Inflammation involves the activation of redox-sensitive transcription factors, e.g., nuclear factor κB (NF-κB). Administration of (−)-epicatechin to high-fructose-fed rats prevented NF-κB activation and up-regulation of the NADPH oxidase 4 (NOX4) in the kidney cortex. These results add mechanistic insights into the action of (−)-epicatechin diminishing inflammatory responses.