Seeds of Vitis vinifera L. with a high content of bioactive compounds are valuable by-products from grape processing. However, little is known about the bioactivity of seeds from other Vitis species. The aim of this study has been to compare the phenolic composition, antimicrobial activity, and antioxidant activity of extracts from seeds of four Vitis species (V. riparia Michx., V. californica Benth., V. amurensis Rupr., and V. vinifera L.). Antioxidant activities were assessed as ferric-reducing antioxidant power (FRAP), 2,2-diphenyl-1-picrylhydrazyl radical (DPPH^•) scavenging activity, and oxygen radical absorbance capacity (ORAC). The antimicrobial activity was determined using the microdilution method against some Gram-negative (Escherichia coli, Salmonella enterica ser. Typhimurium, and Enterobacter aerogenes) and Gram-positive (Enterococcus faecalis and Staphylococcus aureus) bacteria. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to evaluate the phenolic profile of extracts. Flavan-3-ols, procyanidins, phenolic acids, flavonols, anthocyanins, and stilbenoids were detected. (+)-Catechin and (−)-epicatechin turned out to be the most abundant in the phenolic profile of V. amurensis seed extract. Phenolic acids prevailed in the extract from V. vinifera seeds. The V. riparia and V. californica seed extracts had higher contents of most individual phenolics compared to the other Vitis species. They also showed a higher total phenolic content, DPPH^• scavenging activity, ORAC, and overall antibacterial activity. Total phenolic content significantly correlated with antioxidant activity and antimicrobial activity against E. coli. The principal component analysis (PCA) showed discrimination between V. vinifera, V. amurensis, and clustered V. riparia and V. californica with respect to variables. To recapitulate, this research demonstrates that seeds of different Vitis species, especially V. riparia and V. californica, are sources of molecules with antioxidant and antimicrobial activities that can be used in different sectors, such as in the food, cosmetic, and pharmaceutical industries.

Recently, green microalgae have gained importance due to their nutritional and bioactive compounds, which makes them some of the most promising and innovative functional foods. The aim of this study was to evaluate the chemical profile and the in vitro antioxidant, antimicrobial and antimutagenic activity of an aqueous extract of the green microalga Ettlia pseudoalveolaris, obtained from the freshwater lakes of the Ecuadorian Highlands. Human microvascular endothelial cells (HMEC-1) were used to determine the ability of the microalga to reduce the endothelial damage caused by hydrogen peroxide-induced oxidative stress. Furthermore, the eukaryotic system Saccharomyces cerevisiae was used to evaluate the possible cytotoxic, mutagenic and antimutagenic effect of E. pseudoalveolaris. The extract showed a notable antioxidant capacity and a moderate antibacterial activity mostly due to the high content in polyphenolic compounds. It is likely that the antioxidant compounds present in the extract were also responsible for the observed reduction in endothelial damage of HMEC-1 cells. An antimutagenic effect through a direct antioxidant mechanism was also found. Based on the results of in vitro assays, E. pseudoalveolaris proved to be a good source of bioactive compounds and antioxidant, antibacterial and antimutagenic capacities making it a potential functional food.

Green microalgae are single-celled eukaryotic organisms that, in recent years, are becoming increasingly important in the nutraceutical, cosmetic, and pharmaceutical fields because of their high content of bioactive compounds. In this study, a particular green microalga was isolated from freshwater highland lakes of Ecuador and morphologically and molecularly identified as Chlamydomonas agloeformis (ChA), and it was studied for nutritional and nutraceutical properties. The phenolic composition and the fatty acids profile of lyophilized cells were determined. The methanolic extract was analyzed for the phenolic compounds profile and the antioxidant capacity by means of in vitro tests. Finally, Human Microvascular Endothelial Cells (HMEC-1) were exploited to explore the capacity of ChA to reduce the endothelial damage induced by oxidized LDL-mediated oxidative stress. The extract showed a good antioxidant ability thanks to the high content in polyphenolic compounds. The observed decrease in HMEC-1 cells endothelial damage also was probably due to the antioxidant compounds present in the extract. Based on the outcomes of our in vitro assays, ChA demonstrated to be a promising source of bioactive compounds possessing exceptional antioxidant capacities which make it a prospective functional food.

Agresto is the unfermented juice traditionally obtained from boiled unripe grapes, typically using fruit that would otherwise be discarded, and enriched with spices, herbs, and fruit. In this study, the phenolic profile, antioxidant and antibacterial activity, and volatile organic compounds (VOCs) of Agresto produced from two grape varieties (Sangiovese, and Vermentino) harvested in Mount Amiata (Tuscany) were evaluated. Agresto from Vermentino showed a higher total phenolic content (TPC), 1.31 mg GAE/mL, as well as a greater total flavonoid and flavonol content and FRAP activity compared to Agresto from Sangiovese. The highest ORAC value was observed in Agresto from Vermentino, 41.01 mg TE/mL, compared to that from Sangiovese. TPC, flavonols, apocarotenes, sulfur derivatives, and non-terpene derivatives were positively correlated with antimicrobial activity against E. coli, FRAP, and ORAC. Overall, our results showed that grape variety significantly influences the chemical composition of Agresto, particularly in terms of both VOCs and phenolic compounds. The observed variations in phenolic composition also affected the antioxidant and antimicrobial activity of Agresto. These experimental findings clearly suggest the utmost importance of identifying the optimal chemical profile of “unripe grapes” used as raw material for Agresto production, considering both variety and the specific ripening degree achievable through vine green harvesting.