Amomum muricatum (Zingiberaceae) – a potential inhibitor of tumor sphere formation and cell cycle progression by inducing apoptosis

Rhizome extract of Amomum muricatum was evaluated for antiproliferative and apoptotic effects in HT-29 colon cancer cells. Antiproliferative activity was assessed using MTT assay, and apoptosis by acridine orange/ethidium bromide staining. Cell cycle analysis was done by flow cytometry. The colon cancer cells expressing nuclear targeted Green fluorescent proteins were used for analyzing the effect of the extract on the growth of tumor spheres. Increasing extract concentrations reduced cell viability, with only 25.12 ± 2.74% viable cells at 100 µg mL−1. The extract induced apoptosis and caused G1 phase cell cycle arrest. Treatment also reduced the size and number of tumor spheroids.