The mechanism by which Ginkgo biloba extract induces the apoptosis of human laryngeal cancer Hep-2 cells by reducing reactive oxygen species level and activating JNK signaling pathway / 中国基层医药

ABSTRACT

Objective:To investigate the apoptosis-inducing effect of Ginkgo biloba extract (Ginaton) on human laryngeal cancer Hep-2 cells and the underlying molecular mechanism.Methods:Human laryngeal cancer Hep-2 cells were cultured in vitro and human laryngeal cancer Hep-2 cells in the log phase were treated with Ginaton in time and concentration gradients. The cell counting kit-8 (CCK-8) assay was performed to investigate the inhibitory effects of Ginaton on Hep-2 cells. Flow cytometry was performed to detect apoptosis and determine the level of reactive oxygen species (ROS). Western blot assay was performed to detect apoptosis and signaling pathway-related protein expression. Results:Ginaton inhibited the proliferation of Hep-2 cells in a time-dependent and concentration-dependent manner. Malondialdehyde level decreased gradually in a time-dependent manner, and decreased to 2.98 μmol/g after 24 hours of Ginaton treatment. Superoxide dismutase level increased gradually in a time-dependent manner and increased to 90.35 U/g after 24 hours of Ginaton treatment. ROS level decreased gradually in a time-dependent manner and deceased to 18.7% of the level before treatment after 24 hours of Ginaton treatment. There was no significant difference in ROS level between before and after 24 hours of Ginaton treatment ( F = 14.98, 19.65, 11.47, all P < 0.001). After 3, 6, 12 and 24 hours of Ginaton treatment, the expression of phosphorylated N-terminal protein kinase increased to 1.98, 2.57, 2.91 and 3.28 in a time-dependent manner. There was significant difference in the expression of phosphorylated N-terminal protein kinase between before treatment and after 3, 6, 12 and 24 hours of Ginaton treatment ( F = 16.37, P < 0.001). Conclusion:Ginaton can effectively inhibit the proliferation and induce apoptosis of human laryngeal cancer Hep-2 cells in vitro, which may be related to regulating ROS level and activating JNK signaling pathway.