Posidonia oceanica (L.) Delile Extract Reduces Lipid Accumulation through Autophagy Activation in HepG2 Cells

Abstract

Posidonia oceanica (L.) Delile is a marine plant traditionally used as an herbal medicine for various health disorders. P. oceanica leaf extract (POE) has been shown to be a phytocomplex with cell-safe bioactivities, including the ability to trigger autophagy. Autophagy is a key pathway to counteract non-alcoholic fatty liver disease (NAFLD) by controlling the breakdown of lipid droplets in the liver. The aim of this study was to explore the ability of POE to trigger autophagy and reduce lipid accumulation in human hepatoma (HepG2) cells and then verify the possible link between the effect of POE on lipid reduction and autophagy activation. Expression levels of autophagy markers were monitored by the Western blot technique in POE-treated HepG2 cells, whereas the extent of lipid accumulation in HepG2 cells was assessed by Oil red O staining. Chloroquine (CQ), an autophagy inhibitor, was used to study the relationship between POE-induced autophagy and intracellular lipid accumulation. POE was found to stimulate an autophagy flux over time in HepG2 cells by lowering the phosphorylation state of ribosomal protein S6, increasing Beclin-1 and LC3-II levels, and decreasing p62 levels. By blocking autophagy with CQ, the effect of POE on intracellular lipid accumulation was clearly reversed, suggesting that the POE phytocomplex may reduce lipid accumulation in HepG2 cells by activating the autophagic process. This work indicates that P. oceanica may be considered as a promising molecule supplier to discover new natural approaches for the management of NAFLD.

Ameliorative Effect of Posidonia oceanica on High Glucose-Related Stress in Human Hepatoma HepG2 Cells

“…Accordingly, these results support the efficacy and reproducibility of hydroalcoholic extractions from P. oceanica leaves [ 26 , 27 , 34 , 35 ].…”

“…The hydroalcoholic extraction protocol, previously described [ 26 , 34 ], was applied to 4 g of dried and minced leaves of P. oceanica . The total yield of P. oceanica dry extract was 45 mg. POE was constituted by resuspending 1.8 mg of dry extract in 0.5 mL of EtOH 70% ( v / v ), yielding a hydrophilic analyte concentration of 3.6 mg/mL.…”

“…POE was then characterized for total polyphenol content (TP) by the Folin–Ciocalteau colorimetric method, as previously described [ 22 , 34 ]. Briefly, a solution of Folin–Ciocalteu’s phenol reagent (diluted 1:10 in distilled water) was added to scalar volumes of POE (final volume 20 µL) in a 96-well plate.…”

“…In addition, the antioxidant and radical-scavenging activities of POE were studied using the ferric-reductive/antioxidant power (FRAP) assay and the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, respectively [ 22 , 34 ].…”

Special Issue on Plant and Marine-Derived Natural Product Research in Drug Discovery: Strengths and Perspective

“…Posidonia oceanica is a marine plant used in traditional medicine for the treatment of several health conditions, such as diabetes and inflammation. The aim of the study carried out by Vasarri et al [ 4 ] was to analyze the ability of P. oceanica hydroalcoholic extract to trigger autophagy and reduce intracellular lipid accumulation, in an in vitro model of hepatic steatosis using the human hepatoma cell line HepG2. The authors found that the extract protected against lipid accumulation in HepG2 cells by promoting autophagy through inhibition of the mTOR pathway, offering new insights for possible complementary treatments of non-alcoholic fatty liver disease.…”