Figure 1. The cytotoxicity and effect of andrographolide on OCSCs self-renewal property.

(A)The chemical structure of andrographolide; (B) NHOK cells and two ALDH⁺CD44⁺ OCSCs from primary cultivated OSCC were treated with various concentrations of andrographolide for 24 hr followed by MTT assay; (C) OCSCs treated with or without andrographolide were subjected to a secondary sphere-forming assay. The number of spheres was calculated and data was presented as percentage of control. Experiments were performed in triplicate. Values are expressed as mean ± SD. *p < .05 compared to control.