# Antioxidative and Photoprotective Activity of _Pinus nigra_, _Pinus strobus_ and _Pinus mugo_
## 3 Results
Moreover, a statistically significant linear relationship of _SPF_ values determined for all the studied extracts of _Pinus strobus_ versus antioxidant activity determined either by the DPPH or ABTS methods (correlation coefficients were 0.7903 and 0.9356, respectively) was found (Figure 10). No statistically significant correlation between the polyphenol content vs. _SPF_ and between the polyphenol content vs. antioxidant activity determined with either the DPPH or ABTS method was observed for _Pinus strobus_ extracts. The sun protection factor (_SPF_) for diluted alcoholic extracts of _Pinus nigra_ varied from 0.854 \(\pm\) 0.031 in 99% methanol after 15 min of extraction to 3.403 \(\pm\) 0.071 in 40% n-propanol after one hour of extraction. Similarly to _Pinus strobus_, it can be seen that, in general, higher values of _SPF_ was found for extracts in more diluted alcohols used as extractants. Regarding other parameters, the _UVA_/_UVB_ ratio, indicating protection against _UVA_ as compared to _UVB_, varied from 0.241 \(\pm\) 0.007 for extracts in 40% methanol after 30 min of extraction, to 0.568 \(\pm\) 0.039 in undiluted isopropanol after 30 min of extraction. The protection against _UVA_ of this last extract can be considered as moderate. Unfortunately, in the case of the studied raw materials, the _SPF_ values of the extracts in undiluted alcohols were the lowest, for instance, 1.171 \(\pm\) 0.073 for the above-mentioned extract in undiluted isopropanol. Another evaluated parameter was the critical wavelength--for all the extracts, it varied between 293 and 295 nm. This value is similar to the respective values of other extracts prepared from all the studied raw material. Moreover, this observation confirmed that the protection against _UVA_ was low (Table 3). Additionally, a statistically significant linear relationship of _SPF_ values determined for all the studied extracts of _Pinus nigra_ vs. antioxidant activity determined either by the DPPH or ABTS methods (correlation coefficients were 0.7903 and 0.9356, respectively) was found (Figure 11). A significant (\(p<\) 0.001) linear relationship between the polyphenol content (F-C method) and _SPF_ (r = 0.7658) was also observed (Figure 11). The sun protection factor (_SPF_) for diluted alcoholic extracts of _Pinus mugo_ varied from 0.460 \(\pm\) 0.031 in 99% isopropanol to 6.718 \(\pm\) 0.020 in 40% methanol, both after 15 min of extraction. In general, higher _SPF_ values was found for extracts in more diluted alcohols used as extractants. Regarding other parameters, the _UVA_/_UVB_ ratio, indicating protection against _UVA_ as compared to _UVB_, varied from 0.367 \(\pm\) 0.001 for extracts in 70% methanol after 30 min of extraction, to 0.556 \(\pm\) 0.006 in undiluted isopropanol after 15 of min extraction. The protection against _UVA_ of this last extract can be considered as moderate. Unfortunately, in the case of the studied raw materials, the _SPF_ values of the extracts in undiluted alcohols were the lowest, for instance, 1.070 \(\pm\) 0.030 for the above-mentioned extract in undiluted isopropanol. Another evaluated parameter was the critical wavelength--for all the extracts, it varied between 295 and 296 nm. This value is similar to the respective values of other extracts prepared from all the studied raw material. This observation confirmed that the protection against _UVA_ was low (Table 4). Additionally,a statistically significant linear relationship of _SPF_ values determined for all the studied extracts of _Pinus mugo_ vs. antioxidant activity determined either by the DPPH or ABTS methods was seen (correlation coefficients were 0.7948 and 0.8437, respectively) (Figure 12). A significant (\(p<0.001\)) linear relationship between the polyphenol content (F-C method) and _SPF_ (r = 0.6672) was also found (Figure 12). Figure S4 in the Supplementary Materials presents the comparison of the _SPF_ parameters determined in vitro of all studied extracts of _Pinus strobus_, _Pinus nigra_, and _Pinus mugo_.