The molecular mechanism of the cholesterol-lowering effect of dill and kale: The influence of the food matrix components.

Foods are complex matrices containing many different compounds, all of which contribute to the overall effect of the food itself, although they have different mechanisms of action. While evaluating the effect of bioactive compounds, it is important to consider that the use of a single compound can hide the effects of the other molecules that can act synergistically or antagonistically in the same food. The aim of the present study was to evaluate the influence of food matrix components by comparing two edible plants (dill and kale) with cholesterol-lowering potential and similar contents of their most representative bioactive, quercetin. The molecular effects of the extracts were evaluated in HepG2 cells by measuring the expression of sterol-regulatory element-binding proteins (SREBPs), 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR) and low density lipoprotein receptor (LDLR) at the mRNA and protein level. The results reported here show that both extracts reduced the cellular cholesterol level with a similar trend and magnitude. It is conceivable that the slightly different results are due to the diverse composition of minor bioactive compounds, indicating that only by considering food as a whole is it possible to understand the complex relationship between food, nutrition, and health in a foodomics vision.

Mixed pro- and anti-oxidative effects of pomegranate polyphenols in cultured cells.

In recent years, the number of scientific papers concerning pomegranate (Punica granatum L.) and its health properties has increased greatly, and there is great potential for the use of bioactive-rich pomegranate extracts as ingredients in functional foods and nutraceuticals. To translate this potential into effective strategies it is essential to further elucidate the mechanisms of the reported bioactivity. In this study HepG2 cells were supplemented with a pomegranate fruit extract or with the corresponding amount of pure punicalagin, and then subjected to an exogenous oxidative stress. Overall, upon the oxidative stress the gene expression and activity of the main antioxidant enzymes appeared reduced in supplemented cells, which were more prone to the detrimental effects than unsupplemented ones. No differences were detected between cells supplemented with the pomegranate juice or the pure punicalagin. Although further studies are needed due to the gaps existing between in vitro and in vivo studies, our results suggest caution in the administration of high concentrations of nutraceutical molecules, particularly when they are administered in concentrated form.

Traditional foods for health: screening of the antioxidant capacity and phenolic content of selected Black Sea area local foods.

BACKGROUND: The nutritional characteristics of the Black Sea area (BSA) traditional foods are almost unknown, and they could be interesting sources of antioxidant compounds. In this study, carried out within the BaSeFood project, the in vitro total antioxidant capacity (TAC) and phenolic content of 39 BSA traditional foods were determined using different assays. RESULTS: An ample range of TAC and phenolics content was detected in the examined foods that were ranked according to their scavenging activity expressed per weight unit and per serving size. Based on serving size, the highest TAC was in the order blueberries > nettle soup > sunflower seeds, and the fruits/fruit-based foods group was the one having the highest activity. Correlation analysis evidenced that the TAC is highly dependent on total phenolic content, while hydroxycinnamic acids and compounds having o-diphenolic structure did not show specific prominent effects. Finally, correlations between the two methods used for measuring the TAC suggest that they are both suitable in a wide range of foods. CONCLUSION: Our data represent the first contribution to further research on the health effects of BSA traditional foods. This could enhance the interest of consumers, with potential benefits to stakeholders at all levels of the production chain.

Rocket salad (Diplotaxis and Eruca spp.) sensory analysis and relation with glucosinolate and phenolic content.

BACKGROUND: Salad crops of the Brassicaceae family, such as Diplotaxis tenuifolia and Eruca vesicaria, commonly referred to as 'rocket salads', have attracted considerable interest as culinary vegetables because of their strong flavour and their content of putative health-promoting compounds. Among such compounds, glucosinolates and phenolics are well-known phytochemicals with an important role also in determining the characteristic flavour of these species. In this study, to identify potentially high-value rocket salads, 37 cultivated types were examined for sensory characters and their relations with glucosinolate and phenolic contents, which ranged from 0.76 to 3.03 g kg(-1) dry weight (DW) and from 4.68 to 31.39 g kg(-1) DW, respectively. RESULTS: The perception of bitter taste was significantly affected by specific glucosinolates, namely progoitrin/epiprogoitrin and dimeric glucosativin. Aroma intensity was negatively related to glucoalyssin content, whereas pungency was significantly related to total glucosinolate content. Kaempferol-3-(2-sinapoyl-glucoside)-4'-glucoside was positively and significantly related to all flavour trait perceptions. Aroma intensity, pungency, crunchiness and juiciness were positively related to typical rocket salad flavour perception through a prominent direct effect. CONCLUSION: Aroma intensity, pungency, crunchiness and juiciness were strong determinants of overall rocket salad flavour perception. Visual traits also characterised sensory components. Bitterness, usually considered a negative flavour trait, was moderately perceived in the examined material, without negatively affecting typical flavour perception. In the range of the examined material, glucosinolate content did not contrast with typical flavour, demonstrating that good taste and putative health-promoting properties may coexist.