Newly Synthesized Citral Derivatives Serve as Novel Inhibitor in HepG2 Cells

Graphical Compound 3h has been found to show inhibitory effects on the survival of HepG2 liver cancer cells.The results show that 3h induces cell-cycle arrest in the S phase. Additionally, 3h exerts a strong pro-apoptotic effect. Specifically, compound 3h reduces the phosphorylation of PI3K, AKT, and ERK, thereby inhibiting both the MAPK/ERK and PI3K/AKT signaling pathways. 2H-pyran compound 1 synthesized from 6-methylpyridine-2,4-diol and citral, has been used for Cu-catalyzed N -arylation with a range of arylboric acids to obtain arylated pyranopyridine core structure derivatives (yield up to 77 %). Among them, compound 3 h exhibited a much better inhibitory effect on HepG2 liver cancer cells compared to citral, and the IC 50 value was 5.3 μM following exposure with the newly synthesized derivatives (herein named 3 h for short in this paper), which was lower than that of the cisplatin (6.5 μM). Meanwhile, the cell-cycle arrest of HepG2 cells occurred in the S phase, and the apoptosis of HepG2 cells was significantly increased with increasing drug concentration. In addition, real-time fluorescence quantification PCR and Western blotting experiments showed that the expression of apoptotic protein BAX was increased, while the expression of anti-apoptotic protein BCL2 was inhibited in a dose-dependent fashion. The results of these experiments indicated that apoptosis was promoted in HepG2 cells via apoptotic signaling pathway activated by 3 h . Furthermore, 3 h effectively decreased the phosphorylation levels of PI3 K, ATK and ERK, resulting in the inhibitions of MAPK/ERK and PI3 K/ATK signaling pathways. Briefly, 3 h has been found to show inhibitory effects on the survival of HepG2 liver cancer cells and may be used as anti-cancer drug in the future.