Effects of berberine and its derivatives on atherosclerotic plaque area. ApoE−/− mice were fed with the Western diet for 16 weeks and then treated with BBR (b) or its derivatives, Di-MeBBR (c) and dhBBR (d) for 16 weeks. Mice receiving PBS served as the control group (a). (A) The atherosclerotic lesions were stained by Oil RedO. (B) Plaque area was quantified as the percentage of Oil Red O-stained area to total aortic surface area.*P < 0.05 vs. the control group.