## 4 Discussion  
Topical application of the ethyl acetate extract of the _C. aconitifolius_ leaf showed an anti-inflammatory biological activity in mouse ear edema induced by croton oil by decreasing the ear edema weight (Figure 2). In agreement with this, the percentage inhibition of the extract of _C. aconitifolius_ ethyl acetate extract significantly inhibited the ear edema by 23.52% and 49.41% at 25 and 50 mg/kg doses, respectively (Table 4). The approach to determine flavonoid content confirmed the presence of quercetin in the _C. aconitifolius_ ethyl acetate extract, which could be responsible for the decrease in inflammation. Flavonoids belong to the group of natural polyphenolic compounds with more than 4000 identified varieties. A large number of epidemiological, in vitro, and in vivo studies have documented the anti-inflammatory properties of a wide variety of flavonoids in different chronic inflammatory \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Treatment** & **Dose (mg/kg)** & **Change in Ear Weight (g)** & **Inhibition (\%)** \\ \hline Control & - & 0.0085 \(\pm\) 0.00028 & 0.00 \\ Indomethacin & 10 & 0.0011 \(\pm\) 0.00106 *** & 87.05 \\ _C. aconitifolius_ & 25 & 0.0065 \(\pm\) 0.00014 * & 23.52 \\ _C. aconitifolius_ & 50 & 0.0043 \(\pm\) 0.00021 ** & 49.41 \\ \hline \hline \end{tabular} Results of change in weight are expressed as mean \(\pm\) standard error of mean (SEM). N = 6 in each group * \(p\) < 0.05; **_p_ < 0.01; **_p_ < 0.001. One-way ANOVA. Control treatments refer to application of croton oil to induce acute inflammation.  
\end{table} 
Table 4: Ear weight differences and inhibition percentage in croton-oil-induced ear edema test. Figure 2: Anti-inflammatory effect by topical application of _C. aconitifolius_ ethyl acetate extract on croton oil-induced ear edema. _C. aconitifolius_ ethyl acetate extract in both doses decreased the ear edema. Indomethacin was used as positive control. Results are expressed as means \(\pm\) SEM. N = 6. * \(p\) < 0.05; **_p_ < 0.01; ***_p_ < 0.001. One-way ANOVA was followed by [PERSON]’s test. conditions, such as autoimmune diseases, cancer, diabetes, cardiovascular disorders, and neurodegenerative diseases [24]. Our results suggest that _C. aconitifolius_ extract has anti-inflammatory activity in the induced mouse ear edema by inhibiting the action of croton oil. A previous report describes the edema inhibition by topical application of _Cniidoscolus chayamansa_ agents [7], another species of the genus _Cniidoscolus_. Similar results have been reported using an aqueous and ethanolic extract of _C. aconitifolius_ with anti-inflammatory activity, decreasing the cytokines TNF-\(\alpha\) and IL-6 by 46 and 48.38% in macrophages stimulated by lipopolysaccharidesaccharide [25]. The in vitro anti-inflammatory activity exherted by _C. aconitifolius_ ethyl acetate extract coincides with the effects reported on a carrageenanan-induced paw edema of an _C. aconitifolius_ ethanolic extract by percolation [1; 26]. On other hand, the effect of indomethacin, a non-selective inhibitor of cyclooxygenase (COX) that reduces the production of prostaglandandins, promoting pain and inflammation [27; 28], as was expected, was the most effective to prevent mouse ear edema. Nevertheless, the outcome of this study will serve as the basis for further investigations in order to isolate bioactive compounds from _C. aconitifolius_ ethyl acetate extract and test its anti-inflammatory properties in order to obtain a compound with similar activity to the indomethacin drug. The presence of quercetin flavonoids in _C. aconitifolius_ ethyl acetate reported in this study and in the ethanolic extract was determined in the phytochemical characterization using TLC and aluminum chloride colorimetric assay [25]. Among flavonoids, quercetin has been described as the most abundant in vegetables, and their biological effects have been extensively studied [29]. Flavonoids target prostaglandandins which are involved in the late phase of acute inflammation [30].