Eurycomalactone as a potent NF-κB inhibitor with the IC50 value of less than 1 uM. It shows antiplasmodial activity against Gombak A isolate. Eurycomalactone displays potent activity against all the tested cell lines [colon 26-L5 carcinoma (IC50 = 0.70 microM), B16-BL6 melanoma (IC50 = 0.59 microM), Lewis lung carcinoma (IC50 = 0.78 microM), and a human lung A549 adenocarcinoma (IC50 = 0.73 microM)].