Effects of grape seed procyanidin extract over low-grade chronic inflammation of obese Zucker fa/fa rats

Abstract

Obesity is associated with chronic inflammation and is related to the accumulation and release of several cytokines from adipose tissue. It has been reported that a grape seed extract (GSPE) containing large amounts of procyanidins, phenolic compounds widely distributed in food, has anti-inflammatory effects in vivo against chronic inflammation related to obesity induced by the diet. In this study, several Zucker fa/fa rats were used as the obese control group (n=10) and received vehicle treatments, whereas other Zucker fa/fa rats (n=10) were treated with a moderate dose of 35mg/kg∗day of GSPE for a period of 10weeks. Importantly, GSPE treatment significantly decreased the average level of C-reactive protein (CRP) at 5weeks of treatment. However, at the end of the experiment (10weeks of treatment), GSPE could not decrease any of the pro-inflammatory markers tested such as MCP-1, TNF-α or CRP. On the contrary, GSPE showed anti-inflammatory effects on mesenteric adipose tissue, as GSPE treatment down-regulated the expression of iNos and Il-6 and up-regulated the expression of Adiponectin in the adipocytes. In conclusion, a moderate dose of GSPE exerts an anti-inflammatory effect in genetically obese rats, modulating the expression of several genes in the adipose tissue and being the adipocyte a target cell of procyanidins. However, this dose could not counteract the pro-inflammatory state at systemic level.