## 3 Discussion
Mechanistically, sea buckthorn polyphenols enhance the expression of microRNA (miR)-195-5p and miR-497-5p and suppress the expression of miR-1247-3p to downregulate the expression of cyclins, thereby inhibiting cell cycle arrest in the G1 phase and further proliferation of colon cancer. In addition, sea buckthorn polyphenols (50 mg/kg) significantly decreased tumor volume and controlled its proliferation in xenografted BALB/c nude mice in vivo [11]. In another study, polyphenic compound isfornamentin enhanced expression of the mitochondrial pathway pro-apoptotic protein (cytochrome c-aspase 9-caspase 3) in gastric cancer cells in hypoxic conditions, considerably inhibited the autophagy of MKN-45 gastric cancer cells and favored the programmed death of gastric cancer cells by activating the phosphoinositide 3-kinase (PI3K)-protein kinase B (AKT)-mammalian target of rapamycin (mTOR) signaling pathway [13]. In our previous study, we tested the content of flavonoids, phenolic acids and anthocyanins in the extracts obtained from the cookies with wild-grown fruits with the application of Reversed Phase-High Performance Liquid Chromatography (RP-HPLC) and High Performance Liquid Chromatography (HPLC) [3]. Six different polyphenic compounds have been found in sea-buckthorn cookies and their presence were of rather moderate quantities (mg\(\cdot\)100 g\({}^{-1}\) dm) (Table S1): chlorogenic acid (51.00 \(\pm\) 0.87); catechin (11.70 \(\pm\) 0.52); quercetin (200.73 \(\pm\) 0.76); quercetin-3-galactosidase (190.86 \(\pm\) 1.79); rutin (304.96 \(\pm\) 2.06); luteolin 7-O-glucoside (294.36 \(\pm\) 0.26) [3]. No isfornamentin or kaempfer was detected. Nevertheless, as shown in this study, sea buckthorn was the plant with the most outstanding potential. This may indicate a need for further analyses with the use of other bioactive compounds (i.e., carotenoids) from sea buckthorn for their antitumor activity in ready-to-eat food products, including cookies. Apart from sea buckthorn extracts, the samples containing chokeberry and elderberry had a positive influence on the viability of MCF7 cancer cells, regardless of the dose used, resulting in the lowest percentage of neoplastic cell viability, averaging 38% and 39%, respectively (Table 3). On the contrary, the cytotoxicity of the MCF7 breast cancer cell lines was not affected by these two types of extracts. In the available literature, the effective anticancer activity of both plants has been described. For instance, aronia berries and aronia juice showed promising activity against several different cancer cell lines, including human colon cancer cells HT-29 cells [32] and Caco-2 human colon cancer [33; 34], but were not toxic to human NCM460 normal colon cells at the same time [20]. The berry anthocyanin exhibited selective cell growth inhibitory activity against A549 and H1299 human non-small-cell lung cancer (NSCLC) cells [35]. _Aronia melanocarpa_ polyphenols were assumed to regulate the expression of key regulators of G2/M cell cycle transition and apoptosis. The antitumor activity was associated predominantly with chlorogenic acids, some cyanidin glycosides, and derivates of quercetin [36]. Aronia or chokeberry (_Aronia melanocarpa_ L.) is a shrub, the fresh fruits of which are not usually consumed directly due to their unpleasant bitter taste [20]. Phytochemical studies have shown that _Aronia melanocarpa_ fruits are abundant in phenolic compounds (from 10 to 5500 mg per 100 g of dried fruits): procyanidins, anthocyanins (cyanidin-3-O-galactoside), phenolic acids (chlorogenic acid), quercetin, a fused flavonoid-coumarin-phenol unit, also possess hydroxyl radical scavenging and quinone reductase inducing activities [18; 37].