Modulation of LDL receptor expression and promoter methylation in HepG2 cells treated with a Corylus avellana L. extract

The aim of our study was to evaluate the impact of an ethanolic extract of C. avellana on the molecular pathway(s) regulating the low-density lipoprotein receptor (LDLR) in HepG2 cells, mainly in terms of epigenetics. We demonstrated that viability, proliferation and cell cycle distribution were not affected up to 72 h of treatment, whereas LDLR expression was stimulated as early as 24 h following administration (P < 0.05 at 0.04 mg/ml, P < 0.01 at 0.4 mg/ml). The level of DNA Methyl Transferase 3A was up-regulated (P < 0.001 at 0.004 mg/ml, P < 0.05 at 0.4 and 4 mg/ml), without any change in global DNA methylation, whereas the percentage of 5-methyl cytosine was significantly (P < 0.05) reduced at LDLR promoter level in response to treatment (0.04 mg/ml). Overall, our data demonstrate that the ethanolic extract of C. avellana stimulates the LDLR expression in HepG2 cells by epigenetic mechanisms. © 2018