MATERIALS AND METHODS: Cytotoxicity was measured by the MTT assay and further confirmed via apoptosis, ROS, cell cycle, DNA fragmentation and cytokine assays.
RESULTS: ITHB4 demonstrated a lower IC50 compared to zerumbone in inhibiting the proliferation of MCF-7 cells. ITHB4 showed no toxicity against normal breast and human immune cells. Apoptosis assay revealed that ITHB4, at a concentration equal to the IC50, induces apoptosis of MCF-7 cells and cell cycle arrest at the sub-G1 and G2/M phases. ITHB4 triggered accumulation of intracellular ROS and nuclear DNA fragmentation. Secretion of pro-inflammatory cytokines induced inflammation and potentially immunogenic cell death.
CONCLUSION: ITHB4 has almost similar chemotherapeutic properties as zerumbone in inhibiting MCF-7 growth, and hence provide the basis for further experiments in animal models.