Fig. 1

Concentration responses of NQO1 suppression by β-eudesmol

KKU-100 cells were seeded onto a 96-well microtiter plate overnight and cells were exposed to β-eudesmol (1–100 μM) and dicoumarol as a potent positive NQO1 inhibitor (1 μM) for 24 h. a The effect of β-eudesmol on NQO1 enzyme activity of KKU-100 cells analyzed by the enzymatic method, b The effect of β-eudesmol on NQO1 enzyme activity of cell lysates analyzed by the enzymatic method, and c The effect of β-eudesmol on the expression of the NQO1 protein by Western blot analysis using β-actin as an internal control for equal protein loading. The relative bar that was normalized with β-actin of each band is shown below. Each bar represents mean ± SD of three independent experiments, triplicate each. * indicates statistically significant difference with untreated control (paired t-test, p < 0.05)