Pomegranate Seed Oil Attenuates Cardiac Cell Death Induced by 4-hydroxy-2-nonenal: Regulation of Cellular Survival

Luteolin (LUT) and hydroxytyrosole (HYD) are dietary flavones and exhibit a broad spectrum of biological activities including antioxidant, anti-inflammatory and anti-cancer effects (1). The pomegranate, Punicagranatum L., has been the subject of current interest as a medicinal agent with wide-ranging therapeutic indications. This study was designed to examine the cytoprotective effects of pomegranate seed oil (PSEO) which have antiproliferative, pro-apoptotic and anti-inflammatory effects (2), in comparison of LUT and HYD in 4-HNE-induced cardiomyocyte toxicity.

Since the viability of adult murine cardiomyocytes declines quickly during the first few hours of isolation, embryonic rat heart cardiac myoblast cells (H9c2; ATCC) were used instead in this study. The cells were incubated in 6-well plates at 37°C in Dulbecco’s modified Eagle’s medium supplemented with 10% fetal bovine serum and 1% penicillin-streptomycin under a humidified atmosphere of 5% CO2 in air and maintained at low confluence. PSEO, LUT and HYD were added to the media in the presence and the absence of 4-HNE in a dose- and time- dependent manners.

The lipid peroxidation product 4-hydroxy-2-nonenal (4-HNE) has been implicated as a causative cytotoxic agent (3). Our results revealed that 4-HNE reduced the cell viability in a dose- and time- dependent manners. All of the three compounds induced cell survival in the presence of 4-HNE. Interestingly, PSEO-induced cell survival was higher than those of LUT and HYD. Western blot demonstrated that PSEO reduced the levels of apoptotis- and autophagy-related proteins in the presence of 4-HNE. In addition, PSEO reduced phosphorylation of MAPK and increased phosphorylation of Akt which inhibited mTOR activity.

In summary, our results suggested that PSEO may rescue cardiac cells from 4-HNE-induced death, which may, at least in part, be attributed to regulation of apoptosis and autophagy signaling pathways.

1. Bali EB et al. (2014). Planta Med. 80: 984-92.

2. Račková L1 et al (2014). Int J VitamNutr Res. 84: 295-309.

3. Sakul A et al. (2013). ExpGerontol. 48: 476-484