Furocoumarins from Angelica dahurica with hepatoprotective activity on tacrine-induced cytotoxicity in Hep G2 cells.

Fractionation of the MeOH extract of Angelica dahurica Benth et Hook resulted in the isolation of six furocoumarins, imperatorin (1), isoimperatorin (2), (+/-)-byakangelicol (3), (+)-oxypeucedanin (4), (+)-byakangelicin (5), and (+)-aviprin (6). Among these, compounds 1 and 5 exhibited strong hepatoprotective activities, displaying EC(50) values of 36.6 +/- 0.98 and 47.9 +/- 4.6 microM, respectively. Compounds 3 and 4 showed moderate activities with EC(50) values of 112.7 +/- 5.35 and 286.7 +/- 6.36 microM, respectively. Silybin as a positive control showed the EC(50) value with 69.0 +/- 3.4 microM. Comparison of hepatoprotective activities for six furocoumarins 1 - 6 suggested that oxy-substitution at the C-9 position increased the hepatoprotective activity.