Identification of Plants That Inhibit Lipid Droplet Formation in Liver Cells: Rubus suavissimus Leaf Extract Protects Mice from High-Fat Diet-Induced Fatty Liver by Directly Affecting Liver Cells

Figure 2

Lipid droplet formation in hepatoma cells treated with oleic acid and inhibition of lipid droplet formation by RSE. The mouse hepatoma cell line Hepa 1–6 was used for the experiments. Dried Rubus suavissimus leaves or Nuphar japonicum rhizome was ground with a mill and 0.05 g of the resulting powder was extracted with 500 μL of water at 60°C for 1 h. The cells (20,000 cells/well) were seeded on a 96-well microtiter plate and incubated overnight. The next day, 0.6 mM oleic acid conjugated with BSA and the plant extract (RSE, 5% final or Nuphar japonicum rhizome extract, 1% final) was added and cells were further incubated for 24 h. After the incubation, the cells were fixed and oil droplets were visualized by Oil Red staining. Lipid droplets stained by Oil Red are seen as red particles. Details are described in Section 2. (a) Control, (b) 0.6 mM oleic acid, (c) 0.6 mM oleic acid and 5% RSE, and (d) 0.6 mM oleic acid and 1% Nuphar japonicum rhizome extract.

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