# Antioxidative and Photop Protective In Vitro Potential of Lavandula Angustifolium
## 3 Results  
Figures 1 and 2 present the antioxidant activity of _Lavandula angustifolia_ herb and flower extracts in four short-chain alcohols determined with the DPPH method immediately after preparation and after twelve months of storage at room temperature. As concerns the herbal extracts, the lowest activity was observed for extracts prepared in undiluted alcohols except for those in methanol. Significant differences were found between flower extracts assayed immediately and after twelve months (\(p<0.0001\)) and between herb and flower extracts assayed twelve months after preparation (\(p=0.0001\)) (Table 2). Figure 1: Mean antioxidant activity of _Lavandula angustifolia_ herb alcoholic extracts evaluated immediately and twelve months after preparation using the DPPH method. The results are presented as TEAC (mg Trolox/g RW). Vertical lines denote standard deviations (SD). No statistically significant differences were found between herb extracts assayed immediately and after twelve months. Figure 2: Mean antioxidant activity of _Lavandula angustifolia_ flower alcoholic extracts evaluated immediately and twelve months after preparation using the DPPH method. The results are presented in mg Trolox/g raw material (TEAC). Vertical lines denote standard deviations (SD). The statistically significant differences were found between flower extracts assayed immediately and after twelve months (\(p<0.0001\)). Figures 3 and 4 present the antioxidant activity of _Lavandula angustifolia_ herb and flower extracts in four short-chain alcohols determined with the ABTS method immediately after preparation and after twelve months of storage at room temperature. The higher activities were found for extracts prepared in shorter-chain alcohols. Significant differences were found between herb and flower extracts assayed after twelve months (\(p\) = 0.0009) (Table 2). \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Compared Parameters** & **Z-Value** & \(\boldsymbol{p}\) \\ \hline \multicolumn{4}{c}{Antioxidant activity evaluated with DPPH method} \\ \hline herb assayed in 2024 & herb assayed in 2025 & \(-\)1.7909 & 0.0733 (NS) \\ flower assayed in 2024 & flower assayed in 2025 & \(-\)5.7612 & \(<\)0.00001 \\ herb assayed in 2024 & flower assayed in 2024 & \(-\)1.3517 & 0.1765 (NS) \\ herb assayed in 2025 & flower assayed in 2025 & \(-\)3.8693 & 0.0001 \\ \hline \multicolumn{4}{c}{Antioxidant activity evaluated with ABTS method} \\ \hline herb assayed in 2024 & herb assayed in 2025 & \(-\)1.6724 & 0.0944 (NS) \\ flower assayed in 2024 & flower assayed in 2025 & \(-\)0.0056 & 0.9955 (NS) \\ herb assayed in 2024 & flower assayed in 2024 & \(-\)1.4247 & 0.1542 (NS) \\ herb assayed in 2025 & flower assayed in 2025 & \(-\)3.3230 & 0.0009 \\ \hline \multicolumn{4}{c}{Sun protection factor} \\ \hline herb assayed in 2024 & herb assayed in 2025 & \(-\)1.0755 & 0.2821 (NS) \\ flower assayed in 2024 & flower assayed in 2025 & \(-\)0.0169 & 0.9865 (NS) \\ herb assayed in 2024 & flower assayed in 2024 & \(-\)2.9901 & 0.0028 \\ herb assayed in 2025 & flower assayed in 2025 & \(-\)2.8935 & 0.0038 \\ \hline \end{tabular} NS—not statistically significant.  
\end{table} 
Table 2: Statistical analysis of the examined parameters of _Lavandula angustifolia_ extracts. Figure 3: Mean antioxidant potential of _Lavandula angustifolia_ herb alcoholic extracts (in mg Trolox/g raw material (TEAC)) evaluated immediately and twelve months after preparation using the ABTS method. Vertical lines correspond to standard deviations (SD). No statistically significant differences were found between herb extracts assayed immediately and after twelve months. Figures 5 and 6 present the in vitro sun protection factor (SPF) of _Lavandula angustifolia_ herb and flower extracts in four short-chain alcohols determined immediately after preparation and after twelve months of storage at room temperature. Higher values were found for extracts prepared in shorter-chain alcohols, particularly for herbal extracts.