Anti-oxidant and anti-inflammatory effects of ellagic and punicic acid in an in vitro model of cardiac fibrosis

Cardiac fibrosis is a pathological process characterized by an excessive deposition of extracellular matrix (ECM) and an increased production of fibrillar collagen in the cardiac interstitium, mainly caused by the activation of cardiac fibroblasts and their transition into myofibroblasts. Oxidative stress is deeply implicated in the pathogenesis of cardiac fibrosis both directly and via its involvement in the tumor growth factor 01 (TGF-01) signaling. Ellagic acid (EA) and punicic acid (PA) are the main components of the Punica granatum L (pomegranate) fruit and seed oil respectively, whose antioxidant, anti-inflammatory and anti-fibrotic effects have been previously described. Therefore, the aim of this study was to investigate the effects of EA or PA or EA+PA in an in vitro model of cardiac fibrosis. Immortalized Human Cardiac Fibroblasts (IM-HCF) were stimulated with 10 ng/ml of TGF-01 for 24 h to induce a fibrotic damage. Cells were then treated with EA (1 mu M), PA (1 mu M) or EA+PA for additional 24 h. Both EA and PA reduced the pro-fibrotic proteins expressions and the intracellular reactive oxygen species (ROS) accumulation. The anti-oxidant activity was also observed by Nrf2 activation with the consequent TGF-01-Smad2/3-MMP2/9 and Wnt/0-catenin signaling inhibition, thus reducing collagen production. EA and PA significantly inhibit NF-xB pathway and, consequently, TNF-a, IL-10 and IL-6 levels: the greater effect was observed when EA and PA were used in combination. These results suggest that EA, PA and in particular EA+PA might be effective in reducing fibrosis through their antioxidant and anti-inflammatory properties by the modulation of different molecular pathways.

Automated summary

Cardiac fibrosis is characterized by excessive deposition of extracellular matrix and increased collagen production, mainly caused by activation of cardiac fibroblasts. Oxidative stress and TGF-01 signaling play important roles in the pathogenesis of cardiac fibrosis. Ellagic acid (EA) and punicic acid (PA) have been shown to have antioxidant, anti-inflammatory and anti-fibrotic effects. In this study, EA and PA were found to reduce pro-fibrotic protein expression and intracellular reactive oxygen species accumulation, inhibit NF-xB pathway, and reduce cytokine levels. Combination of EA and PA had a greater inhibitory effect. These findings suggest that EA, PA, and especially EA+PA, may be effective in reducing fibrosis through antioxidant and anti-inflammatory mechanisms.