Figure 1. In vitro treatment of HNSCC cells with honokiol inhibits the cell viability in a dose- and time-dependent manner.

The HNSCC cells (SCC-1, SCC-5, OSC-19 and FaDu) were treated with various concentrations of honokiol (0, 20, 40 and 60 μM) for 24 h, 48 h and 72 h and cell viability was determined using the MTT assay. The data are expressed in terms of percent of control cells (non-honokiol-treated) as the mean ± SD of 5 replicates. Significant difference vs. control group, *P < 0.05; ^¶P < 0.01; ^**P < 0.001.