Lucia Seta

Malvidin, a red wine polyphenol, modulates mammalian myocardial and coronary performance and protects the heart against ischemia/reperfusion injury.

A moderate red wine consumption and a colored fruit-rich diet protect the cardiovascular system, thanks to the presence of several polyphenols. Malvidin-3-0-glucoside (malvidin), an anthocyanidine belonging to polyphenols, is highly present in red grape skin and red wine. Its biological activity is poorly characterized, although a role in tumor cell inhibition has been found. To analyze whether and to which extent, like other food-derived polyphenols, malvidin affects the cardiovascular function, in this study, we have performed a quantitative analysis by high-performance liquid chromatography of polyphenolic content of red grape skins extract, showing that it contains a high malvidin amount (63.93 ±12.50 mg/g of fresh grape skin). By using the isolated and Langendorff perfused rat heart, we found that the increasing doses (1-1000 ng/ml) of the extract induced positive inotropic and negative lusitropic effects associated with coronary dilation. On the same cardiac preparations, we observed that malvidin (10(-10)-10(-6) mol/L) elicited negative inotropism and lusitropism and coronary dilation. Analysis of mechanism of action revealed that malvidin-dependent cardiac effects require the activation of the phosphatidylinositol 3-kinase (PI3K)/nitric oxide (NO)/cGMP/PKG pathway and are associated with increased intracellular cGMP and the phosphorylation of endothelial NO synthase (eNOS), PI3K-AKT, ERK1/2, and GSK-3β. AKT and eNOS phosphorylation was confirmed in human umbilical vein endothelial cell. We also found that malvidin act as a postconditioning agent, being able to elicit cardioprotection against ischemia/reperfusion damages. Our results show the cardioactivity of polyphenols-rich red grape extracts and indicate malvidin as a new cardioprotective principle. This is of relevance not only for a better clarification of the beneficial cardiovascular effects of food-derived polyphenols but also for nutraceutical research.

Rheological investigation of pectin-based emulsion gels for pharmaceutical and cosmetic uses

Emulsion gels are structured emulsions suitable for different uses for their specific behaviour, which is strongly dependent on the characteristics of the gelled dispersing phase. Therefore, it is important to adopt the specific gelling agent to tune the final emulsion rheological behaviour properly. Pectin is extremely interesting among potential hydrophilic gelling agents owing to its specific characteristics. In the present work, four different low-methoxyl pectins were adopted to prepare gels to be used as the dispersing phase in cosmetic or pharmaceutical emulsion gels. The rheological characterisation of pectin gels, prepared at room temperature to avoid the damage to potential thermolabile components, was carried out with small amplitude oscillations. The obtained gels were used, together with a common non-ionic surfactant (Tween 60), to prepare olive oil emulsion gels suitable to design new cosmetic products. A simple empirical model, proposed to relate the emulsion complex modulus to the oil fraction and properties of the dispersing phase, has shown itself to be a potentially useful tool to design formulations with desired properties.