Chromatin remodeling, particularly histone acetylation, plays a critical role in the progression of pathological cardiac hypertrophy and heart failure. We hypothesized that curcumin, a natural polyphenolic compound abundant in the spice turmeric and a known suppressor of histone acetylation, would suppress cardiac hypertrophy through the disruption of p300 histone acetyltransferase-dependent (p300-HAT-dependent) transcriptional activation. We tested this hypothesis using primary cultured rat cardiac myocytes and fibroblasts as well as two well-established mouse models of cardiac hypertrophy. Curcumin blocked phenylephrin-induced (PE-induced) cardiac hypertrophy in vitro in a dose-dependent manner. Furthermore, curcumin both prevented and reversed mouse cardiac hypertrophy induced by aortic banding (AB) and PE infusion, as assessed by heart weight/BW and lung weight/BW ratios, echocardiographic parameters, and gene expression of hypertrophic markers. Further investigation demonstrated that curcumin abrogated histone acetylation, GATA4 acetylation, and DNA-binding activity through blocking p300-HAT activity. Curcumin also blocked AB-induced inflammation and fibrosis through disrupting p300-HAT-dependent signaling pathways. Our results indicate that curcumin has the potential to protect against cardiac hypertrophy, inflammation, and fibrosis through suppression of p300-HAT activity and downstream GATA4, NF-kappaB, and TGF-beta-Smad signaling pathways.

Caloric restriction extends longevity and reduces the onset of chronic disease in many animal models. Recently, caloric restriction was shown in humans to be associated with lower blood pressure, decreased systemic inflammation, and improved cardiac diastolic parameters. However, the causation and mechanisms of caloric restriction were obscured by the varied diet composition of the participants. The Dahl salt-sensitive rat which develops gradual, hypertension-associated diastolic dysfunction was used in this study to assess the impact of caloric restriction upon decompensated pressure-overload hypertrophy. Male Dahl salt-sensitive rats were provided either a low-salt diet or a high-salt diet to initiate heart failure progression. A further subset of high-salt rats underwent 15% calorie restriction, with salt load held constant. Parameters measured included serial systolic blood pressure, body weight, and changes of left ventricular systolic and diastolic parameters and ventricular geometry by echocardiography. After 18 weeks, fasting glucose, blood lipids, heart weight, kidney weight, lung weight, plasma interleukin-6 and TNF-alpha, and cardiac lipid peroxidation were measured. Low-salt rats did not develop heart failure. While high-salt rats displayed features of decompensated pressure-overload hypertrophy, moderate calorie restriction remarkably reduced morbidity. Compared to the high-salt fed group, the high-salt, calorie-restricted group showed reduced blood pressure, delayed onset of cachexia, lower fasting hyperlipidemia, lower cardiac, renal and lung weight, less plasma IL-6 and TNF-alpha, less cardiac oxidative damage, and improved diastolic chamber function and cardiac index. Modest calorie restriction, independent of salt intake, reduced pathogenesis in this well described model of decompensated pressure-overload hypertrophy.