Effects of Sinapic Acid Combined with Cisplatin on the Apoptosis and Autophagy of the Hepatoma Cells HepG2 and SMMC-7721

Sinapic acid (Sa) is a small-molecule phenolic acid compound predominant in fruits, vegetables, and grains. This study investigated the antitumor effects of cisplatin (DDP) combined with Sa (Sa/DDP) on the hepatic cancer cells (HCC), HepG2 and SMMC-7721. The HepG2 and SMMC-7721 cells were treated with Sa or Sa/DDP, and the cell proliferation and cell cycle were detected using the MTT assay. The cell migration was detected using the transwell and scratch assays, while apoptosis and autophagy were detected using Hoechst, MDC, and Annexin V-FITC/PI staining. The protein expression was quantitated using the western blot. Sa/DDP was found to not only inhibit cancer cell proliferation and migration but also induce cell apoptosis. Simultaneously, the Sa/DDP combination was found to activate autophagy, and the HCQ autophagy inhibitor enhanced the apoptosis in the Sa/DDP-induced liver cancer cells. The combined use of Sa and DDP makes it an attractive adjuvant therapy strategy for tumors, establishing the prospect of phenolic acid compounds for the adjuvant treatment of hepatocellular carcinoma.