## 4 Discussion  
All examined plants evinced the presence of phenolic acids, flavonoids, and tannins; demonstrated antiradical activity; and showed inhibitory properties towards \(\alpha\)-amylase. The freeze-dried samples revealed a higher abundance of polyphenols. The ethanol extract samples have resulted in higher concentrations of tannins, increased antioxidant capacity, and elevated \(\alpha\)-amylase inhibition activity. Generally, freeze-dried extracts tend to show higher TPC values compared to ethanol extracts in both VM and VV. The type and concentration of solvent can affect TPC; the 70% ethanol/water was based on the research data of [PERSON] et al. to achieve the maximum attainable concentration of polyphenols in both ethanol extracts and frozen samples [54]. Both are used in pharmaceutical preparation; the production of ethanol extract is more cost-effective and straightforward; however, freeze-dried extracts offer advantages in terms of standardisation and formulation into dosage form. The highest TPC values were detected in freeze-dried samples of VV aerial parts from Sigulda, while the lowest values were found in Deksare VM leaves. The differences could be attributed to the concentration effect during the freeze-drying process. In a research study conducted by [PERSON] et al., the VM leaf extracts demonstrated a TPC of 142.9 \(\pm\) 19.2 mg/100 g dry extract [15]. Furthermore, in a separate investigation by the same researcher, the TPC of VV leaf extracts was documented as 158.9 \(\pm\) 6.0 mg/100 g dry extract [14]. The difference between the data obtained in this study and reference data lies in the location of plant germination. The increase in TPC in freeze-dried samples indicates that this method of processing may enhance the preservation of phenolic compounds compared to traditional ethanol extracts. Furthermore, geographical factors [55; 56; 57] contribute to differences in phenolic content, as evidenced by the variations between Deksare and Sigulda. The data confirmed that the amount of TPC in the VM and VV aerial parts is higher than in berries [58; 59]. New sources of biological substances could be discovered by continuing the study of leaves and stems. Variations in tannin content are observed between locations, as evidenced in both ethanol extracts and freeze-dried preparations. Ethanol extracts of VV leaves from Deksare have a significantly higher tannin content (2.85%) compared to Sigulda (1.79%). Tannins have previously been studied in the berries of VM and VV [60; 61] and leaves [62]. The presence of tannins was indicated, but no specific results were mentioned. Therefore, the data obtained in our study can be used to compare the number of tannins in VM and VV. Freeze-dried extracts generally show lower tannin content compared to VM leaf ethanol extracts. VV consistently demonstrates a higher tannin content compared to VM in all categories analysed. According to the European Pharmacopoeia, 8 th edition [39], the tannin content in VM berries must be a minimum (min) of 1%, but for the _Bistorate_ rhizome 3%, cortex _Quercus_ min 3%, radix _Pelargonii_ 2%, _Tormenti_luncture (ethanol extract) 1.5%, and _Hamamelis_ leaf 3%. Taking this into account, the leaves and stems of VM and VV contain the optimal amount of tannins. Understanding the tannin content in different plant parts and processing methods is essential for applications in the food and pharmaceutical industries [63]. The DPPH radical scavenging activity is usually expressed as IC\({}_{50}\) (the concentration required to inhibit 50% of free radicals). It varied between different plants and their parts. Freeze-dried samples have lower results than ethanol extracts. Despite this, the results obtained confirm the antioxidant abilities of VM and VV leaves and aerial parts [64]. It has been proven above [65] that there is a correlation between antioxidant activity and \(\alpha\)-amylase inhibition activity. A strong negative correlation was observed in our study as well.