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From the perspective of circular economy, it is extremely useful to recycle waste products for human health applications. Among the health-beneficial properties of bioactive phyto-compounds, grape pomace represents a precious source of bioactive molecules with potential antitumor properties. Here, we describe the effects of a Sicilian grape pomace hydroalcoholic extract (HE) in colon and breast cancer cells. The characterization of HE composition revealed the predominance of anthoxanthins and phenolic acids. HE treatment was more effective in reducing the viability of colon cancer cells, while breast cancer cells appeared more resistant. Indeed, while colon cancer cells underwent apoptosis, as shown by DNA fragmentation, caspase-3 activation, and PARP1 degradation, breast cancer cells seemed to not undergo apoptosis. To elucidate the underlying mechanisms, reactive oxygen species (ROS) were evaluated. Interestingly, ROS increased in both cell lines but, while in colon cancer, cells' ROS rapidly increased and progressively diminished over time, in breast cancer, cells' ROS increase was persistent up to 24 h. This effect was correlated with the induction of pro-survival autophagy, demonstrated by autophagosomes formation, autophagic markers increase, and protection by the antioxidant NAC. The autophagy inhibitor bafilomycin A1 significantly increased the HE effects in breast cancer cells but not in colon cancer cells. Overall, our data provide evidence that HE efficacy in tumor cells depends on a balance between ROS-mediated autophagy and apoptosis. Therefore, inhibiting pro-survival autophagy may be a tool to target those cells that appear more resistant to the effect of HE. [ABSTRACT FROM AUTHOR]

Ferulago nodosa (L.) Boiss. (Apiaceae) is a species occurring in the Balkan-Tyrrhenian area being present in Crete, Greece, Albania, and probably in Macedonia. From the roots of this accession of species, not previously investigated, four coumarins, grandivittin, aegelinol benzoate, felamidin and aegelinol, and two terpenoids, (2E)-3-methyl-4-[(3-methyl-1-oxo-2-buten-1yl)oxy]-2-butenoic acid and pressafonin-A, were isolated and spectroscopically characterized. The last one was never detected in Ferulago species. The evaluation of the anti-tumor effects of F. nodosa coumarins on colon cancer HCT116 cells showed only a modest effect on reduction of tumor cell viability. For aegelinol, the reduction of colon cancer cell viability already appears with 25 µΜ, while using 50 e 100 µM doses of marmesin the residual viability amounted to 70% and 54%, respectively. This effect resulted more evident at higher doses of compounds (at 200 µM from 80% to 0%). The most effective compounds resulted coumarins lacking ester group. [ABSTRACT FROM AUTHOR]