## 4 Discussion
In order to assess the effect of phenolic compounds on the antioxidant and antiviral effects of the extracts, we used solid-phase extraction, which led to a significant increase in their polyphenol and anthocyanin contents [32]. During purification, impurities such as sugars, acids, proteins, and pectin are removed from the raw extract, thereby concentrating polyphenols, flavonoids, and anthocyanins. The purpose of purification was to remove primary metabolites and obtain polyphenol-enriched extracts. From the results on the phenolic content and composition of the extracts, it is evident that solid-phase extraction resulted in the production of extracts with a higher content of phenolic acids, flavonoids, and anthocyanins. This is likely a prerequisite for increased biological activity of the extracts, since a significant number of studies have demonstrated the effectiveness of polyphenols against different pathogens, including herpes simplex virus (HSV) [10; 63]. To more fully characterize the obtained dry extracts and their expected high biological activity, we determined their antioxidant and anti HSV-2 activities. Since polyphenols have been described in the literature as potent antioxidants, we hypothesized that enriched polyphenol extracts would exhibit both higher antioxidant and antiviral activities against HSV-2. Given the differences in the polyphenol content and composition of the studied extracts, it could be expected that there would also be differences in their antioxidant and antiviral activities. As far as we know, no previous research has reported ORAC, HORAC, and anti-HSV-2 activities of polyphenol-enriched SN and SE fruit, flower, and leaf extracts. For this reason, we were unable to make comparisons of our results with literature data. The highest ORAC antioxidant activity was measured for PSNFrE (11,443.1 \(\pm\) 495.2 \(\mu\)mol TE/g) followed by PSNFIE (7742.9 \(\pm\) 338.4 \(\mu\)mol TE/g) and PSEFrE (6837.6 \(\pm\) 429.8 \(\mu\)mol TE/g). SEFIE (3035.2 \(\pm\) 162.7 \(\mu\)mol TE/g) and SELE (611.1 \(\pm\) 26.4 \(\mu\)mol GAE/g) revealed a lower activity measured using ORAC and HORAC, respectively. Due to the high amount of polyphenols, including anthocyanins, in PSNFrE, its ORAC value was extremely high. The HORAC value of PSNFrE was also high (8198.9 \(\pm\) 315.4 mol GAE/g). The ORAC and HORAC values of PSNFIE were 7742.9 \(\pm\) 338.4 mol TE/g and 2107.8 98.1 mol GAE/g, respectively. Similarly to TPC, ORAC and HORAC antioxidant activity values in purified extracts were significantly higher than those of the unpurified ones. Given the scarcity of research on the antiviral effects against HSV-2 of studied plants, particularly of their polyphenol-enriched extracts, this study continued by investigating their activity against HSV-2. Our results confirmed the safety of _S. nigra_ L. fruits, which have been recognized as a safe food additive by the US Food and Drug Administration(FDA) and the European Medical Agency (EMA) [64]. A number of medicinal plants have shown antiviral activity against different virus types and polyphenols have shown an ability to inhibit viruses via different mechanisms [65]. In the available literature, there are data on the antiviral activity mainly for SN and SE fruits, while flowers and leaves are less studied. Fruit extracts have been studied mainly for their effects against influenza viruses--type A and type B, H5N1, and H1N1--HIV-1; coronavirus (CoV), causing infectious bronchitis in birds; and other human coronaviruses (HCoV 229E, HCoV OC43, HCoV HKU1, and HCoV NL63), which are responsible for about 20% of common colds and other respiratory diseases [12; 66]. According to [PERSON] et al., the results from several in vitro and in vivo human studies suggest that the aqueous elderberry extract Sambucol(r) (derived from _S. nigra_ fruits) demonstrates potential in treating viral infections [67]. However, data for activity against herpes viruses of both species are scarce.