# Sea Buckthorn Leaves as a Potential Source of Antioxidant Substances
## 3 Results and Discussion
This is not a positive finding from the point of view of obtaining stable quality raw material. The change in the quality of the raw material of the Ascola cv. can be taken as an example. There is a clear decrease in the anthocyanin content in favour of other active components (especially flavonoids, flavonoids, and total tannins) in the following years of this study. In the Leikora cv., the content of mainly cheylethrine and delphinidin increased with successive growing seasons. The analysis of the correlations between the determined raw material properties showed a correlation coefficient close to statistical significance (\(p\) = 0.091) (r = 0.509) between the DPPH and ABTS methods but, at the same time, confirmed the lack of correlation between these methods and the PCL-ACW method (r = 0.180 and 0.029, respectively) (Tables 2 and 3). PCL methods are less frequently used to assess the quality of plant material, so this lack of correlation is difficult to discuss with respect to sea buckthorn AA analyses. Nevertheless, [PERSON] et al. (2019), in their study on the AA assessment of buckwheat sprouts, showed a correlation of sprout AA measured by DPPH with PCL-ACW methods (r = 0.81). The correlations of the analysed properties with cheylethrine are also interesting. The content of this alkaloid does not show a correlative relationship with AA, but statistically significant relationships were observed between its content and the \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Factor** & **Rutoside** & **Quercetin** & **Delphinidin** & **Peonidin** & **Cyanidin** & **Cheylethrine** \\  & & & Year & & & \\ \(p\)\({}^{3}\) & =0.001 & =0.003 & =0.045 & =0.335 & =0.005 & =0.005 \\
2014 & 0.246 a \({}^{4}\) & 0.178 a & 0.794 a & 36.668 a & 0.681 a & 0.681 a \\
2015 & 0.295 b & 0.203 b & 0.815 a & 41.141 a & 0.687 a & 0.885 ab \\
2016 & 0.335 c & 0.223 b & 0.972 b & 35.942 a & 0.723 b & 1.043 b \\ \hline  & & & Cultivar & & & \\ \(p\) & =0.402 & =0.270 & =0.017 & =0.298 & =0.052 & =0.096 \\ Ascola & 0.280 a & 0.190 a & 0.723 a & 33.034 a & 0.685 a & 0.749 a \\ Habego & 0.296 a & 0.207 a & 0.783 a & 37.863 a & 0.700 a & 0.845 a \\ Hergo & 0.287 a & 0.207 a & 1.026 b & 39.662 a & 0.687 a & 0.898 a \\ Leikora & 0.305 a & 0.200 a & 0.909 ab & 41.108 a & 0.716 a & 0.988 a \\ \hline  & & & & & & \\ \end{tabular} \({}^{1}\) SBT—sea buckthorn; \({}^{2}\) DM—dry matter; \({}^{3}\) p—probability of null hypothesis rejection (H0; m\({}_{1}\) = m\({}_{2}\) \(\ldots\) = m\({}_{n}\)); \({}^{4}\) means with at least one same letter (a, b, c) do not differ statistically at \(p\) = 0.05 (for all columns, separately).  
\end{table} 
Table 5: Content of secondary metabolites in SBT \({}^{1}\) leaves. content of anthocyanins and flavonols (rutin, quercetin). The correlation relationship with anthocyanins is negative (r = \(-\)0.724), and with flavonoids, it is positive (r = 0.902 and 0.800, respectively) (Tables 2 and 3). Figure 3: The first two principal component axes for bioactive compound content in SBT leaves for variables (**A**) and for the scores (**B**), (C—Cyanidin; CHE—Chelerythrine; DE—Delphinidin; P—Peonidin; PAC—Proanthocyanidin; QE—Quercetin; R—Rutoside; TA—Total Anthocyanin; TF—Total Flavonoid; TFL—Total Flavonoid; TT—Total Tannin; A—cv. Ascola; HA—cv. [PERSON]; HE—cv. [PERSON]; L—cv. Leikora). Diet, along with genetic and environmental factors, is considered a major aspect affecting longevity, as well as vascular disease outcome. Cardiovascular disease (CVD) is the major cause of mortality and morbidity in the world [81]. Therefore, the prevention of and reduction in risk factors, which are associated with CVD, are the major tasks of health care professionals and scientists. Several investigators have studied the role of different bioactive components such as antioxidants and flavonoids in the prevention and management of CVD.