{ab}}\)A & 5.450 (0.045) \({}^{\ast}\) \\ \hline F-value (\(p\)) & 7.331 (0.002) \({}^{\ast\ast}\) & 24.163 (0.000) \({}^{\ast\ast\ast}\) & 24.676 (0.000) \({}^{\ast\ast\ast}\) & \\ \hline \hline \end{tabular}  
* Means with different letters in each column (common letter (a–c): the level of significance for each organs) and row (capital letter (A–D: the level of significance for each treatment with ug/mL) are significantly different by [PERSON]’s multiple range test (\(p\) < 0.05). Values are mean \(\pm\) SD (n = 3).
* \(p\) < 0.5,
* \(p\) < 0.01, *
* \(p\) < 0.001 compared to the control by ANOVA.
* \end{table}
Table 5: Effect of ethanol extract on nitric oxide (NO) production with mean \(\pm\) S.D. from the cotyledon, stem, and leaf of the ice plant.