FIGURE 2.

Toxicity of bakuchiol against MDCK cells. The indicated concentrations of (+)-(S)-bakuchiol, (−)-(R)-bakuchiol, or ME in DMSO (concentrations of DMSO: 100 μm, 1%; 50 μm, 0.5%; 25 μm, 0.25%; and 12.5 μm, 0.125%) were added to the MDCK cells. Cell viabilities were determined by MTT assay after 24 h (n = 4 each) (A) or 96 h (n = 6 each) (B). Data represent the mean ± S.E. (error bars) and are representative of three independent experiments. **, p < 0.01; ***, p < 0.001 for the comparison with DMSO.