## 4 Discussion  
It is well-known that plant extracts bear bioactivities that, due to their high selectivity and, often, their capacity to be biodegradable in nontoxic products, can be applied similarly to other usual chemical drugs [37; 38]. In particular, several studies described the important biological properties of extracts from the _F. sellowiana_ fruit, including a strong antimicrobial (also against _H. pylori_) and antioxidant activity [16; 25; 26] and significant nephro- and hepatoprotective, anti-inflammatory and antidepressant effects [39; 40; 41], as well as relevant anticancer activity [22; 42; 43]. In a previous study, [PERSON] et al. demonstrated a protective effect of _F. sellowiana_ fruit extract on gastric mucosa [44]. Furthermore, several studies remarked that the main biological activities of _F. sellowiana_ extract, such as antitumor, antimicrobial and anti-inflammatory effects, could be ascribable to several compounds. Among them, it is widely believed that flavone plays a very important role [16; 22; 33]. Indeed, epidemiological studies associated flavonoid ingestion to a lower risk of different types of cancer, including GC [45]; nonetheless, there is a risk of chronic disease [46]. Moreover, flavonoids seem to have no adverse effects, even at high dosages, and they are not chemically degraded by human stomach milieu [47]. Therefore, in the last years, the capacity of flavonoids to inhibit cell proliferation and/or induce apoptosis in human cancer cells has driven many researchers to investigate their potential as anticancer drugs. Increasing data revealed that one of the most active flavonoids was found to be flavone [22; 48]. Based on these evidences, and considering the possible, still little-known, role played by _F. sellowiana_ acetonic extract in the gastrointestinal tract, we investigated its anticancer effects, as well as its antioxidant activity, comparing them with those determined by the well-known flavone. In this study, we demonstrated that, among three different gastric cancer cell lines, the _F. sellowiana_ acetonic extract displayed antiproliferative effects and a concomitant apoptosis induction on SNU-1 cells. On the contrary, AGS and KATOIII cancer cells were poorly responsive to this treatment, according to previous studies that emphasized a cell line-specific sensitivity to _F. sellowiana_ extract [22]. These evidences were supported also by some different characteristics between the cell lines used for the experiments. Indeed, since SNU-1 are ERBB2-positive cells, we can speculate that the apoptotic effects induced by the _F. sellowiana_ acetonic extract could be similar to those induced by other flavonoids in other ERBB2+ tumor cell lines [49; 50]. In agreement with the well-established anticancer activity of flavone and structurally related flavones in other types of cancer [51; 52; 53], we found that flavone was also able to induce apoptosis in all the three gastric cancer cell lines we used, reaching the maximal activity at 100 \(\upmu\)g/mL. Moreover, the different behavior of the gastric cancer cell lines could reflect, once again, the strong gastric cancer heterogeneity. Our study supplied novel insights into the anticancer activities of the _F. sellowiana_ acetonic extract related to gastric cancer. Regarding the antioxidant properties, the choice to use PMNs to evaluate the effect of the extract on the activity of antioxidant enzymes is due to the fact that these cells represented a study model to evaluate the antioxidant response in previous studies on _F. sellowiana_ extracts [26]. As for the anticancer effect, our results show that the antioxidant activity of SOD, CAT and GPX enzymes are higher in PMN cells treated with flavone compared to the _F. sellowiana_ acetonic extracts. We can hypothesize that the greater activity of it could be ascribable to a lesser amount