Figure 2

MTE ( M. tenacissima extract) enhances gefitinib induced cytotoxicity in gefitinib-sensitive non-small cell lung cancer cell lines. H292 (A) or HCC827 (B) cells were incubated with increasing concentrations of gefitinib and MTE alone or different schedule combinations. Treatment schedule: (1) M → M + G, MTE pretreated for 12 h, then M + G (MTE + gefitinib) for another 72 h. (2) M + G, MTE and gefitinib concomitantly treated for 72 h. (3) G → G + M, gefitinib pretreated for 12 h, then G + M (gefitinib + MTE) for another 72 h. Growth assays were performed by MTT assay and IC50 values were calculated by Graphpad Prism 5.0 software (San Diego, CA, USA). CI values for the combinations of gefitinib and MTE in H292 (C) and HCC827 (D) cells were calculated using the Calcusyn software (Cambridge, UK), as described in the Methods section. Each data point represented the mean of 3 to 4 replicates; r values for all curves were >0.95. ^* P < 0.05, ^** P < 0.01 vs. control group.