Impact of Polyphenols on Cardiomyocyte Function in Normal and Hyperglycemic Conditions: Experimental Study

Objective: Cardiovascular complications are the leading causes of morbidity and mortality in diabetic patients. Hyperglycemia plays a significant role in the pathogenesis of these complications, leading to detrimental cardiovascular effects, including hypertrophy and functional abnormalities. Conversely, dietary polyphenols are known to have preventive effects on the development of cardiac diseases. These polyphenols regulate blood glucose levels and offer protective effects in diabetes. Nevertheless, to our knowledge, their direct cardiac effects at the cellular level remain unknown. Thus, we aimed to investigate the effects of various commonly consumed polyphenolic substances from different classes (resveratrol, quercetin, apigenin, genistein) under normal and high glucose concentrations. Material and Methods: Isolated rat ventricular cardiomyocytes were incubated under normal (5.5 mM) or high (25.5 mM) glucose conditions in the presence or absence of polyphenols. Contractile function was evaluated using a video-based edge-detection system by measuring changes in cell length during shortening and relengthening. Protein expression levels of sarcoplasmic/endoplasmic reticulum Ca²⁺-ATPase (SERCA) and Na⁺/K⁺-ATPase were determined by Western blot analysis. Results: High glucose impaired contractility, inducing a ''diabetes-like'' condition without affecting protein expression levels. Among the tested polyphenols, resveratrol most effectively preserved contractile function. The other polyphenols had partial or limited effects. Conclusion: Resveratrol showed superior cardioprotective properties against hyperglycemiainduced dysfunction at the cellular level, highlighting its potential as a therapeutic adjunct in diabetes.