Effects of magnolol treatment on UVB induced skin tumors in SKH-1 mice. Mice were exposed five days a week to 30 mJ/cm2 UVB one hour before different topical treatments. Control group (n = 20) was treated with 200 μ l of acetone. Treatment groups (n = 20 each) received 30, 45 or 60 μ g of magnolol dissolved in 200 μ l of acetone. Pictures were taken at the end of the 25th week. Animals were randomly chosen for the pictures.