D. Di Majo

Distinct signalling mechanisms are involved in the dissimilar myocardial and coronary effects elicited by quercetin and myricetin, two red wine flavonols

BACKGROUND AND AIMS Moderate red wine consumption associates with lower incidence of cardiovascular diseases. Attention to the source of this cardioprotection was focused on flavonoids, the non-alcoholic component of the red wine, whose intake inversely correlates with adverse cardiovascular events. We analysed whether two red wine flavonoids, quercetin and myricetin, affect mammalian basal myocardial and coronary function. METHODS AND RESULTS Quercetin and myricetin effects were evaluated on isolated and Langendorff perfused rat hearts under both basal conditions and α- and β-adrenergic stimulation. The intracellular signalling involved in the effects of these flavonoids was analysed on perfused hearts and by western blotting on cardiac and HUVEC extracts. Quercetin induced biphasic inotropic and lusitropic effects, positive at lower concentrations and negative at higher concentrations. Contrarily, Myricetin elicits coronary dilation, without affecting contractility and relaxation. Simultaneous administration of the two flavonoids only induced vasodilation. Quercetin-elicited positive inotropism and lusitropism depend on β1/β2-adrenergic receptors and associate with increased intracellular cAMP, while the negative inotropism and lusitropism observed at higher concentrations were α-adrenergic-dependent. NOS inhibition abolished Myricetin-elicited vasodilation, also inducing Akt, ERK1/2 and eNOS phosphorylation in both ventricles and HUVEC. Myricetin-dependent vasodilation increases intracellular cGMP and is abolished by triton X-100. CONCLUSIONS The cardiomodulation elicited on basal mechanical performance by quercetin and the selective vasodilation induced by myricetin point to these flavonoids as potent cardioactive principles, able to protect the heart in the presence of cardiovascular diseases.

THE ROLE OF BUTYRIC ACID AS A OPROTECTIVE AGENT AGAINST INFLAMMATORY BOWEL DISEASE

SUMMARY Inflammatory bowel diseases (IBD), such as Crohns disease and ulcerative colitis, are pa- thologies characterized by a chronic inflammation of the gastrointestinal tract. Their etiopathogenesis is not yet fully understood. Immune system and heat shock proteins (Hsps) dysfunctions are considered to be among the most likely causes of these diseases. Butyrate is a short-chain fatty acid mainly produced by intestinal microflora. It has a tro- phic, beneficial and protective role in the colonic mucosa, and it also induces changes in Hsp levels and localization. It may therefore be a valuable complementary therapeutic agent when used alongside traditional drugs (mesalazine and corticosteroids) to treat such conditions. The administration of specific probiotic formulations in order to increase the production of butyrate in the endoluminal environment may promote clinical remis- sion in IBD patients. Due to these characteristics, there has been keen interest in the use of butyrate as a novel therapeutic supplement in the recent years. The current findings need to be validated through further clinical trials to better define the biomolecular dy- namics of butyrate in the colonocytes of IBD patients.

Polyphenolic compounds of red wine: relationship with the antioxidant properties and effects on the metabolic syndrome induced in high-fructose fed rats

Epidemiologists have observed that a diet rich in polyphenolic compounds may provide a positive effects due to their antioxidant properties. Red wine is an excellent source of polyphenolic compounds. Objective of this work is a review of the polyphenolic compounds of red wine. The first study evaluates the antioxidant properties of Sicilian red wines in relationship with their polyphenolic composition; the second investigates the corrective offects of some phenolic molecules on the metabolic syndrome induced in high-fructose fed rats.