Deciphering the Molecular Mechanism of Red Raspberry in Apoptosis of Liver Cancer Cells

Red raspberry contains a variety of bioactive ingredients and has high edible and medicinal value. Red raspberry extractions (RREs) have strong antioxidant capacity and anticancer ability in vivo and in vitro. This study was to explore the specific mechanism of RREs inhibiting the proliferation of liver cancer HepG2 cells and provide a theoretical basis for the prevention and treatment of liver cancer by RREs. HepG2 cells were cultured in vitro, and MTT assay was adopted to detect the effect of RREs on HepG2 cell activity. Colony formation assay was applied to detect the growth and proliferation of cells, cell apoptosis was detected by flow cytometry, and dichloro-dihydro-fluorescein diacetate (DCFH-DA) assay was adopted to detect the effect of RREs on the production of reactive oxygen species (ROS) in cells. The effect of RREs on cell mitochondrial membrane potential was evaluated by mitochondrial membrane potential assay kit with JC-1 (JC-1 assay), and western blot was used to detect the expression of apoptosis-related proteins (B-cell lymphoma-2 (Bcl-2), Bcl-2-associated x (Bax), and Caspase-3), thus investigating the effect of RREs on the molecular mechanism of HepG2 cell apoptosis. The results showed that RREs could inhibit the proliferation activity of HepG2 cells and promote their apoptosis in a concentration-dependent manner. The level of ROS in HepG2 cells interfered by RREs increased markedly, while the cell mitochondrial membrane potential decreased sharply. As the concentration of HepG2 increased, the mitochondrial membrane potential reduced steeply. Western blot results showed that the expression of apoptosis-related protein Bcl-2 in the RREs treatment group dropped, but the expression of Bax and Caspase-3 rose. In summary, RREs could inhibit the proliferation of liver cancer HepG2 cells and promote their apoptosis. This inhibition might be executed by inducing HepG2 cells to produce ROS, a decrease in Bcl-2/Bax protein ratio, and an obvious reduction in mitochondrial membrane potential.