Obesity constitutes a major public health concern, being frequently associated with
type 2 diabetes (T2D). Evidence from studies in humans and experimental animals suggest that consumption of the
flavan-3-ol (-)-
epicatechin (EC) and of EC-rich foods may improve
insulin sensitivity. To further understand the potential benefits of dietary EC consumption on
insulin resistance, this study investigated the capacity of EC supplementation to prevent high fat diet (HFD)-induced
insulin resistance in mice. To assess the underlying mechanisms, the effects of HFD and EC consumption on the activation of the
insulin cascade and of its negative modulators were evaluated. HFD consumption for 15 w caused
obesity and
insulin resistance in C57BL/6J mice as evidenced by high fasted and fed plasma
glucose and
insulin levels, and impaired ITT and GTT tests. This was associated with alterations in the activation of components of the
insulin-triggered signaling cascade (
insulin receptor, IRS1, ERK1/2, Akt) in adipose and liver tissues. EC supplementation prevented/ameliorated all these parameters. EC acted improving
insulin sensitivity in the HFD-fed mice in part through a downregulation of the inhibitory molecules JNK, IKK, PKC and
protein tyrosine phosphatase 1B (PTP1B). Thus, the above results suggest that consumption of EC-rich foods could constitute a dietary strategy to mitigate
obesity-associated
insulin resistance.