Raspberry and blackberry act in a synergistic manner to improve cardiac redox proteins and reduce NF-κB and SAPK/JNK in mice fed a high-fat, high-sucrose diet

Abstract

Background and aims: Increased cardiac inflammation and oxidative stress are common features in obesity, and toll-like receptor (TLR)4 signaling is a key inflammatory pathway in this deleterious process. This study aimed to investigate whether berries could attenuate the detrimental effects of a high-fat, high-sucrose (HFHS) diet on the myocardium at the molecular level.

Methods and results: Eight-week-old male C57BL/6 mice consumed a low-fat, low-sucrose (LFLS) diet alone or supplemented with 10% blackberry (BL), 10% raspberry (RB) or 10% blackberry + raspberry (BL + RB) for four weeks. Animals were then switched to a HFHS diet for 24 weeks with or without berry supplementation or maintained on a LFLS control diet without berry supplementation. Left ventricles of the heart were isolated for protein and mRNA analysis. Berry consumption, particularly BL + RB reduced NADPH-oxidase (NOX)1 and NOX2 and increased catalase (CAT) and superoxide dismutase (SOD)2, expression while BL and RB supplementation alone was less efficacious. Downstream TLR4 signaling was attenuated mostly by both RB and BL + RB supplementation, while NF-κB pathway was attenuated by BL + RB supplementation. Stress-activated protein kinase (SAPK)/Jun amino-terminal kinase (JNK) was also attenuated by BL + RB supplementation, and reduced TNF-α transcription and protein expression was observed only with BL + RB supplementation.

Conclusion: The synergistic effects of BL + RB may reduce obesity-induced cardiac inflammation and oxidative stress to a greater extent than BL or RB alone.

Keywords: Berries; Cardiovascular; Inflammation; Oxidative stress; Polyphenols.