Sialic acid and sialidase activity in acute stroke
Authors: Nanetti, L. | Vignini, A. | Raffaelli, F. | Taffi, R. | Silvestrini, M. | Provinciali, L. | Mazzanti, L.
Article Type: Research Article
Abstract: Stroke is a heterogeneous syndrome caused by multiple disease mechanisms, resulting in a disruption of cerebral blood flow with subsequent tissue damage. It is well known that erythrocytes have a large amount of sialic acid and could represent a model to investigate changes occurring in a pathology like stroke. The aim of this study was to investigate a possible relationship among erythrocyte membrane, plasma and sialic acid content. The possible impact of the sialic acid content and the activity of sialidase on stroke severity was also evaluated. The study population consisted of 54 patients with a first stroke and of …53 age-and sex matched healthy volunteers. The total bound sialic acid was substantially decreased in patients. There was a significant correlation between the sialidase activity values and the severity of the neurological deficit defined by the National Institute of Health Stroke Scale. This study shows that low sialic acid erythrocyte concentrations with contemporary high sialic acid plasma levels and elevated sialidase activity can be considered as markers of ischemic stroke. Further investigations are needed to clarify the possible role of these biochemical changes in producing and sustaining cerebral ischemic damage. Show more
Keywords: Sialic acid, sialidase, erythrocytes, plasma, acute stroke
Citation: Disease Markers, vol. 25, no. 3, pp. 167-173, 2008
Effect of consumption of dark chocolate on lipoproteins and serum lipids
Authors: Nanetti, L. | Vignini, A. | Gregori, A. | Raffaelli, F. | Moroni, C. | Bertoli, E. | Faloia, E. | Mazzanti, L.
Article Type: Research Article
Abstract: Background and aim: Epidemiological studies suggest that regular consumption of foods and beverages rich in flavonoids is associated with a decreased risk of cardiovascular mortality. Cocoa, the main ingredient of chocolate, is rich in polyphenols. The aim of this study was to investigate the effects of consumption of 50 g daily for 3 weeks of flavonoid-rich dark chocolate on lipoprotein oxidative stress in vitro and in vivo. In particular, levels of thiobarbituric acid-reactive substances (TBARS), conjugated dienes, lipoperoxide and hydroperoxide in HDL and LDL before and after consumption of flavonoid-rich dark chocolate were assessed. The serum lipid profile was also …studied. Methods and results: Ten healthy Italian-Caucasian volunteers were recruited without restriction as to age, gender, or socioeconomic status. Their BMI was between 21 and 26 kg/m2 , and the subjects included men and premenopausal women. The study protocol was conducted in accordance with the principles of the Declaration of Helsinki as revised in 2001, and all subjects gave written informed consent. TBARs concentrations, lipid hydroperoxides as determined using the FOX assay, and conjugate formation in HDL and in LDL were significantly decreased after 3 weeks of dark chocolate consumption with respect to the baseline values. To summarize, the present study showed favourable effects of chocolate consumption both on HDL cholesterol, and on some of the lipid peroxidation markers such as conjugated dienes, lipid hydroperoxides (FOX assay) and TBARS. Similar results were obtained with regard to LDL fractions. Our study also showed that 3 weeks consumption of dark chocolate might improve endothelial function in healthy humans and might exert a protective effect on the cardiovascular system. Show more
Keywords: Dark chocolate, Lipoprotein, Lipid peroxidation, Conjugate diene, TBARs, FOX
DOI: 10.3233/s12349-008-0004-5
Citation: Mediterranean Journal of Nutrition and Metabolism, vol. 1, no. 1, pp. 25-31, 2008