# Antioxidative and Photop Protective In Vitro Potential of Lavandula Angustifolium
## 4 Discussion
For this purpose, 100 g of plant powder was added to 1 L of methanol and mixed by continuous agitation for 24 h. The prepared methanolic extract at the concentration of 250 \(\upmu\)g/mL scavenged 63.5% radicals in a DPPH assay [59]. However, the observed differences can be related to the use of a slightly different procedure as well as a different source of raw material. [PERSON] et al. determined the antioxidant potential of _Lavandula x internedia_ 'Budrovka' and _Lavandula angustifolia_[43]. To compare these two plants, several methods frequently used to evaluate antioxidant potential, including the DPPH assay, were applied. The extracts were obtained by ultrasound-assisted extraction using 30 g of powdered plant material in 500 mL of 80% ethanol. The IC\({}_{50}\) values for DPPH scavenging activity were 11.4 \(\pm\) 0.7 and 10.62 \(\pm\) 0.02 \(\upmu\)g/mL for flower and leaf extracts, respectively [55]. [PERSON] et al. evaluated the extracts obtained from the infloreses of different cultivars of _Lavandula angustifolia_[22]. The authors used three different techniques to obtain the extracts, including ultrasound-assisted extraction. Plant material consisted, among others, of the _Lavandula angustifolia_ Hidcote variety. To obtain the extracts, 20 mL of 50% ethanol was added to 1.0 g of raw material and subjected to sonication for 30 min, with 10 mL added in the second and third stages, lasting 15 min. The antioxidant activity determined using the DPPH method was 156.8 \(\upmu\)M Trolox/g d.w., found for extracts obtained using ultrasound-assisted extraction. This result was higher as compared with the extracts obtained using maceration or decoction [22]. [PERSON] et al. estimated the antioxidant potential of flower and leaf extracts of _Lavandula angustifolia_ cultivated in southern Poland [48]. The extracts were prepared by shaking 10 g of lavender (either flower or leaf) in 60% ethanol for 72 h. The mean DPPH radical scavenging activity was 97.5 \(\upmu\)mol Trolox/g for flower extracts and 198.2 \(\upmu\)mol Trolox/g for leaf extracts [60]. In the presented study, the same extracts were also evaluated twelve months later. They showed slightly higher activity determined by the DPPH method. For herb extracts, the highest activity was found for extracts in 70% methanol after 30 and 60 min extractions and in 70% ethanol after a 60 min extraction (4.11 \(\pm\) 0.01, 4.05 \(\pm\) 0.09 and 4.20 \(\pm\) 0.03 TEAC). The differences between the antioxidant activities of lavender herb extracts determined at an interval of 12 months were statistically insignificant. This result proved that the prepared extracts were, in general, stable during the observation period. In the case of flower extracts evaluated after twelve months, the highest antioxidant potential was observed for extracts prepared in undiluted isopropanol after 15 and 30 min of ultrasound-assisted extraction (4.48 \(\pm\) 0.09 and 4.51 \(\pm\) 0.04 TEAC, respectively). The differences between the antioxidant activities of lavender flower extracts determined at an interval of 12 months were statistically significant (_p_ < 0.001, Table 2). Moreover, the differences in the antioxidant activity in herb and flower extracts determined immediately after their preparation were statistically insignificant, but for determinations carried out twelve months later, the differences were statistically significant (Table 2). The second method applied in our study to evaluate the antioxidant potential of the obtained extracts was the ABTS technique. In the presented study, the highest antioxidant potential assayed by the ABTS method (expressed similarly to the DPPH method as TEAC in mg Trolox/g of raw material) in extracts of the _Lavandula angustifolia_ herb determined immediately after their preparation was found in extracts prepared in 40% n-propanol and in 70% ethanol after a 15 min extraction and in 40% ethanol after a 60 min extraction (24.6 \(\pm\) 0.8, 23.6 \(\pm\) 1.4 and 23.2 \(\pm\) 0.6 TEAC, respectively).