Evaluation of Colombian Vaccinium meridionale Swartz consumption on adipocytokines, inflammation and oxidative stress markers in women with metabolic syndrome

Abstract

ABSTRACT: Metabolic syndrome (MetS) is a cluster of cardiovascular risk factors, which increases the risk of type 2 diabetes and cardiovascular disease (CVD). Additionally, MetS is characterized by increased oxidative stress, a pro-inflammatory state and vascular endothelial dysfunction. The increased consumption of fruits and vegetables has been associated with reduced risk for CVD and mortality. Vaccinium meridionale Swartz (known as “agraz”) is a berry rich in polyphenolic compounds with demonstrated antioxidant activity and modulation of inflammatory pathways in animal and cell models. Thus, agraz consumption could be a strategy to reduce MetS parameters and to prevent CVD. Objective: The aim of this study was to evaluate the effects of agraz consumption on inflammatory and oxidative stress markers in women with MetS. Methodology: 40 volunteer women with MetS (47 ± 9 years) were randomly assigned to consume daily either 200 mL of agraz nectar or placebo during 4 weeks in a double-blind, cross-over design study, separated by a 4-week washout period. Participants were asked to maintain their usual diet and physical activity during the whole study, including the washout period, and to abstain from consuming foods rich in polyphenols. Serum concentrations of blood lipids and glucose, insulin, high-sensitivity C- reactive protein (hs-CRP), antioxidant capacity by the reaction of the radical 2,2-diphenyl-1- picrylhydrazyl (DPPH) method), total phenols, adiponectin, leptin and resistin, Reactive Thiobarbituric Acid Reactive Substances (TBARS) and the urinary concentration of isoprostanes, and 8-hydroxy-2'- deoxyguanosine (8-OHdG) were measured at the end of each period. Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) was also calculated. Results: Antioxidant capacity measured by DPPH was higher (p=0.028) and urinary concentration of 8- OHgG was lower (p=0.041) after agraz consumption, compared to placebo. Serum concentration of hs- CRP was lower in patients who had 3 components of MetS compared with those who had 4 or more, after agraz consumption compared to placebo. Additionally, there was a positive correlation between the concentration of triglycerides (TG) and TBARS after the placebo period (r=0.355, p=0.025) that lost significance after agraz period (r=0.206; p=0.209). In addition, after agraz consumption, a positive correlation was observed between the concentration of high-density lipoprotein cholesterol (HDL-c) and adiponectin (r=0,385 p=0,019). Changes in other markers were not significant. Conclusions: The chronic consumption of agraz during 4 weeks improved antioxidant capacity and decreased DNA oxidative damage. Compared to placebo, agraz consumption decreased hs-CRP in patients with 3 MetS components, but not in those with 4 or 5 components. These results suggest that agraz consumption may play a protective role in patients with MetS.