Isolation and Characterization of Wheat Derived Nonspecific Lipid Transfer Protein 2 (nsLTP2).

Numerous studies support the protective role of bioactive peptides against cardiovascular diseases. Cereals represent the primary source of carbohydrates, but they also contain substantial amounts of proteins, therefore representing a potential dietary source of bioactive peptides with nutraceutical activities. The analysis of wheat extracts purified by chromatographic techniques by means of HPLC-UV/nanoLC-nanoESI-QTOF allowed the identification of a signal of about 7 kDa which, following data base searches, was ascribed to a nonspecific lipid-transfer protein (nsLTP) type 2 from Triticum aestivum (sequence coverage of 92%). For the first time nsLTP2 biological activities have been investigated. In particular, in experiments with human umbilical vein endothelial cells (HUVEC), nsLTP2 displayed antioxidant and cytoprotective activities, being able to significantly decrease reactive oxygen species (ROS) levels and to reduce lactate dehydrogenase (LDH) release, generated following oxidative (hydrogen peroxide) and inflammatory (tumor necrosis factor α, interleukin-1ß, and lipopolysaccharide) stimulation. The obtained promising results suggest potential protective role of nsLTP2 in vascular diseases prevention. PRACTICAL APPLICATION: nsLTP 2 peptide is resistant to proteases throughout the gastrointestinal tract and exerts antioxidant and cytoprotective activities. These characteristics could be exploited in vascular diseases prevention.

Steviol glycosides modulate glucose transport in different cell types.

Extracts from Stevia rebaudiana Bertoni, a plant native to Central and South America, have been used as a sweetener since ancient times. Currently, Stevia extracts are largely used as a noncaloric high-potency biosweetener alternative to sugar, due to the growing incidence of type 2 diabetes mellitus, obesity, and metabolic disorders worldwide. Despite the large number of studies on Stevia and steviol glycosides in vivo, little is reported concerning the cellular and molecular mechanisms underpinning the beneficial effects on human health. The effect of four commercial Stevia extracts on glucose transport activity was evaluated in HL-60 human leukaemia and in SH-SY5Y human neuroblastoma cells. The extracts were able to enhance glucose uptake in both cellular lines, as efficiently as insulin. Our data suggest that steviol glycosides could act by modulating GLUT translocation through the PI3K/Akt pathway since treatments with both insulin and Stevia extracts increased the phosphorylation of PI3K and Akt. Furthermore, Stevia extracts were able to revert the effect of the reduction of glucose uptake caused by methylglyoxal, an inhibitor of the insulin receptor/PI3K/Akt pathway. These results corroborate the hypothesis that Stevia extracts could mimic insulin effects modulating PI3K/Akt pathway.

Phytochemical profile and nutraceutical value of old and modern common wheat cultivars.

Among health-promoting phytochemicals in whole grains, phenolic compounds have gained attention as they have strong antioxidant properties and can protect against many degenerative diseases. Aim of this study was to profile grain phenolic extracts of one modern and five old common wheat (Triticum aestivum L.) varieties and to evaluate their potential antiproliferative or cytoprotective effect in different cell culture systems.Wheat extracts were characterized in terms of antioxidant activity and phenolic composition (HPLC/ESI-TOF-MS profile, polyphenol and flavonoid contents). Results showed that antioxidant activity (FRAP and DPPH) is mostly influenced by flavonoid (both bound and free) content and by the ratio flavonoids/polyphenols. Using a leukemic cell line, HL60, and primary cultures of neonatal rat cardiomyocytes, the potential antiproliferative or cytoprotective effects of different wheat genotypes were evaluated in terms of intracellular reactive oxygen species levels and cell viability. All tested wheat phenolic extracts exerted dose-dependent cytoprotective and antiproliferative effects on cardiomyocytes and HL60 cells, respectively. Due to the peculiar phenolic pattern of each wheat variety, a significant genotype effect was highlighted. On the whole, the most relevant scavenging effect was found for the old variety Verna. No significant differences in terms of anti-proliferative activities among wheat genotypes was observed.Results reported in this study evidenced a correspondence between the in vitro antioxidant activity and potential healthy properties of different extracts. This suggests that an increased intake of wheat grain derived products could represent an effective strategy to achieve both chemoprevention and protection against oxidative stress related diseases.