Synergistic evaluation of GJ/CDDP combination on cytotoxicity in U87MG and U373MG cells. (a) Combination index (CI) (left) and logarithmic CI (right) of GJ/CDDP combination was evaluated. (b) An MTT assay was performed to compare the cell viability in GJ-, CDDP-, and GJ/CDDP-treated U87MG cells. (c) Microscopic observation of cell morphology in GJ/CDDP combination-treated U87MG cells was performed. (d) Crystal violet staining was performed in GJ/CDDP combination-treated U87MG cells. (e) An MTT assay was performed to compare the cell viability in GJ-, CDDP-, and GJ/CDDP-treated U373MG cells. (f) Microscopic observation of cell morphology in GJ/CDDP combination-treated U373MG cells was performed. (g) Crystal violet staining was performed in GJ/CDDP combination-treated U373MG cells. Results are displayed as mean ± S.E. of three or more separate experiments. * p < 0.05 vs. untreated cells, ** p < 0.01 vs. untreated cells, *** p < 0.005 vs. untreated cells. GJ, Gardenia jasminoides; CDDP, cisplatin.