Figure 3.

Reducing power and inhibition of β-carotene-linoleic acid system oxidation and depigmenting activity. (a) The reducing power of all extracts in the concentration range from 0.005 to 0.2 mg/mL. BHT was used as the positive control. (b) Inhibition of β-carotene-linoleic acid system oxidation by the extracts of Idesia polycarpa at 2 mg/mL. BHT was used as a positive control, and a negative control was completed instead of tests samples. (c) The metal chelating activity of all extracts in the concentration range from 2 to 10 mg/mL, compared to EDTA at the same concentration. (d) The tyrosinase inhibitory activity of different concentration of EAE/hydroquinone in mouse B16 melanoma cells (*P < 0.05; **P < 0.01 compared with the control). (e) The inhibitory effect of EAE and hydroquinone on melanogenesis of mouse B16 melanoma cells. Each value is expressed as mean with an error bar of standard deviation (n = 3). (f) Time course of skin-whitening index (L value) of mice; averaged L values (n = 8) with an error bar of standard deviation are plotted over the experimental period (P < 0.01 compared with the control group).