## 1 Introduction
Tannins from Spondias Mombin have been found to have several benefits: they improve body and organ weight, reduce serum amylase levels, and have significant antidiabetic effects. These tannins helped lower blood sugar levels and improve lipid profiles in diabetic rats. Additionally, tannin treatment provided antioxidant properties, reducing oxidative stress [21]. It is important to note that while tannins and their derivates are a component of the overall chemical composition of VM leaves, these leaves also contain other bioactive compounds, such as flavonoids and phenolic acids [20]. Some pharmacologically important compounds are galloyl glucose, chlorogenic acid, neochlorogenic acid, catechin, and epicatechin, etc. [22; 23]. This study will further discuss the effects of individual phenolic compounds, especially tannin derivates. They can lower blood sugar levels after meals and prevent or delay glucose absorption by blocking alpha-glucose [6]. Various analytical techniques, including chemical assays and spectroscopic methods like infrared spectroscopy, can confirm the presence of tannins in the leaves of the VM and VV aerial parts [24]. The total phenolic content in VM and VV may vary depending on the specific plant species involved, growing conditions, differences in analytical methods, and specific parts of the plant under analysis. Leaves and aerial parts exhibit a higher concentration compared to berries [25]. These aerial parts exhibit the most robust antioxidant activities, suggesting their potential as an alternative reservoir of bioactive natural substances [25]. Research in the literature indicates that although VM and VV leaves contain fewer anthocyanins than their fruits, they have a higher phenolic compound content and have promising biological activities [26; 27; 28]. Additionally, the choice of solvents and extraction methods can influence the results. For example, the total phenolic content can be elevated when using an 80% methanol solvent, while 70% ethanol also demonstrates effective extraction of phenolics. Interestingly, the use of acetone-water (70:30) yields even higher extraction results compared to ethanol [11; 20]. In this study, 70% ethanol was used since it is less harmful compared to methanol and acetone and it extracts effectively. Most studies compare the same type of prepared plant extracts and their effects on T2 DM [29; 30]. There are relatively fewer studies investigating freeze-dried samples and their successful effects on T2 DM [31]. In our study, the investigation of the developing leaves and aerial parts of VM and VV in Latvia has been specifically selected. These plants are present in the human diet in the form of fruits and aerial part preparations, as well as being used historically in folk medicine [32; 33; 34]. VM and VV, belonging to the Vaccinium genus, are well known for their traditional uses in folk medicine, especially their leaves [7; 35; 36]. These plants have a history of being used to address various health concerns, including conditions related to metabolic imbalances [7; 36]. Drawing on information from the scientific literature [10; 17; 36; 37], our objectives were to characterise polyphenols and evaluate tannins, the total phenolic content, antioxidant activity, and the \(\alpha\)-amylase inhibition activity of the leaves and the aerial parts of VM and VV in both ethanol extracts and freeze-dried samples. The plant samples were collected from two distinct locations: the Deksare district and the Sigulda district.