Eurycomalactone is an active quassinoid could be isolated from Eurycoma longifolia Jack . Eurycomalactone is a potent NF-κB inhibitor with an IC 50 value of 0.5 μM. Eurycomalactone inhibits protein synthesis and depletes cyclin D1. Eurycomalactone enhances radiosensitivity through arrest cell cycle at G2/M phase and delayed DNA double-strand break repair. Eurycomalactone inhibits the activation of AKT/NF‑κB signaling, induces apoptosis and enhances chemosensitivity to Cisplatin In Vitro Eurycomalactone (24, 48 and 72 h) selectively inhibits the viability of A549 and COR-L23 cells Eurycomalactone inhibits the viability of A549 cells with IC 50 values of 20.17, 3.77, and 1.90 μM for 24, 48 and 72 hours, respectively. Eurycomalactone inhibits the viability of COR-L23 cells with IC 50 values of 25.02, 2.74, and 1.80 μM for 24, 48 and 72 hours, respectively. Eurycomalactone (2.29-156.3 μM; 24 h; A549 and Calu-1 cells) promotes Non-small cell lung cancer (NSCLC) cells apoptosis. Eurycomalactone (0-25.05 μM; 24 h; A549 and COR-L23 cells) induces cell cycle arrest at the radiosensitive G2/M phase and induces apoptosis in irradiated Non-small cell lung cancer (NSCLC) cells. Eurycomalactone downregulated the key G2/M regulatory proteins in irradiated Non-small cell lung cancer (NSCLC) cells. Eurycomalactone (2.5-25 μM; 24 h; A549 cells) suppressed the repair of radiation-Induced DNA double-strand breaks. Eurycomalactone (2.29-156.3 μM; 24 h; A549 and Calu-1 cells) suppresses AKT/NF-κB activation in Non-small cell lung cancer (NSCLC) cells. MCE has not independently confirmed the accuracy of these methods. They are for reference only. Apoptosis AnalysisCell Line: A549 and Calu-1 cells Concentration: 2.29, 10.14, 12.02, 20.81, 80.77, and 156.3 μM Incubation Time: 24 hours Result: Increased the apoptotic rates in a dose-dependent manner. Cell Cycle AnalysisCell Line: A549 and COR-L23 cells Concentration: 1.57, 2.57, 20.17 and 25.05 μM Incubation Time: 24 hours Result: Induced cell cycle arrest at G2/M phase in irradiated cells and increased the sub-G1 population.\nA549 and COR-L23 cells Western Blot AnalysisCell Line: A549 and Calu-1 cells Concentration: 2.29, 10.14, 12.02, 20.81, 80.77, and 156.3 μM Incubation Time: 24 hours Result: Induced the expression levels of active caspase-3 and active PARP (cleaved form), while decreased Bcl-xL and surviving. Western Blot AnalysisCell Line: A549 and COR-L23 cells Concentration: 1.57, 2.57, 20.17 and 25.05 μM Incubation Time: 24 hours Result: Downregulated the expression of both G2/M regulatory proteins in a dose-dependent manner. Western Blot AnalysisCell Line: A549 and COR-L23 cells Concentration: 2.29, 10.14, 12.02, 20.81, 80.77, and 156.3 μM Incubation Time: 24 hours Result: inhibited the expression levels of p (S473) -AKT, total AKT, p (S536) -NF-κB p65 and total NF-κB p65. Form:Solid IC50& Target:IC50: 0.5 μM (NF-κB)