Dietary Cocoa Prevents Aortic Remodeling and Vascular Oxidative Stress in Diabetic Rats

Abstract

Scope:The aim of the present study is to investigate the potential protective effect of a cocoa-rich diet on functional and structural vascular alterations in diabetes and the mechanism involved. Methods and results: Male Zucker diabetic fatty (ZDF) rats are fed on a standard (ZDF-C) or cocoa-rich diet (ZDF-Co) from week 10 to 20 of life. Diabetic ZDF-C rats showed increased blood pressure and enhanced aortic stiffness, as demonstrated by the increased pulse pressure and the augmented aortic medial thickness with loss and disruption of elastic fibres. Interestingly, cocoa intake strongly avoided all these adverse effects and reduced aortic oxidative stress. Mechanistically, cocoa diet prevented sirtuin-1 (SIRT-1) depletion and increased NADPH oxidases (NOXs) and reactive oxygen species production as well as reduced active nuclear factor E2 related factor 2 (Nrf2) and their antioxidant products. Conclusion: The results demonstrate for the first time that a cocoa-rich diet strongly prevents aortic stiffening and remodeling in diabetic animals and avoids aortic oxidative stress. It is suggested that this effect could be mediated via its effects on SIRT-1, NOXs, and Nrf2. Conflict of InterestThe authors declare no conflict of interest.

Supplementation with a Cocoa–Carob Blend, Alone or in Combination with Metformin, Attenuates Diabetic Cardiomyopathy, Cardiac Oxidative Stress and Inflammation in Zucker Diabetic Rats

“…These results are consistent with several current studies evidencing the ability of certain flavonoids to prevent cardiac oxidative stress through the activation of Nrf2 and the consequent induction of antioxidant enzymes [ 40 , 41 , 42 , 43 ]. In particular, we recently found that supplementation with a cocoa rich diet prevented arterial oxidative damage by increasing the levels of Nrf2 and its antioxidant enzymes in the arteries of ZDF diabetic animals [ 19 ]. Collectively, these data indicate that CCB may alleviate myocardial fibrosis and the development of DCM in part by increasing Nrf2 levels and reducing oxidative stress in the myocardium.…”

“…ROS were quantified by the dichlorofluorescein (DCFH) assay based on the oxidation of dichlorofluorescein (DCF) that emits fluorescence [ 19 ]. LV homogenates were diluted with ice-cold Locke’s buffer (154 mM NaCl, 5.6 mM, KCl, 3.6 mM NaHCO 3 , 2 mM CaCl 2 , 10 mM D-glucose and 5 mM 4-(2-hydroxyethyl)-1-piperazineethanesulfocnic acid, pH 7.4) and incubated with 5 μM DCFH for 30 min at 37 °C in darkness.…”

“…It has been indicated that flavonoids have the potential to alleviate DCM by their anti-hyperglycaemic, antioxidant and anti-inflammatory properties [ 15 ]. In this regard, cocoa flavonoids could be considered very good candidates for DCM treatment since they possess antioxidants and antidiabetic properties [ 16 , 17 ], as well as favourable cardiovascular effects [ 18 , 19 , 20 ]. However, cocoa is characterised by a bitter taste, rejected by many people.…”

Urinary Metabolomics Study on the Protective Role of Cocoa in Zucker Diabetic Rats via 1H-NMR-Based Approach

“…In this regard, cocoa constitutes one of the richest sources of dietary flavonoids, mainly flavanols which is gaining importance in research since it has been proven to reduce the pathogenesis of diabetes and its complications [ 6 ]. Notably, our previous studies have demonstrated that cocoa supplementation improves the glucose metabolism in diabetic animals [ 7 ] and has beneficial effects on associated diabetic complications, mainly arterial stiffness [ 8 ] and nephropathy [ 9 ]. Several mechanisms have been described as being involved in these positive outcomes [ 10 ], including a possible prebiotic effect of cocoa [ 11 ].…”

Traceability of polyphenols in cocoa during the postharvest and industrialization processes and their biological antioxidant potential

“…Although the factors mentioned above decrease the polyphenol content in cocoa and its derivatives, other studies have demonstrated that, even under these circumstances, with a low content of total polyphenols, they have a protective effect due to their functional property of antioxidant capacity [ 20 , 21 , 22 ]. In addition, food synergy may be responsible for the biological potential of cocoa derivatives, despite being subjected to chemical and physical transformations that cause said decrease in polyphenols [ 23 ].…”