Wheat sprout extract induces changes on 20S proteasomes functionality.

Wheat sprouts contain a very high level of organic phosphates and a powerful cocktail of different molecules such as enzymes, reducing glycosides and polyphenols. The antioxidant properties of wheat sprouts have been widely documented and it has been shown that they are able to protect DNA against free-radicals mediated oxidative damage. Furthermore, we have recently reported on the effects of several polyphenols on 20S proteasomes, underlying the dual role of epigallocatechin-3-gallate as an antioxidant and a proteasome effector in cancer cells. The aim of this study was to investigate the effects of wheat sprout extracts on 20S proteasome functionality. Wheat sprout extracts have been analysed and characterized for their polyphenolic content using the Folin-Ciocalteau reagent and RP-HPLC technique. Comparing our data with a polyphenol standard mixture we identified five different polyphenols: gallic acid, epigallocatechin-3-gallate, epigallocatechin, epicatechin and catechin. The treatment of isolated 20S proteasomes with the extract induced a gradual inhibition of all the tested components, ChT-L, T-L, PGPH and BrAAP, in both the complexes. At low extract concentration a slight activation of the enzyme was evident only for the BrAAP component of the constitutive enzyme and the ChT-L activity of the immunoproteasome. b-casein degradation rate decreased, particularly with the immunoproteasome. Human Colon adenocarcinoma (Caco) cells, stimulated with 12-O-tetradecanoylphorbol-13-acetate, showed activation of the 20S proteasome activities at short incubation times and an increase in intracellular oxidative proteins. Cells treatment with wheat sprout extract led to proteasome inhibition in unstimulated cells and attenuated the effects mediated by TPA. Finally, exposure to the extract affected the expression levels of pro-apoptotic proteins

Analisi comparativa di antiossidanti sintetizzati durante la germinazione in differenti cereali

Abstrac

Antioxidant activity of extracts from calf thymus and wheat sprouts. Potential relation with their activity in aging reversibility.

The potential presence in animal and vegetal tissues of compounds able to reactivate some metabolic pathways slowed down in aging fascinated, in the last century, many researchers. Old rats treated with calf thymus extract re capable of recovering altered glycogen and lipid levels, RNA/DNA ratio and transcriptional activity of DNA dependent-RNA polymerase in rat liver. More recently aging reversibility has been obtained with extracts from wheat sprouts. Old mice treated with wheat sprouts extract showed a recovery of decreased DNA synthesis in hepatocytes primary cultures when compared with the old untreated ones. Moreover old dogs orally treated for a month with wheat sprouts powder showed a 25-40% reduction of lens opacity. At the same time it was reported that wheat sprout contain a strong cocktail of antioxidant compounds. The association of this results is interesting because the oxidative stress has been soundly referred to several pathologies and to aging. Accordingly, in the last two decades, an increasing interest has been focused on the study of natural products with antioxidant activity. Antioxidants may contribute to prevent cancer and delay aging. In this context we compared the antioxidant activities of extracts from calf thymus and wheat sprouts. This to evaluate how much it is plausible that the previously observed effects on the aging reversibility could be due to the action of antioxidant compounds. The results reported in this paper demonstrated that extracts from wheat sprout and calf thymus show very similar strong activity both in ferrocianide reduction and on superoxide radical scavenging. Calf thymus extract shows a remarkable presence of taurine and glutathione. However it is surprising that this extract contain also a significant level of polyphenol molecules. The level of taurine and compounds containing thiol groups are in wheat sprout extract much lower respect to calf thymus extract. On the contrary a remarkable content of reducing glycosides and flavonoids was observed. The very similar antioxidant activity demonstrated in this paper strongly support the exciting hypothesis that the cocktails of antioxidant molecules, contained in calf thymus and wheat sprouts, are responsible for the previously reported aging reversibility effects

Interaction of DDSDEEN peptide with N-CAM protein. Possible mechanism enhancing neuronal differentiation.

Interaction of DDSDEEN peptide with N-CAM protein. Possible mechanism enhancing neuronal differentiation Valeria Marsili a,b,*, Giulio Lupidi c, Giuliano Berellini d, Isabella Calzuola a,b, Stefano Perni a,b, Gabriele Cruciani d, Gian Luigi Gianfranceschi a,b a Dipartimento di Biologia Cellulare e Ambientale, Universita` di Perugia, 06123 Perugia, Italy b CEMIN (Centro Eccellenza Materiali Innovativi Nanostrutturati), 06123 Perugia, Italy c Dipartimento di Biologia MCA, Universita` di Camerino, 62032 Camerino, Italy d Dipartimento di Chimica, Universita` di Perugia, 06123 Perugia, Italy ab s t r a c t DDSDEEN chromatin peptide, after dansylation, was studied for its ability to bind N-CAM protein. The binding causes a quenching of the Dns-peptide fluorescence emission. Doseand time-dependent binding of Dns-peptide with N-CAM has been shown. Fluorescence quenching is completely lost if the Dns-peptide is subjected to carboxypeptidase digestion. Moreover the undansylated peptide pEDDSDEEN competes with the DnsDDSDEEN peptide for the binding with the N-CAM protein. The Dns-peptide–N-CAM bond has been related to the peptide biological activity probably involved in the promotion of neuronal differentiation. An attempt to recognize a possible N-CAM binding site for Dns-peptide was performed by alignment of N-CAM from various sources with some sequences that have been previously reported as binding sites for the pEDDSDEEN and DDSDEEN peptides. Interestingly, the alignment of N-CAM from various sources with the peptides WHPREGWAL and WFPRWAGQA recognizes on rat and human N-CAM a unique sequence that could be the specific binding site for chromatin peptide: WHSKWYDAK. This sequence is present in fibronectin type-III domain of N-CAM. In addition molecular modeling studies indicate the N-CAM sequence WHSKWYDAK as, probably, the main active site for DnsDDSDEEN (or pEDDSDEEN) peptide ligand. Accordingly the binding experiments show a high affinity between WHSKWYDAK and DnsDDSDEEN peptides

Antioxidant activity of wheat sprouts extract in vitro: Inhibition of DNA oxidative damage

Wheat sprouts contain a remarkable level of various antioxidants. A fraction containing high amounts of powerful antioxidant glycoside molecules has been isolated. In a dose-dependent manner, this fraction reduces the lucigenin-amplified chemiluminescence produced by the superoxide anion generated from the xanthine/xanthine oxidase system, thus indicating a superoxide-scavenging activity. A protective effect of this wheat sprouts fraction on the oxidative damage of pBR322 plasmid DNA induced by Fenton reaction (Fe2+/H2O2) was subsequently demonstrated. Moreover, the results reported here show that the amount of antioxidant compound strongly increases during the germination phase, while scantly present in the wheat germ, and virtually absent in the young wheat plant