Protective Effects of Neutral Lipids from Phaeodactylum tricornutum on Palmitate-Induced Lipid Accumulation in HepG2 Cells: An In Vitro Model of Non-Alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD), often associated with obesity, has become a serious public health matter. NAFLD is characterized by an excessive lipid accumulation in hepatocytes, mainly stored as triglycerides. The marine microalga Phaeodactylum tricornutum is well known for its richness of bioactive compounds, particularly lipids. Therefore, different natural lipid extracts from P. tricornutum are deciphered to jugulate or prevent obesity leading to NAFLD. In this study, the main focus was on the effects of purified neutral and polar lipid extracts from P. tricornutum in a cellular model of NAFLD. Human HepG2 cells were used and exposed for 24 h to 250 μM palmitate to induce NAFLD with or without microalgal lipid extracts. Data showed that neutral lipid extract presented lower viability and cytotoxic activities on HepG2 at 75 µg/mL. The impact on apoptosis was around 5% and below the threshold. Nevertheless, the use of neutral lipid at 50 µg/mL induced a decrease in the number and size of lipid droplets, and so, preventing NAFLD. On the contrary, the polar lipid extract had no effect on the accumulation of triglycerides in HepG2 cells. To conclude, neutral lipid extract seemed to be a good candidate to prevent NAFLD.