Allicin protects against cardiac hypertrophy and fibrosis via attenuating reactive oxygen species-dependent signaling pathways.

Increased oxidative stress has been associated with the pathogenesis of chronic cardiac hypertrophy and heart failure. Since allicin suppresses oxidative stress in vitro and in vivo, we hypothesized that allicin would inhibit cardiac hypertrophy through blocking oxidative stress-dependent signaling. We examined this hypothesis using primary cultured cardiac myocytes and fibroblasts and one well-established animal model of cardiac hypertrophy. Our results showed that allicin markedly inhibited hypertrophic responses induced by Ang II or pressure overload. The increased reactive oxygen species (ROS) generation and NADPH oxidase activity were significantly suppressed by allicin. Our further investigation revealed this inhibitory effect on cardiac hypertrophy was mediated by blocking the activation of ROS-dependent ERK1/2, JNK1/2 and AKT signaling pathways. Additional experiments demonstrated allicin abrogated inflammation and fibrosis by blocking the activation of nuclear factor-κB and Smad 2/3 signaling, respectively. The combination of these effects resulted in preserved cardiac function in response to cardiac stimuli. Consequently, these findings indicated that allicin protected cardiac function and prevented the development of cardiac hypertrophy through ROS-dependent mechanism involving multiple intracellular signaling.