# Antioxidative and Photoprotective Activity of _Pinus nigra_, _Pinus strobus_ and _Pinus mugo_
## 3 Results
A statistically significant (_p_ < 0.001) linear relationship between the antioxidant activities of _Pinus nigra_ extracts evaluated with both the DPPH and ABTS methods and the polyphenol content evaluated with the Folin-Ciocalteu (F-C) method were found; the correlation coefficient was r = 0.9148, r = 0.7215, and r = 0.6843 for ABTS vs. DPPH, F-C vs. DPPH, and F-C vs. ABTS, respectively  
In the Supplementary Materials, the graphs presented the comparison of the antioxidant potential of all extracts evaluated with the DPPH (Figure S1) and the ABTS methods (Figure S2); in addition, the polyphenol content in all extracts (Figure S3) are included. In Tables 2-4, the parameters of photoprotection applied for the preliminary in vitro evaluation of the studied extracts of _Pinus strobus_, _Pinus mugo_, and _Pinus nigra_ are summarized, depending on the applied solvent for the ultrasound-assisted extraction and time of extraction. As the absorbance of the extracts was high, to evaluate these parameters, samples were diluted more than 25 times as described in Material and Methods. Figure 3.0 Mean polyphenol content in _Pinus nigra_ alcoholic extracts evaluated using Folin-Ciocalteu method and expressed as GAE (mg gallic acid/g raw material). Vertical lines represent standard deviations (SD). Different letters indicate significant differences between the extracts prepared in the same alcohol of different concentrations in individual extraction time (_p_ < 0.05). \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Solvent**} & \multirow{2}{*}{**Time**} & \multicolumn{2}{c}{**SPF**} & \multicolumn{2}{c}{**_IVVA/UVB_**} & \multicolumn{1}{c}{**Critical**} \\ \cline{3-6}  & & **Mean** & **SD** & **Mean** & **SD** & **Wavelength** \\ \hline  
\hline \end{tabular}
\end{table} 
Table 2: Parameters of photoproduction evaluated in vitro for _Pinus strobus_ alcoholic extracts. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Solvent**} & \multirow{2}{*}{**Time**} & \multicolumn{2}{c}{**SPF**} & \multicolumn{2}{c}{**_IVVA/UVB_**} & \multirow{2}{*}{**Critical**} \\ \cline{3-3} \cline{5-6}  & & **Mean** & **SD** & **Mean** & **SD** & **Wavelength** \\ \hline  
\hline \end{tabular}
\end{table} 
Table 3: Parameters of photoproduction evaluated in vitro for _Pinus nigra_ alcoholic extracts. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Solvent**} & \multirow{2}{*}{**Time**} & \multicolumn{2}{c}{_SPF_} & \multicolumn{2}{c}{_IVVA/UVB_} & \multicolumn{1}{c}{**Critical**} \\ \cline{3-6}  & & **Mean** & **SD** & **Mean** & **SD** & **Wavelength** \\ \hline  
\hline \end{tabular}
\end{table} 
Table 4: Parameters of photoproduction evaluated in vitro for _Pinus mugo_ alcoholic extracts. methanol after one hour of extraction. It can be seen that, in general, higher values of _SPF_ were found for _Pinus strobus_ extracts in more diluted alcohols, except for those in methanol, for which an inverse relationship was observed. Regarding other parameters, the _UVA_/_UVB_ ratio indicating protection against _UVA_ as compared to _UVB_ varied from 0.349 \(\pm\) 0.01 for extracts in 40% methanol after 30 min of extraction to 0.500 \(\pm\) 0.023 in undiluted isopropanol after 60 min of extraction. The values below 0.4 described the minimal protection category, whereas, from 0.4 to 0.6, they are considered as among the moderate _UVA_ protection category. Unfortunately, in the case of the studied raw materials, the _SPF_ values of the extracts in undiluted alcohols were the lowest--for undiluted isopropanol used as a solvent after one hour of extraction, it was 0.794 \(\pm\) 0.048. Another evaluated parameter was the critical wavelength--for all the extracts, it varied between 295 and 296 nm. This value confirmed that the protection against _UVA_ was low (Table 2).