## 3 Results
### Antioxidant Activity
RGEO was able to to reduce the stable free radical DPPH with an IC\({}_{50}\) value of 0.25 \(\pm\) 0.09 mg/mL (Table 5). Even if the effect of the radical scavenging activity of RGEO is comparable to that of the delta-tocopherol (IC\({}_{50}\): 0.16 \(\pm\) 0.02 mg/mL), it is not statistically significant (\(p\) = 0.133) according to the Games-Howell test. In contrast, BHA (IC\({}_{50}\): 0.09 \(\pm\) 0.01 mg/mL) and BHT (IC\({}_{50}\): 0.02 \(\pm\) 0.02 mg/mL) exhibited significantly (\(p\) < 0.05) better antioxidant activity than RGEO (Table 5). Recently, [PERSON] et al. (2020) reported DPPH scavenging abilities for Morocco oil of R. montana with an IC\({}_{50}\) value of 0.244 mg/mL [53]. In contrast, [PERSON] et al. (2018) found IC\({}_{50}\) values ranging from 0.0496 to 0.0634 mg/mL for R. montana oils collected from different regions in Algeria [54]. Similar results were reported by [PERSON] et al. (2017) that found IC\({}_{50}\) values ranging from 0.0069 to 0.0199 mg/mL for Palestinian R. chalepensis volatile oils [55], and by [PERSON] et al. (2021) that reported an IC\({}_{50}\) value of 0.035 mg/mL for Jordanian R. chalepensis oil [56]. The \(\beta\)-Carotene bleaching test is based on the discoloration of \(\beta\)-carotene determined to its reaction with radicals produced by linoleic acid oxidation in an emulsion. The antioxidants' presence can decrease the rate of \(\beta\)-carotene bleaching [57; 58]. The relative antioxidant activity percentage (RAA%) of RGEO was calculated with the formula RAA = A\({}_{\text{RGEO}}\)/ A\({}_{\text{BHT}}\), where A\({}_{\text{RGEO}}\) is the absorption of RGEO, and A\({}_{\text{BHT}}\) is the absorption of BHT (positive control used). Compared with BHT, R. graveolens oil bleached \(\beta\)-carotene by 77.42 \(\pm\) 0.07% (Table 5). Similar results were reported by [PERSON] et al. (2017) for leaf extracts obtained from _R. calapensis_[59]. However, no previous research were available in the literature concerning the in vitro and in vivo antioxidant activity of RGEO to support us to compare the results directly. \begin{table}
\begin{tabular}{c c c c c} \hline \hline  & \multicolumn{4}{c}{**TBA (\(\mu\)g Malondialdehydedehyde g\({}^{-1}\))**} \\ \hline
**Storage Time (Days)** & **Control Sample** & **BHT** & **BHA** & **RGEO** \\ \hline
0 days & 2.62 \(\pm\) 0.04 a  & 2.55 \(\pm\) 0.08 ab  & 2.56 \(\pm\)0.06 ab  \\ \hline
4 days & 3.08\(\pm\) 0.04 ab  & 2.85 \(\pm\) 0.04 c  & 2.88 \(\pm\) 0.05 ac  & 4.4 \(\pm\) 0.06 b  \\ \hline
8 days & 7.51 \(\pm\) 0.07 a  & 3.46 \(\pm\) 0.05 b  & 4.55 \(\pm\) 0.11 ac  \\ \hline
12 days & 10.97 \(\pm\) 0.06 a  & 5.18 \(\pm\) 0.08 b  & 6.66 \(\pm\) 0.15 bc  & 9.49 \(\pm\) 0.1 ac  \\ \hline
16 days & 15.77 \(\pm\) 0.1 a  & 5.9 \(\pm\) 0.05 b  & 8.06 \(\pm\) 0.07 bc  & 10.38 \(\pm\) 0.11 ac  \\ \hline
20 days & 19.48 \(\pm\) 0.2 a  & 6.67 \(\pm\) 0.22 b  & 11.43 \(\pm\) 0.08 bc  & 12.41 \(\pm\) 0.16 ac  \\ \hline
24 days & 28.93 \(\pm\) 0.04 a  & 7.3 \(\pm\) 0.13 b  & 14.55 \(\pm\) 0.08 ac  & 14.35 \(\pm\) 0.12 bc  \\ \hline \hline \end{tabular}
\end{table} 
Table 4: The antioxidant effects of RGEO, BHA, and BHT in terms of thiobarbituric acid value (TBA) (\(\mu\)g malondialdehydedehyde g\({}^{-1}\)).