Fig. 2

Potentiating effect of β-eudesmol on cytotoxic activities of 5-FU and DOX. KKU-100 cells were seeded onto a 96-well microtiter plate overnight and cells were treated with β-eudesmol (1, 10, 30 and 100 μM) in the absence and presence of 5-FU or DOX for 24 and 48 h. Cell death was determined using SRB assay. a KKU-100 cells were incubated with β-eudesmol (1, 10, 30 and 100 μM) for 24 and 48 h. The results are presented as the percentage of viable cells. b-e The cytotoxic effect of β-eudesmol in combination with chemotherapeutic agents was determined. b-c KKU-100 cells were treated with β-eudesmol (30 μM) in the absence and presence of 5-FU (3, 10, 30 and 100 μM) for 24 and 48 h. d-e KKU-100 cells were treated with β-eudesmol (30 μM) in the absence and presence of DOX (0.01, 0.1, 1 and 10 μM) for 24 and 48 h. Each bar represents mean ± SD of three independent experiments, triplicate each. * indicates statistically significant difference with each drug alone (t-test, p < 0.05). β-Eu; β-Eudesmol, 5-FU; 5-Fluorouracil, DOX; Doxorubicin