# Antioxidative and Photoprotective Activity of _Pinus nigra_, _Pinus strobus_ and _Pinus mugo_
## 4 Discussion
The results obtained with the ABTS method were statistically significantly higher than those determined with the DPPH technique (_p_ < 0.001). A significant correlation between the activities evaluated with both methods (r = 0.91) was found. Moreover, contrary to _P. strobus_, statistically significant correlations between the polyphenol content and antioxidant potential of the extracts evaluated with the DPPH and ABTS methods were found (r = 0.72 and 0.68, respectively; \(p\) < 0.001). With regard to the _SPF_, these values were higher for the extracts of _P. nigra_ in diluted alcohols, and, in general, the highest _SPF_ was found for extracts in 40% alcohols. A statistically significant correlation was observed between the _SPF_ and antioxidant activity evaluated with both the DPPH and ABTS method, as well as with the polyphenol content (r = 0.83, 0.85, and 0.76, respectively). [PERSON] et al. evaluated ethanol extracts obtained from 19 samples of _Pinus nigra_[21]. The ratio of raw material to solvent was the same as in our study, but the needles were extracted by continuous shaking for 24 h. The mean phenol content varied between 15.7 and 47.5 mg GAE/g and was higher than in our study. The antioxidant activity evaluated by the DPPH method varied from 36 to 93%. These values were higher than observed in our study, although the lowest activity was comparable [21]. [PERSON] et al. evaluated the antioxidant potential of hydroxyethanolic extracts of _Pinus nigra_, _Pinus strobus_, and _Pinus mugo_ needles using peroxy-oxalate and lumininol chemiluminescence methods [14]. They found a similar mean antioxidant potential of the examined extracts of the studied needles [14]. [PERSON] et al. evaluated _Pinus nigra_ bark extracts in 70% ethanol obtained with ultrasound-assisted extraction for 30 min using the same ratio of raw material to the solvent to prepare the extracts [23]. The antioxidant activity evaluated by the DPPH and ABTS methods was presented as per cent of inhibition. The antioxidant potential determined by the DPPH method was lower compared with our results (expressed as % of inhibition), whereas the opposite results were obtained with the ABTS method. With regard to the polyphenol content, this parameter was markedly higher in bark extracts obtained by [PERSON] et al. compared to the needle extract in the same solvent [23]. The antioxidant activity of the _Pinus mugo_ needle extracts evaluated in the present study was significantly higher than those of _P. strobus_ and _P. nigra_ (_p_ < 0.001). Similarlyto the _Pinus strobus_ extracts, the higher activity evaluated with the DPPH method was observed for extracts in diluted alcohols--they were comparable in the same solvents regardless of the extraction time. The highest activity was found for 40% ethanol used as a solvent after 15 min of extraction and for 40% methanol after 30 min of extraction. If the ABTS method was applied, the antioxidant activity of extracts in undiluted alcohols decreased with the extension of extraction time. In addition, the antioxidant potential evaluated with the ABTS method was statistically significantly higher than the activities obtained with the DPPH method (\(p<0.001\)). A statistically significant correlation of r = 0.82 was observed between these parameters (\(p<0.001\)), as well as between the _SPF_ values vs. antioxidant activity determined either by the DPPH or ABTS methods (correlation coefficients were 0.79 and 0.84, 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. The studied extracts were effective in photoproduction against _UVB_, while, in most cases, their effectiveness in the _UVA_ range based on the _UVA_/_UVB_ ratio was low. [PERSON] et al. evaluated the antioxidant activity and total polyphenol content in _Pinus mugo_ needle extracts prepared in 70% methanol using ultrasound-assisted extraction for 30 min [62].