## 2 Materials and Methods
### Chemical Analysis of the Samples  
Several factors were chosen for the evaluation of the properties of the obtained extracts. The analysis of composition of extracts included the determination of total phenolic content and anthocyanins (a group of pigments responsible for the intense coloration of chokeberries). The tests employing two artificial radicals (ABTS\({}^{\bullet+}\) and DPPH\({}^{\bullet}\)) were chosen to monitor the antioxidant activity of the extracts because of their widespread use, regardless of the minor connection with biological activity. The assays investigating the scavenging of \({}^{\bullet}\)OH, O\({}_{2}\)\({}^{\bullet-}\), and NO\({}^{\bullet}\), despite their imperfection, gave the results of a much higher in vivo significance. The total phenolic content (TPC) was determined using a fast spectrophotometric method described by [PERSON] et al. [27]. The reaction mixtures composed of 0.1 mL of sample, 2.0 mL of water, 0.2 mL of Folin-Ciocalteu reagent, and 1.0 mL of sodium carbonate solution (15%) were incubated for 2 h at room temperature. The phenolic content was determined by measuring absorbance at 765 nm. The results were expressed as equivalents of gallic acid. An HPLC method described by [PERSON] was employed for quantifying the anthocyanins [28]. A Sunfire C18 reversed-phase column, 5 \(\upmu\)m, 4.6 \(\times\) 250 mm (Waters, Milford, MA, USA) was used at 25 \({}^{\circ}\)C with an appropriate precolumn. The samples were eluted with 4.5% formic acid in water (A) and acetonitrile (B), with a flow rate of 1.0 mL per min and the following gradient: 0 min--100% A; 7 min--88% A; 15 min--88% A; 21 min--20% A; 26 min--100% A. The anthocyanins were quantified at 520 nm. The concentrations were presented as equivalents of cyanidin-3-O-glucoside. The scavenging activity against ABTS\({}^{\bullet+}\) was measured with a protocol described by [PERSON] et al. [29]. The radical cations were generated by preparing a solution composed of 7 mM of ABTS and 2.45 mM of potassium persulfate. After 16 h of incubation in darkness, the solution was diluted with ethyl alcohol to achieve an absorbance of 0.7 at 734 nm. The 25 \(\upmu\)L samples were combined with 2.5 mL of ABTS\({}^{\bullet+}\) solution and incubated for 6 min. The degradation of green-colored radical cations was measured at 734 nm. Trolox was chosen as a reference antioxidant. A method described by [PERSON] and [PERSON] was used to determine the activity against DPPH\({}^{\bullet}\)[30]. The 0.1 mL samples were combined with 2 mL of DPPH\({}^{\bullet}\) solution (1 mM) and incubated at ambient temperature for 30 min. The degradation of violet-pigmented radicals was evaluated spectrophotometrically at 517 nm. Trolox was chosen as a reference antioxidant. The hydroxyl radical scavenging activity of extracts was determined using a method by [PERSON] and [PERSON] [31]. The radicals were generated during the Fenton reaction, which was started by mixing equal volumes of solutions of: EDTA (ethylenediaminetetraacetic acid), FeCl\({}_{3}\), ascorbic acid (1 mM each), and H\({}_{2}\)O\({}_{2}\) (10 mM). The 400 \(\upmu\)L of the mixture was merged with 500 \(\upmu\)L of sample and 100 \(\upmu\)L of deoxy-2-ribose solution (28 mM). After 1 h of thermostating at 37 \({}^{\circ}\)C, 1 mL of trichloroacetic acid and 1 mL of thiobarbituric acid were added and the mixture was incubated at 100 \({}^{\circ}\)C for 20 min. After cooling, the amount of oxidized deoxy-2-ribose was measured spectrophotometrically at 532 nm. The results were presented as equivalents of sorbitol. A method described by [PERSON] and [PERSON] was used to determine the activity against the superoxide radical [32]. The sample (250 \(\upmu\)L) was mixed with 250 \(\upmu\)L of 0.45 mM NADH (nicotinamide adenine dinucleotide), 250 \(\upmu\)L of 0.15 mM nitroblue tetrazolium and 1 mL of phosphate-buffered saline. The chemical reaction was started by adding 250 \(\upmu\)L of 0.12 mM phenazine methosulfate.