This chapter focuses on certain natural polyphenolic extracts from Aronia melanocarpa (Michx.) Elliott and also on their effects in insulin-dependent diabetes mellitus. The phenolic profile of berries ethanolic extract was characterized by HPLC/DAD/ESI-MS. HPLC/DAD/ESI-MS allowed identification of five phenolic compounds: chlorogenic acid, kuromanin, rutin, hyperoside, and quercetin. The results reveal that the glycosylated hemoglobin values are much higher in the diabetic group (DM) and they are significantly lower in the group protected by polyphenols (DM+P). It is found that due to the polyphenolic protection of the rats from the DM+P, the atherogen risk is preserved at normal limits. The serous activity of glutathione-peroxidase (GSH-Px) and superoxide-dismutase (SOD) has significantly lower values in the diabetic group as compared to the group protected by polyphenols. Renal function indicators like creatinine and blood-urea nitrogen (BUN) were also elevated in the streptozotocin diabetic rats when compared with control rats. When compared with the diabetic group the elevated levels of BUN was significantly (p < 0.001) reduced in animals treated with natural polyphenols. Through the hypoglycemiant, hypolipemiant, and antioxidant effects, A. melanocarpa represents a possible dietary adjunct for the treatment of diabetes and a potential source of active agents for the prevention of microvascular diabetes complications.
Part of the book: Phenolic Compounds
The aim of this study is to estimate the influence of polyphenolic compounds, renin inhibitors (Aliskiren) and their association on clinical and biochemical parameters, on an experimental model of arterial hypertension (AHT). The combination of Aliskiren and polyphenolic extract has the effect of reducing systolic and diastolic blood pressure. Experimental data highlight the hypocholesterolemic, antiatheromatous, hypolipidemic and cardioprotective effects of polyphenolic extracts. The results demonstrate a significant decrease in the measured biochemical parameters of the oxidative stress (unspecific - ceruloplasmin, uric acid and enzyme - GSH-Px and SOD) of the groups treated with polyphenolic extracts. In the polyphenolically protected AHT group there are statistically significant differences compared to the AHT group, regarding the platelet adhesion index. Aliskiren has more evident vascular protective effects when associated with polyphenols in the experimental AHT compared to unprotected hypertensive group. The antioxidant properties of anthocyanins, combined with the vascular properties of these substances, recommend them as promising therapeutic agents in the prevention/therapy of cardiovascular disorders in general and of AHT in particular. The characterization of polyphenolic extracts, as well as the studies on biocompatibility, will constitute the baseline for understanding the mechanisms, by which phytopreparations can be used for preventive or adjuvant therapeutic purposes.
Part of the book: Blood Pressure